Charles H Shea

• Doctor of Philosophy
• Professor at Texas A&M University

Background and Aims Sleep after a new sequence memory training can enhance the explicit memory in children. However, children’s sleep-dependent motor memory consolidation particularly in implicit complex sequence tasks is unclear. Therefore, this study aims to investigate the role of night-time sleep and wakefulness on children’s motor memory conso...

The aim of this experiment was to determine if dyad practice helped individuals become aware, use, and retain information in a dynamically changing perceptual-motor task compared with practice alone. We used a computerized perceptual-motor task, where individuals were required to intercept balls that dropped from the top of the screen. A colored li...

The objective of the experiment was to assess the change in attentional demands of a movement sequence guided by visual-spatial and motor representations across practice sessions in a dual-task probe paradigm. Participants were randomly assigned to either a 1-day or 2-day practice group. Following acquisition of the motor sequence task, participant...

Study aim : The purpose of this study was to investigate the role of sleep and awareness on consolidation of general and Sequence-Specific learning in children. Material and methods : Male participants (n = 48, 10 to 12 years old) were assigned to one of four groups based on awareness and sleep. Acquisition phase took place in the morning (wake gro...

Multiple diverse pathologies result in the clinical presentation of myelopathy. The preferred way to image the spinal cord depends on clinical history, anatomic site of interest, and patient issues limiting certain imaging modalities. This radiology-focused article discusses pertinent physiological considerations, reviews basic and newer imaging te...

In an experiment conducted by Kennedy et al. (Exp Brain Res 233:181–195, 2016), dominant right-handed individuals were required to produce a rhythm of isometric forces in a 2:1 or 1:2 bimanual coordination pattern. In the 2:1 pattern, the left limb performed the faster rhythm, while in the 1:2 pattern, the right limb produced the faster pattern. In...

An experiment was designed to determine whether accuracy constraints can influence how unimanual and bimanual motor sequences are produced and learned. The accuracy requirements of the task were manipulated using principles derived from Fitts' Law to create relatively low (ID = 3) and high (ID = 5) accuracy demands. Right-limb dominant participants...

An experiment was designed to investigate the impact of a dual-task on the response structure of a 16-element movement sequence. The primary task was to move a lever to targets sequentially presented horizontally on the screen by elbow extension/flexion movements. The secondary task was a simple reaction time task triggered by moving the lever thro...

Two experiments were designed to determine response biases resulting from production of force in the contralateral limb and head position. Participants were required to react with one limb while tracking a sinewave template by generating a pattern of force defined by the sinewave with the contralateral limb or watching a cursor move through the sin...

The purpose of the experiment was to determine the extent to which observation and the inter-trial dialogue in a dyad training protocol enhance the development of a movement sequence representation. The task was to reproduce a 1300ms spatial-temporal pattern of elbow extension/flexion movements. An inter-manual transfer design with a retention test...

Research has indicated that older adults perform movement sequences more slowly than young adults. The purpose of the present experiment was to compare movement sequence learning in young and older adults when the time to perform the sequence was extended, and how the elderly’s cognitive status (Montreal Cognitive Assessment [MoCA]) interacted with...

Two tasks (A and B) were designed which required participants to sequentially move through four target positions in a Lissajous display. Task A was designed so that participants could complete the task using either unimanual or bimanual control strategies. Task B was designed so that participants could complete the task using relatively simple or m...

An experiment was conducted to determine if the performance and learning of a multi-frequency (1:2) coordination pattern between the limbs are enhanced when a model is provided prior to each acquisition trial. Research has indicated very effective performance of a wide variety of bimanual coordination tasks when Lissajous plots with goal templates...

Previous theoretical and empirical work indicates that intentional changes in a bimanual coordination pattern depends on the stability of the bimanual coordination pattern (Kelso, Schotz, & Schöner, 1988; Scholz & Kelso, 1990). The present experiments retest this notion when online Lissajous displays are provided. Switching to and from in-phase and...

Unimanual (left and right limbs) and bimanual (in-phase) reciprocal aiming tasks were tested to determine if the control processes used to perform the unimanual aiming tasks were also present in bimanual aiming tasks. Participants were asked to move a cursor as quickly and accurately as possible between the two targets presented in a Lissajous feed...

An experiment was designed to determine the impact of the force requirements on the production of bimanual 1:2 coordination patterns requiring the same (symmetric) or different (asymmetric) forces when Lissajous displays and goal templates are provided. The Lissajous displays have been shown to minimize the influence of attentional and perceptual c...

Two experiments utilizing a spatial-temporal movement sequence were designed to determine if the memory of the sequence is lateralized in the left or right hemisphere. In Experiment 1, dominant right-handers were randomly assigned to one of two acquisition groups: a left-hand starter and a right-hand starter group. After an acquisition phase, react...

