Activation of the limbic system under 30% oxygen during a visuospatial task: An fMRI study

The purpose of this study was to observe activation of the limbic system during the performance of visuospatial tasks under 21% O2 or 30% O2. Eight right-handed male college students were selected as subjects for this study. A visuospatial task was presented while brain images were scanned by a 3 T fMRI system. The experiment consisted of the following two runs: a visuospatial task under normal air (21% O2) and a visuospatial task under hyperoxia (30% O2). The accuracy rate on the visuospatial task was enhanced during 30% O2 compared to 21% O2. The neural activation areas of the limbic system were similar in the cingulate gyrus, thalamus, limbic lobe and parahippocampal gyrus. Increased neural activation was observed in the cingulate gyrus and thalamus under 30% O2 compared to 21% O2. Under 30% O2, the improvement in visuospatial task performance was related to an increase in neural activation of subcortical structures, such as the thalamus and cingulate gyrus, as well as the cerebral cortex.