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SHORT COMMUNICATION Action observation activates premotor and parietal areas in a somatotopic manner: an fMRI study
Abstract
resonance imaging (fMRI) was used to localize brain areas that were active during the observation of actions made by another individual. Object- and non-object-relat ed actions made with different effectors (mouth, hand and foot) were presented. Observation of both object- and non-object-relat ed actions determined a somatotopically organized activation of premotor cortex. The somatotopic pattern was similar to that of the classical motor cortex homunculus. During the observation of object-related actions, an activation, also somatotopically organized,
... In neurologically healthy participants, observation and execution of object-directed actions, such as reaching and grasping, activate areas of the posterior parietal cortex more strongly than intransitive hand gestures 21,22 . ...
Action observation and imitation may facilitate movement in Parkinson’s disease (PD). People with PD have been found to imitate intransitive actions similarly to neurologically healthy older adults, but their imitation of object-directed hand movements has not previously been investigated using kinematic measures. The present study examined observation and imitation of object-directed hand movements in 18 participants with PD and 21 neurologically healthy age-matched control participants. Participants observed and immediately imitated sequences showing a human hand reaching for and transferring an object between horizontal positions. Both groups significantly modulated their finger movements, showing higher vertical amplitude when imitating elevated compared to direct trajectories. In addition, movements were lower in vertical amplitude and higher in velocity when imitating the reaching segment than the transfer segment. Eye-tracking revealed that controls made smaller saccades when observing predictable than unpredictable elevated movements, but no effects of predictability on eye movements were found for the PD group. This study provides quantitative evidence that people with mild to moderate PD can imitate object-directed hand movement kinematics, although their prediction of such movements may be reduced. These findings suggest that interventions targeting object-directed actions may capitalize on the ability of people with PD to imitate kinematic parameters of a demonstrated movement.
... In contrast, much less is known about lower limb movements and motor resonance. Buccino et al. (2001) described the activation of a dorsal sector of Brodmann Area 6 during the observation of feet movements. Later, Liepert and Neveling (2009) reported that observation of foot dorsiflexion induced motor resonance. ...
The activation of the Mirror Neuron System (MNS) has been described to reflect visible movements, but not postural, non-visible, adaptations that accompany the observed movements. Since any motor act is the result of a well-tailored dialogue between these two components, we decided to investigate whether a motor resonance to nonvisible postural adaptations could be detected. Possible changes in soleus corticospinal excitability were investigated by eliciting the H-reflex during the observation of three videos, corresponding to three distinct experimental conditions: 'Chest pass', 'Standing' and 'Sitting', and comparing its size with that measured during observation of a control videoclip (a landscape). In the observed experimental conditions, the Soleus muscle has different postural roles: a dynamic role in postural adaptations during the Chest pass; a static role while Standing still; no role while Sitting. The H-reflex amplitude was significantly enhanced in the 'Chest pass' condition compared to the 'Sitting' and 'Standing' conditions. No significant difference was found between 'Sitting' and 'Standing' conditions. The increased corticospinal excitability of the Soleus during the 'Chest pass' condition suggests that the mirror mechanisms produce a resonance to postural components of an observed action, although they may not be visible. This observation highlights the fact that mirror mechanisms echo non intentional movements as well and points to a novel possible role of mirror neurons in motor recovery.
... Recently, evidence at the single neuron-level about the existence of the mirror mechanism in the human brain was provided (Mukamel et al. 2010). Several neuroimaging studies have reported the activation of distinct cortical regions within premotor and posterior parietal cortices during the observation/execution of goal-related hand, mouth and foot actions (Buccino et al. 2001; Aziz-Zadeh et al. 2006) during the observation/ execution of meaningless hand movements (Lui et al. 2008; Villarreal et al. 2008) during the execution of a noisy action and listening to the corresponding sound (Gazzola et al. 2006 ). Few studies have demonstrated communicative face and hand actions showing an activation of cortical regions endowed with mirror properties (Nakamura et al. 1999; Nakamura et al. 2004; Montgomery et al. 2007; Villarreal et al. 2008). ...
The main aim of the present study was to explore, by means of high-density EEG, the intensity and the temporal pattern of event-related sensory-motor alpha desynchronization (ERD) during the observation of different types of hand motor acts and gestures. In particular, we aimed to investigate whether the sensory-motor ERD would show a specific modulation during the observation of hand behaviors differing for goal-relatedness (hand grasping of an object and meaningless hand movements) and social relevance (communicative hand gestures and grasping within a social context). Time course analysis of alpha suppression showed that all types of hand behaviors were effective in triggering sensory-motor alpha ERD, but to a different degree depending on the category of observed hand motor acts and gestures. Meaningless gestures and hand grasping were the most effective stimuli, resulting in the strongest ERD. The observation of social hand behaviors such as social grasping and communicative gestures, triggered a more dynamic time course of ERD compared to that driven by the observation of simple grasping and meaningless gestures. These findings indicate that the observation of hand motor acts and gestures evoke the activation of a motor resonance mechanism that differs on the basis of the goal-relatedness and the social relevance of the observed hand behavior.
Neuroscientific research on emotion has developed dramatically over the past decade. The cognitive neuroscience of human emotion, which has emerged as the new and thriving area of 'affective neuroscience', is rapidly rendering existing overviews of the field obsolete. This handbook provides a comprehensive, up-to-date and authoritative survey of knowledge and topics investigated in this cutting-edge field. It covers a range of topics, from face and voice perception to pain and music, as well as social behaviors and decision making. The book considers and interrogates multiple research methods, among them brain imaging and physiology measurements, as well as methods used to evaluate behavior and genetics. Editors Jorge Armony and Patrik Vuilleumier have enlisted well-known and active researchers from more than twenty institutions across three continents, bringing geographic as well as methodological breadth to the collection. This timely volume will become a key reference work for researchers and students in the growing field of neuroscience.
Neuroscientific research on emotion has developed dramatically over the past decade. The cognitive neuroscience of human emotion, which has emerged as the new and thriving area of 'affective neuroscience', is rapidly rendering existing overviews of the field obsolete. This handbook provides a comprehensive, up-to-date and authoritative survey of knowledge and topics investigated in this cutting-edge field. It covers a range of topics, from face and voice perception to pain and music, as well as social behaviors and decision making. The book considers and interrogates multiple research methods, among them brain imaging and physiology measurements, as well as methods used to evaluate behavior and genetics. Editors Jorge Armony and Patrik Vuilleumier have enlisted well-known and active researchers from more than twenty institutions across three continents, bringing geographic as well as methodological breadth to the collection. This timely volume will become a key reference work for researchers and students in the growing field of neuroscience.
Neuroscientific research on emotion has developed dramatically over the past decade. The cognitive neuroscience of human emotion, which has emerged as the new and thriving area of 'affective neuroscience', is rapidly rendering existing overviews of the field obsolete. This handbook provides a comprehensive, up-to-date and authoritative survey of knowledge and topics investigated in this cutting-edge field. It covers a range of topics, from face and voice perception to pain and music, as well as social behaviors and decision making. The book considers and interrogates multiple research methods, among them brain imaging and physiology measurements, as well as methods used to evaluate behavior and genetics. Editors Jorge Armony and Patrik Vuilleumier have enlisted well-known and active researchers from more than twenty institutions across three continents, bringing geographic as well as methodological breadth to the collection. This timely volume will become a key reference work for researchers and students in the growing field of neuroscience.
Families, communities and societies influence children's learning and development in many ways. This is the first handbook devoted to the understanding of the nature of environments in child development. Utilizing Urie Bronfenbrenner's idea of embedded environments, this volume looks at environments from the immediate environment of the family (including fathers, siblings, grandparents and day-care personnel) to the larger environment including schools, neighborhoods, geographic regions, countries and cultures. Understanding these embedded environments and the ways in which they interact is necessary to understand development.
Families, communities and societies influence children's learning and development in many ways. This is the first handbook devoted to the understanding of the nature of environments in child development. Utilizing Urie Bronfenbrenner's idea of embedded environments, this volume looks at environments from the immediate environment of the family (including fathers, siblings, grandparents and day-care personnel) to the larger environment including schools, neighborhoods, geographic regions, countries and cultures. Understanding these embedded environments and the ways in which they interact is necessary to understand development.
