Howard Zelaznik

Purdue University | Purdue · Department of Health and Kinesiology

This study tested the hypothesis that affordances for grasping with the corresponding hand are activated more strongly by three-dimensional (3D) real objects than by two-dimensional (2D) pictures of the objects. In Experiment 1, participants made left and right keypress responses to the handle or functional end (tip) of an eating utensil using comp...

Three experiments used compatible and incompatible mappings of images of eating utensils to test the hypothesis that these images activate affordances for grasping with the corresponding hand when the required response is a key-press. In Experiment 1, stimuli were photographs of a plastic spoon oriented on the horizontal axis, with the handle locat...

Over the past 18 years, Zelaznik and colleagues have promoted what is known as the event-emergent timing distinction. According to this framework, control of timing can be based upon a neurological clock-like process or upon an emergent process. I review the highlights of this research program that supports this distinction, then describe a new lin...

Increased time-delay in the neuromuscular system caused by neurological disorders, concussions, or advancing age is an important factor contributing to balance loss (Chagdes et al., 2013, 2016). We present the design and fabrication of an active balance board system that allows for a systematic study of stiffness and time-delay induced instabilitie...

Purpose: Our objective was to delineate components of motor performance in specific language impairment (SLI); specifically, whether deficits in timing precision in one effector (unimanual tapping) and in two effectors (bimanual clapping) are observed in young children with SLI. Method: Twenty-seven 4- to 5-year-old children with SLI and 21 age-...

Mathematical models predict limit cycle oscillations (LCOs) in postural sway when the combination of neuromuscular time-delay and feedback gains are excessively large. LCOs have been observed in the standing posture of various populations known to have longer time-delays including concussed young adults and adults with neuromuscular impairment such...

Purpose: Stuttering involves a breakdown in the speech motor system. We address whether stuttering in its early stage is specific to the speech motor system or whether its impact is observable across motor systems. Method: As an extension of Olander, Smith, and Zelaznik (2010), we measured bimanual motor timing performance in 115 children: 70 ch...

The Microsoft Kinect has been used in studies examining posture and gait. Despite the advantages of portability and low cost, this device has not been used to assess interlimb coordination. Fundamental insights into movement control, variability, health, and functional status can be gained by examining coordination patterns. In this study, we inves...

Poster presented at 2016 Annual Meeting of the North American Society for the Psychology of Sport and Physical Activity (NASPSPA)

Proponents of the action-specific account of perception and action posit that participants perceive their environment relative to their capabilities. For example, softball players who batted well judge the ball as being larger compared to players who did not hit as well. In the present study, we examined this issue in the context of a well-known sp...

Background: Many disease-specific factors such as muscular weakness, increased muscle stiffness, varying postural strategies, and changes in postural reflexes have been shown to lead to postural instability and fall risk in people with Parkinson's disease (PD). Recently, analytical techniques, inspired by the dynamical systems perspective on moveme...

Mathematical models of human posture on a rigid surface predict two types of balance instabilities – a static tipping instability and a dynamic instability leading to large oscillations. Although a common technique to improve balance performance is placing patients on balance boards, little research has modeled bipedal posture on rotational boards...

Imagined movements are purported to simulate many characteristics asreal actions (Decety, 1996). Interestingly Fitts’ law is obeyed when participants make movement time (MT) judgments while imagining a Fitts’task (Wonget al. 2013).However, judgments of MTare more similar to real movements if participants have experience performing the task (Chandra...

Many researchers have examined expert performance in competition in dual sports such as squash and tennis. The focus of those studies has been either on short term shot dependencies, or the movements of the players. In these dual sports, player movements usually oscillate, because the player usually returns to the center of the baseline (tennis) or...

Over the past 40 years the research area of motor learning and control has developed into a field closely aligned with information processing in neuroscience. The basic, implicit assumption is that motor learning and control is the domain of the brain. Several crucial studies and developments from the past and the present are presented and discusse...

This experiment manipulated digit uncertainty, duration uncertainty, and response duration (dit or dah) in a choice reaction time key press task. A new method of precueing was developed that effectively “precued” the digit and/or the duration of the key press task without confounding the number of stimulus response alternatives with the levels of u...

Recent reaction time analysis of motor programming has utilized a precue stimulus that provides advance information about some or all of the attributes for the upcoming motor response. This kind of precue typically confounds the number of remaining stimuli with the motoric processes under investigation (Zelaznik, 1978). In Experiments 1 and 2 the p...

A balance board is an unstable platform which is currently used for training and rehabilitation to stabilize an individual’s upright posture. Models that examine how individuals remain upright while standing on an unstable surface are therefore needed to understand the mechanisms behind balance improvements. Most research in this area has focused o...

