James Lyons

• PhD
• Professor (Full) at McMaster University

Two studies were conducted to examine the relation between the gambler's fallacy (GF) and attentional processes associated with inhibition of return (IOR). In Study 1, participants completed rapid aiming movements to equally probable targets presented to the left and right. They also completed a gambling protocol in which they bet on the illuminati...

Several years ago, our research group forwarded a model of goal-directed reaching and aiming that describes the processes involved in the optimization of speed, accuracy, and energy expenditure (Elliott et al. 2010). One of the main features of the model is the distinction between early impulse control, which is based on a comparison of expected to...

Dynamic stability provided by muscles is integral for function and integrity of the glenohumeral joint. Although the high degree of inter-individual variation that exists in musculoskeletal geometry is associated with shoulder injuries, there is limited research associating the effects of muscle geometry on the potential stabilizing capacities of s...

Biomechanical investigations examining shoulder function commonly observe a high degree of inter-individual variability in muscle activity and kinematic patterns during static and dynamic upper extremity exertions. Substantial differences in musculoskeletal geometry between individuals can alter muscle moment arms and lines of action that, theoreti...

This study compared productivity measures of 6 popular ergonomic mouse designs with varying degrees of palmer tilt using methods in accordance with ISO 9241-400:2007. Quantitative measures of throughput, movement time, and error rate were used to assess productivity and qualitative self-report measures were used to assess comfort, fatigue, accuracy...

The continuous pointing task uses target-directed pointing responses to determine how perceived distance traveled is estimated during forward linear walking movements. To more precisely examine the regulation of this online process, the current study measured upper extremity joint angles and step-cycle kinematics in full vision and no-vision contin...

The anxiety-perceptual-motor performance relationship may be enriched by investigations involving discrete manual responses due to the definitive demarcation of planning and control processes, which comprise the early and late portions of movement, respectively. To further examine the explanatory power of self-focus and distraction theories, we exp...

Tool use is typically explored via actor-tool interactions. However, the target-object (that which is being acted on) may influence perceived action possibilities and thereby guide action. Three different tool-target-object pairings were tested (Experiment 1). The hammering action demonstrated the greatest sensitivity and therefore subsequently use...

Recently our group forwarded a model of speed-accuracy relations in goal-directed reaching. A fundamental feature of our multiple process model was the distinction between two types of online regulation: impulse control and limb-target control. Impulse control begins during the initial stages of the movement trajectory and involves a comparison of...

Energy optimization in goal-directed aiming has been demonstrated as an undershoot bias in primary movement endpoint locations, especially in conditions where corrections to target overshoots must be made against gravity. Two-component models of upper limb movement have not yet considered how joint angles are organized to deal with the energy const...

Fitts’ Law holds that, to maintain accuracy, movement times of aiming movements must change as a result of varying degrees of movement difficulty. Recent evidence has emerged that aiming to a target located last in an array of placeholders results in a shorter movement time than would be expected by the Fitts’ equation – a violation of Fitts’ Law....

Background/study context: A manipulation check was used to investigate whether there is an age-related difference in the adherence to specific external- and internal-focus instructional constraints. Methods: Participants stood on a force platform and were to maintain a feedback cursor (representing their center of pressure) along the horizontal...

Sensorimotor experiences can modify the internal models for action. These modifications can govern the discrepancies between predicted and actual sensory consequences, such as distinguishing self- and other-generated actions. This distinction may also contribute toward the inhibition of movement interference, which is strongly associated with the c...

The multiple process model contends that there are two forms of online control for manual aiming: impulse regulation and limb-target control. This study examined the impact of visual information processing for limb-target control. We amalgamated the Gunslinger protocol (i.e., faster movements following a reaction to an external trigger compared to...

During rapid aiming, movements are planned and executed to avoid worst-case outcomes that require time and energy to correct. As such, downward movements initially undershoot the target to avoid corrections against gravity. Illusory target context can also impact aiming bias. Here, the authors sought to determine how strategic biases mediate illuso...

