Biomedical subjects

M Audiffren

Publications and source records attributed to M Audiffren.

4 recordsLinked to original sources

PubMed2000

Local muscular fatigue and attentional processes in a fencing task.

Study of the effects of brief exercise on mental processes by Tomporowski and Ellis (1986) has shown that moderate muscular tension improves cognitive performance while low or high tension does not. Improvements in performance induced by exercise are commonly associated with increase in arousal, while impairments are generally attributed to the effects of muscular or central fatigue. To test two hypotheses, that (1) submaximal muscular exercise would decrease premotor time and increase would increase the attentional and preparatory effects observed in premotor time 9 men, aged 20 to 30 years, performed an isometric test at 50% of their maximum voluntary contraction between blocks of a 3-choice reaction-time fencing task. Analysis showed (1) physical exercise did not improve postexercise premotor time, (2) muscular fatigue induced by isometric contractions did not increase motor time, (3) there was no effect of exercise on attentional and preparatory processes involved in the postexercise choice-RT task. The invalidation of hypotheses was mainly explained by disparity in directional effects across subjects and by use of an exercise that was not really fatiguing.

Adult↗

PubMed1998

Age-related differences in the preparatory processes of motor programming.

This article investigates the mechanisms underlying the age-related differences in information processing in the production of motor responses, especially the development of feedforward mechanisms. No age-related differences have emerged from developmental studies aiming at analyzing motor programming. Nevertheless, age effects have seldom been studied in function of motor preparation. The aim of the present experiment was (1) to study age differences in motor preparation, and (2) to validate the early maturation of movement parameters specification. Two conditions were used (1) no advanced information on the movement to be made was given to the subject (neutral prime), and (2) advanced information on which direction should be followed was provided to the subject, allowing him to prepare a response based on a prime (primed condition). Four age groups were studied 6, 8, 10 and 22 years. Our results showed mainly an early maturation of the programming processes. More specifically, (1) beyond 6 years of age, children are capable of using the information provided by the prime to prepare their movement in advance, (2) costs and benefits of pre-programming do not vary significantly with age, (3) deprogramming-reprogramming of effector and direction is quite similar across the four age groups.

Adult↗

PubMed1997

Age differences in using precued information to preprogram interception of a ball.

The present experiment examined the development of programming interception of a ball's movement across three groups of children ages 6, 8, and 10 years, who were compared with adults. In an interception task we manipulated the subjects' preparation by using Rosenbaum's 1980 precuing procedure. Two levels of precued information were used concerning the effector specified (right or left arm) and the direction of the arm projection (outside or inside). We focused particularly on RT and response errors. Analysis indicated RT decreased across the age groups and errors decreased mainly in the nonprecued condition. A critical period in improvement might be at age 8 as children use precue information to program their movements as efficiently as adults. The duration of effector programming was similar for children and adults but was more precise for the older subjects. For children as well as for adults, the specification of direction occurs after movement initiation and not before.

Adult↗

PubMed1997

Influence of physical exercise on simple reaction time: effect of physical fitness.

The influence of physical fitness and energy expenditure on a simple reaction time task performed during exercise was investigated. Two groups of 10 subjects were used, one was composed of trained middle-distance runners and one of students who had no regular physical training. The subjects performed a simple reaction time task while pedalling on a cycloergometer at different relative power output corresponding to 20, 40, 60, and 80% of their own maximal aerobic power and immediately after exercise. During exercise, the results showed a decrease in cognitive performance for both groups whereas no significant effect was found after exercise. A significant effect of physical fitness on simple reaction time was noted during exercise. The data are interpreted in terms of optimization of performance focusing particularly on the relations between energy cost of the physical task and attentional demand.

Adult↗