| Popis: |
We studied the influence of weightlessness on bilateral symmetry detection during prolonged space flight. Supposing that weightlessness may affect visual information processing by the right and left hemispheres in different ways, we studied this phenomenon with regard for the part of the visual field where to a stimulus was presented (the sight fixation center or the left/right half of this field). We used two types of stimuli, i.e., closed figures (polygons) and distributed figures formed by dots. There was a distinct difference between the central and noncentral presentation of stimuli under terrestrial conditions. When a stimulus was presented noncentrally (on the left or right), a manifest dominance of the horizontal axis was observed. However, there was no substantial difference while stimulating the left and right parts of the visual field. This contradicts the hypothesis on hemispheric specialization of the brain in symmetry detection. When stimuli were presented eccentrically, weightlessness did not notably influence information processing. When they were presented centrally, the predominance of the vertical axis in closed figures tended to weaken under the impact of weightlessness. However, this predominance strengthened when multicomponent figures were presented in space. The different influences of weightlessness on perceiving symmetry of stimuli of different types shows that it may be detected at various levels with different degrees of using nonvisual sensory information. |
Full text from SpringerLink