Takahashi Masaharu, Ikegami Masanaga
Department of Psychology, Asahikawa Medical College, Asahikawa, Japan.
Neuropsychobiology. 2008;58(2):55-64. doi: 10.1159/000159773. Epub 2008 Oct 3.
The aim was to measure the prefrontal cortical activity involved in shifting spatial attention to visual stimuli in the left or right visual field using near-infrared spectroscopy.
Eleven participants performed a simple vigilance task, an endogenous attention task and an exogenous attention task. In the endogenous task, the left or the right side of the center diamond brightened, indicating the side for subsequent target appearance (controlled shift of attention). In the exogenous task, the peripheral squares brightened, indicating the appearance of target in those squares (reflexive shift of attention).
Stimuli at validly cued locations were responded to faster than stimuli at invalidly cued locations. Increases in oxyhemoglobin (oxy-Hb) were observed in the right prefrontal cortex throughout the 3 tasks, and in the left prefrontal cortex during the vigilance and the exogenous tasks. In the exogenous task, marked decreases in oxy-Hb were observed in the bilateral ventrolateral prefrontal cortex.
These results suggest that the left and the right prefrontal cortices mediate distinct cognitive processes during the performance of visuospatial attentional tasks.
本研究旨在利用近红外光谱技术测量在将空间注意力转移至左视野或右视野视觉刺激时前额叶皮层的活动。
11名参与者完成了一项简单的警觉任务、一项内源性注意力任务和一项外源性注意力任务。在内源性任务中，中央菱形的左侧或右侧变亮，指示随后目标出现的方向（注意力的可控转移）。在外源性任务中，外周方块变亮，指示目标在那些方块中出现（注意力的反射性转移）。
有效提示位置的刺激比无效提示位置的刺激反应更快。在整个三项任务中，右前额叶皮层的氧合血红蛋白（oxy-Hb）增加，在警觉任务和外源性任务期间左前额叶皮层的氧合血红蛋白增加。在外源性任务中，双侧腹外侧前额叶皮层的氧合血红蛋白显著减少。
这些结果表明，在视觉空间注意力任务执行过程中，左、右前额叶皮层介导不同的认知过程。
