It has been proved that the saccadic suppression is a phenomenon closely related to the presence of contours and structures in the visual field. Experiments were performed to clarify whether the structured background influences the pattern of attention distribution (making the stimulus detection more difficult) or whether the elevation of visual threshold is due to the "masking' effect of the moving background image over the retina. Two types of backgrounds were used therefore: those with symbolic meaning in the processing of which "psychological' mechanisms are presumably involved like picture reproductions of famous painters and photographs of nudes, and those lacking semantic significance like computer figures composed of randomly distributed black and white squares with different grain expressed as the entropy of the pattern. The results show that saccadic suppression is primarily a consequence of peripheral mechanisms, probably of lateral inhibition in the visual field occurring in the presence of moving edges over the retina. Psychological factors have to be excluded as being fundamental for saccadic suppression.

Eye Movements↗

PubMed1975

Evoked responses induced by random polygonal pattern presentation.

An experiment is described which was designated to test the assumption that visual EEG evoked response waveshapes in human beings may be influenced by the presentation of random shapes differing in level of their similarity and in angular position. A clear-cut difference between the blank flash and the patterns which might be determined by the presence of contours was observed. However, neither differences in EEG evoked responses referred to the shape nor to the angular position of the polygons were found.

Electroencephalography↗

PubMed1975

[Psychophysiology of paradox sleep and hypotheses on functions of dreams (author's transl)].

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Animals↗

PubMed1975

An attempt to influence by drugs recovery sleep after sleep deprivation.

Rats were deprived of sleep by placing them for 36 hours in a slowly moving drum. After this procedure, during recovery sleep, the latency of onset of the first rhombencephalic - paradoxical sleep period decreased and the proportion of telencephalic/rhombencephalic - slow wave sleep reversed (during the first hour of recovery sleep). Repeated administration during the deprivation period of physostigmine (0,5 mg/kg i. p. in 30 min intervals 20-30 times) inducing in waking animals in EEG pattern close to that of rhombencephalic sleep, or atropine (1 mg/kg i. p. in 60 min intervals 10-15 times) evoking an activity resembling telencephalic sleep, did not change the above measures of recovery sleep. Pharmacologically induced sleep-like patterns did not substitute for the sleep the rats were deprived off.

Animals↗

PubMed1974