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April 2014 - present
July 2009 - March 2014
September 2003 - June 2009
Publications
Publications (108)
One of the fundamental goals in understanding schizophrenia is linking the observable symptoms to the underlying unobservable pathophysiology. Given recent advances in medical imaging, researchers are increasingly investigating brain-behavior relationships to better understand the neural substrates of negative, positive, and disorganization symptom...
Background:
Relatives of schizophrenia patients demonstrate abnormalities in prefrontal cortical activation during executive processing as measured by functional neuroimaging, albeit not consistently. A meta-analysis was conducted to determine whether reliable patterns of brain hypo- and hyperactivity, especially in the middle frontal region, were...
Dans cet article invité à accompagner le Prix de la Société canadienne de psychologie pour contributions remarquables à l’éducation et à la formation en psychologie, je présente mes réflexions, mes expériences et mes recommandations pour la création d’une profession de psychologie clinique plus réactive sur le plan social. Cet article s’appuie sur...
The health sciences have a public calling to provide socially responsive health care for all of society, particularly those most in need. This call is reverberating in universities and has particular relevance for health science professions. Despite universities’ public mission, admissions practices in the health sciences exhibit a fundamental tens...
Poor emotion recognition is a core deficit in schizo-phrenia and is associated with poor functional outcome. Functional magnetic resonance imaging (fMRI) multi-variate analysis methods were used to elucidate the neural underpinnings of face and emotion processing associated with both genetic liability and disease-specific effects. Schizophrenia pat...
Schizophrenia is characterized by the misattribution of emotional significance to neutral faces, accompanied by overactivations of the limbic system. To understand the disorder’s genetic and environmental contributors, investigating healthy first-degree relatives is crucial. However, inconsistent findings exist regarding their ability to recognize...
Quantitative, empirical approaches to establishing the structure of psychopathology hold promise to improve on traditional psychiatric classification systems. The Hierarchical Taxonomy of Psychopathology (HiTOP) is a framework that summarizes the substantial and growing body of quantitative evidence on the structure of psychopathology. To achieve i...
Oppression, systemic bias, and racism have unfortunately long been part of the human experience. This paper is a review of basic elements of the Indian caste system, understanding its impact on the daily lives of different caste members, the role of colonialism in perpetuating the caste system, the Indian reservation system for mitigating disadvant...
The organization of the Hierarchical Taxonomy of Psychopathology (HiTOP) model provides unique opportunities to evaluate whether neural risk measures operate as indicators of broader latent liabilities (e.g., externalizing proneness) or narrower expressions (e.g., antisociality and alcohol abuse). Following this approach, the current study recruite...
Impulsivity-characterized executive function impairments have been hypothesized to represent mechanisms underlying the symptomology associated with gambling disorder (GD). Despite this, a clear profile of executive function within GD has yet to be established. Furthermore, it remains unclear whether executive function deficits represent a vulnerabi...
Understanding the neurobiological systems involved in psychopathology has been hindered by the limitations of categorical nosologies, spurring the development of alternative dimensional systems for characterizing psychopathology. The Hierarchical Taxonomy of Psychopathology (HiTOP) is one such system, derived from quantitative studies of covariatio...
L’objectif de cet article est de faire la lumière sur la façon dont les politiques instrumentalisées soutiennent un système conçu pour exclure les personnes racisées de la profession de psychologue, contribuant ainsi à la pénurie de prestataires de soins de santé mentale, qui à son tour contribue à une crise de la santé mentale au Canada. Nous décr...
Quantitative, empirical approaches to establishing the structure of psychopathology hold promise to improve on traditional psychiatric classification systems. The Hierarchical Taxonomy of Psychopathology (HiTOP) is a framework that summarizes the substantial and growing body of quantitative evidence on the structure of psychopathology. To achieve i...
Dans cet éditorial, nous présentons l’édition spéciale sur Engendrerune psychologie plus réceptive sur le plan social et culturel. En rassemblant ce recueil, notre objectif est de mettre en valeur les multiples façons de reconnaître et souligner les conceptualisations psychologiques systémiques. Ainsi, nous souhaitons honorer les vaillants efforts...
Je me réjouis de l’occasion qui m’a été donnée d’être, depuis janvier 2019, le rédacteur en chef de la revue Canadian Psychology / Psychologie canadienne. Aux côtés de mon équipe de rédaction formée des professeurs Sharpe, Godbout et Greenman, j’ai mis un point d’honneur, au cours des quatre dernières années, à mettre en valeur l’excellent travail...