Goal-directed aiming movements are planned and executed so that they optimize speed, accuracy and energy expenditure. In particular, the primary submovements involved in manual aiming attempts typically undershoot targets in order to avoid costly time and energy overshoot errors. Furthermore, in aiming movements performed over a series of trials, t...

ABSTRACT Two experiments were conducted to examine time and energy optimization strategies for movements made with and against gravity. In Experiment 1, the authors manipulated concurrent visual feedback, and knowledge about feedback. When vision was eliminated upon movement initiation, participants exhibited greater undershooting, both with their...

Participants: 12 healthy young adults (19-30 years) and 12 healthy older adults (65-84 years).  Procedures: Participants stood on a force plate with their feet together. The participants were instructed to shifted their weight in the mediolateral (ML) direction in order to track a center of pressure (COP) feedback cursor to a spe-cific target loca...

Rating a player's skill level is an essential task for coaches to select the players with greatest potential to reach the top and to further be able to adjust the training program to the skill level of the player in order to most optimally facilitate the player's learning and performance. However, limited research exists on how they do this. This s...

Previous researchers have found that participants associate higher frequencies with locations that are higher in space and lower frequencies with lower locations, creating a phenomenological–spatial association for the frequency of auditory tones. With such an association, the frequency of an auditory tone could potentially bias movements along mul...

Humans are able to perceive unique types of biological motion presented as point-light displays (PLDs). Thirty years ago, Runeson and Frykholm (Human Perception and Performance, 7(4), 733, 1981, Journal of Experimental Psychology: General, 112(4), 585, 1983) studied observers' perceptions of weights lifted by actors and identified that the kinemati...

The online visual control of movement involves contributions from 2 processes: a process early in the trajectory concerned with comparisons between actual and expected sensory consequences and another process late in the trajectory that reduces the discrepancy between the position of the hand and the target. This experiment was designed to determin...

PURPOSE: Social-comparative feedback has been shown to influence learner self-efficacy beliefs and motor skill acquisition. This feedback is provided to make the learner believe that he/she is performing better or worse than the group average, regardless of his/her actual performance. Our objective was to examine the role of social-comparative feed...

Studies of fingertip force production have shown that self-produced forces are perceived as weaker than externally generated ones. This is due to mechanisms of sensory reafference where the comparison between predicted and actual sensory feedback results in attenuated perceptions of self-generated forces. Without an external reference to calibrate...

Interpersonal motor interactions (joint-actions) occur on a daily basis. In joint-action situations, typically developing (TD) individuals consider the end-goal of their partner and adjust their own movements to accommodate the other person. The movement planning processes required for joint-action may, however, be difficult for individuals with an...

An important question in oculomanual control is whether motor planning and execution modulate interference between motion of the eyes and hands. Here we investigated oculomanual interference using a novel paradigm that required saccadic eye movements and unimanual finger tapping. We examined finger trajectories for spatial interference caused by co...

ABSTRACT The authors replicated and extended results from the gunfight paradigm (A. Welchman, J. Stanley, M. Schomers, R. Miall, & H. Bulthoff, 2010a) in which participants moved faster when reacting to the perceived initiation of an opponent compared to initiating an action themselves. In addition to replicating these movement time effects, the au...

Objectives: It is well known that precision skills are best learned when they are practised in the sensorimotor context that is present when performance is most important. However, a particular skill may vary with respect to the sensorimotor context in which it is performed. Certain sensorimotor variations can make a task more or less complex than...

Performers adopt strategies to use visual information if they know that it will be available whereas uncertainty about its availability leads performers to prepare for the worst-case scenario. Since the impact of prior knowledge has generally been examined as performance-based changes across a series of trials, this study investigates the impact of...

