The purpose of this study was to investigate the presence of an apraxic condition in children with meningomyelocele. Subjects were grouped according to the presence or absence of hydrocephalus as diagnosed by a computerized tomography scan. Subjects performed tasks of simple movements and motor sequences first to verbal command and then to imitation. For simple movements there was a significant Group by Cue interaction. The hydrocephalic group, significantly inferior on the verbal cue, were noticeably better on imitation. For those subjects without hydrocephalus, such was unlikely due to a ceiling effect to the verbal cue. For motor sequences, there was a significant Cue and Group effect. Both groups improved to the visual cue with the nonhydrocephalus group being consistently superior. The results are discussed in terms of patterns of response, and a cognitive or brainstem/cerebellar-based disorder.
Timothy N. Welsh and Digby Elliott
Previous research has indicated that individuals with Down syndrome (DS) have difficulties processing auditory movement information relative to their peers with undifferentiated developmental disabilities. The present study was conducted to assess whether a model of atypical cerebral specialization could explain these findings. Thirteen adults with Down syndrome (8 men, 5 women), 14 adults with undifferentiated developmental disabilities (7 men, 7 women), and 14 adults without disabilities (8 men, 6 women) performed rapid aiming movements to targets under three conditions: a visual cue at the target location, a visual cue remote from the target location, or a verbal cue. Results revealed that, while the reaction times did not differ between the two groups with disabilities across conditions, the participants with DS, unlike their peers, had significantly longer movement times in the verbal than in two visual conditions. These results are consistent with the model of biological dissociation.
Cheryl Glazebrook, Digby Elliott, James Lyons and Luc Tremblay
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 stimulus. Both groups were significantly slower when responding to the same target as the previous trial when the target was cued in a different modality. Although participants with DS initiated and executed their movements more slowly, they demonstrated a similar pattern of inhibition as people without DS, suggesting that inhibitory processes are functioning normally in persons with DS.
Digby Elliott, Susan Gray and Daniel J. Weeks
The present study was designed to determine whether the verbal-motor performance deficits sometimes exhibited by Down syndrome persons interfere with their capacity to acquire a novel motor task. Mentally handicapped adults with and without Down syndrome, as well as nonhandicapped adults, practiced a verbally cued three-element movement sequence. When the verbal cue was terminated during retention, Down syndrome subjects made no more errors and performed the motor sequence just as rapidly as did the other mentally handicapped adults. However, Down syndrome subjects took longer to organize and initiate their movements. Both mentally handicapped groups performed more poorly than nonhandicapped subjects. The results provide partial support for the notion that Down syndrome persons have difficulty organizing limb movements on the basis of verbal instruction.
Jo-Anne C. Lazarus
A modified version of Fog’s clip-pinching task developed by Todor and Lazarus (1986) was used to assess associated movement or motor overflow in children with and without learning disabilities (LD). Children with LD as a group displayed greater overflow at all levels of active limb force than their age-equivalent nondisabled peers. Children with LD who also have attention deficit hyperactivity disorder were variable in their ability to consciously inhibit overflow while children with LD without attention deficit hyperactivity disorder were able to override overflow given verbal cues to do so. Results indicate that children with LD, as a group, tend to be more affected by the force output requirement of this task due to other factors such as attention and inhibition that differ in degree from nondisabled age-matched control subjects, or at least that persist for a longer period of time in development. The degree to which the regulation of attention interacts with the regulation of force differs for the two subgroups of children with LD, those with and without attention deficit hyperactivity disorder.
Samuel Ryan, Emidio Pacecca, Jye Tebble, Joel Hocking, Thomas Kempton and Aaron J. Coutts
front of themselves and gently fell toward the floor. Verbal cues were provided to prompt a 50% warm-up repetition (ie, not maximal effort), followed by 3 maximum effort repetitions. Test results were analyzed by peak eccentric force for both limbs in newtons (left, right, and average). This protocol
Samuel Ryan, Thomas Kempton, Emidio Pacecca and Aaron J. Coutts
ensure they maintained a knee joint angle of 60° during testing. Placing the femoral medial condyle of both knees on load cells (sample rate of 50 Hz), players were given a verbal cue to complete a warm-up of 1 repetition at 80% of their maximum effort. After a short break, they were asked to complete a
Jeffrey D. Simpson, Ludmila Cosio-Lima, Eric M. Scudamore, Eric K. O’Neal, Ethan M. Stewart, Brandon L. Miller, Harish Chander and Adam C. Knight
-point stance and 1 m behind the timing gates, to reduce starting errors detected by the timing gates, and completed the 25-m sprint following a verbal cue from the investigator. After another 5-minute rest period, 2 trials of the t -test CoD drill was completed and separated by 60-second rest periods
Tom Clifford, Will Abbott, Susan Y. Kwiecien, Glyn Howatson and Malachy P. McHugh
system (Bolzano, Italy). Participants started the movement upright with hands fixed to their hips and after a verbal cue, descended into a squat prior to performing a maximal effort vertical jump. Participants performed 3 maximal efforts, separated by approximately 60 seconds of standing recovery; the
Malachy P. McHugh, Tom Clifford, Will Abbott, Susan Y. Kwiecien, Ian J. Kremenic, Joseph J. DeVita and Glyn Howatson
-Sensor 2; BTS Bioengineering, Brooklyn, NY). As described previously, participants started the movement standing upright with hands on their hips, and after a verbal cue, descended into a squat (countermovement) prior to performing a maximal effort vertical jump. Participants performed 3 maximal efforts