A simple method to record arm positioning movements in man with an Apple computer

This paper describes a simple method to record arm positioning movements in humans, via the game paddle entry of an Apple computer. A machine language subroutine reads the successive positions of a rotating potentiometer, with an angular accuracy of .5 deg and a time interval between two measures of 2.5 msec, and stores them sequentially in RAM memory. These measures can be retrieved for further computations of movement parameters.     

Reaction times, using fine and gross motor movements of moderately and severely mentally handicapped adults to auditory and visual stimuli

This experiment investigated the reaction times, when using fine and gross motor movements, of 24 moderately and severely mentally handicapped adults to light and sound stimuli. Unlike results of prior studies of normal and mildly mentally handicapped subjects, there were no significant differences among variables.     

A simple and unified approach to human voluntary movements

In his provocative article, F. Mechsner (2004) advances the thesis that human voluntary movements are subject to "psychological" or "perceptual-cognitive" control and are thus organized "without regard to efferent patterns" (p. 355). Rather than considering in detail the experiments that he proffered by way of support, the present author discusses the degree to which that supposition has appeal on the grounds of simplicity and is defined in terms that are compatible with a unified science.     

Criterion movements in motor short-term memory experiments

Analysis of both the criterion and reproduction movements from a motor short-term memory experiment using preselected movement is presented. The movement cues under imvestigation, location and distance, were found to interact significantly with amplitude for both the criterion and reproduction movements. It seems that movement cue affects the amplitude of criterion as well as reproduction movements. Thus previous findings by Gundry (1975) are replicated and extended. An increase in a central tendency effect over trials was found which indicated that the criterion movements were effected by proceding movements. The theoretical and methodological implications of these findings are discussed.     

A stabilometer computerized analog recording system for studying gross motor skill learning

The stabilomotor computerized analog recording system (SCARS) presents a unique data analysis and storage system for studying motor learning strategies. Graphic computer printouts, total time in balance, total number of contacts, time between contacts, standard deviation of the time between contacts, mean angle of balance, and standard deviation of the angle of balance for each trial are derived.     

Associations between gross motor and communicative development in at-risk infants

Infants’ advances in locomotion relate to advances in communicative development. However, little is known about these relations in infants at risk for delays in these domains and whether they may extend to earlier achievements in gross motor development in infancy. We examined whether advances in sitting and prone locomotion are related to communicative development in infants who have an older sibling with autism spectrum disorder (ASD) and are at risk for motor and communication delays (heightened-risk; HR). We conducted a longitudinal study with 37 HR infants who did not receive an ASD diagnosis at 36 months. Infants were observed monthly between the ages of 5 and 14 months. We assessed gross motor development using the Alberta Infant Motor Scales (AIMS) and recorded ages of onset of verbal and nonverbal communicative behaviors. Results indicated increased presence of early gross motor delay from 5 to 10 months. In addition, there were positive relations between sitting and gesture and babble onset and between prone development and gesture onset. Thus, links between gross motor development and communication extend to at-risk development and provide a starting point for future research on potential cascading consequences of motor advances on communication development.     

The role of eye movements in motor sequence learning

An experiment that utilized a 16-element movement sequence was designed to determine the impact of eye movements on sequence learning. The participants were randomly assigned to two experimental groups: a group that was permitted to use eye movements (FREE) and a second group (FIX) that was instructed to fixate on a marker during acquisition (ACQ). A retention test (RET) was designed to provide a measure of learning, and two transfer tests were designed to determine the extent to which eye movements influenced sequence learning. The results demonstrated that both groups decreased the response time to produce the sequence, but the participants in the FREE group performed the sequence more quickly than participants of the FIX group during the ACQ, RET and the two transfer tests. Furthermore, continuous visual control of response execution was reduced over the course of learning. The results of the transfer tests indicated that oculomotor information regarding the sequence can be stored in memory and enhances response production.     

