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Sex differences in brain organisation
Our studies
provided also new information on sex differences in the functional brain
organisation. They showed that lesions to the left and right hemispheres in the
two sexes result in different perceptual deficits. This finding is in agreement
with a hypothesis that male brains are more lateralised than 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.
The aim of our
recent study was to test whether the organization of implicit memory processes
depend on subjects’ sex. We used functional magnetic resonance imaging (fMRI)
to compare the patterns of brain activity in men and women performing the
weather prediction probabilistic classification task which is a tool for
assessing implicit learning. Men and women showed similar levels of behavioral
performance on this task. However, between-sex group analysis of the BOLD
response demonstrated greater activity in men than in women in dorsolateral
prefrontal (BA 9, 46), parietal (BA 7, 40), and occipital (BA 18, 19) cortices,
and greater activity in women than in men in insular (BA 13), temporal (BA 21,
22) and ventrolateral prefrontal (BA 44) cortices. Differences between men and
women in the patterns of brain activity might reflect distinct strategies used
during performance of the weather prediction probabilistic classification task.
Pilacinski A.,
Wolak T., Grabowska A., Królicki L., Szatkowska I. Sex differences in implicit memory: An
fMRI study using the Weather Prediction Probabilistic Classification Task. (poster
presentation, 9th International Congress of The Polish Neuroscience Society,
2009
Rymarczyk
K., Grabowska A. Sex
differences in brain control of prosody. Neuropsychologia,
45(5): 921-930, 2007
Herman-Jeglińska
A, Grabowska A, Dulko S. Masculinity,
femininity and transsexualism. Archives of Sexual Behavior,
31(6): 527-534, 2002
Grabowska A,
Nowicka A, Szymańska O, Szatkowska
I.
Subjective contour
illusion: sex-related effect of unilateral brain lesion. Neuroreport,
12: 2289-2292, 2001
Nowicka A,
Fersten E. Sex-related differences
in interhemispheric transmission time in the human brain. NeuroReport,
12: 4171-4175, 2001
Grabowska A,
Nowicka A, Szymańska O. Sex
related effect of unilateral brain lesions on the perception of the
Mueller-Lyer illusion. Cortex , 35: 231-241, 1999
Herman-Jeglinska
A, Dulko S, Grabowska A. Transsexuality
and adextrality: do they share a common origin? In: L Ellis and
L. Ebertz (Eds.) Sexual Orientation: Toward Biological Understanding. Praeger: Westport,
pp: 164 – 180, 1997
Hines T.M,
Herman-Jeglińska A, Bednarek D, Grabowska A. Sex differences in the processing of odd and even
numbers. Acta Neurobiol. Exp., 56: 263-266, 1996
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