Biomedical subjects

Rena M Eenshuistra

Publications and source records attributed to Rena M Eenshuistra.

3 recordsLinked to original sources

PubMed2006

Developmental changes in oculomotor control and working-memory efficiency.

In the present study, we examined the developmental changes in the efficiency of saccadic inhibitory control. More specifically, the contribution of age-related changes in working-memory engagement was investigated. We manipulated the efficiency of inhibitory oculomotor control in antisaccade tasks by using fixation-offset conditions, which are supposed to affect inhibitory demands, and by adding increasing working-memory loads to the antisaccade task. In general, in comparison to antisaccade performance of adults, the antisaccade performance of 8-year-old and 12-year-old children was characterized by an increase in direction errors, and/or longer saccadic onset latencies on correct antisaccades. However, this pattern was not altered by the fixation-offset manipulations. In contrast, increased working-memory demands deteriorated 8-year-olds' antisaccade performance unequally as compared to older children and young adults. These findings suggest that - at least in young children - the available functional working-memory capacity is engaged in oculomotor inhibition.

Adolescent↗

PubMed2004

Age-related changes in antisaccade task performance: inhibitory control or working-memory engagement?

In antisaccade tasks, subjects are required to generate a saccade in the direction opposite to the location of a sudden-onset target stimulus. Compared to young adults, older adults tend to make more reflex-like eye movements towards the target, and/or show longer saccadic onset latencies on correct direct antisaccades. To better understand the nature of these effects of aging on antisaccade performance, we examined the role of age-related deficiencies in inhibitory control vis-a-vis age changes in the engagement of working memory. Inhibitory demands were manipulated using fixation-offset conditions, while working-memory demands were manipulated by varying memory-updating requirements. The results indicate that inhibitory oculomotor functions remain largely intact with advancing age; older adults' performance breaks down only when their limited working-memory capacity is taxed by increasing updating demands.

Adolescent↗

PubMedDate not supplied

Development of the acquisition and control of action-effect associations.

Voluntary action is anticipatory and, hence, must depend on associations between actions and their perceivable effects. We studied the acquisition of action-effect associations in 4-5-vs. 7-year-old children. Children carried out key-pressing actions that were arranged to produce particular auditory effects. In a subsequent test phase, children were to press keys in response to the previous effect sounds, with the sound-key mapping being either consistent or inconsistent with previous key-sound practice. As the processes underlying voluntary action controls are known to significantly improve between 4 and 7 years of age, it was expected that younger children were more prone to automatic effects of acquired sound-key associations. This hypothesis was confirmed, but reaction times and accuracy measures showed different and dissociable patterns. Four-year-olds but not 7-year-olds were more likely to commit an error--i.e., to perform a sound-compatible rather than the correct action--if the sound-key mapping was inconsistent with previous practice. This effect strongly depended on previous practice, suggesting that it reflects long-term learning. In contrast, reaction time effects of mapping consistency did not depend on previous experience but only on the consistency between stimulus and action effect in the present task. Taken altogether, the results suggest that children acquire response-effect associations automatically and that younger children are more likely to suffer from frequent goal neglect; i.e., they tend to forget the current action goal, so that their behavior is dominated by automatic, stimulus-triggered response tendencies.

Age Factors↗