Tsushima Yoshiaki, Sasaki Yuka, Watanabe Takeo
Department of Psychology, Boston University, 64 Cummington Street, Boston, MA 02215, USA.
Science. 2006 Dec 15;314(5806):1786-8. doi: 10.1126/science.1133197.
Considerable evidence indicates that a stimulus that is subthreshold, and thus consciously invisible, influences brain activity and behavioral performance. However, it is not clear how subthreshold stimuli are processed in the brain. We found that a task-irrelevant subthreshold coherent motion led to a stronger disturbance in task performance than did suprathreshold motion. With the subthreshold motion, activity in the visual cortex measured by functional magnetic resonance imaging was higher, but activity in the lateral prefrontal cortex was lower, than with suprathreshold motion. These results suggest that subthreshold irrelevant signals are not subject to effective inhibitory control.
大量证据表明，一个阈下刺激，因此是有意识不可见的，会影响大脑活动和行为表现。然而，尚不清楚阈下刺激在大脑中是如何被处理的。我们发现，一个与任务无关的阈下连贯运动比阈上运动对任务表现产生更强的干扰。与阈上运动相比，在阈下运动时，通过功能磁共振成像测量的视觉皮层活动更高，但外侧前额叶皮层的活动更低。这些结果表明，阈下无关信号不受有效的抑制控制。
