Activities of daily living in children with developmental coordination disorder: dressing, personal hygiene, and eating skills

In order to understand how age, culture, and problems in motor coordination impact the performance of activities of daily living, we used focus groups and in-depth interviews with Australian and Canadian parents to examine activities of daily living of younger (5-7 years of age) and older (8-9 years of age) children with and without DCD. By comparison with their typically developing age group, children with DCD had more difficulty with dressing, personal hygiene, and eating skills. Difficulties with postural control and fine-motor skills were reported to contribute to poorer performance of activities of daily living. As expected, competence in the performance of activities of daily living improved in the older children with and without DCD and there were few differences in the performance of daily living tasks between typical children in Australia and Canada. Overall, the motor difficulties of children with DCD had a significant impact on performance of a wide range of daily activities.     

Current status of the motor program: Revisited

The motor program is a concept that has had a major influence on theorizing in the field of motor control. However, there has been a lack of consensus as to what exactly is a motor program and its role in movement organization and execution. In 1994 Morris, Summers, Matyas, and Iansek concluded from a review of the application of the motor program concept in the field of physical therapy that continued use of the term may impede progress in the field. In this paper we examine what has happened to the motor program concept in the thirteen years since the previous evaluation. The review indicates that although the term is still being used in different ways, the theoretical existence of a motor program appears to be generally accepted by researchers in experimental psychology, movement science, and neurophysiology. The recent development of powerful brain imaging techniques may allow determination of whether the motor program should be regarded as a metaphorical or literal concept.     

Emotion and motor preparation: A transcranial magnetic stimulation study of corticospinal motor tract excitability

In the present study, we examined whether preparing motor responses under different emotional conditions alters motor evoked potentials (MEPs) elicited by transcranial magnetic stimulation delivered to the motor cortex. Analyses revealed three findings: (1) Reaction times were expedited during exposure to unpleasant images, as compared with pleasant and neutral images; (2) force amplitude was greater during exposure to unpleasant images, as compared with pleasant and neutral images; and (3) MEPs were larger while participants viewed unpleasant images, as compared with neutral images. Hence, coupling the preparation of motor responses with the viewing of emotional images led to arousal-driven changes in corticospinal motor tract excitability, whereas movement speed and force production varied as a function of emotional valence. These findings demonstrate that the effects of emotion on the motor system manifest at varying sensitivity levels across behavioral and neurophysiological measures. Moreover, they validate the action readiness component of emotional experience by demonstrating that emotional states influence the execution of future movements but, alone, do not lead to overt movement.     

Reliability of the amplitude of the return-sweep velocity of eye movements during reading.

A Beckman Type RM Dynograph was used to record the eye movements of 26 professional college men, once without spectacle corrections and then with plano lenses on a trial frame, during reading equivalent print at a distance of 33 cm. Amplitudes of the return-sweep velocity on these two trials were used to calculate an equivalent form reliability coefficient. A Pearson r of 0.88 indicates that their reliability is moderately high, meaning that both the desirable as well as the undesirable reading habits are probably deeply rooted by college, and imply that any reading remediation or improvement training should be performed at some much earlier stages to be efficiently effective.     

Organization,Processing, and Use of Performance Information: A Cognitive Role for Appraisal Instruments1

There is a history of interest in appraisal instruments as a means of improving the accuracy of ratings. But cognitive models have suggested an alternative role for instrumentation. The present study involved 125 subjects in an attempt to examine whether the format of the instrument, and the timing of its introduction, might influence cognitive processing of performance information and, in turn, recall and rating accuracy. Subjects received either a task- or trait-based instrument, either before observing performance, before a recall task, or before ratings. Both the type of scale and the timing of its introduction affected the organization of information in memory which, in turn, was related to recall accuracy. Rater judgment processes were affected as well. Implications for future research, and especially practice, are discussed.     

The cognitivist's revenge?

The recent articles by F. Mechsner (2004) and his colleagues (F. Mechsner, D. Kerzel, G. Knoblich, & W. Prinz, 2001) have once again fuelled the cognition vs. motor debate. In this commentary, the author takes an historical perspective and argues that Mechsner' stance represents just another phase in this continuing dialogue. Finally, the value of such false dichotomies in the progress of the field is questioned.     

Interlimb coordination following stroke

Studies investigating whether simultaneous bilateral movements can facilitate performance of the impaired limb(s) of stroke patients have returned mixed results. In the present study we compared unilateral limb performance (amplitude, cycle duration) with performance during an interlimb coordination task involving both homologous (both arms, both legs) and non-homologous (one arm, one leg) limbs in stroke participants (n=7) and healthy age-matched controls (n=7). In addition, the effect of on-line augmented visual feedback on interlimb coordination was investigated. Participants performed cyclical flexion-extension movements of the arms and legs in the sagittal plane paced by an auditory metronome (1 Hz). Movement amplitudes were larger and cycle durations shorter during homologous limb coordination than non-homologous coordination. Compared with unilateral movements both groups had reduced movement amplitudes and the stroke group increased cycle duration when interlimb coordination tasks were performed. These effects were most evident during non-homologous (arm and leg) coordination. No evidence of facilitation of the impaired limb(s) was found in any of the interlimb coordination conditions. Augmented visual feedback had minimal effect on the movements of control participants but lead to an increase of cycle duration for stroke participants.     

The role of playing and efference in the recall location and distance cues in short-term motor memory

Previous studies have suggested that the superior accuracy of preselected (subject-defined) over constrained (experimenter-defined) movements is due to both the availability of a movement plan and efferent-command information. The present experiment examined the contribution of the planning and efferent components to the preselection effect in a location and a distance task. The availability of a movement plan was manipulated by providing preselected and constrained groups of subjects with a rehearsal movement. Furthermore, the amount of efferent information available was varied by requiring both active and passive rehearsal movements. The results suggested that while strategy alone is responsible for the superiority of preselected location, both strategy and efferent information underlie the superiority of preselected distance reproduction.