A study on spatial memory span task by functional magnetic resonance imaging

Objective To study the activation of brain regions in normal volunteers during spatial memory span task by functional magnetic resonance imagine (fMRI) technique. Methods 10 right-handed normal volunteers participated in a test of spatial memory span, while the fMRI data were recorded. A control task was performed for the block-design. SPM 99 was used to analyze the data and get the activated brain regions. Results The bilateral Brodmann Area (BA) 6, right BA 9 and left BA 47 regions in the frontal lobe, the BA 7 and 40 regions in the parietal lobe, the BA 18 and 19 regions in the occipital lobe and the BA 30 region in the right parahippocampal gyrus were significantly activated during the spatial memory span task (P〈0.0001). The BA 37 region in the left temporal cortex adjacent to the occipital lobes, the bilateral BA 3 and left BA 2 regions in the postcentral gyrus, the BA 4 region in the precentral gyrus, the left substania nigra in the midbrain and the right cerebellum were also activated (P〈0.0001).The parietal lobe was the most activated region by the spatial memory span task followed by the frontal and occipital lobes. Moreover, the BA 9 region in the frontal lobe, the BA 18 and 19 regions in the occipital lobe, the parahippocampal gyrus and the cerebellum were activated with the right hemisphere predominance. When the threshold was set as P0.001, the BA 25 region in the right anterior cingulate gyrus, the BA 47 region in the right inferior frontal gyrus,the BA 9 region in the left frontal lobe, the BA 17, 18 and 19 regions in the left occipital lobe, the right claustrum nucleus and the left posterior nucleus of thalamus were also activated. Conclusions The main brain regions that were involved in the spatial memory span task might be the BA 9, 6, 7, 40, 19 regions, parahippocampal gyrus and cerebellum. They might play different roles in performing spatial memory span tasks. It is helpful to reveal the process of spatial information in the brain by fMRI technique.