The manuscript reviews the theoretical underpinnings proposed to account for the production and effector transfer of simple and more complex movement sequences. Special attention is given to the Hikosaka perspective, which, in our opinion, has the potential to provide, with some modifications, a unifying way to understand the various factors that i...

An experiment by Boyle, Kennedy, and Shea (2012) demonstrated that practice tracking a template created from a sine wave results in enhanced performance and transfer on a reciprocal aiming task with an index of difficulty (ID) of 6. An experiment was conducted to determine whether tracking a template constructed from recorded participants' performa...

The experiment was conducted to determine the influence of mirror movements in bimanual coordination during life span. Children, young adults, and older adults were instructed to perform a continuous 1:2 bimanual coordination task by performing flexion-extension wrist movements over 30s where symmetrical and non-symmetrical coordination patterns al...

Results from a recent experiment (Kennedy et al. in Exp Brain Res 233:181-195, 2015) indicated consistent and identifiable distortion of the left limb forces that could be attributable to the production of right limb forces during a multi-frequency bimanual force task. However, distortions in the forces produced by the right limb that could be attr...

Bimanual 1:1 coordination patterns other than in-phase (0(00)) and anti-phase (180(00)) have proven difficult to perform even with extended practice. The difficulty has traditionally been attributed to phase attraction that draws the coordination between the limbs towards the bimanual patterns of in-phase and anti-phase and variability associated w...

For nearly four decades bimanual coordination, "a prototype of complex motor skills" and apparent "window into the design of the brain," has been intensively studied. Past research has focused on describing and modeling the constraints that allow the production of some coordination patterns while limiting effective performance of other bimanual coo...

Abstract at: http://journals.humankinetics.com/AcuCustom/Sitename/Documents/DocumentItem/PDF-All%20Abstracts%20for%20the%202015%20Conference.pdf Page 63 of PDF or 56 of document.

An experiment was designed to investigate the inflence of movement diffiulty on the control process and organization of bimanual (in-phase and anti-phase) sequential movements. Participants were asked to move as quickly and smoothly as possible from one illuminated target to the next. When they achieved the target location the illumination was turn...

Behavioral research produced many task-specific cognitive models that do not say much about the underlying information processing architecture. Such an architecture is badly needed to understand better how cognitive neuroscience can benefit from existing cognitive models. This problem is especially pertinent in the domain of sequential behavior whe...

Two recent experiments have demonstrated that young adult participants were able to make faster and more harmonic movements in a typical reciprocal Fitts task (ID = 6) following a practice session of sine wave tracking (Boyle et al. in Exp Brain Res 223:377-387, 2012; J Mot Behav 46:277-285, 2014). The purpose of the present experiment was to repli...

The purpose of this study was to determine the extent to which participants could effectively switch from on-line (OL) to pre-planned (PP) control (or vice versa) depending on previous practice conditions and whether concurrent visual feedback was available during transfer testing. The task was to reproduce a 2000 ms spatial-temporal pattern of a s...

Three experiments were designed to determine the level of cooperation or interference observed from the forces generated in one limb on the forces exhibited by the contralateral limb when one or both limbs were producing a constant force (Experiment 1), one limb was producing a dynamic force while the other limb was producing a constant force (Expe...

The experiment was designed to determine participants' ability to coordinate a bimanual multifrequency pattern of isometric forces using homologous or non-homologous muscles. Lissajous feedback was provided to reduce perceptual and attentional constraints. The primary purpose was to determine whether the activation of homologous and non-homologous...

Practice tracking a sine wave template has been shown (J. B. Boyle, D. Kennedy, & C. H. Shea, 2012) to greatly enhance performance on a difficult Fitts task of the same amplitude. The purpose of the experiment was to replicate this finding and determine whether enhancements related to the sine wave practice are specific to the amplitude experienced...

Unlabelled: BACKGROUND/STUDY CONTEXT: The purpose was to determine if aging interacts with the coding of a simple spatial-temporal movement sequence. Methods: An interlimb practice paradigm (24 participants; 12 young adults [age: 23-29]; 12 old adults [age: 65-78]) was designed to determine the coordinate system (visual-spatial/motor) that is us...

A recent experiment by Boyle et al. (Exp Brain Res 223:377-387, 2012a) demonstrated that providing a sine-wave template for participants to follow enhances performance and transfer on difficult (ID = 6) Fitts tasks. Another experiment (Fernandez and Bootsma in Acta Psychol 129:217-227, 2008) demonstrated the effectiveness of applying a nonlinear tr...