Families, communities and societies influence children's learning and development in many ways. This is the first handbook devoted to the understanding of the nature of environments in child development. Utilizing Urie Bronfenbrenner's idea of embedded environments, this volume looks at environments from the immediate environment of the family (including fathers, siblings, grandparents and day-care personnel) to the larger environment including schools, neighborhoods, geographic regions, countries and cultures. Understanding these embedded environments and the ways in which they interact is necessary to understand development.
Families, communities and societies influence children's learning and development in many ways. This is the first handbook devoted to the understanding of the nature of environments in child development. Utilizing Urie Bronfenbrenner's idea of embedded environments, this volume looks at environments from the immediate environment of the family (including fathers, siblings, grandparents and day-care personnel) to the larger environment including schools, neighborhoods, geographic regions, countries and cultures. Understanding these embedded environments and the ways in which they interact is necessary to understand development.
Families, communities and societies influence children's learning and development in many ways. This is the first handbook devoted to the understanding of the nature of environments in child development. Utilizing Urie Bronfenbrenner's idea of embedded environments, this volume looks at environments from the immediate environment of the family (including fathers, siblings, grandparents and day-care personnel) to the larger environment including schools, neighborhoods, geographic regions, countries and cultures. Understanding these embedded environments and the ways in which they interact is necessary to understand development.
The Cambridge Handbook of Consciousness is the first of its kind in the field, and its appearance marks a unique time in the history of intellectual inquiry on the topic. After decades during which consciousness was considered beyond the scope of legitimate scientific investigation, consciousness re-emerged as a popular focus of research towards the end of the last century, and it has remained so for nearly 20 years. There are now so many different lines of investigation on consciousness that the time has come when the field may finally benefit from a book that pulls them together and, by juxtaposing them, provides a comprehensive survey of this exciting field. An authoritative desk reference, which will also be suitable as an advanced textbook.
The Cambridge Handbook of Consciousness is the first of its kind in the field, and its appearance marks a unique time in the history of intellectual inquiry on the topic. After decades during which consciousness was considered beyond the scope of legitimate scientific investigation, consciousness re-emerged as a popular focus of research towards the end of the last century, and it has remained so for nearly 20 years. There are now so many different lines of investigation on consciousness that the time has come when the field may finally benefit from a book that pulls them together and, by juxtaposing them, provides a comprehensive survey of this exciting field. An authoritative desk reference, which will also be suitable as an advanced textbook.
The Cambridge Handbook of Consciousness is the first of its kind in the field, and its appearance marks a unique time in the history of intellectual inquiry on the topic. After decades during which consciousness was considered beyond the scope of legitimate scientific investigation, consciousness re-emerged as a popular focus of research towards the end of the last century, and it has remained so for nearly 20 years. There are now so many different lines of investigation on consciousness that the time has come when the field may finally benefit from a book that pulls them together and, by juxtaposing them, provides a comprehensive survey of this exciting field. An authoritative desk reference, which will also be suitable as an advanced textbook.
The Cambridge Handbook of Consciousness is the first of its kind in the field, and its appearance marks a unique time in the history of intellectual inquiry on the topic. After decades during which consciousness was considered beyond the scope of legitimate scientific investigation, consciousness re-emerged as a popular focus of research towards the end of the last century, and it has remained so for nearly 20 years. There are now so many different lines of investigation on consciousness that the time has come when the field may finally benefit from a book that pulls them together and, by juxtaposing them, provides a comprehensive survey of this exciting field. An authoritative desk reference, which will also be suitable as an advanced textbook.
The Cambridge Handbook of Consciousness is the first of its kind in the field, and its appearance marks a unique time in the history of intellectual inquiry on the topic. After decades during which consciousness was considered beyond the scope of legitimate scientific investigation, consciousness re-emerged as a popular focus of research towards the end of the last century, and it has remained so for nearly 20 years. There are now so many different lines of investigation on consciousness that the time has come when the field may finally benefit from a book that pulls them together and, by juxtaposing them, provides a comprehensive survey of this exciting field. An authoritative desk reference, which will also be suitable as an advanced textbook.
Embodied theories of cognition consider many aspects of language and other cognitive domains as the result of sensory and motor processes. In this view, the appraisal and the use of concepts are based on mechanisms of simulation grounded on prior sensorimotor experiences. Even though these theories continue receiving attention and support, increasing evidence indicates the need to consider the flexible nature of the simulation process, and to accordingly refine embodied accounts. In this consensus paper, we discuss two potential sources of variability in experimental studies on embodiment of language: individual differences and context. Specifically, we show how factors contributing to individual differences may explain inconsistent findings in embodied language phenomena. These factors include sensorimotor or cultural experiences, imagery, context-related factors, and cognitive strategies. We also analyze the different contextual modulations, from single words to sentences and narratives, as well as the top-down and bottom-up influences. Similarly, we review recent efforts to include cultural and language diversity, aging, neurodegenerative diseases, and brain disorders, as well as bilingual evidence into the embodiment framework. We address the importance of considering individual differences and context in clinical studies to drive translational research more efficiently, and we indicate recommendations on how to correctly address these issues in future research. Systematically investigating individual differences and context may contribute to understanding the dynamic nature of simulation in language processes, refining embodied theories of cognition, and ultimately filling the gap between cognition in artificial experimental settings and cognition in the wild (i.e., in everyday life).
Families, communities and societies influence children's learning and development in many ways. This is the first handbook devoted to the understanding of the nature of environments in child development. Utilizing Urie Bronfenbrenner's idea of embedded environments, this volume looks at environments from the immediate environment of the family (including fathers, siblings, grandparents and day-care personnel) to the larger environment including schools, neighborhoods, geographic regions, countries and cultures. Understanding these embedded environments and the ways in which they interact is necessary to understand development.
The Cambridge Handbook of Consciousness is the first of its kind in the field, and its appearance marks a unique time in the history of intellectual inquiry on the topic. After decades during which consciousness was considered beyond the scope of legitimate scientific investigation, consciousness re-emerged as a popular focus of research towards the end of the last century, and it has remained so for nearly 20 years. There are now so many different lines of investigation on consciousness that the time has come when the field may finally benefit from a book that pulls them together and, by juxtaposing them, provides a comprehensive survey of this exciting field. An authoritative desk reference, which will also be suitable as an advanced textbook.
The Cambridge Handbook of Consciousness is the first of its kind in the field, and its appearance marks a unique time in the history of intellectual inquiry on the topic. After decades during which consciousness was considered beyond the scope of legitimate scientific investigation, consciousness re-emerged as a popular focus of research towards the end of the last century, and it has remained so for nearly 20 years. There are now so many different lines of investigation on consciousness that the time has come when the field may finally benefit from a book that pulls them together and, by juxtaposing them, provides a comprehensive survey of this exciting field. An authoritative desk reference, which will also be suitable as an advanced textbook.
Background:
The alarming disability burden and a high prevalence rate of stroke in India has encouraged the researchers to develop regenerative therapies to reduce clinical deficits. This study evaluates safety, feasibility and efficacy of autologous mononuclear and mesenchymal cell transplantation in stroke patients evaluated on clinical scores and functional imaging (fMRI and DTI).
Methods:
Forty (n=40) stroke patients were recruited with the inclusion criteria as: 3 months to 2 years of index event, power of hand muscles of at least 2; Brunnstrom stage: 2-5; conscious and comprehendible. Fugl Meyer (FM), modified Barthel Index (mBI), Medical Research Council (MRC) grade for strength, Ashworth tone scale and functional imaging was used for assessments at baseline, 8 weeks and 24 weeks. 50-60 million cells in 250 ml saline were infused intravenously over 2-3 h.
Results:
The safety test profile was normal with no mortality or cell related adverse reactions in stem cell patients. Among outcome parameters, only modified Barthel Index (mBI) showed statistical significant improvement (p<0.05) in the stem cell group. An increased number of cluster activation in Brodmann areas BA 4, BA 6 was observed post stem cell infusion indicating neural plasticity.