Children with Attention-Deficit/Hyperactivity Disorder (ADHD) are thought to have fundamental deficits in the allocation of attention for information processing. Furthermore, it is believed that these children possess a fundamental difficulty in motoric timing, an assertion that has been explored recently in adults and children. In the present stud...

We report a new experiment in a series of studies in which research participants perform a Fitts’ Law repetitive task, and then are required to judge the width of the target that was utilized. The first two experiments previously reported showed no relation between perception and performance. However in those two experiments subjects were never pro...

An internal clock-like process has been implicated in the control of rhythmic movements performed for short (250-2,000 ms) time scales. However, in the past decade, it has been claimed that a clock-like central timing mechanism is not required for smooth cyclical movements. The distinguishing characteristic delineating clock-like (event) from non-c...

People often grasp objects with an awkward grip to ensure a comfortable hand posture at the end of the movement. This end-state comfort effect is a predominant constraint during unimanual movements. However, during bimanual movements the tendency for both hands to satisfy end-state comfort is affected by factors such as end-orientation congruency a...

Differences in timing control processes between tapping and circle drawing have been extensively documented during continuation timing. Differences between event and emergent control processes have also been documented for synchronization timing using emergent tasks that have minimal event-related information. However, it is not known whether the o...

Accurate timing performance during auditory-motor synchronization has been well documented for finger tapping tasks. It is believed that information pertaining to an event in movement production aids in detecting and correcting for errors between movement cycle completion and the metronome tone. Tasks with minimal event-related information exhibit...

1/f β noise represents a specific form of (long-range) correlations in a time series that is pervasive across many sensorimotor variables. Recent studies have shown that the precise properties of the correlations demonstrated by a group of test participants may vary as a function of experimental conditions or factors characterizing the group. Our p...

A transfer of training design was used to examine the role of the Index of Difficulty (ID) on transfer of learning in a sequential Fitts's law task. Specifically, the role of the ratio between the accuracy and size of movement (ID) in transfer was examined. Transfer of skilled movement is better when both the size and accuracy of movement are chang...

Event timing is manifested when participants make discrete movements such as repeatedly tapping a key. Emergent timing is manifested when participants make continuous movements such as repeatedly drawing a circle. Here we pursued the possibility that providing salient perceptual events to mark the completion of time intervals could allow circle dra...

To examine whether children with specific language impairment (SLI) differ from normally developing peers in motor skills, especially those skills related to timing. Standard measures of gross and fine motor development were obtained. Furthermore, finger and hand movements were recorded while children engaged in 4 different timing tasks, including...

That individual timing variability is correlated across some tasks but not others has instigated the notion of distinct timing processes, referred to as 'event' timing and 'emergent' timing for tasks with and without salient events, respectively. The delineation of the event-emergent framework owes much to the circle drawing task as it can be perfo...

To determine whether young children who stutter have a basic motor timing and/or a coordination deficit. Between-hands coordination and variability of rhythmic motor timing were assessed in 17 children who stutter (4-6 years of age) and 13 age-matched controls. Children clapped in rhythm with a metronome with a 600-ms interbeat interval and then at...

Discrete wavelet analysis is used to resolve the center of pressure time series data into several timescale components, providing new insights into postural control. Healthy young and elderly participants stood quietly with their eyes open or closed and either performed a secondary task or stood quietly. Without vision, both younger and older parti...

Author Summary A fundamental question in motor control research is whether distinct movement classes exist. Candidate classes are discrete and continuous movement. Discrete movements have a definite beginning and end, whereas continuous movements do not have such discriminable end points. In the past decade there has been vigorous, predominantly em...

Spectral power in the human data. The amount of spectral power in the human data as a function of instruction condition and frequency at the sub-harmonic (P[ω/2]) (left panel), the fundamental frequency (P[ω]) (middle panel), and the first super-harmonic (P[2ω]) (right panel). For the natural conditions, the data for the participants who adopted th...

Probability density distributions. The position and velocity axes are indicated in the lower right panel, and the extracted 3-bin summed probability values are provided for each distribution. (A) Probability density distributions of model simulations in the mono-stable regime (upper panel) and limit cycle regime (lower panel) at 0.5 Hz, 2.0 Hz, and...

