LABORATORY OF PSYCHOPHYSIOLOGY

| Head: Anna GRABOWSKA Ph.D. e-mail: a.grabowska@nencki.gov.pl Staff: Dorota BEDNAREK Ph.D., Małgorzata GUT (Ph.D. student), Anna NOWICKA Ph.D., Krystyna RYMARCZYK MSc., Iwona SZATKOWSKA Ph.D. Renata ZALEWSKA Cooperating graduate students: Artur MARCHEWKA, Cezary BIELE

The investigation focuses on the neurobiological mechanisms and principles underlying cognitive and emotional brain functions. Our approach is to combine various methodologies (behavioural, psychophysical, electrophysiological, clinical) to provide a wide perspective for understanding the mechanisms of the mind. Studying both normal subjects and patients of neurological and neurosurgical clinics enable us to identify specific brain regions involved in behaviour.

Recent findings

In the research that specifically focused on the role of the medial temporal lobe structures and dorsolateral and ventro-medial prefrontal cortices in the mediation of various memory function a series of investigations were performed on patients with focal brain lesions localised in the mentioned areas. Both temporal and ventro-medial prefrontal cortices were found to be involved in retention of image-based representation of objects and to show right-hemispheric specialisation in that function. Moreover, a dissociation between object- and object-location-memory after lesion to the ventro-medial region was demonstrated. These findings support the current view that discrete regions of the brain subserve different aspects of memory.

In a study on brain organisation of prosodic function (comprehension of emotional cues in voice) patients with damage to frontal, temporo-parietal or subcortical parts of the right hemisphere (RH) and normal adult controls made judgements of emotions expressed by intonation in natural and pseudo-sentences. The results showed that: 1/ women outperformed men in prosodic abilities; 2/ RH damaged subjects had decreased comprehension of emotional prosody, 3/ frontal lesions led to more severe impairment in women than in men; 4/ subcortical lesions had more disturbing effect in men. This study revealed sex differences in brain organization of prosodic functions. The results provide further evidence for the notions that women are more sensitive to emotional signals than are men.

Sex differences in the functional brain organisation were also found in a study of the effects of brain lesions on the susceptibility to visual illusions. In females, perceptual deficits were observed after both left and right hemisphere lesions whereas in males such deficits were present only after damage to the right hemisphere. This finding is in agreement with a hypothesis that male brains are more lateralised than are female brains. Moreover, in line with anatomical observations of other authors, we have found that interhemispheric transmission time is shorter and shows lesser directional differentiation in women than in man. The studies on transsexual subjects provided further evidence that prenatal action of sex hormones may change both the brain lateralisation and gender identity.

Several studies were performed to search for the mechanisms and principles underlying the functional differences between the two hemispheres. The studies performed both on patients with brain lesions and normal subjects showed that a variety of functions (e. g. perception of faces, stereoscopic depth, spatial frequency, visual illusion, tilt effects and other visual-spatial patterns) is mediated primarily by the right hemisphere. Moreover, they provided evidence that hemispheric differences may emerge at relatively early stage of processing. This changed the widely accepted view, which attributed the functional brain asymmetry to processes that occur at a higher cognitive level. Our data pointed to the importance of callosal communication. The accumulated data allowed to formulate a new dynamic model in which hemispheric specialisation is conceptualised as a complex system of different asymmetrically represented modules tied by callosal pathways that serve to integrate the operations carried out by those modules.

The research concerned also a controversial issue of the relationship between handedness and cerebral organisation. We have found that this relationship is modified by the sex factor.

Selected publications:

1. Grabowska A., Nowicka A., Szymanska O.; Sex related effects of unilateral brain lesions on the perception of the Mueller-Lyer illusion. Cortex 35: 231-241 (1999)

2. Nowicka A., Ringo J.L.; Eye position-sensitive units in hippocampal formation and inferotemporal cortex of the Macaque monkey. Eur. J.Neurosci. 12: 751-759 (2000)

3. Szatkowska I., Grabowska A., Szymanska O.; Phonological and semantic fluencies are mediated by different regions of the prefrontal cortex. Acta Neurobiol. Exp. 60: 503-508 (2000)

4. Ulatowska H., Sadowska M., Kadzielawa D., Kordys J., Rymarczyk K.; Linguistic and cognitive aspects of proverb processing in aphasia. Aphasiology 14: 227-250 (2000)

5. Szatkowska I., Grabowska A., Szymanska O.; Evidence for the involvement of the ventro-medial prefrontal cortex in a short-term storage of visual images. NeuroReport 12: 1187-1190 (2001)

6. Grabowska A., Nowicka A., Szymanska O., Szatkowska I.; Subjective contour illusion: sex- related effect of unilateral brain damage. NeuroReport 12: 2289-2292 (2001)

7. Nowicka A., Fersten E.; Sex-related differences in interhemispheric transmission time in the human brain. NeuroReport 12: 4171-4175 (2001)

8. Pfeffer A., Styczynska M., Czyzewski K., Luczywek E., Golebiowski M., Nowicka A., Bracikowska M.; Apolipoprotein E genotype and the rate of decline in Alzheimer’s disease: the gender effect. Alzheimer’s Reports 4: 31-35 (2001)

9. Kowalczyk M., Nowicka A., Antkowiak B., Kocik J., Antkowiak O.; Psychosomatic reactions to a stressful environment and an attempt at pharmacological modification. Med. Sci Monit 7: 953-961 (2001)

10. Luczywek E., Nowicka A., Pfeffer A., Czyzewski K., Styczynska M., Lalowski M., Bracikowska M.; Cognitive deficits and polymorphism of apolipoprotein E in Alzheimer’s disease. Dement Geriatr Cogn Disord 13: 171-177 (2002)

11. Herman-Jeglinska A., Grabowska A., Dulko S.; Masculinity, femininity and transsexualism. Arch Sex Behav 31: 1-8 (2002)

12. Bednarek D., Grabowska A.; Luminance and chromatic contrast sensitivity in dyslexia: The magnocellular deficit hypothesis revisited. NeuroReport 13 (18): 2521-2525 (2002)

13. Szatkowska I, Grabowska A, Szymańska O. Memory for object and object location after lesion to ventro-medial prefrontal cortex in humans. Acta Neurobiol. Exp., 2003, 63: 31-38