ИСТИНА

Introduction Interhemispheric interaction is impaired not only after commissure injury, but also in hemispheric brain damage. Neuropsychological deficit in unilateral hemispheric damage cannot be explained solely by dysfunction of the injured hemisphere.Goal: To explore symptoms of interhemispheric interaction impairments in unilateral brain injury. Methods Study included 55 healthy adults, 32 patients with left-side brain injury (18 with stroke), 30 patients with right-side brain injury (13 with stroke) and 17 with various corpus callosum pathology. Participants underwent perceptive priming, male and female photographs of a human with average appearance were used as targets. The same photographs were used as primes: prime was either congruent or non-congruent to target. Targets and primes were presented to different visual hemifields. Results In conditions 4, 6, 7, 9 primes are interpreted as non-congruent in all groups, but in corpus callosum injury there are no other answers. Thus, these answers are symptoms of interhemispheric disconnection due to corpus callosum injury. Answer “prime is not seen” was specific to left hemisphere injury, and “prime in interpreted as congruent” – to right hemisphere injury. These answers are symptoms of hemispheric injury. In conditions 8, 10, 4, 6 (see table) primes are interpreted as congruent when they are presented to different visual hemifields and targets are presented to right hemifield. Right hemisphere injury leads to impairment in qualitative prime analysis, which indicates predominant dysfunction of posterior regions. Priming-effects shows changes in type of reaction to prime presentation in comparison to absence of prime. Answers “prime not seen” are observed with primes in right hemifiels and targets – to different hemifields. Left brain injury leads to difficulties in production of new way of reaсting, which indicates dysfunction of anterior regions. Presentation of primes does not lead to changes in response time in comparison with situations of prime absence. Conclusions Hemisphere injury leads to interhemispheric disconnection. In corpus callosum injury symptoms, typical for left anterior and right posterior brain injury, are present.