Interpersonal motor interactions (joint-action) occur on a daily basis. In joint-action situations, typically developing (TD) individuals consider the end-goal of their partner and adjust their own movements to accommodate the other person. The movement planning processes required for joint-action may, however, be difficult for individuals with an...

The Lombard effect describes the automatic and involuntary increase in vocal intensity that speakers exhibit in a noisy environment. Previous studies of the Lombard effect have typically focused on the relationship between speaking and hearing. Automatic and involuntary increases in motor output have also been noted in studies of finger force produ...

Posture prediction algorithms, particularly those that consider comfort (or discomfort), are typically based on gross movements rather than on the finer movements of the upper extremity. However, understanding these finer movements, particularly during goal-directed reaching tasks, is critical to accurately predicting postures, and the associated p...

Examinations of goal-directed movements reveal a process of control that operates to make adjustments on the basis of the expected visual afference associated with the limb's movement. This experiment examined the impact of perturbations to the perceived and actual velocity of aiming movements when each was presented alone or in tandem with the oth...

Recent investigations have revealed the kinematics of horizontal saccades are less variable near the end of the trajectory than during the course of execution. Converging evidence indicates that oculomotor networks use online sensorimotor feedback to correct for initial trajectory errors. It is also known that oculomotor networks express saccadic c...

Sharing a drink or passing a tool to another person is frequently done in our daily lives. However, a second thought is rarely given about how the object should be handed; instead we pay attention to other factors (e.g., the company). This interaction (handing a tool to someone) is interesting, since it may give insight to how motor intentions are...

Medical Education 2011: 45: 119–131 Objectives The motor behaviours or ‘actions’ that provide the basis for precision limb control, including the performance of complex medical procedures, are represented at different levels in the central nervous system. This review focuses on how these representations influence the way people perceive, execute an...

Although elite athletes have been reported to be high academic achievers, many elite soccer players struggle with a stereotype of being low academic achievers. The purpose of this study was to compare the academic level (pre-university or pre-vocational) and self-regulatory skills (planning, self-monitoring, evaluation, reflection, effort, and self...

This study compared the gross motor skills of school-age children (mean age 7 y 8 mo, range 6-9 y) with developmental speech and language disorders (DSLDs; n=105; 76 males, 29 females) and typically developing children (n=105; 76 males, 29 females). The relationship between the performance parameters and the children's age was investigated as well...

This article reviews the behavioral literature on the control of goal-directed aiming and presents a multiple-process model of limb control. The model builds on recent variants of Woodworth's (1899) two-component model of speed-accuracy relations in voluntary movement and incorporates ideas about dynamic online limb control based on prior expectati...

Previous research suggests that removal of visual feedback of force output in a sequential force production task results in a continuous escalation of the force magnitudes produced. Central predictive mechanisms involving reafference result in self-generated forces being perceived as weaker, thus leading to a systematic over-production of force. Wh...

This study was designed to examine the impact of a delay between a self-initiated movement and a subsequent auditory event on temporal judgements of movement or sound onset. Participants watched a red dot move in a clockwise direction around a circle displayed on a computer screen and reported when they had pressed the spacebar or heard a tone. In...

The objective of this study was to determine if active cervical range of motion (ROM) and Fitts' task movement time differences occurred after high-velocity low-amplitude cervical spinal manipulation (SM) across various indexes of difficulty. A single-blind randomized before-after trial was performed in a motor performance laboratory. Fifteen volun...

To determine whether youth athletes with an "average" (regional), "high" (sub-elite), and "very high" (elite) level of performance differ with respect to their self-assessed tactical skills, 191 youth field hockey players (mean age 15.5 years, s = 1.6) completed the Tactical Skills Inventory for Sports (TACSIS) with scales for declarative ("knowing...

To interact with the environment, an individual must code, store, and translate spatial information into the appropriate motor commands for achieving an outcome. Working from this premise, Vision and Goal-Directed Movement: Neurobehavioral Perspectives discusses how visual perception, attention, and memory are linked to the processes of movement pr...

