[The hemispheric functional specialization of visual perception].

In this review the modern concepts on psychophysical mechanisms of hemispheric functional specialization of human visual perception are considered. The problems are discussed on three basic historical aspects: interhemispheric relations in patients with localized cerebral lesions, interhemispheric differences in the "Bisected Brain", and the functional asymmetry in the intact brain. The neuropsychological data on recognition of geometric figures, faces and objects, and also electrophysiological results on the event-related brain potentials are deliberated.

Disorders of visuo-spatial attention in patients with unilateral brain damage.

Visuo-spatial inattention (VSI) was examined in 390 patients with ischemic insult to the right or left cerebral hemispheres. VSI was revealed in 44 out of 80 patients with right parietal lobe damage and in 30 out of 70 subjects with right occipital lobe injury. Only one patient out of 100 with left hemisphere injury has shown the signs of VSI.

[Various functional features of the contra- and ipsilateral endings of callosal neurons in the cerebral cortex].

Paired stimulation of callosal neurons in the lateral gyrus causes inhibition of the second EP in every part of the cortex with callosal connections. Paired stimulation of callosal neurons in the suprasylvian gyrus causes facilitation of the second EP in the contra- as well as ipsilateral cortex. The possible role of recurrent collaterals in brain functioning is discussed.

[Activity of callosal neurons of the visual cortex in the cat].

Activity of 28 identified neurones of the visual cortex was recorded in cats immobilized by d-tubocurarine. Stimulation of the callosal body with a single stimulus or high-frequency train elicited a short-latency antidromic reaction of neurones in the visual cortex whose axons constitute the main part of the large cerebral commissure. Some commissural neurones responded to a single callosal stimulation by two action potentials the first one being antidromic, the second one being of long-latency postsynaptic origin.

[Inhibition of the imprinting process by treatment with serum from schizophrenic patients].

The influence of blood serum from schizophrenia patients on imprinting was studied in 62 leghorns. Intraperitoneal injection to the chickens in the sensitive period of 1.5-2 ml of schizophrenia patients' blood serum before imprinting results in inhibition of the imprinting process over 1.

[Split brain and the problem of interhemispheric relations].

For the last 15-20 years the study of interhemispheric relations made a big progress. This progress was facilitated by use of new methods in combination with midsagittal sections of comissural connections at different levels. An assumption is made that interhemispheric exchange of sensory information is of certain importance for the short-term memory and for compensatory mechanisms of the brain.

[Mixed and antidromal cortical responses evoked by electrical stimulation of the splenial portion of the corpus callosum].

In anesthetized cats, antidromic and orthodromic components were shown to be represented unequally in the mixed responses to the splenium stimulation recorded from various areas of the cortex. Orthodromic component makes about 50 per cent of the mixed response amplitude in the area 17, while in the area 18 and in middle part of the suprasylvian gyrus it makes about 70 per cent. In the regions beyond focus the mixed responses disappeared because of falling out of the orthodromic impulses.