Effects of gross motor training on attention-deficit behavior in one learning-disabled child

The effects of gross motor training on attention-deficit behavior of one learning disabled boy were studied. An A-B-A-B reversal design was used with motor training administered during B phases and no motor training administered during A phases. At the end of each phase, data on motor coordination, self-concept, locus of control, and attention deficit were collected. Motor coordination, self-concept, locus of control, and teacher's ratings of attention-deficit behavior were more positive at the end of B phases than at the end of immediately previous A phases. Mother's ratings of attention-deficit were also more positive at the end of the first B phase than at the end of the first A phase but worsened from the end of the second A phase to the end of the second B phase.     

Improvement in gross motor performance between 3 and 5 years of age

This study examined gross motor performance of 101 typically developing children between 3 and 5 years of age (48 boys, 53 girls, M age = 3.9 yr., SD = 0.5). All children performed 7 different gross motor tasks which were rated on a 5-point scale. Age and sex were assessed by an ordinal-logistic model, and odds ratios were calculated for each task using age and sex as covariates. For standing on one leg, walking on a beam, hopping on one leg, running, and taking stairs, statistically significant age differences were found, while for rising and jumping down, none were apparent. Mean motor performance did not differ between boys and girls on the tasks. The older the children were, the better they performed on the tasks.     

Latencies of stimulus-driven eye movements are shorter in dyslexic subjects

Eye movements latencies toward peripherally presented stimuli were measured in 10-year-old dyslexic and control children. Dyslexic subjects, previously found to be oversensitive to stimulation of the magnocellular channel, showed reduced latencies as compared to normally reading controls. An attention shifting task was also used which showed no group differences in latencies of eye movements. The data are discussed in terms of the hypothesis of magnocellular system alteration and attention dysfunction in dyslexia. Additionally, sex differences in eye movement latencies were found and are discussed.     

A note on the gross configurations of the human auditory cortex

Gross inspection of 30 human brains (60 hemispheres) from patients without hearing impairment revealed the following configurations of gyri: one on left and two on right (14 of 30); two on left and two on right (11 of 30); one on left and one on right (3 of 30); two on left and one on right (1 of 30); and two on left and three on right (1 of 30). The last group has since been extended to include all combinations other than the first four and the proportions of these combinations appear to persist in larger tallies. Thirteen of the 30 brains displayed double gyri on the left while 25 had double gyri on the right. Seventeen of the 30 brains possessed a single gyrus on the left and four specimens had a single gyrus on the right. In general, the left side has a tendency to fewer gyral markings. The average cortical surface area on the left is 1198 mm² compared to 1380 on the right.     

The effects of instructions to subjects on the programming of visually directed reaching movements

Numerous studies of human motor control have examined the effects of constraints on the programming and execution of visually directed limb movements. Only a few studies, however, have explored how the subject's objective in making the movement affects the coordinated sequence of eye and limb movements that unfolds as the subject points to or grasps an object in space. In the present study, the characteristics of the targets and the environment remained constant while the demands for speed and accuracy were varied across blocks of trials by changing the instructions to the subject. In other words, the constraints operating in the situation were kept constant, but the objective of the movement was systematically varied by changing the relative demands for speed and accuracy. All subjects were required to point to visual targets presented on a screen in front of them. Eye position was monitored by infrared reflection. The position of each subject's hand in three-dimensional space was reconstructed by a computer-assisted analysis of the images provided by two rotary-shutter video cameras. The speed and accuracy demands of the task were varied in blocks of trials by requiring the subjects to point to the target "as quickly as you can" (speed condition); "as accurately as you can" (accuracy condition); or both "quickly and accurately" (speed/accuracy condition). The time to initiate an eye movement to the target was found to be reduced by increasing either the speed or accuracy demands of the task although the time to initiate the hand movement was reduced only in the speed condition. While the duration of the acceleration phase of the reach remained constant in real time, the duration of the deceleration phase was increased with increased demands for accuracy. As expected, both variable and absolute errors were largest in the speed condition. The findings indicated that the programming of the limb movement and its coordination with the associated eye movements were affected by varying the objective of the task.