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Biomedical subjects

J I Laszlo

Publications and source records attributed to J I Laszlo.

17 recordsLinked to original sources
PubMed1994

The size illusion in children from five years of age and adults.

First it was established that the size illusion occurs not only when complex patterns are presented kinaesthetically but even with simple stimuli such as straight lines and circles. Thus it was established that information overload is not the underlying cause of the illusion. The size illusion was investigated in children aged from five to twelve years and in adults. The stimulus circle was presented in passive kinaesthetic, sequential visual, in combined kinaesthetic and sequential visual, in static visual, and in combined kinaesthetic and static visual conditions either at fast or at slow speeds. A between-subjects design was used. In all conditions where the stimulus presentation included the kinaesthetic modality alone or in combination with visual or sequential visual conditions, size overestimation was found, while in the sequential visual and static visual conditions overestimation of the size of the stimulus was absent. Further, the kinaesthetic illusion was stable across the age range tested, indicating that the illusion is a property of the kinaesthetic system and is not influenced by learning, ie is hard wired.

Adolescent↗
PubMed1993

Perceptual-motor development and prevention of clumsiness.

This longitudinal study, following children's development over three years, examines the developmental trends in the processes underlying perceptual-motor behaviour. Entry into the study was at first year of primary school, at age 6. The study has three aims: (1) to obtain developmental trends in kinaesthesis and motor-programming processes; (2) to examine the relationship between slow kinaesthetic and motor development; (3) to establish the effect of accelerated kinaesthetic development and prevention of perceptual-motor dysfunction (clumsiness). The results to date show that over 60% of children entering primary school have not developed the kinaesthetic ability necessary for the acquisition and learning of educationally demanded motor skills. Kinaesthetic development is accelerated spontaneously in some children as a response to educational demands; in others a single exposure to kinaesthetic input triggers significant improvement. In the remaining 17% kinaesthetic training can alleviate the kinaesthetic dysfunction. At age 5-6 years only 25 children (8.1%) performed the Perceptual-Motor Abilities Test at levels indicative of perceptual-motor dysfunction. Of these, 13 children (4.2%) were identified as having motor difficulties. These low incidence rates indicate that a low level of kinaesthetic ability has no effect on general motor function at the beginning of schooling, and that only when competence in complex motor skills is expected, from the third year of schooling, does perceptual-motor dysfunction (PMD) become manifest.

Aptitude↗
PubMed1987

The drawing of squares and diamonds: a perceptual-motor task analysis.

The aim of the present study was to establish the role of perceptual-motor factors in copying an equilateral four-sided figure. Children, 5 to 12 years, and adults, were asked to copy the figure presented in either "square" or "diamond" orientation under five conditions: control; large model presentation; neutral picture frame surround; partial visual information reduction; and total visual information loss. The model was present at all times. Scores were orientation and angular variability. Developmental trends were found for both figures; the diamond was less well performed than the square at all ages tested. Three perceptual-motor factors were found to be important: formulation of the movement plan; movement programming, and sensory feedback. The difficulty of the diamond is thought to be due to the high programming and hence planning demands in drawing oblique lines. Both kinaesthesis and sequential vision are important factors in drawing; and only from 12 years of age are environmental cues used efficiently to orient the figure.

Adolescent↗
PubMed1986

Measurement of kinaesthetic sensitivity: a reply to Doyle and colleagues.

Doyle and colleagues (1986) are critical of the methodology employed in previous studies on the measurement of kinaesthetic sensitivity. Their criticisms are inappropriate in the context of the purpose and the final form of a standardized test of kinaesthetic sensitivity (Laszlo and Bairstow 1985b). They suggest an alternative methodology and imply--on the basis of a lack of correlation between different measures of sensitivity--that it is superior to the earlier methodology. The two methodologies give different measures of kinaesthetic sensitivity, and the reasons for a lack of correlation are discussed.

Humans↗
PubMed1985

The size illusion: visual and kinaesthetic information in size perception.

Earlier studies have shown the size of kinaesthetically presented two-dimensional movement patterns to be significantly overestimated. Whether this size overestimation is characteristic of the kinaesthetic system alone has not been established. Two experiments are reported which were designed to investigate size judgment made after kinaesthetic and visual pattern presentation and the effect of environmental cues on the perception of movement patterns. In experiment 1 patterns were presented kinaesthetically (experimenter guided hand movements around the outline of the pattern) or in combination with visual information given by a moving light (pinpoint light attached to the stylus which was moved around the pattern); visual and kinaesthetic cues were either congruent or conflicting with each other; and environmental cues were either present or absent. In experiment 2 static visual display was compared with visually traced pattern presentation, again with or without environmental cues. Overall the results showed that, regardless of experimental manipulation, in all cases where the information was given over time the subject perceived the pattern larger than reality. After static visual display, overestimation of size did not occur.

Adolescent↗
PubMed1981

Kinaesthetic sensitivity to passive movements and its relationship to motor development and motor control.