Conclusion:
Autologous intravenous stem cell therapy is safe and feasible. Stem cells act as "scaffolds" for neural transplantation and may aid in repair mechanisms in stroke.
Imitation is a crucial process for learning and brain development. It is based on the mirror neuron mechanism and underlies our understanding of actions and the gestures of others. Some researchers hypothesized a possible correlation between a low functioning mirror neuron system (MNS) and developmental coordination disorder, including dysgraphic deficit. However, no studies have verified whether imitation of graphic gestures by exploiting the properties of the MNS could improve handwriting. This study evaluates the effects of imitation training of handwriting in five children with handwriting difficulties aged 8 to 10 years. The training lasted for five months, and was undertaken three times a week, for a total number of 60 sessions for each child. Before and after the training, we evaluated the degree of handwriting impairment using the Concise Evaluation Scale for Children’s Handwriting (BHK). Our results suggest that handwriting imitation training produced a significant qualitative change in the children’s writing, likely due to exercises that stimulated fine motor imitation. Furthermore, the imitation also involved ergonomic and biomechanical aspects relevant to improving imitative writing after observing the model. Each child has therefore reached an adequate level of writing, suggesting the effectiveness of the proposed intervention.
This article is an answer to a report called “What is the evidence on the role of the arts in improving health and well-being?” The authors conclude that the arts have an impact on mental and physical health. Yet, the question of the role of the arts remains unanswered. What is and what is not an art effect? Recently, embodied theory has inspired articles on the perception of art. These articles have not yet received attention in the field of Arts and Health. Scholars in psychosomatic medicine have argued for an approach based on recent work in enactive embodied theory to investigate the connection between the body and the mind. The present article examines how key concepts in this theory relate to art. This leads to a discussion of art in terms of empathy—the relation between the internal state of the artist and the internal state of the beholder. I exemplify with a conceptual framework of musical empathy. Implications for health are addressed.
Advances in the fields of neurobiology, cognitive neuroscience and behaviour genetics pose a significant philosophical and epistemological challenge to the models of mind and psychotherapeutic practice advocated by counselling psychology. Drawing on contemporary work within psychoanalysis, however, I argue that a marriage of neuroscientific and psychotherapeutic research is not only possible but necessary. This paper discusses current research in the fields of memory, mental state understanding and behavioural genetics and examines some of the inherent methodological and conceptual problems facing interdisciplinary research within counselling psychology. The paper concludes with a brief discussion about the ways in which counselling psychology may be well-placed to contribute to a psychotherapeutically-informed neuroscience.
Eylem Gözlem Terapisi (EGT) hareketlerin izlenmesi sonrası aynı hareketlerin taklit edilmesi ile merkezi sinir sistemi restorasyonunu destekleyen nörorehabilitasyon temelli bir tedavi yaklaşımıdır. Serebral palsi, parkinson, inme, ortopedik yaralanmalar, alzheimer ve konuşma bozuklukları gibi pek çok hastalıkta, fonksiyonu gerçekleştiren nöral yapıları aktive etmek için nörofizyolojik mekanizmadan yararlanan yeni bir rehabilitasyon yaklaşımı olarak bilinir. Sağlıklı bireylerde ve nörolojik veya ortopedik etkilenimi olan bireylerde yapılan araştırmalar; EGT uygulamasının gözlemcinin motor sisteminde kolaylaştırmayı indüklediği ve eylem-algı eşleştirme mekanizmasını desteklediği bilinir. Bu derleme, Serebral Palsi (SP) tanılı çocuklarda üst ekstremiteye yönelik uygulanan EGT programlarının kullanımı ve etkinliği ile ilgili mevcut bilgileri gözden geçirmek amacıyla planlanmıştır. EGT kullanımının farklı koşullara kolayca adapte edilebilmesi, nöral plasitisiteyi destekleyerek motor öğrenmeyi fasilite etmesi ve ekonomik olması nedeniyle, SP’li çocukların üst ekstremite rehabilitasyonunda kullanımının uygun olduğu; ancak protokol, süre ve uygulama şekli açısından optimal uygulama prensiplerinin belirlenebilmesi için daha detaylı çalışmalara ihtiyaç olduğu düşünülmektedir.
The human Action Observation Network (AON) encompasses brain areas consistently engaged when we observe other's actions. Although the core nodes of the AON are present from childhood, it is not known to what extent they are sensitive to different action features during development. Because social cognitive abilities continue to mature during adolescence, the AON response to socially-oriented actions, but not to object-related actions, may differ in adolescents and adults. To test this hypothesis, we scanned with functional magnetic resonance imaging (fMRI) male and female typically-developing teenagers (n = 28; 13 females) and adults (n = 25; 14 females) while they passively watched videos of manual actions varying along two dimensions: sociality (i.e. directed towards another person or not) and transitivity (i.e. involving an object or not). We found that action observation recruited the same fronto-parietal and occipito-temporal regions in adults and adolescents. The modulation of voxel-wise activity according to the social or transitive nature of the action was similar in both groups of participants. Multivariate pattern analysis, however, revealed that decoding accuracies in IPS/SPL for both sociality and transitivity were lower for adolescents compared to adults. In addition, in the LOTC generalization of decoding across the orthogonal dimension was lower for sociality only in adolescents. These findings indicate that the representation of the content of others' actions, and in particular their social dimension, in the adolescent AON is still not as robust as in adults.SIGNIFICANCE STATEMENT:The activity of the action observation network in the human brain is modulated according to the purpose of the observed action, in particular the extent to which it involves interaction with an object or with another person. How this conceptual representation of actions is implemented during development is largely unknown. Here, using multivoxel pattern analysis of fMRI data, we discovered that, while the action observation network is in place in adolescence, the fine-grain organization of its posterior regions is less robust than in adults to decode the abstract social dimensions of an action. This finding highlights the late maturation of social processing in the human brain.
In recent years there has been an increasing awareness that a comprehensive understanding of language, cognitive and affective processes, and social and interpersonal phenomena cannot be achieved without understanding the ways these processes are grounded in bodily states. The term 'embodiment' captures the common denominator of these developments, which come from several disciplinary perspectives ranging from neuroscience, cognitive science, social psychology, and affective sciences. For the first time, this volume brings together these varied developments under one umbrella and furnishes a comprehensive overview of this intellectual movement in the cognitive-behavioral sciences. The chapters review current work on relations of the body to thought, language use, emotion and social relationships as presented by internationally recognized experts in these areas.
In recent years there has been an increasing awareness that a comprehensive understanding of language, cognitive and affective processes, and social and interpersonal phenomena cannot be achieved without understanding the ways these processes are grounded in bodily states. The term 'embodiment' captures the common denominator of these developments, which come from several disciplinary perspectives ranging from neuroscience, cognitive science, social psychology, and affective sciences. For the first time, this volume brings together these varied developments under one umbrella and furnishes a comprehensive overview of this intellectual movement in the cognitive-behavioral sciences. The chapters review current work on relations of the body to thought, language use, emotion and social relationships as presented by internationally recognized experts in these areas.
In two freestanding volumes, Textbook of Neural Repair and Rehabilitation provides comprehensive coverage of the science and practice of neurological rehabilitation. Revised throughout, bringing the book fully up to date, this volume, Medical Neurorehabilitation, can stand alone as a clinical handbook for neurorehabilitation. It covers the practical applications of the basic science principles presented in Volume 1, provides authoritative guidelines on the management of disabling symptoms, and describes comprehensive rehabilitation approaches for the major categories of disabling neurological disorders. New chapters have been added covering genetics in neurorehabilitation, the rehabilitation team and the economics of neurological rehabilitation, and brain stimulation, along with numerous others. Emphasizing the integration of basic and clinical knowledge, this book and its companion are edited and written by leading international authorities. Together they are an essential resource for neuroscientists and provide a foundation of the work of clinical neurorehabilitation professionals.