Symmetry ratios in the mono-stable regime. The symmetry ratio of the simulated data in the mono-stable regime is presented as a function of parameter b and frequency. (0.76 MB TIF)

Goal frequency versus coefficient of variation. Note that in conditions where participants were slowing down, the CVs are plotted in the reverse order of which they were performed. (0.27 MB TIF)

Supporting information. (0.07 MB DOC)

Spectral power in the mono-sable regime. The amount of spectral power in the mono-stable regime as a function of parameter b and frequency at the sub-harmonic (P[ω/2]) (left panel), the fundamental frequency (P[ω]) (middle panel), and the first super-harmonic (P[2ω]) (right panel). (0.59 MB TIF)

Goal frequency versus observed frequency. Note that in conditions where participants were slowing down, the observed frequency values are plotted in the reverse order of which they were performed. (0.24 MB TIF)

Symmetry ratios of the human data. The average symmetry ratio for the participants (n = 8) adopting a ‘discrete’ motor solution (D; n = 4) and a ‘smooth’ motor solution (S; n = 4) in the natural condition as a function of frequency for the natural, discrete, and smooth condition (left, middle, and right panel, respectively). The vertical bars indic...

Goal frequency versus normalized mean squared jerk. Note that in conditions where participants were slowing down, the values of jerk are plotted in the reverse order of which they were performed. (0.27 MB TIF)

Goal frequency versus percentage of time to peak negative velocity. Note that in conditions where participants were slowing down, the values of percent time to peak negative velocity are plotted in the reverse order of which they were performed. (0.29 MB TIF)

It has been hypothesized that timing in tapping utilizes event timing; a clock-like process, whereas timing in circle drawing is emergent. Three experiments examined timing in tapping and circle drawing by the dominant and non-dominant hand. Participants were right-hand dominant college aged males and females. The relationship between variance and...

The notion that a limited number of ‘motor primitives’ underwrites complex (human) movements is pertinent to various theoretical perspectives on motor control. Consequently, motor primitives have been classified according to different (and often empirically driven) criteria. Departing from the perspective that dynamical systems are unambiguously de...

Kinesiology has a long and storied tradition and history. The growth of our discipline and what might be called our subdisciplines has been the shining achievement of the 1970-2006 era, spurred on by Henry's (1964) call for an academic discipline. In this short thought paper, we argue that we have lost sight of the discipline in a quest to become s...

A distinction in temporal performance has been identified between two classes of rhythmic movements: those requiring explicit timing of salient events marking successive cycles, i.e., event timing, and continuous movements in which timing is hypothesized to be emergent. Converging evidence in support of this distinction is reviewed, including neuro...

The authors manipulated the width of a timing target in continuous circle drawing to determine whether a more stringent spatial-timing criterion would produce an increase in participants' (N = 30) temporal variability. They also examined the effect of the computational method of determining cycle duration. There was no effect of spatial precision o...

R. Ivry, R. M. Spencer, H. N. Zelaznik, and J. Diedrichsen (2002) have proposed a distinction between timed movements in which a temporal representation is part of the task goal (event timing) and those in which timing properties are emergent. The issue addressed in the present experiment was how timing in conditions conducive to emergent timing be...

Patients with cerebellar damage are impaired on a range of timed tasks. However, recent research has indicated that the impairment on temporal production tasks is limited to discontinuous movements. The present experiments were designed to compare two accounts for the increased temporal variability observed in these patients when producing disconti...

Adults produce rapid, interleaved sequences of speech sounds by controlling the relative motions in time and space of the oral articulators. The control and coordination of these effectors appear to be automatic, effortless, and usually error free. If speech production is viewed within the framework of classical motor control theories, we can infer...

Timing variability in continuous drawing tasks has not been found to be correlated with timing variability in repetitive finger tapping in recent studies (S. D. Robertson et al., 1999; H. N. Zelaznik, R. M. C. Spencer, & R. B. Ivry, 2002). Furthermore, the central component of timing variability, as measured by the slope of the timing variance vers...

Patients with cerebellar damage are known to exhibit deficits in the temporal control of movements. We report that these deficits are restricted to discontinuous movements. Cerebellar patients exhibited no deficit in temporal variability when producing continuous, rhythmic movements. We hypothesize that the temporal properties of continuous movemen...

Damage to the cerebellum disrupts performance on a range of tasks that require precise timing including the production of skilled movements, eyeblink conditioning, and perceptual tasks such as duration discrimination. We hypothesize that such tasks involve event timing, a form of representation in which the temporal goals are explicitly represented...

Four experiments explored the hypothesis that temporal processes may be represented and controlled explicitly or implicitly. Tasks hypothesized to require explicit timing were duration discrimination, tapping, and intermittent circle drawing. In contrast, it was hypothesized that timing control during continuous circle drawing does not rely on an e...

Four experiments explored the hypothesis that temporal processes may be represented and controlled explicitly or implicitly. Tasks hypothesized to require explicit timing were duration discrimination, tapping, and intermittent circle drawing. In contrast, it was hypothesized that timing control during continuous circle drawing does not rely on an e...