Commercial computerized cognitive training (CCT) programs have grown rapidly in popularity over the past several years. However, the effectiveness of commercial CCT at improving cognition is highly contested, and the degree to which expectations of CCT outcomes affect self-reported gains remains unclear. Here, we examined the malleability of CCT ex...
Stress has a detrimental impact on memory, the hippocampus, and psychological health. Psychopathology research on stress has centered mainly on psychiatric diagnoses rather than symptom dimensions, and less attention has been given to the neurobiological factors through which stress might be translated into psychopathology. The present work investi...
Background
Brain networks involved in language, attentional and response processes are detectable by fMRI during lexical decision (LD). Here, we investigated possible abnormalities in the functional networks involved in LD in patients with bipolar disorder (BD).
Methods
fMRI and behavioural data were compared between BD (n = 25) and control (n = 2...
Marek et al. analyzed three very large magnetic resonance imaging (MRI) datasets and concluded that thousands of participants are necessary to ensure replicable results in “brain-wide associations studies,” which they defined as “studies of the associations between common inter-individual variability in human brain structure/function and cognition...
Background:
Impaired emotion processing constitutes a key dimension of schizophrenia and a possible endophenotype of this illness. Empirical studies consistently report poorer emotion recognition performance in patients with schizophrenia as well as in individuals at enhanced risk of schizophrenia (“at risk”). fMRI studies also report consistent pa...
Background
Impaired emotion processing constitutes a key dimension of schizophrenia and a possible endophenotype of this illness. Empirical studies consistently report poorer emotion recognition performance in patients with schizophrenia as well as in individuals at enhanced risk of schizophrenia (“at risk”). fMRI studies also report consistent pat...
Anhedonia, the reduced capacity to experience pleasure, has long been considered a prominent feature of schizophrenia spectrum disorders. Many domain-specific conceptualizations of anhedonia and pleasure capacity have been developed, and there currently exist a variety of self-report assessment tools that purport to assess these various domains. Th...
Research indicates that people with schizophrenia often achieve similar levels of subjective well-being (SWB) compared to healthy controls despite prominent symptomatology and significant functional difficulties. Furthermore, compared to healthy controls, young-adult people with schizophrenia differ in the relative importance they place on values,...
Evidence suggests that theory of mind (TOM) and social perception (SP) may be impaired within bipolar disorder (BD). However, it remains unclear whether these deficits are facet specific and predictive of functioning. This study assessed the manifestation of TOM and SP in a BD sample. Twenty-six individuals diagnosed with BD and 25 controls were re...
L’éditorial présente la livraison spéciale consacrée à l’enseignement de la psychologie — en particulier à l’éducation et à la formation — un volet fondamental de notre profession. Dix articles portent sur des questions et des tendances importantes dans le domaine de l’enseignement de la psychologie, dont a) l’amélioration de l’équilibre travail-vi...
White matter pathology likely contributes to the pathogenesis of bipolar disorder (BD). Most studies of white matter in BD have used diffusion tensor imaging (DTI), but the advent of more advanced multi-shell diffusion MRI imaging offers the possibility to investigate other aspects of white matter microstructure. Diffusion kurtosis imaging (DKI) ex...
Numerous studies demonstrate that working memory training benefits cognitive performance; however, such findings are controversial and the field is polarized. Despite a multitude of behavioural studies, investigation into the neurobiological mechanisms underlying working memory training remains limited. Diffusion tensor imaging (DTI) allows for the...
Objectives: White matter pathology is thought to contribute to the pathogenesis of bipolar disorder (BD). However, most studies of white matter in BD have used the simple diffusion tensor imaging (DTI) model, which has several limitations. DTI studies have reported heterogenous results, leading to a lack of consensus about the extent and location o...
L’auteur fournit un aperçu des activités de la revue au cours des deux dernières années, dont une mise à jour sur sa vision et son mandat. La revue réaffirme son engagement envers la publication de recherches dans tous les domaines de la psychologie et le maintien d’un cadre équitable et inclusif. Le Programme de mentorat en évaluation d’articles p...
Au cours de la dernière décennie, la crise de la reproductibilité de la recherche a suscité de nombreux débats et de vives controverses. Dans ce numéro spécial, des chercheurs et des leaders d’opinion se sont rassemblés pour se pencher sur les acquis de la dernière décennie et pour formuler des suggestions aux intervenants du secteur de la recherch...