A test of kinaesthetic sensitivity to passive movements of the upper limbs was constructed consisting of two tasks: position and movement discrimination, and movement pattern perception and memory. 475 subjects ranging in age from five years to adult were tested and developmental trends were established. The test was found to be a useful tool in measuring the kinaesthetic sensitivity of normal subjects, as well as of intellectually and physically handicapped children. Results for right and left arms did not differ in the test of kinaesthetic perception and memory. Kinaesthetic sensitivity was found to be correlated with everyday motor functions involving fine manual control, as well as with co-ordinated gross body movements.

Adolescent↗
PubMed1980

Distracting information, motor performance and sex differences.

It is often argued that, in general, men are superior to women in perceptual motor skills (for example, car driving). Extensive reviews of the relevant literature do not give convincing evidence of sex differences in manual dexterity or motor skills in general. However, in the studies reported here, variables have been isolated which demonstrate that sex differences do exist in two perceptual motor tasks. These studies showed that females are adversely affected by irrelevant stimuli while performing tasks permitting freedom in movements but perform as well as males when the movement is stereotyped.

Adult↗
PubMed1980

Motor commands and the perception of movement patterns.

Electrophysiological experiments have shown that during voluntary movement, the activity of kinesthetic receptors relevant to actively contracting muscles is modified. Furthermore, efferent motor commands interact with the central transmission and processing of kinesthetic sensory input. This article addresses itself to the question of whether the efferent motor commands of voluntary movement influence the perception and processing of kinesthetic spatial information. In two experiments, subjects moved around unfamiliar and unseen criterion stencil patterns with their right hands. In the first experiment subjects were required to concurrently track the constrained movements with their left hands. In the second experiment, following movement around a criterion pattern, the subjects had to recall it with their right hands. Tracking and recall movements in the two experiments showed a systematic spatial bias in the direction in which the right-hand constrained movements were commanded. It is argued that when a limb movement is contrained, the interaction between the efferent command pattern and the returning kinesthetic sensory input results in its position being perceived with a constant error in the direction in which the movement was commanded.

Cerebral Cortex↗
PubMed1980

The measurement of kinaesthetic sensitivity in children and adults.

A test of kinaesthetic sensitivity was constructed, consisting of three tasks: localization, discrimination of position and movement, and perception of pattern. The purposes were to devise a test of kinaesthetic perception in children and adults, and to study possible developmental trends in such sensitivity. 180 children (five to 12 years) and adults were tested. The localization task was found to be not suitable and was omitted from the test, but the other two tasks proved to be suitable. Developmental trends in kinaesthetic acuity and perception were established.

Adult↗
PubMed1979

Effect of task similarity on transfer performance.

Transfer of training was studied using a discrete tracking task which involved aiming at targets on a moving paper strip. The effects of target speed, target size, and task demand, (number of targets aimed at in each trial) were examined separately in three experiments. In Experiment 1, a difference in stimulus input (i.e., target speed) produced large differences in task strategy (i.e., speed vs. accuracy bias). No significant transfer was found. A difference in target size (Experiment 2) involves a change in stimulus input, but this did not result in large strategy differences. Significant transfer was found when transferring from large to small targets. In Experiment 3, a variation in task demand produced different task strategies without a change in stimulus input. Significant transfer was found in all groups. The results were discussed in terms of similarity in perceptual elements and task strategy between transfer and training tasks. Greater similarity overall led to greater transfer.

Journal Article↗
PubMed1979

Perception of movement patterns: tracking of movement.

The tracking of complex two-dimensional movement patterns was studied. Subjects were blindfolded, and their right hand moved around stencil patterns in the midsagittal plane, while the left hand concurrently reproduced the right-hand movement. The accuracy with which the left hand shadowed the criterion movements of the right hand was measured in shape and size. Right-hand movements were active or passive. Present tracking performance was contrasted with errors in recall reported by Bairstow and Laszlo (1978). Results showed that tracking performance was accurate. Active and passive criterion movements were tracked differently. Tracking was clearly superior to recall performance.

Journal Article↗
PubMed1978

Perceptions of movement patterns: recall of movement.

The present study attempted to characterize the perception retention, and recall of kinaesthetic information regarding movement sequences (patterns). An attempt was made to draw on and extend conclusions relevant to simple movements (movement amplitude). One group of 10 blindfolded subjects recalled criterion movement patterns that had been actively commanded and 10 subjects recalled passively induced movements. The following conclusions were made. (1) Previous reports of algebraic errors in the recall of simple movement amplitudes are consistency with the finding that criterion perimeter, area, and depth of features were underestimated when recalled. (2) Measures of the accuracy of kinaesthetic perception do not alone account for the generally low level of pattern recall, the large range of individual differences or the underestimation of amplitude. The process of percept formation and of translating a percept into recalled movement are implicated. (3) Conclusions based on the short-term retention and recall of simple movements do not account for the coding, retention, and recall of movement sequences (patterns). (4) Percepts were formed, and patterns were recalled as a sequence of features but not as a sequence of key positions. (5) No direct difference was demonstrated between the recall of actively commanded and passively induced criterion movement patterns. However, the finding of a high gross angle change in the active condition was explained in terms of an unfavourable interaction between corollary discharge and sensory information.

Female↗