Cerebral Asymmetry of fMRI-BOLD Responses to Visual Stimulation

摘要: Hemispheric asymmetry of a wide range functions is hallmark the human brain. The visual system has traditionally been thought as symmetrically distributed in brain, but growing body evidence challenged this view. Some highly specific tasks have shown to depend on hemispheric specialization. However, possible lateralization cerebral responses simple checkerboard stimulation not focus previous studies. To investigate this, we performed two sessions blood-oxygenation level dependent (BOLD) functional magnetic resonance imaging (fMRI) 54 healthy subjects during with black and white stimulus. While carefully excluding non-physiological causes left-to-right bias, compared activation left right hemispheres related grey matter volume, handedness, age, gender, ocular dominance, interocular difference acuity, well line-bisection performance. We found general towards hemisphere early cortical areas higher-level processing, involved visuospatial attention, especially top-down (i.e., goal-oriented) attentional processing. This was partly, completely, explained by an increased volume areas. Difference superior parietal lobule correlated subject suggesting shift increasing age. Our findings suggest right-hemispheric dominance these areas, which could lend support generally observed leftward bias hemifield advantage for some perception tasks.