The Relationships Between Cortical Activity while Observing Images Featuring Different Degrees of Ambiguity and Ambiguity Tolerance.

We performed a fMRI study during which 18 healthy subjects passively viewed abstract images and tried to name them. The images were geometric primitives, impossible images (Penrose images), and ambiguous images (Rorschach inkblots). Activation and deactivation areas were revealed for each task. The results of psychological assessment of ambiguity tolerance according to MSTAT-I inventory were used as regressors. Deactivation of the precuneus (Brodmann area 7) and neighboring structures (especially when observing geometric primitives and inventing names for them) and in the fronto-temporal areas was associated with high ambiguity tolerance. Similar links were observed for both activation and deactivation (depending on the certain contrast) of the occipito-cerebellar area.

On Methods for the Analysis of Indefinite Stimuli Perception Characteristics: an fMRT Study of Gender-Specific Differences.

Comparative identification of cerebral regions activated in men and women during perception of indefinite images was carried out by fMRT and psychological testing. Nine men and nine women aged 20-26 years took part in the study. The volunteers examined simple geometric figures, slightly structurized images (tables from Rorschach's test), and images of impossible figures. Activation in the cerebellum and visual cortex (bilateral) was more pronounced in women in response to all types of images and less so in the right G. temporalis medius. The right frontal regions (G. precentralis, G. frontalis superior, G. frontalis medius) were also stronger activated in women in response to indefinite stimuli.