Landman Rogier, Spekreijse Henk, Lamme Victor A F
Graduate School of Neurosciences, Amsterdam, The Netherlands.
J Cogn Neurosci. 2003 Aug 15;15(6):873-82. doi: 10.1162/089892903322370799.
Attentive processing is often described as a competition for resources among stimuli by mutual suppression. This is supported by findings that activity in extrastriate cortex is suppressed when several stimuli are presented simultaneously, compared to a single stimulus. In this study, we randomly varied the number of simultaneously presented figures (set size) in an attention-demanding change detection task, while we recorded multiunit activity in striate cortex (V1) in monkeys. After figure-background segregation, activity was suppressed as set size increased. This effect was stronger and started earlier among cells stimulated by the background than those stimulated by the figures themselves. As a consequence, contextual modulation, a correlate of figure-background segregation, increased with set size, approximately 100 msec after its initial generation. The results indicate that suppression of responses under increasing attentional demands differentially affects figure and background responses in area V1.
注意力加工通常被描述为刺激之间通过相互抑制对资源的竞争。这一观点得到了以下研究结果的支持：与单个刺激相比，当同时呈现多个刺激时，纹外皮层的活动会受到抑制。在本研究中，我们在一项需要注意力的变化检测任务中随机改变同时呈现的图形数量（集合大小），同时记录猴子纹状皮层（V1）中的多单位活动。在图形-背景分离之后，随着集合大小的增加，活动受到抑制。这种效应在由背景刺激的细胞中比在由图形本身刺激的细胞中更强且开始得更早。因此，作为图形-背景分离相关指标的上下文调制，在其最初产生后约100毫秒随着集合大小的增加而增加。结果表明，在注意力需求增加的情况下对反应的抑制会对V1区域的图形和背景反应产生不同的影响。