In two freestanding volumes, Textbook of Neural Repair and Rehabilitation provides comprehensive coverage of the science and practice of neurological rehabilitation. Revised throughout, bringing the book fully up to date, this volume, Medical Neurorehabilitation, can stand alone as a clinical handbook for neurorehabilitation. It covers the practical applications of the basic science principles presented in Volume 1, provides authoritative guidelines on the management of disabling symptoms, and describes comprehensive rehabilitation approaches for the major categories of disabling neurological disorders. New chapters have been added covering genetics in neurorehabilitation, the rehabilitation team and the economics of neurological rehabilitation, and brain stimulation, along with numerous others. Emphasizing the integration of basic and clinical knowledge, this book and its companion are edited and written by leading international authorities. Together they are an essential resource for neuroscientists and provide a foundation of the work of clinical neurorehabilitation professionals.
In two freestanding volumes, Textbook of Neural Repair and Rehabilitation provides comprehensive coverage of the science and practice of neurological rehabilitation. Revised throughout, bringing the book fully up to date, this volume, Medical Neurorehabilitation, can stand alone as a clinical handbook for neurorehabilitation. It covers the practical applications of the basic science principles presented in Volume 1, provides authoritative guidelines on the management of disabling symptoms, and describes comprehensive rehabilitation approaches for the major categories of disabling neurological disorders. New chapters have been added covering genetics in neurorehabilitation, the rehabilitation team and the economics of neurological rehabilitation, and brain stimulation, along with numerous others. Emphasizing the integration of basic and clinical knowledge, this book and its companion are edited and written by leading international authorities. Together they are an essential resource for neuroscientists and provide a foundation of the work of clinical neurorehabilitation professionals.
In two freestanding volumes, Textbook of Neural Repair and Rehabilitation provides comprehensive coverage of the science and practice of neurological rehabilitation. Revised throughout, bringing the book fully up to date, this volume, Medical Neurorehabilitation, can stand alone as a clinical handbook for neurorehabilitation. It covers the practical applications of the basic science principles presented in Volume 1, provides authoritative guidelines on the management of disabling symptoms, and describes comprehensive rehabilitation approaches for the major categories of disabling neurological disorders. New chapters have been added covering genetics in neurorehabilitation, the rehabilitation team and the economics of neurological rehabilitation, and brain stimulation, along with numerous others. Emphasizing the integration of basic and clinical knowledge, this book and its companion are edited and written by leading international authorities. Together they are an essential resource for neuroscientists and provide a foundation of the work of clinical neurorehabilitation professionals.
In two freestanding volumes, Textbook of Neural Repair and Rehabilitation provides comprehensive coverage of the science and practice of neurological rehabilitation. Revised throughout, bringing the book fully up to date, this volume, Medical Neurorehabilitation, can stand alone as a clinical handbook for neurorehabilitation. It covers the practical applications of the basic science principles presented in Volume 1, provides authoritative guidelines on the management of disabling symptoms, and describes comprehensive rehabilitation approaches for the major categories of disabling neurological disorders. New chapters have been added covering genetics in neurorehabilitation, the rehabilitation team and the economics of neurological rehabilitation, and brain stimulation, along with numerous others. Emphasizing the integration of basic and clinical knowledge, this book and its companion are edited and written by leading international authorities. Together they are an essential resource for neuroscientists and provide a foundation of the work of clinical neurorehabilitation professionals.
In two freestanding volumes, Textbook of Neural Repair and Rehabilitation provides comprehensive coverage of the science and practice of neurological rehabilitation. Revised throughout, bringing the book fully up to date, this volume, Medical Neurorehabilitation, can stand alone as a clinical handbook for neurorehabilitation. It covers the practical applications of the basic science principles presented in Volume 1, provides authoritative guidelines on the management of disabling symptoms, and describes comprehensive rehabilitation approaches for the major categories of disabling neurological disorders. New chapters have been added covering genetics in neurorehabilitation, the rehabilitation team and the economics of neurological rehabilitation, and brain stimulation, along with numerous others. Emphasizing the integration of basic and clinical knowledge, this book and its companion are edited and written by leading international authorities. Together they are an essential resource for neuroscientists and provide a foundation of the work of clinical neurorehabilitation professionals.
In two freestanding volumes, Textbook of Neural Repair and Rehabilitation provides comprehensive coverage of the science and practice of neurological rehabilitation. Revised throughout, bringing the book fully up to date, this volume, Medical Neurorehabilitation, can stand alone as a clinical handbook for neurorehabilitation. It covers the practical applications of the basic science principles presented in Volume 1, provides authoritative guidelines on the management of disabling symptoms, and describes comprehensive rehabilitation approaches for the major categories of disabling neurological disorders. New chapters have been added covering genetics in neurorehabilitation, the rehabilitation team and the economics of neurological rehabilitation, and brain stimulation, along with numerous others. Emphasizing the integration of basic and clinical knowledge, this book and its companion are edited and written by leading international authorities. Together they are an essential resource for neuroscientists and provide a foundation of the work of clinical neurorehabilitation professionals.
In two freestanding volumes, Textbook of Neural Repair and Rehabilitation provides comprehensive coverage of the science and practice of neurological rehabilitation. Revised throughout, bringing the book fully up to date, this volume, Medical Neurorehabilitation, can stand alone as a clinical handbook for neurorehabilitation. It covers the practical applications of the basic science principles presented in Volume 1, provides authoritative guidelines on the management of disabling symptoms, and describes comprehensive rehabilitation approaches for the major categories of disabling neurological disorders. New chapters have been added covering genetics in neurorehabilitation, the rehabilitation team and the economics of neurological rehabilitation, and brain stimulation, along with numerous others. Emphasizing the integration of basic and clinical knowledge, this book and its companion are edited and written by leading international authorities. Together they are an essential resource for neuroscientists and provide a foundation of the work of clinical neurorehabilitation professionals.
In two freestanding volumes, Textbook of Neural Repair and Rehabilitation provides comprehensive coverage of the science and practice of neurological rehabilitation. Revised throughout, bringing the book fully up to date, this volume, Medical Neurorehabilitation, can stand alone as a clinical handbook for neurorehabilitation. It covers the practical applications of the basic science principles presented in Volume 1, provides authoritative guidelines on the management of disabling symptoms, and describes comprehensive rehabilitation approaches for the major categories of disabling neurological disorders. New chapters have been added covering genetics in neurorehabilitation, the rehabilitation team and the economics of neurological rehabilitation, and brain stimulation, along with numerous others. Emphasizing the integration of basic and clinical knowledge, this book and its companion are edited and written by leading international authorities. Together they are an essential resource for neuroscientists and provide a foundation of the work of clinical neurorehabilitation professionals.
In two freestanding volumes, Textbook of Neural Repair and Rehabilitation provides comprehensive coverage of the science and practice of neurological rehabilitation. Revised throughout, bringing the book fully up to date, this volume, Medical Neurorehabilitation, can stand alone as a clinical handbook for neurorehabilitation. It covers the practical applications of the basic science principles presented in Volume 1, provides authoritative guidelines on the management of disabling symptoms, and describes comprehensive rehabilitation approaches for the major categories of disabling neurological disorders. New chapters have been added covering genetics in neurorehabilitation, the rehabilitation team and the economics of neurological rehabilitation, and brain stimulation, along with numerous others. Emphasizing the integration of basic and clinical knowledge, this book and its companion are edited and written by leading international authorities. Together they are an essential resource for neuroscientists and provide a foundation of the work of clinical neurorehabilitation professionals.
In two freestanding volumes, Textbook of Neural Repair and Rehabilitation provides comprehensive coverage of the science and practice of neurological rehabilitation. Revised throughout, bringing the book fully up to date, this volume, Medical Neurorehabilitation, can stand alone as a clinical handbook for neurorehabilitation. It covers the practical applications of the basic science principles presented in Volume 1, provides authoritative guidelines on the management of disabling symptoms, and describes comprehensive rehabilitation approaches for the major categories of disabling neurological disorders. New chapters have been added covering genetics in neurorehabilitation, the rehabilitation team and the economics of neurological rehabilitation, and brain stimulation, along with numerous others. Emphasizing the integration of basic and clinical knowledge, this book and its companion are edited and written by leading international authorities. Together they are an essential resource for neuroscientists and provide a foundation of the work of clinical neurorehabilitation professionals.