First-degree relatives of patients diagnosed with schizophrenia (SZ-FDRs) show similar patterns of brain abnormalities and cognitive alterations to patients, albeit with smaller effect sizes. First-degree relatives of patients diagnosed with bipolar disorder (BD-FDRs) show divergent patterns; on average, intracranial volume is larger compared to co...
Family studies can provide a wealth of information regarding risk factors in psychological disorders. No studies have compared the trauma experiences and coping strategies of problem gamblers with those of their first-degree relatives. Therefore, in this study, childhood trauma and coping strategies were investigated among participants with gamblin...
La déclaration de la pandémie de coronavirus 2019 (COVID-19), en mars 2020, a touché toute la société et a eu des effets transformationnels sans précédent sur la formation en psychologie professionnelle en quelques mois seulement. La présente étude recueille les connaissances des dirigeants de trois des principaux partenaires de formation au Canada...
Introduction
In recent years, computerized cognitive training (CCT) programs have been developed commercially for widespread public consumption. Despite early enthusiasm, whether these programs enhance cognitive abilities in healthy adults is a contentious area of investigation. Given the mixed findings in the literature, researchers are beginning...
The Hierarchical Taxonomy of Psychopathology (HiTOP) is an empirical structural model of psychological symptoms formulated to improve the reliability and validity of clinical assessment. Neurobiology can inform assessments of early risk and intervention strategies, and the HiTOP model has greater potential to interface with neurobiological measures...
Functional magnetic resonance imaging (fMRI)5 studies on lexical decision (LD)6 attempting to isolate the brain network underlying access to lexical representations can be confounded by attentional and response processes. However, manipulating the "wordlikeness" of the LD stimuli can facilitate functional interpretation of each emerging brain netwo...
Le présent éditorial est une introduction à ce numéro spécial intitulé Graduate Education, Research, and Professional Training in Psychology (L’enseignement supérieur, la recherche, et la formation professionnelle en psychologie), lequel a été commandé par l’Association canadienne de psychologie. Ce numéro spécial est fondé en grande partie sur des...
Background:
A domain of cognition that has been found to be impaired in bipolar disorder across mood states is working memory. Working memory can be separated into two components, maintenance and manipulation. Bipolar patients also demonstrate structural brain abnormalities in prefrontal and parietal regions, which are regions associated with work...
Individuals with schizophrenia exhibit deficits in facial emotion processing, which have been associated with abnormalities in visual gaze behavior and functional brain activation. However, the relationship between gaze behavior and brain activation in schizophrenia remains unexamined. Studies in healthy individuals and other clinical samples indic...
Deficits in response inhibition have been observed in schizophrenia and bipolar disorder; however, the neural origins of the abnormalities and their relevance to genetic liability for psychosis are unknown. We used a stop‐signal task to examine motor inhibition and associated neural processes in schizophrenia patients (n = 57), bipolar disorder pat...
Background:
Schizophrenia and bipolar disorder share genetic liability, and some structural brain abnormalities are common to both conditions. First-degree relatives of patients with schizophrenia (FDRs-SZ) show similar brain abnormalities to patients, albeit with smaller effect sizes. Imaging findings in first-degree relatives of patients with bi...
The present study investigated self-reported impulsivity in gambling disorder (GD) and bipolar disorder (BD). Participants with GD (n = 31), BD (n = 19), and community controls (n = 68) completed diagnostic interviews and symptom severity and functioning assessments. Participants also completed the UPPS-P Impulsive Behavior Scale composed of five d...
Anxiety symptoms and anxiety disorders are common in both mood and psychotic disorders. However, limited comparative information exists regarding the long-term course of anxiety in schizoaffective disorder, bipolar disorder, and major depressive disorder. Prospective evaluation of the 20-year trajectory of self-reported anxiety and somatic-related...
Attempts to determine the cognitive benefits of adaptive working memory training in healthy adults has resulted in a polarized and stagnating field. Heterogeneous approaches and problematic methodological choices have contributed to the controversy. Structural neuroimaging has the potential to identify biological changes present after working memor...
Response inhibition, one component of cognitive control, refers to the ability to inhibit automatic responses and has been found to be impaired in gambling disorder. Recent models of cognitive control distinguish between two mechanisms: reactive control, the ability to stop in response to a stop-stimulus, and proactive control, the ability to antic...
Background
Although prior research has shown that cognitive training may improve cognition for schizophrenia patients, it is currently unclear which domains of cognition should be targeted in training. One suggestion is to target low- or mid-level cognitive processes. In particular, working memory (WM) and processing speed (PS) have been named as t...
