The brain activity of 13 right-handed students (6 men and 7 women) was determined using high resolution ^99mTc-HMPAO brain SPECT images during visuospatial tasks. The results showed that there was no significant gender-specific difference in solving the visuospatial tasks and that no meaningful statistical difference in brain activity between the two sexes could be found. When the sample was split into groups of good and poor performers, the results showed that there was a relatively symmetrical brain activity both frontal and parietal in subjects with poor test results. The results for those who performed the tests well, on the other hand, showed increased left frontal and right parietal brain activity. These results would suggest an asymmetric type of processing for better visuospatial brain performance independent of gender.

Summary, The relationship between anatomical sizes of different regions of the corpus callosum and functional visuospatial skills was investigated in 24 fight-handed students (12 males and 12 females) using midsagittal magnetic resonance imaging (MRI). Men had significantly larger absolut ca[losal areas and in some cases wider callosal measurements than women but there were no sex differences in relative sizes of the corpus callosum compared to the total brain. The results showed a tendency toward male superiority in solving visuospatial tasks, some subtests even reached a high significance favoring males. Both sexes showed a strong negative correlation between the size of the corpus callosum and enhanced visuospatial skills. These findings indicate that the corpus callosum plays a minor role in interhemispheric communication of higher order cognitive processing.

No abstract

The putative generators of the event-related P3 component are still a matter of debate. There is reasonable evidence that the mesial temporal lobe structures are crucial in the generation of event-related potentials. Transient global amnesia (TGA) is characterized by anterograde and retrograde amnesia without neurological deficits in which a temporal hypoperfusion is the most likely pathomechanism. The aim of this study is to evaluate a possible delay in the P3 latency in a cohort of patients with TGA (n = 18). We used classic oddball paradigms with visual and auditory stimuli. The P3 latencies were compared to 18 age-matched patients with transient ischaemic attacks (TIAs) in the carotid artery territory and 23 age-matched controls. The mean age of the patients was 60.1 years (SD 14.1), in the TIA group 64.7 (SD 12.1) and 57.7 (SD 10.1) in the controls; the mean time interval between onset of TGA symptoms and performance of P3 investigations was 4.3 days (range 1-7 days); and the mean latencies measured at the vertex (Cz electrode) were 422.9 ms (SD 44.6) for the TGA patients, 436.4 ms (SD 62.1) for the TIA group, and 409.3 ms (SD 48.5) for the controls in the visual paradigm and 371.7 ms (SD 41.7), 399.7 ms (SD 51.2) and 385.3 ms (SD 46.5) in the auditory paradigm for the TGA, the TIA and the control groups. The P-values were not significant. These results suggest different neuronal networks in the generation of scalp P3 from those responsible for the disturbance of episodic memory in TGA.