In two freestanding volumes, Textbook of Neural Repair and Rehabilitation provides comprehensive coverage of the science and practice of neurological rehabilitation. Revised throughout, bringing the book fully up to date, this volume, Medical Neurorehabilitation, can stand alone as a clinical handbook for neurorehabilitation. It covers the practical applications of the basic science principles presented in Volume 1, provides authoritative guidelines on the management of disabling symptoms, and describes comprehensive rehabilitation approaches for the major categories of disabling neurological disorders. New chapters have been added covering genetics in neurorehabilitation, the rehabilitation team and the economics of neurological rehabilitation, and brain stimulation, along with numerous others. Emphasizing the integration of basic and clinical knowledge, this book and its companion are edited and written by leading international authorities. Together they are an essential resource for neuroscientists and provide a foundation of the work of clinical neurorehabilitation professionals.
In two freestanding volumes, Textbook of Neural Repair and Rehabilitation provides comprehensive coverage of the science and practice of neurological rehabilitation. Revised throughout, bringing the book fully up to date, this volume, Medical Neurorehabilitation, can stand alone as a clinical handbook for neurorehabilitation. It covers the practical applications of the basic science principles presented in Volume 1, provides authoritative guidelines on the management of disabling symptoms, and describes comprehensive rehabilitation approaches for the major categories of disabling neurological disorders. New chapters have been added covering genetics in neurorehabilitation, the rehabilitation team and the economics of neurological rehabilitation, and brain stimulation, along with numerous others. Emphasizing the integration of basic and clinical knowledge, this book and its companion are edited and written by leading international authorities. Together they are an essential resource for neuroscientists and provide a foundation of the work of clinical neurorehabilitation professionals.
In two freestanding volumes, Textbook of Neural Repair and Rehabilitation provides comprehensive coverage of the science and practice of neurological rehabilitation. Revised throughout, bringing the book fully up to date, this volume, Medical Neurorehabilitation, can stand alone as a clinical handbook for neurorehabilitation. It covers the practical applications of the basic science principles presented in Volume 1, provides authoritative guidelines on the management of disabling symptoms, and describes comprehensive rehabilitation approaches for the major categories of disabling neurological disorders. New chapters have been added covering genetics in neurorehabilitation, the rehabilitation team and the economics of neurological rehabilitation, and brain stimulation, along with numerous others. Emphasizing the integration of basic and clinical knowledge, this book and its companion are edited and written by leading international authorities. Together they are an essential resource for neuroscientists and provide a foundation of the work of clinical neurorehabilitation professionals.
In two freestanding volumes, Textbook of Neural Repair and Rehabilitation provides comprehensive coverage of the science and practice of neurological rehabilitation. Revised throughout, bringing the book fully up to date, this volume, Medical Neurorehabilitation, can stand alone as a clinical handbook for neurorehabilitation. It covers the practical applications of the basic science principles presented in Volume 1, provides authoritative guidelines on the management of disabling symptoms, and describes comprehensive rehabilitation approaches for the major categories of disabling neurological disorders. New chapters have been added covering genetics in neurorehabilitation, the rehabilitation team and the economics of neurological rehabilitation, and brain stimulation, along with numerous others. Emphasizing the integration of basic and clinical knowledge, this book and its companion are edited and written by leading international authorities. Together they are an essential resource for neuroscientists and provide a foundation of the work of clinical neurorehabilitation professionals.
In two freestanding volumes, Textbook of Neural Repair and Rehabilitation provides comprehensive coverage of the science and practice of neurological rehabilitation. Revised throughout, bringing the book fully up to date, this volume, Medical Neurorehabilitation, can stand alone as a clinical handbook for neurorehabilitation. It covers the practical applications of the basic science principles presented in Volume 1, provides authoritative guidelines on the management of disabling symptoms, and describes comprehensive rehabilitation approaches for the major categories of disabling neurological disorders. New chapters have been added covering genetics in neurorehabilitation, the rehabilitation team and the economics of neurological rehabilitation, and brain stimulation, along with numerous others. Emphasizing the integration of basic and clinical knowledge, this book and its companion are edited and written by leading international authorities. Together they are an essential resource for neuroscientists and provide a foundation of the work of clinical neurorehabilitation professionals.
In two freestanding volumes, Textbook of Neural Repair and Rehabilitation provides comprehensive coverage of the science and practice of neurological rehabilitation. Revised throughout, bringing the book fully up to date, this volume, Medical Neurorehabilitation, can stand alone as a clinical handbook for neurorehabilitation. It covers the practical applications of the basic science principles presented in Volume 1, provides authoritative guidelines on the management of disabling symptoms, and describes comprehensive rehabilitation approaches for the major categories of disabling neurological disorders. New chapters have been added covering genetics in neurorehabilitation, the rehabilitation team and the economics of neurological rehabilitation, and brain stimulation, along with numerous others. Emphasizing the integration of basic and clinical knowledge, this book and its companion are edited and written by leading international authorities. Together they are an essential resource for neuroscientists and provide a foundation of the work of clinical neurorehabilitation professionals.
In two freestanding volumes, Textbook of Neural Repair and Rehabilitation provides comprehensive coverage of the science and practice of neurological rehabilitation. Revised throughout, bringing the book fully up to date, this volume, Medical Neurorehabilitation, can stand alone as a clinical handbook for neurorehabilitation. It covers the practical applications of the basic science principles presented in Volume 1, provides authoritative guidelines on the management of disabling symptoms, and describes comprehensive rehabilitation approaches for the major categories of disabling neurological disorders. New chapters have been added covering genetics in neurorehabilitation, the rehabilitation team and the economics of neurological rehabilitation, and brain stimulation, along with numerous others. Emphasizing the integration of basic and clinical knowledge, this book and its companion are edited and written by leading international authorities. Together they are an essential resource for neuroscientists and provide a foundation of the work of clinical neurorehabilitation professionals.
In two freestanding volumes, Textbook of Neural Repair and Rehabilitation provides comprehensive coverage of the science and practice of neurological rehabilitation. Revised throughout, bringing the book fully up to date, this volume, Medical Neurorehabilitation, can stand alone as a clinical handbook for neurorehabilitation. It covers the practical applications of the basic science principles presented in Volume 1, provides authoritative guidelines on the management of disabling symptoms, and describes comprehensive rehabilitation approaches for the major categories of disabling neurological disorders. New chapters have been added covering genetics in neurorehabilitation, the rehabilitation team and the economics of neurological rehabilitation, and brain stimulation, along with numerous others. Emphasizing the integration of basic and clinical knowledge, this book and its companion are edited and written by leading international authorities. Together they are an essential resource for neuroscientists and provide a foundation of the work of clinical neurorehabilitation professionals.
This experiment was designed to investigate the neural network engaged by the perception of human movements using positron emission tomography. Perception of meaningful and of meaningless hand actions without any purpose was contrasted with the perception of the same kind of stimuli with the goal to imitate them later. A condition that consisted of the perception of stationary hands served as a baseline level. Perception of meaningful actions and meaningless actions without any aim was associated with activation of a common set of cortical regions. In both hemispheres, the occipito-temporal junction (Ba 37/19) and the superior occipital gyrus (Ba 19) were involved. In the left hemisphere, the middle temporal gyrus (Ba 21) and the inferior parietal lobe (Ba 40) were found to be activated. These regions are interpreted as related to the analysis of hand movements. The precentral gyrus, within the area of hand representation (Ba 4), was activated in the left hemisphere. In addition to this common network, meaningful and meaningless movements engaged specific networks, respectively: meaningful actions were associated with activations mainly located in the left hemisphere in the inferior frontal gyrus (Ba 44/45) and the fusiform gyrus (Ba 38/20), whereas meaningless actions involved the dorsal pathway (inferior parietal lobe, Ba 40 and superior parietal lobule, Ba 7) bilaterally and the right cerebellum . In contrast, meaningful and meaningless actions shared almost the same network when the aim of the perception was to im itate. Activations were located in the right cerebellum and bilaterally in the dorsal pathway reaching the prem otor cortex. Additional bilateral activations were located in the SMA and in the orbitofrontal cortex during observation of meaningful actions.