Background:
Schizophrenia is associated with poor cognitive function and elevated cardiometabolic disease risk. These health concerns may exacerbate neurocognitive dysfunction associated with hippocampal abnormalities, particularly hippocampal volume reductions. Regular exercise is thought to improve symptom severity, reduce depression, and improv...
The idea that individualized, computer-based cognitive training improves cognitive functioning in non-trained domains is highly contested. An understudied area is whether cognitive training improves one’s own perception of cognitive and day-to-day functioning. Furthermore, no studies have compared working memory training to programs that train high...
Theory of mind (ToM) refers to the ability to make inferences about mental states. Thus far, little research has examined ToM development in middle childhood. Importantly, recent studies have distinguished between making inferences about beliefs (cognitive ToM) and emotions (affective ToM). ToM has also been associated with executive functioning, t...
Working memory (WM) and fluid intelligence (Gf) are thought to be highly related, though psychometrically distinct cognitive constructs. Both are important in a wide range of cognitively demanding tasks, and predictive of success in educational, occupational, and social domains. From a cognitive perspective, WM and Gf may share a capacity constraint...
Training of working memory as a method of increasing working memory capacity and fluid intelligence has received much attention in recent years. This burgeoning field remains highly controversial with empirically-backed disagreements at all levels of evidence, including individual studies, systematic reviews, and even meta-analyses. The current stu...
Bayesian factors for time × group interactions, by measure derived from the JZS Bayesian repeated measures ANOVAs.
(DOCX)
Pre- to post-training effect sizes for transfer tasks following Melby-Lervåg & Hulme (2016), and Morris (2008).
(DOCX)
Recent attention has focused on the benefits of cognitive training in healthy adults. Many commercial cognitive training programs are available given the attraction of not only bettering one's cognitive capacity, but also potentially preventing age-related declines, which is of particular interest to older adults. The issue of whether cognitive tra...
The present study evaluated subjective and objective cognitive measures as predictors of fluid intelligence in healthy older adults. We hypothesized that objective cognitive measures would predict fluid intelligence to a greater degree than self-reported cognitive functioning. Ninety-three healthy older (>65 years old) community-dwelling adults par...
Schizophrenia patients have impaired performance and abnormal brain activation during facial emotion recognition, which may represent a marker of genetic liability to schizophrenia. However, it remains unclear whether the impairment is specific to recognizing emotion from faces or is instead attributable to more generalized dysfunction. The current...
Hallucinations are a salient feature of both psychotic and mood disorders. Currently there is a call for more research on the phenomenology of different forms of hallucinations, in a broader array of disorders, to further both theoretical knowledge and clinical utility. We investigated auditory, visual, and olfactory hallucinations at index hospita...
Unlabelled:
Enhancing cognitive ability is an attractive concept, particularly for middle-aged adults interested in maintaining cognitive functioning and preventing age-related declines. Computerized working memory training has been investigated as a safe method of cognitive enhancement in younger and older adults, although few studies have consid...
Average intelligence quotient (IQ) scores have been rising throughout the 20th century and likely before—a pattern now known as the Flynn effect. The central thesis of this paper is that the Flynn effect does not represent genuine increases in general intelligence but rather an increasing aptitude for the types of modern thinking that modern life r...
In most domains of cognition, individuals with schizophrenia are generally found to be one standard deviation below the mean of the controls. As a result, examining the impact of cognitive remediation in individuals with schizophrenia has been a burgeoning area of research. However, the state of the literature remains unclear as to which domains of...
Little research has examined the association between disordered gambling and psychosis. In addition, clinicians treating schizophrenia or schizoaffective disorders rarely screen for or treat comorbid gambling problems due to diagnostic overshadowing. Thus, the effects of disordered gambling on symptoms of schizophrenia and vice versa remain largely...
Schizophrenia is associated with deficits in face perception and emotion recognition. Despite consistent behavioural results, the neural mechanisms underlying these cognitive abilities have been difficult to isolate, in part due to differences in neuroimaging methods used between studies for identifying regions in the face processing system. Given...
Violent video game playing has been associated with both positive and negative effects on cognition. We examined whether playing two or more hours of violent video games a day, compared to not playing video games, was associated with a different pattern of recognition of five facial emotions, while controlling for general perceptual and cognitive d...
Schizophrenia is associated with abnormalities in cortical thickness, including both thicker and thinner cortices than controls. Although less reliably than in patients, non-psychotic relatives of schizophrenia patients have also demonstrated both thicker and thinner cortices than controls, suggesting an effect of familial or genetic liability. We...