An experiment was designed to determine whether the activation of a muscle group (flexors or extensors) used to produce an ongoing movement of one limb influenced the reaction time and associated initiation of elbow flexion or extension movements of the contralateral limb. Right-handed participants in the bimanual groups were asked to produce a pat...

Both discrete and continuous bimanual coordination patterns are difficult to effectively perform when the two limbs are required to perform different movements patterns, move at different velocities and/or move different amplitudes unless some form of integrated feedback is provided. The purpose of the present experiment was to determine the degree...

An experiment was designed to determine the degree to which reducing movement amplitude (16, 8, to 4) while keeping the relative accuracy requirements (IDs 1.5, 3, 4.5, and 6) and visual feedback display constant by increasing the display gain proportional to the decrease in amplitude (1×, 2×, 4×) influences reciprocal aiming movements of the wrist...

The purpose of the present study was to determine velocity discrimination characteristics of subjects in a difference threshold paradigm. After recruitment, 180 male and female subjects were randomly assigned to 1 of 6 groups differentiated by the length of the stimulus runway and the subjects' orientation to the stimulus. Stimulus velocities were...

Three similar six-element key press sequences were practiced under blocked or random practice schedules with acquisition conducted on one day and retention and transfer on the next day. The task required participants to type, as quickly as possible, one of three 6-element sequences as observed on a computer monitor. In blocked practice, participant...

An experiment was conducted to determine the impact of an auditory model on blocked, random, and mixed practice schedules of three five-segment timing sequences (relative time constant). We were interested in whether or not the auditory model differentially affected the learning of relative and absolute timing under blocked and random practice. Par...

An experiment was designed to determine the effectiveness of auditory and visual models in the learning of a 2:3 bimanual tapping pattern. Participants were randomly assigned to an auditory model, visual model, auditory + visual model, or a control (visual metronome) group. The task for all groups was to tap a left side force transducer with the le...

The main purpose of the present experiment was to determine the coordinate system used in the development of movement codes when observational and physical practice are scheduled across practice sessions. The task was to reproduce a 1,300-ms spatial–temporal pattern of elbow flexions and extensions. An intermanual transfer paradigm with a retention...

An experiment was designed to determine the degree to which instruction and visual display influence participants' performance and control characteristics when executing difficult reciprocal aiming movements. Participants were randomly assigned to one of the three acquisition conditions (Fitts, Impulse and Sine). Participants in the Fitts condition...

An experiment using reciprocal arm and wrist aiming movements with an amplitude of 16(o) and target width of .5° (ID = 6) was conducted to determine the impact of adding external loads. We predicted that wrist and arm performance may be differentially impacted by the added mass. Participants were asked to flex/extend their limb/lever in a horizonta...

Ziel der vorliegenden Studie war es, den Einfluss spezifischer visueller Wahrnehmungseffekte auf die Handlungskontrolle von closed-loop-kontrollierten Zielbewegungen zu untersuchen. Mittels einer simultanen Grosen-Kontrast-Illusion (Ebbinghaus-Titchener-Illusion) wurden die Wahrnehmungseffekte manipuliert. Die Handlung und die inharenten informatio...

An experiment was conducted to determine if gating information to different hemispheres during observational training facilitates the development of a movement representation. Participants were randomly assigned to one of three observation groups that differed in terms of the type of visual half-field presentation during observation (right visual h...

The main purpose of the present experiment was to determine the coordinate system used in the development of movement codes when observational and physical practice are scheduled across practice sessions. The task was to reproduce a 1,300-ms spatial–temporal pattern of elbow flexions and extensions. An intermanual transfer paradigm with a retention...

The main purpose of the present experiment was to determine the coordinate system used in the development of movement codes when observational and physical practice are scheduled across practice sessions. The task was to reproduce a 1,300-ms spatial–temporal pattern of elbow flexions and extensions. An intermanual transfer paradigm with a retention...

An experiment was conducted to determine whether multi-frequency continuous bimanual circling movements of varying difficulty (1:2, 2:3, 3:4, and 4:5) could be effectively performed following relatively little practice when on-line continuous relative velocity feedback is provided. The between-subjects results indicate extremely effective bimanual...

The experiment was designed to replicate and extend to an integrated feedback condition the pattern of movement time results found by Kelso et al. (J Exp Psychol Hum Percept Perform 5:229-238, 1979a, Science 204:1029-1031, 1979b) where the simultaneous movement of one hand to a low ID target and the other to a higher ID target indicated "a tight co...

The manuscript reviews recent experiments that use inter-manual transfer and inter-manual practice paradigms to determine the coordinate system (visual–spatial or motor) used in the coding of movement sequences during physical and observational practice. The results indicated that multi-element movement sequences are more effectively coded in visua...