When the left and right hands produce 2 different rhythms simultaneously, coordination of the hands is difficult unless the rhythms can be integrated into a unified temporal pattern. In the present study, the authors investigated whether a similar account can be applied to the spatial domain. Participants (N = 8) produced a movement trajectory of s...

Recently, researchers have discovered that individuals who are consistent timers in a tapping task are not necessarily consistent timers when they perform a continuous drawing task. In other words, nonsignificant correlations were found among tapping and drawing movements for timing precision (S. D. Robertson et al., 1999). In the present experimen...

Three experiments were conducted to examine whether timing processes can be shared by continuous tapping and drawing tasks. In all 3 experiments, temporal precision in tapping was not related to temporal precision in continuous drawing. There were modest correlations among the tapping tasks, and there were significant correlations among the drawing...

Three experiments were conducted to examine whether timing processes can be shared by continuous tapping and drawing tasks. In all 3 experiments, temporal precision in tapping was not related to temporal precision in continuous drawing. There were modest correlations among the tapping tasks, and there were significant correlations among the drawing...

The motor coordination of adults who stutter was examined in the performance of a bimanual movement task. Fifteen subjects who stutter and 15 matched subjects who do not stutter performed three trials of a bimanual finger movement task. Subjects were required to produce a flexion and extension movement of the metacarpophalangeal joint of each index...

Several issues are raised concerning the notion that a single strategy explains Fitts' law and the linear speed/accuracy trade-off. Two additional concerns are discussed: (1) distance is programmed, (2) the fact that movements produced without the aid of vision obey Fitts' law does not mean that sighted movements must be explained without rega...

In the present experiment the role of vision in the control of repetitive circular movements was examined. Subjects drew circles at a 600 ms per circle rate. During the first nine seconds of the trial subjects moved with full vision and were paced by a metronome. During the latter 15 seconds, vision could be removed and/or the pacing signal could b...

In order to examine the stability and patterning of speech movement sequences, movements of the lip were recorded as subjects produced a phrase at normal, fast, and slow rates. Three methods of analysis were employed. First, a new index of spatiotemporal stability was derived by summing the standard deviations computed across amplitude- and time-no...

Recently it has been suggested that speech and manual timing tasks share a common central process (Franz, Zelaznik, & Smith, 1992): Because stuttering is thought to be related to deficits in motoric processes such as timing, stutterers (n = 15) were compared with a set of age-, education-, and sex-matched nonstutterers on timing and isometric force...

In the following discussion reaction to both Mounoud and Bremner is provided. The major point concerns the study of action in its own right versus the use of action as a tool to study development of cognitive abilities. Several research examples are provided that highlight the recommendations for the study of infant motor development.

Recent investigations of timing in motor control have been interpreted as support for the concept of brain modularity. According to this concept, the brain is organized into functional modules that contain mechanisms responsible for general processes. Keele and colleagues (Keele & Hawkins, 1982; Keele & Ivry, 1987; Keele, Ivry, & Pokorny, 1987; Kee...

The present study attempted to determine if during short-duration movements visual feedback can be processed in order to make adjustments to changes in the environment. The effect that varying the importance of monitoring target position has on the relative importance of vision of hand and vision of target (Carlton 1981a; Whiting and Cockerill 1974...

Previous research has shown that the concurrent performance of two manual tasks results in a tight temporal coupling of the limbs. The intent of the present experiment was to investigate whether a similar coupling exists in the spatial domain. Subjects produced continuous drawing of circles and lines, one task at a time or bimanually, for a 20 s tr...

In an influential study, Henry and Harrison (1961) examined the capability of subjects to inhibit an already-programmed response. Their experiment showed that when a stop signal was presented only 100 ms after the imperative go signal; a subject could not inhibit the movement. The inferences were that rapid ballistic actions are programmed and the...

This chapter describes the stimulus-response compatibility and the programming of motor activity. In the generalized motor-program framework, a skilled motor action is composed of two sets of characteristics, invariant characteristics and parameters. Invariant characteristics are aspects of the motor program that make one generalized motor program...

Investigators searching for principles underlying the control and coordination of complex movement sequences recently have explored a variety of experimental paradigms in which measures from performance of different effector systems are compared. These comparative methodologies have yielded data relevant to a number of significant theoretical issue...

It is well known that the risk of a debilitating injury from a fall is much higher for elderly than for young individuals. In addition, it is well documented that healthy elderly subjects exhibit increased postural sway during normal stance tasks. In the present experiment, we explored the notion that control of minor postural instability in elderl...