Biomedical subjects

E M van Loon

Publications and source records attributed to E M van Loon.

3 recordsLinked to original sources

PubMed1998

Effects of age on performance in a finger-precuing task.

This study investigated age-related precuing effects in the finger-precuing task (J. Miller, 1982). In this task, a spatial precue provides partial advance information about which fingers to use for responding. Results indicated a substantial age-related deficit in preparing 2 fingers on 2 hands, but not on 1 hand. This disparate set of findings does not provide strong support for A. A. Hartley's (1993) hypothesis that anterior brain attention systems responsible for selection-for-action are compromised with advancing age. Finally, the authors report that advancing age increasingly slows reaction time more to the inner than to the outer stimulus-response positions. A possible mechanism of this age-related bowed stimulus-response position effect is discussed.

Adult↗

PubMed1998

Temporal and spatial adaptations during the acquisition of a reversal movement.

Adjustments of the biphasic movement in a coincidence anticipation task were studied using an erroneous knowledge of results (KR) paradigm. Forty participants received either no KR, correct KR, erroneous (+100 ms) KR, or 100 trials of correct KR followed by 50 trials of erroneous KR. Kinematic analyses revealed that for this 100-50 KR group the extension part of the movement was temporally adjusted under the influence of erroneous KR. Although accompanied by a decrease in movement amplitude, this did not account for the temporal shift in movement outcome, because all groups showed a reduction in amplitude. It is argued that changing external time constraints mainly results in temporal adaptations. However, spatial adaptations do play a role in kinematic changes during acquisition.

Adaptation, Physiological↗

PubMed1995

Spatial localization: tests of a two-process model.

The present study examined the recently proposed two-process model of localization performance in which a shift of attention, providing coarse location information, is followed by a saccadic eye movement, providing fine location information. In experiment 1 the nature of the localization response was manipulated. In contrast to the indirect response mode used in the study by Adam et al., i.e., manipulating the "arrow" keys to move the cursor to the target location, experiment 1 required subjects to point to the target location. The high degree of similarity between the pattern of results obtained with the pointing and cursor response indicated that performance in the localization paradigm was not differentially affected by the nature of the required response. In experiment 2 the characteristics of the backward masking stimulus was manipulated by employing three masking conditions: (1) a long-duration mask; (2) a short-duration mask (100 ms); and (3) a no-mask condition. Results showed that the long-duration mask caused interference at short and facilitation at long intervals between onset of target and mask; the short-duration mask caused interference only at short intervals. Overall the findings were consistent with the two-process model of localization performance.

Adult↗