Experimentelle Untersuchungen und Simulation zum Körperschema des Menschen

Blindfolded subjects are stimulated mechanically at one of eight possible stimulation sites at the legs and then asked to move one of both hands as fast as possible to the stimulated site. In nine different postures of legs and hands the frequency is registered by which the right or the left hand is used. Furthermore, reaction times (RT) are measured. The behavioural results indicate that two criteria are involved in hand selection. The first is a spatial parameter which is represented by trajectory length of each hand. The hand with the shorter path is preferred. The second is a criterion based on morphology: There is a preference for the hand ipsilateral to the stimulus site. These results support the hypothesis that the representation of body position is based on two systems. One uses proprioceptive information, the other uses a morphological frame of reference. In chap. 5 and 6 the information processing of tactile stimuli is further investigated. In different experiments tactile stimuli are given at the fingers or the legs, while the subjects take different hand and leg postures. The subjects are asked to release a button to measure reaction times (RT). To a large degree, results support the classical idea of S-R compatibility. However, there are also some exceptions. Taken together, the results suggest that RT depends on at least three independent criteria which describe the properties of the experimental situation. One is whether the hands are held in a parallel or a crossed position. The second one is whether the stimulus occurs at the morphological same (ipsilateral) or the other (contralateral) side compared to the site of the required reaction. Third, as a quantitative basis for S-R compatibility, which uses the spatial relation between stimulus site and response site, some measure of the spatial distance between stimulus and response site is proposed. In another chapter the information processing of tactile stimuli is investigated concerning the question of whether the stimulation site is spatially represented. Variation of transversal distance between two stimuli reveals that reaction time (RT) is prolonged when two stimulus sites are placed close to each other. A second experiment in which the position of the stimulus sites is varied on a circle such that the distance is kept constant shows that the RT does not depend merely on the distance. The results show that RT is not only influenced by the spatial relation between two stimulus sites, but also by a morphological attribute, i.e., whether the stimulus is applied at the right or the left side of the body.

Level thesis:degree_level

thesis.doctoral

Grantor dc:publisher

Universität Bielefeld

Year

2000

Author dc:creator

• Kim, Dong-Hak

Repository record source_url

https://pub.uni-bielefeld.de/record/2306465

OAI identifier oai:identifier

oai:pub.uni-bielefeld.de:2306465