Deficits in facial emotion perception in schizophrenia may be a marker of disorder liability. Previous functional magnetic resonance imaging (fMRI) studies investigating these deficits have been limited by task demands that may recruit other impaired cognitive processes in schizophrenia.
We used a family study design along with a passive viewing ta...
Research on individuals at clinical high risk for psychological and physical disorders has grown exponentially in recent years, with a variety of new screening tools and early intervention techniques being implemented. One recent example is Attenuated Psychosis Syndrome, a diagnosis for individuals who are at clinical high risk for psychosis, which...
Cognitive deficits are consistently demonstrated in individuals with schizophrenia. Cognitive training involves structured exercises prescribed and undertaken with the intention of enhancing cognitive abilities such as attention, memory, and problem solving. Thus, cognitive training represents a potentially promising intervention for enhancing cogn...
Background:
The ability to accurately judge facial expressions is important in social interactions. Individuals with bipolar disorder have been found to be impaired in emotion recognition; however, the specifics of the impairment are unclear. This study investigated whether facial emotion recognition difficulties in bipolar disorder reflect genera...
Impaired recognition of happy facial expressions in bipolar disorder Background: The ability to accurately judge facial expressions is important in social interactions. Individuals with bipolar disorder have been found to be impaired in emotion recognition; however, the specifics of the impairment are unclear. This study investigated whether facial...
Schizophrenia is a severe disorder affecting approximately 1% of the population. In 2004, the health care and productivity lost cost of schizophrenia in Canada was estimated at $7 billion (Goeree et al., 2005). Deficits in interacting with the social world are some of the most debilitating aspects of the disorder. Specifically, problems in recognis...
Deficits in facial emotion perception have been linked to poorer functional outcome in schizophrenia. However, the relationship between abnormal emotion perception and functional outcome remains poorly understood. To better understand the nature of facial emotion perception deficits in schizophrenia, we used the Bubbles Facial Emotion Perception Ta...
The goal of this investigation was to clarify the nature of spatial working memory difficulties in individuals at ultra high risk (UHR) for psychosis. We evaluated spatial working memory and intelligence in 96 individuals at UHR for psychosis, 28 patients with first episode psychosis (FEP), and 23 healthy controls. Fourteen UHR individuals develope...
Background:
Hallucinations are a major aspect of psychosis and a diagnostic feature of both psychotic and mood disorders. However, the field lacks information regarding the long-term course of hallucinations in these disorders. Our goals were to determine the percentage of patients with hallucinations and the relationship between hallucinations an...
Temporal lobe abnormalities and emotion recognition deficits are prominent features of schizophrenia and appear related to the diathesis of the disorder. This study investigated whether temporal lobe structural abnormalities were associated with facial emotion recognition deficits in schizophrenia and related to genetic liability for the disorder....
Abnormalities in connectivity are thought to contribute to the symptoms of schizophrenia. Accumulating evidence suggests that antipsychotic medication affects both subcortical and cortical grey and white matter volumes. The goal of this study was to investigate the effects of antipsychotic medication on two white matter tracts: a subcortical-cortic...
The functional neuroanatomy of tasks that recruit different forms of response selection and inhibition has to our knowledge, never been directly addressed in a single fMRI study using similar stimulus–response paradigms where differences between scanning time and sequence, stimuli, and experimenter instructions were minimized. Twelve right-handed p...
Schizophrenia and bipolar disorder, although diagnostically separate, likely share elements of their genetic etiology. This study assessed whether the COMT Val158Met polymorphism has shared or specific associations with clinical phenotypes evident in schizophrenia and bipolar disorder. Schizophrenia and bipolar patients completed a clinical assessm...
Schizophrenia has been reliably associated with impairments in backward masking performance, while bipolar disorder has less consistently been tied to such a deficit. To examine the genetic determinants of visual perception abnormalities in schizophrenia and bipolar disorder, this study evaluated the diagnostic specificity of backward masking perfo...
Abstract A number of experimental techniques are commonly used within the field of functional neuroimaging to measure successive cognitive processes within a single trial. This study evaluated three experimental techniques to assess the comparability of behavioral and functional outcome measures in a task involving higher-level cognitive processing...
People with schizophrenia may demonstrate cortical abnormalities, with gyri and sulci potentially being differentially affected.
To measure frontal and temporal sulcal cortical thickness, surface area and volume in the non-psychotic relatives of patients with schizophrenia as a potential vulnerability indicator for the disorder.
An automated parcel...