First published in 1995, this book presents a model for understanding the visual processing underlying perception and action, proposing a broad distinction within the brain between two kinds of vision: conscious perception and unconscious 'online' vision. It argues that each kind of vision can occur quasi-independently of the other, and is separately handled by a quite different processing system. For this new edition, the text from the original edition has been left untouched, standing as a coherent statement of the authors' position. However, a very substantial epilogue has been added to the book, which reviews some of the key developments that support or challenge the views that were put forward in the first edition. The new chapter summarizes developments in various relevant areas of psychology, neuroscience, and behaviour. It supplements the main text by updating the reader on the contributions that have emerged from the use of functional neuroimaging, which was in its infancy when the first edition was written. Neuroimaging, and functional MRI in particular, has revolutionized the field by allowing investigators to plot in detail the patterns of activity within the visual brains of behaving and perceiving humans. The authors show how its use now allows scientists to test and confirm their proposals, based largely on evidence accrued from primate neuroscience in conjunction with studies of neurological patients.
Positron emission tomography imaging of cerebral blood flow was used to localize brain areas involved in the representation of hand grasping movements. Seven normal subjects were scanned under three conditions. In the first, they observed precision grasping of common objects performed by the examiner. In the second, they imagined themselves grasping the objects without actually moving the hand. These two tasks were compared with a control task of object viewing. Grasp observation activated the left rostral superior temporal sulcus, left inferior frontal cortex (area 45), left rostral inferior parietal cortex (area 40), the rostral part of left supplementary motor area (SMA-proper), and the right dorsal premotor cortex. Imagined grasping activated the left inferior frontal (area 44) and middle frontal cortex, left caudal inferior parietal cortex (area 40), a more extensive response in left rostral SMA-proper, and left dorsal premotor cortex. The two conditions activated different areas of the right posterior cerebellar cortex. We propose that the areas active during grasping observation may form a circuit for recognition of hand-object interactions, whereas the areas active during imagined grasping may be a putative human homologue of a circuit for hand grasping movements recently defined in nonhuman primates. The location of responses in SMA-proper confirms the rostrocaudal segregation of this area for imagined and real movement. A similar segregation is also present in the cerebellum, with imagined and observed grasping movements activating different parts of the posterior lobe and real movements activating the anterior lobe.
1. We stimulated the motor cortex of normal subjects (transcranial magnetic stimulation) while they 1) observed an experimenter grasping 3D-objects, 2) looked at the same 3D-objects, 3) observed an experimenter tracing geometrical figures in the air with his arm, and 4) detected the dimming of a light. Motor evoked potentials (MEPs) were recorded from hand muscles. 2. We found that MEPs significantly increased during the conditions in which subjects observed movements. The MEP pattern reflected the pattern of muscle activity recorded when the subjects executed the observed actions. 3. We conclude that in humans there is a system matching action observation and execution. This system resembles the one recently described in the monkey.
Positron emission tomography (PET) was used to localize brain regions that are active during the observation of grasping movements. Normal, right-handed subjects were tested under three conditions. In the first, they observed grasping movements of common objects performed by the experimenter. In the second, they reached and grasped the same objects. These two conditions were compared with a third condition consisting of object observation. On the basis of monkey data, it was hypothesized that during grasping observation, activations should be present in the region of the superior temporal sulcus (STS) and in inferior area 6. The findings in humans demonstrated that grasp observation significantly activates the cortex of the middle temporal gyrus including that of the adjacent superior temporal sulcus (Brodmann's area 21) and the caudal part of the left inferior frontal gyrus (Brodmann's area 45). The possible functional homologies between these areas and the monkey STS region and frontal area F5 are discussed.
To look at or reach for what we see, spatial information from the visual system must be transformed into a motor plan. The posterior parietal cortex (PPC) is well placed to perform this function, because it lies between visual areas, which encode spatial information, and motor cortical areas. The PPC contains several subdivisions, which are generally conceived as high-order sensory areas. Neurons in area 7a and the lateral intraparietal area fire before and during visually guided saccades. Other neurons in areas 7a and 5 are active before and during visually guided arm movements. These areas are also active during memory tasks in which the animal remembers the location of a target for hundreds of milliseconds before making an eye or arm movement. Such activity could reflect either visual attention or the intention to make movements. This question is difficult to resolve, because even if the animal maintains fixation while directing attention to a peripheral location, the observed neuronal activity could reflect movements that are planned but not executed. To address this, we recorded from the PPC while monkeys planned either reaches or saccades to a single remembered location. We now report that, for most neurons, activity before the movement depended on the type of movement being planned. We conclude that PPC contains signals related to what the animal intends to do.
PET was used to map brain regions that are associated with the observation of meaningful and meaningless hand actions. Subjects were scanned under four conditions which consisted of visually presented actions. In each of the four experimental conditions, they were instructed to watch the actions with one of two aims: to be able to recognize or to imitate them later. We found that differences in the meaning of the action, irrespective of the strategy used during observation, lead to different patterns of brain activity and clear left/right asymmetries. Meaningful actions strongly engaged the left hemisphere in frontal and temporal regions while meaningless actions involved mainly the right occipitoparietal pathway. Observing with the intent to recognize activated memory-encoding structures. In contrast, observation with the intent to imitate was associated with activation in the regions involved in the planning and in the generation of actions. Thus, the pattern of brain activation during observation of actions is dependent both on the nature of the required executive processing and the type of the extrinsic properties of the action presented.
The monkey premotor cortex contains neurons that discharge during action execution and during observation of actions made by others. Transcranial magnetic stimulation experiments suggest that a similar observation/execution matching system also is present in humans. We recorded neuromagnetic oscillatory activity of the human precentral cortex from 10 healthy volunteers while (i) they had no task to perform, (ii) they were manipulating a small object, and (iii) they were observing another individual performing the same task. The left and right median nerves were stimulated alternately (interstimulus interval, 1.5 s) at intensities exceeding motor threshold, and the poststimulus rebound of the rolandic 15- to 25-Hz activity was quantified. In agreement with previous studies, the rebound was strongly suppressed bilaterally during object manipulation. Most interestingly, the rebound also was significantly diminished during action observation (31-46% of the suppression during object manipulation). Control experiments, in which subjects were instructed to observe stationary or moving stimuli, confirmed the specificity of the suppression effect. Because the recorded 15- to 25-Hz activity is known to originate mainly in the precentral motor cortex, we concluded that the human primary motor cortex is activated during observation as well as execution of motor tasks. These findings have implications for a better understanding of the machinery underlying action recognition in humans.
We recorded electrical activity from 532 neurons in the rostral part of inferior area 6 (area F5) of two macaque monkeys. Previous data had shown that neurons of this area discharge during goal-directed hand and mouth movements. We describe here the properties of a newly discovered set of F5 neurons ("mirror neurons', n = 92) all of which became active both when the monkey performed a given action and when it observed a similar action performed by the experimenter. Mirror neurons, in order to be visually triggered, required an interaction between the agent of the action and the object of it. The sight of the agent alone or of the object alone (three-dimensional objects, food) were ineffective. Hand and the mouth were by far the most effective agents. The actions most represented among those activating mirror neurons were grasping, manipulating and placing. In most mirror neurons (92%) there was a clear relation between the visual action they responded to and the motor response they coded. In approximately 30% of mirror neurons the congruence was very strict and the effective observed and executed actions corresponded both in terms of general action (e.g. grasping) and in terms of the way in which that action was executed (e.g. precision grip). We conclude by proposing that mirror neurons form a system for matching observation and execution of motor actions. We discuss the possible role of this system in action recognition and, given the proposed homology between F5 and human Brocca's region, we posit that a matching system, similar to that of mirror neurons exists in humans and could be involved in recognition of actions as well as phonetic gestures.
In area F5 of the monkey premotor cortex there are neurons that discharge both when the monkey performs an action and when he observes a similar action made by another monkey or by the experimenter. We report here some of the properties of these 'mirror' neurons and we propose that their activity 'represents' the observed action. We posit, then, that this motor representation is at the basis of the understanding of motor events. Finally, on the basis of some recent data showing that, in man, the observation of motor actions activate the posterior part of inferior frontal gyrus, we suggest that the development of the lateral verbal communication system in man derives from a more ancient communication system based on recognition of hand and face gestures.