We present three experiments that show a clear influence of pitch on reaching movements. The first experiment shows that when there are incompatibilities between the spatial representations of target coordinates and perceived pitches, response times are longer than when spatial representations are congruous. The second experiment shows that pitch c...

Non-informative spatial cues presented prior to a goal-directed movement influence not only movement initia-tion time but also the spatial characteristics of the movement trajectories. These trajectory effects are thought to stem from an integration of competing motor responses. In the present experiments, trajectories of rapid aiming movements wer...

When participants make judgments about the onset of self-initiated movements they typically report the movement occurred earlier than it had [Obhi, S. S., & Haggard, P. (2004). Free will and free won't. American Scientific, 92, 358-365.]. One interpretation is that feed-forward processes lead to awareness of the movement prior to execution. Because...

Inhibition of return (IOR) has been shown to occur when an individual returns to a target location (within-person IOR) and when an individual moves to a location just engaged by another individual (between-person IOR). Although within- and between-person IOR likely result from the same inhibitory mechanisms, different processes must activate these...

A discrete aiming head movement task was developed to replicate Fitts'movement paradigm. Movement time (MT) differences between young (age range 24-29 years, n = 8) and old adults (age range 75-85 years, n = 8) were examined. Cervical spine (CS) range of motion (ROM) was recorded.A head mounted motion capture device was used to evaluate task perfor...

This study was conducted to assess the degree to which verbal prosody may differentially influence verbal processing in DS relative to age and mental-age matched controls. Nine individuals with DS, 7 mental-age matched (DD), and 10 chronological age matched controls (CG) participated in a dichotic free recall paradigm in which words were presented...

When task requirements were known in advance, Glazebrook et al. [C.M. Glazebrook, V.P. Dhillon, K.M. Keetch, J. Lyons, E. Amazeen, D.J. Weeks, D. Elliott, Perception-action and the Müller-Lyer illusion: amplitude or endpoint bias?, Exp. Brain Res. 160 (2005) 71-78.] demonstrated that perceptual biases associated with the Müller-Lyer illusion result...

Recent studies have shown that the initial impulse associated with goal-directed aiming movements typically brings the limb to a position short of the target. This is because target overshooting is associated with greater temporal and energy costs than target undershooting. Presumably these costs can be expected to vary not only with the muscular f...

We examined the planning and control of goal-directed aiming movements in young adults with autism. Participants performed rapid manual aiming movements to one of two targets. We manipulated the difficulty of the planning and control process by varying both target size and amplitude of the movements. Consistent with previous research, participants...

This study examined the performance of the upper limbs during responses to previously cued and un-cued locations. Participants made unimanual and bimanual responses under homologous and non-homologous muscular control, within a cuetarget (Experiment 1; n = 10), and a target-target (Experiment 2; n = 10) aiming protocol. The inhibition of return (IO...

The authors conducted 2 experiments in which participants (N = 16 in each) executed successive unimanual aiming movements to target locations that were indicated by the onset of either an auditory or a visual stimulus. In Experiment 1 (exogenous orientation), inhibition of return (IOR) effects were observed, with reliable reaction time (RT) costs a...

Two experiments used Müller-Lyer stimuli to test the predictions of the planning-control model (S. Glover, 2002) for aiming movements. In Experiment 1, participants aimed to stimuli that either remained the same or changed upon movement initiation. Experiment 2 was identical except that the duration of visual feedback for online control was manipul...

Williams syndrome (WS) is a genetic disorder that causes general cognitive and developmental delays. Compared to persons with Down syndrome (DS) at the same developmental level, individuals with WS generally exhibit superior expressive language abilities, but have difficulty with tasks that require the visual control of movement. Recently it has be...

Inhibition of return (IOR) refers to the slowing of responses to a target that appears in the same location as a previous event. Many researchers have speculated that IOR arises from inhibitory neural processes that have developed through evolution to facilitate efficient search patterns by biasing the action and/or attention of an individual towar...