Results from recent experiments (e.g., Kovacs, Buchanan, & Shea, 2009a-b, 2010a,b) suggest that when salient visual information is presented using Lissajous plots bimanual coordination patterns typically thought to be very difficult to perform without extensive practice can be performed with remarkably low relative phase error and variability with...

An experiment was conducted to determine the coordinate system used in the development of movement codes during observation and utilized on later physical practice performance of a simple spatial-temporal movement sequence. The task was to reproduce a 1.3-s spatial-temporal pattern of elbow flexions and extensions. An intermanual transfer paradigm...

Hikosaka et al. (1999) proposed that sequential movements are acquired in independent visual-spatial and motor coordinate systems with coding initially represented in visual-spatial coordinates, and later after extended practice in motor coordinates. One aspect of sequence learning that has not been systematically studied, however, is the question...

Two experiments were conducted to determine if multi-frequency (2:1 and 3:2) coordination between the limbs is enhanced when integrated feedback is provided in the form of Lissajous plots, attention demands are reduced, and attempts to consciously coordinate the limbs are not encouraged. To determine the influence of vision of the limbs, covered an...

The purpose of the experiment was to determine the influence of Lissajous feedback on 1:1 bimanual coordination patterns (0 degrees , 90 degrees , and 180 degrees phase lags) when the movement amplitudes of the two limbs were different (30 degrees , 60 degrees ). The present data supports the notion that the lead-lag relationship as well as amplitu...

This experiment investigated differencesin transfer to novel task dynamicsin movement sequence learningand handed- ness. Increased loads were used to determine the transfer profiles of movement sequences to practiced and unpracticed limbs. The task required participants to move a horizontal lever to 16 sequentially projected targets. One group prac...

Objectives Findings from the contemporary psychological and movement science literature that appear to have implications for medical training are reviewed. Specifically, the review focuses on four factors that have been shown to enhance the learning of motor skills: observational practice; the learner’s focus of attention; feedback, and self-contro...

An experiment was designed to determine if the addition of a load altered the effector transfer profile observed in earlier experiments using multi-element movement sequences. The acquisition task required participants to move a horizontal lever (with 0.567kg load) to 16 sequentially projected targets. One group practiced the movement sequence with...

Recent experiments have demonstrated that complex multi-element movement sequences were coded in visual-spatial coordinates even after extensive practice, while relatively simple spatial-temporal movement sequences are coded in motor coordinates after a single practice session. The purpose of the present experiment was to determine if the control p...

The present findings demonstrate that when participants are provided a Lissajous display with cursor indicating the position of the limbs and a template illustrating the desired movement pattern they can rapidly (10 min) and effectively (continuous relative phase errors and variability ~10 degrees ) tune in a difficult 5:3 bimanual coordination pat...

Recent experiments have produced mixed results in terms of performance when, after learning a sequential task, the same visual-spatial coordinates or the same motor coordinates were reinstated on a subsequent effector transfer test. Given the diversity of tasks and especially sequence characteristics used in previous experiments, the cross-experime...

Bimanual 1:1 coordination patterns other than in-phase (0 degrees ) and anti-phase (180 degrees ) have proven difficult to perform even with extended practice. The difficulty has been attributed to phase attraction that draws the coordination between the limbs towards the bimanual patterns of in-phase and anti-phase and variability associated with...

Previous research suggests that movements are represented early in practice in visual-spatial coordinates/codes, which are effector independent, and later in practice in motor coordinates/codes (e.g., joint angles, activation patterns), which are effector dependent. In the present experiments, the task was to reproduce 1.3 s patterns of elbow flexi...

Three experiments utilizing a 14-element arm movement sequence were designed to determine if reinstating the visual-spatial coordinates, which require movements to the same spatial locations utilized during acquisition, results in better effector transfer than reinstating the motor coordinates, which require the same pattern of homologous muscle ac...

An interlimb practice paradigm was designed to determine the role that visual-spatial (Cartesian) and motor (joint angles, activation patterns) coordinates play in the coding and learning of complex movement sequences. Participants practised a 16-element movement sequence by moving a lever to sequentially presented targets with one limb on Day 1 an...

The purpose of the present experiment was to observe the performance of participants attempting to produce a 1:1 bimanual coordination pattern with 90 degrees relative phase between the arms when feedback concerning the movement of the two limbs was integrated within a Lissajous plot and when this information was withdrawn. One group was paced with...

An experiment was conducted to determine the impact of an auditory model on blocked, random, and mixed practice schedules of three five-segment timing sequences (relative time constant). We were interested in whether or not the auditory model differentially affected the learning of relative and absolute timing under blocked and random practice. Par...