The sizes of Brodmann's areas 44 and 45 (Broca's speech region) and their extent in relation to macroscopic landmarks and surrounding areas differ considerably among the available cytoarchitectonic maps. Such variability may be due to intersubject differences in anatomy, observer-dependent discrepancies in cytoarchitectonic mapping, or both. Because a reliable definition of cytoarchitectonic borders is important for interpreting functional imaging data, we mapped areas 44 and 45 by means of an observer-independent technique. In 10 human brains, the laminar distributions of cell densities were measured vertical to the cortical surface in serial coronal sections stained for perikarya. Thousands of density profiles were obtained. Cytoarchitectonic borders were defined as statistically significant changes in laminar patterns. The analysis of the three-dimensional reconstructed brains and the two areas showed that cytoarchitectonic borders did not consistently coincide with sulcal contours. Therefore, macroscopic features are not reliable landmarks of cytoarchitectonic borders. Intersubject variability in the cytoarchitecture of areas 44 and 45 was significantly greater than cytoarchitectonic differences between these areas in individual brains. Although the volumes of area 44 differed across subjects by up to a factor of 10, area 44 but not area 45 was left-over-right asymmetrical in all brains. All five male but only three of five female brains had significantly higher cell densities on the left than on the right side. Such hemispheric and gender differences were not detected in area 45. These morphologic asymmetries of area 44 provide a putative correlate of the functional lateralization of speech production. J. Comp. Neurol. 412:319–341, 1999. © 1999 Wiley-Liss, Inc.
This study of somatosensory discrimination of rectangular parallelepipeds with the right hand had three purposes: (i) to describe the exploratory finger movements; (ii) to reveal the anatomical brain structures specifically engaged in the production of exploratory finger movements; and (iii) to reveal the anatomical structures specifically engaged in the discrimination of tactually sensed shape. The thumb was the most active finger, moving with a mean exploration frequency of 2.4 Hz, as evident from videotape records of the exploratory finger movements. The cerebral structures activated during somatosensory discrimination were mapped by measurements of regional cerebral blood flow (rCBF) in six healthy male volunteers with positron emission tomography (PET) and the use of the computerized brain atlas of Greitz et al. (1991, J. Comp. Ass. Tomogr., 15, 26–38). The rCBF changes caused by somatosensory discrimination were compared point-to-point to a PET-study on right-hand finger movements and a PET-study on vibration stimulation of the right hand. From these results the following conclusions were drawn. The rCBF increase in the left superior parietal lobule indicated the site engaged in the analysis of shape. The rCBF increases in the left supplementary sensory area, bilaterally in premotor areas, in the left putamen, the right dentate nucleus and bilaterally in the posterior cerebellum were related to the control of the tactile exploratory finger movements. The rCBF increases in the right homologue of Broca's area, bilaterally in the superior prefrontal cortex and in the right midfrontal cortex probably resulted from working memory, the direction of attention, and the discrimination process.
This paper presents a general approach to the analysis of functional MRI time-series from one or more subjects. The approach is predicated on an extension of the general linear model that allows for correlations between error terms due to physiological noise or correlations that ensue after temporal smoothing. This extension uses the effective degrees of freedom associated with the error term. The effective degrees of freedom are a simple function of the number of scans and the temporal autocorrelation function. A specific form for the latter can be assumed if the data are smoothed, in time, to accentuate hemodynamic responses with a neural basis. This assumption leads to an expedient implementation of a flexible statistical framework. The importance of this small extension is that, in contradistinction to our previous approach, any parametric statistical analysis can be implemented. We demonstrate this point using a multiple regression analysis that tests for effects of interest (activations due to word generation), while taking explicit account of some obvious confounds.
This paper concerns how motor actions are neurally represented and coded. Action planning and motor preparation can be studied using a specific type of representational activity, motor imagery. A close functional equivalence between motor imagery and motor preparation is suggested by the positive effects of imagining movements on motor learning, the similarity between the neural structures involved, and the similar physiological correlates observed in both imaging and preparing. The content of motor representations can be inferred from motor images at a macroscopic level, based on global aspects of the action (the duration and amount of effort involved) and the motor rules and constraints which predict the spatial path and kinematics of movements. A more microscopic neural account calls for a representation of object-oriented action. Object attributes are processed in different neural pathways depending on the kind of task the subject is performing. During object-oriented action, a pragmatic representation is activated in which object affordances are transformed into specific motor schemas (independently of other tasks such as object recognition). Animal as well as human clinical data implicate the posterior parietal and premotor cortical areas in schema instantiation. A mechanism is proposed that is able to encode the desired goal of the action and is applicable to different levels of representational organization.
How does imitation occur? How can the motor plans necessary for imitating an action derive from the observation of that action?
Imitation may be based on a mechanism directly matching the observed action onto an internal motor representation of that
action (“direct matching hypothesis”). To test this hypothesis, normal human participants were asked to observe and imitate
a finger movement and to perform the same movement after spatial or symbolic cues. Brain activity was measured with functional
magnetic resonance imaging. If the direct matching hypothesis is correct, there should be areas that become active during
finger movement, regardless of how it is evoked, and their activation should increase when the same movement is elicited by
the observation of an identical movement made by another individual. Two areas with these properties were found in the left
inferior frontal cortex (opercular region) and the rostral-most region of the right superior parietal lobule.
The most anterior part of area 7 of awake, behaving macaque monkeys was investigated using single cell recording technique. Eighty-five cells from three hemispheres of two monkeys were isolated and studied. These cells showed more complex functional properties than the cells in the primary and secondary cortical fields. Of the cells 61% responded to somatosensory (26%) or visual (2%) or both somatosensory and visual (33%) stimulation; 39% of the cells were active only during the monkey's own movements.
Most of the cells studied were active while the monkey was bringing an object to the mouth with its hand, when reaching for an object with lips, or while chewing. The neurons responded selectively to, e.g., palpation of the flexors of the arm, a visual stimulus approaching the face, passive movement of the monkey's hand towards the mouth, or they were active only when the monkey was reaching for an object with its lips or was mouthing it.
The cellular activity in the anterolateral part of area 7 was prominently related to the stimulation or motor activity of the face (especially the mouth). In this respect, it differed from the more posterior part of area 7 adjacent to it. The results thus indicate that there is a separate and rather extensive mouth (or face) area in the parietal association cortex of the monkey.
The definition of visual areas remains a key problem in the effort to elucidate cortical functions. Visual areas vary along a number of dimensions and are increasingly difficult to define according to traditional criteria at higher levels of the hierarchy. Three recently discovered areas in monkey parietal association cortex illustrate a new approach to this problem. Their definition depends on assessment of neuronal response properties in the alert, behaving animal combined with precise reconstruction of recording sites. This approach permits recognition of functionally distinct areas in the absence of retinotopic maps.
Somatosensory and motor disturbances of hand function were examined in 9 patients with parietal lobe lesions. A quantitative score was used for the elaboration of sensorimotor profiles displaying the relative degree of functional impairment. In patients with anterior parietal lobe lesions somaesthesis was clearly more disturbed than motor function. Simple aspects of somaesthesis (surface sensibility, two-point discrimination, position sense) were disturbed to about the same degree as complex somatosensory (tactile recognition) tasks. On the other hand, patients with lesions of the posterior parietal lobe showed preferential impairment of complex somatosensory and motor functions (exploratory and manipulative finger movements). In 4 patients, analysis of motor behaviour by means of an optoelectronic system showed that reaching, formation of hand aperture and target acquisition were less disturbed than manipulative behaviour. Finger movement trajectories during dynamic digital palpation of objects were grossly deranged in the patients with posterior parietal damage. The temporal characteristics of the finger movements during active touch were completely destroyed. This leads to a breakdown of the finely tuned digital scanning process required for the sequential sampling of mechanoreceptive information. Remarkably, these patients could produce the exploratory finger movements imitatively. The motor disability of the parietal hand does not lie in the loss of the kinetic memory to perform these movements, but in the loss of their evocation by appropriate sensory stimuli. This deficit is not due to a lack of somatosensory information because that may be relatively well preserved. It is concluded that the motor disturbance in posterior parietal lobe disease lies essentially in the conception and execution of the spatiotemporal movement patterns necessary to bring those receptors into action which would normally provide the information about tactile objects. This illustrates the intricate mutual dependence of the spatiotemporal organization of receptor activation by movement and of the formation of movement trajectories on the basis of adequate sensory processing.