Adults with Down syndrome (DS), an undifferentiated developmental delay (UnD) and no developmental delay practiced a manual target aiming task either with or without on-line visual feedback. Following acquisition, participants performed a retention test involving the same sensory condition available during practice, followed by a transfer test unde...

This study investigated inhibition of return in persons with and without Down syndrome (DS) when visual or verbal cues were used to specify a target in a crossmodal paradigm. Individuals with DS and without DS performed manual aiming movements to a target located in right or left hemispace. The target was specified by an endogenous visual or verbal...

Over the past decade there has been a great deal of controversy regarding the relative impact of visual illusions on cognitive judgments and the control of goal-directed action. We report the results of two experiments indicating that perceptual biases associated with the Müller-Lyer illusion involve a misjudgment of amplitude/extent while aiming b...

This study investigated the degree to which inhibition of return (IOR) is influenced when endogenous visual and auditory stimuli are used to specify a target in a cross-modal paradigm. Twelve participants performed rapid manual aiming movements to a target located in right (red target) or left (green target) hemispace. On each trial, the target was...

Tipper (1985; Q J Exp Psychol A 37:571-590) has suggested that competing responses programmed to distracting stimuli are inhibited based on their relationship to the action being performed. The present paper reports two experiments designed to examine the influence of the terminal action of a task on the allocation of visual attention. Taken togeth...

Two experiments were conducted in which participants (N = 12, Experiment 1; N = 12, Experiment 2) performed rapid aiming movements with and without visual feedback under blocked, random, and alternating feedback schedules. Prior knowledge of whether vision would be available had a significant impact on the strategies that participants adopted. When...

Two experiments were conducted to examine the role of vision in the execution of a movement sequence. Experiment 1 investigated whether individual components of a sequential movement are controlled together or separately. Participants executed a rapid aiming movement to two targets in sequence. A full vision condition was compared to a condition in...

A recent action-centred model of selective attention holds that attention depends upon the relation between the intended target, distracting stimuli, and the action to be performed (S. P. Tipper et al; see record 1993-12302-001). In contrast to many earlier studies, where perception and action seem to be dissociated, an action-centred approach str...

In 2 experiments, binocular and monocular vision were compared and interocular integration in 1-hand ball catching was examined. Participants (N = 10 in each experiment) were required to catch tennis balls projected over a distance of 15 m. Participants wore liquid-crystal visual occlusion goggles so that the duration and frequency of visual sample...

Two experiments were conducted to examine manual asymmetries in a one-dimensional aiming task. In Exp. 1, 10 right-handed adults slid a computer mouse 13 cm on a graphics tablet with both the right and left hands to targets of 3 different diameters. Under these conditions, the movement time for the right hand was significantly faster as expected. I...

Fifteen participants practiced a two-target sequential aiming movement with either full vision of the movement environment, vision during flight, or vision while in contact with the first target. After 100 acquisition trials, participants performed a retention test in their own condition and then were transferred to each of the other two vision con...

Two experiments were conducted to explore the interaction of the two cerebral hemispheres in motor control, by examining hand, space and attentional asymmetries in goal- directed aiming. In Experiment 1, right-handed subjects moved to targets more quickly with their right hand than their left hand. In addition, each hand was faster when moving in i...

In this study, 2 competing views of interceptive action were examined by assessing the influence of variability in the interval between visual samples in a unimanual ball-catching task. Subjects were required to catch tennis balls projected over a distance of 14 m, under conditions of intermittent vision in which the between-sample intervals were e...

Two experiments were conducted to explore the interaction of the two cerebral hemispheres in motor control, by examining hand, space and attentional asymmetries in goal-directed aiming. In Experiment 1, right-handed subjects moved to targets more quickly with their right hand than their left hand. In addition, each hand was faster when moving in it...