The pattern of finger grip formation during natural prehension movements was described in normal subjects with the help of a quantified film technique. Movements were studied in one condition with visual feedback from the moving hand available, and one condition without visual feedback. The studied parameters, including the maximum size of the anticipatory grip and the final size of the grip before contact with the object, were not affected by shifting from one condition of visual feedback to the other. The same technique was applied to a group of patients with cerebral lesions. In two patients with unilateral lesions involving the motor cortex, grip formation with the hand contralateral to the lesion, was found to be severely affected, in that fingers and particularly the index finger, remained stretched until contact with the object was made. In two patients with unilateral lesions in the posterior parietal cortex, grip formation of the contralateral hand was absent specifically in the no-visual feedback condition. The same result was obtained in two other patients with a lesion (subcortical in one case, cortical in the other) of somatosensory pathways corresponding to one hand. These results are interpreted as evidence for the role of cerebral cortex in the control of finger grip formation during prehension of visual objects. Integration at cortical level of visual and somatosensory cues from the involved hand is a necessary condition for grip formation to be adapted to the grasp.
Grasping requires coding of the object's intrinsic properties (size and shape), and the transformation of these properties into a pattern of distal (finger and wrist) movements. Computational models address this behavior through the interaction of perceptual and motor schemas. In monkeys, the transformation of an object's intrinsic properties into specific grips takes place in a circuit that is formed by the inferior parietal lobule and the inferior premotor area (area F5). Neurons in both these areas code size, shape and orientation of objects, and specific types of grip that are necessary to grasp them. Grasping movements are coded more globally in the inferior parietal lobule, whereas they are more segmented in area F5. In humans, neuropsychological studies of patients with lesions to the parietal lobule confirm that primitive shape characteristics of an object for grasping are analyzed in the parietal lobe, and also demonstrate that this 'pragmatic' analysis of objects is separated from the 'semantic' analysis performed in the temporal lobe.
We studied the functional properties of the hand manipulation task-related neurons (N = 136) in the posterior bank of the intraparietal sulcus (IPS) using four kinds of objects for manipulation. We performed cluster analysis by comparing the profiles of activity of these neurons across objects during manipulation in the light, and classified them into nine groups, four highly selective, four moderately selective, and one nonselective group. Activity profiles of these neurons across objects were analyzed in four task conditions: object manipulation and object fixation both in the light and in the dark. Cells were classified as "motor-dominant," "visual-dominant," and "visual and motor" neurons, and the latter two were further subdivided into object type and non-object type. Most of the highly selective neurons (35 of 136) preferred the same object for manipulation in the dark as in the light. The object type "visual and motor" neurons preferred the same object for manipulation and fixation, suggesting that these neurons play an important role in matching the pattern of hand movement to the visuo-spatial characteristics of the object to be manipulated. A large majority of highly selective hand manipulation neurons were localized in the rostral part of the posterior bank of IPS, which we designated as the anterior intraparietal (AIP) area. We propose a conceptual model of the system for visual guidance of hand action including parietal hand manipulation neurons.
In area F5 of the monkey premotor cortex there are neurons that discharge both when the monkey performs an action and when he observes a similar action made by another monkey or by the experimenter. We report here some of the properties of these 'mirror' neurons and we propose that their activity 'represents' the observed action. We posit, then, that this motor representation is at the basis of the understanding of motor events. Finally, on the basis of some recent data showing that, in man, the observation of motor actions activate the posterior part of inferior frontal gyrus, we suggest that the development of the lateral verbal communication system in man derives from a more ancient communication system based on recognition of hand and face gestures.
We recorded electrical activity from 532 neurons in the rostral part of inferior area 6 (area F5) of two macaque monkeys. Previous data had shown that neurons of this area discharge during goal-directed hand and mouth movements. We describe here the properties of a newly discovered set of F5 neurons ("mirror neurons', n = 92) all of which became active both when the monkey performed a given action and when it observed a similar action performed by the experimenter. Mirror neurons, in order to be visually triggered, required an interaction between the agent of the action and the object of it. The sight of the agent alone or of the object alone (three-dimensional objects, food) were ineffective. Hand and the mouth were by far the most effective agents. The actions most represented among those activating mirror neurons were grasping, manipulating and placing. In most mirror neurons (92%) there was a clear relation between the visual action they responded to and the motor response they coded. In approximately 30% of mirror neurons the congruence was very strict and the effective observed and executed actions corresponded both in terms of general action (e.g. grasping) and in terms of the way in which that action was executed (e.g. precision grip). We conclude by proposing that mirror neurons form a system for matching observation and execution of motor actions. We discuss the possible role of this system in action recognition and, given the proposed homology between F5 and human Brocca's region, we posit that a matching system, similar to that of mirror neurons exists in humans and could be involved in recognition of actions as well as phonetic gestures.
Quantified electroencephalography (qEEG) was used to compare cerebral electrical variations while human subjects (10 males and 10 females) were observing and executing finger movements and while they were resting. Video recording enabled elimination of subjects performing involuntary movements. EEGs were recorded from 14 sites in seven frequency bands: theta 1, theta 2, alpha 1, alpha, beta 1, beta 2 and beta 3. Analyses were performed on logarithmically transformed absolute spectral power values. Both observation and execution of finger movements involved a decrease in spectral power compared with resting. This decrease was significant only for the alpha 1 frequency band (7.5-10.5 Hz) and it involved nine of the 14 electrode locations (F7, F8, F4, T6, T5, C3, C4, P3 and P4). This indicates that the motor cortex and the frontal cortex are specifically activated by both observation and execution of finger movements. These results provide evidence that observation and execution of movement share the same cortical network.
Functional magnetic resonance imaging (fMRI) was used to localize brain areas active during manipulation of complex objects. In one experiment subjects were required to manipulate complex objects for exploring their macrogeometric features as compared to manipulation of a simple smooth object (a sphere). In a second experiment subjects were asked to manipulate complex objects and to silently name them upon recognition as compared to manipulation of complex not recognizable objects without covert naming. Manipulation of complex objects resulted in an activation of ventral premotor cortex [Brodmann's area (BA) 44], of a region in the intraparietal sulcus (most probably corresponding to the anterior intraparietal area in the monkey), of area SII and of a sector of the superior parietal lobule. When the objects were covertly named additional activations were found in the opercular part of BA 44 and in the pars triangularis of the inferior frontal gyrus (BA 45). We suggest that a fronto-parietal circuit for manipulation of objects exists in humans and involves basically the same areas as in the monkey. It is proposed that area SII analyses the intrinsic object characteristics whilst the superior parietal lobule is related to kinaesthesia.
Paired-pulse transcranial magnetic stimulation (TMS) was used to examine changes in cortical excitability during action observation. We stimulated the left primary motor cortex (M1) of eight healthy volunteers during rest, observation of handwriting and observation of arm movements. Motor evoked potentials (MEP) were recorded from the first dorsal intereosseous (FDI) and biceps (BIC) muscles. Our results showed that action observation induced a facilitation of the MEP amplitude evoked by the single test stimulus and reduced intracortical inhibition and facilitation at 3 ms and 12 ms interstimulus intervals (ISIs), respectively, during paired-pulse stimulation. These changes were specific for the muscle involved in the observed action. Our study presents further evidence that motor excitability is significantly modified when the subject observes an action performed by another individual.
Neurons responding to the sight of goal-directed hand/arm actions in the parietal area PF (7b) of the macaque monkey
- L Fogassi
- V Gallese
- L Fadiga
- G Rizzolatti
- K J Friston
- J Ashburner
- J B Poline
- C D Frith
- J D Heather
- R S J Frackowiak
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