Automatic versus contingent mechanisms of sensory-driven neural biasing and reflexive attention
Automatic versus contingent mechanisms of sensory-driven neural biasing and reflexive attention
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DOI：
10.1162/0898929055002445
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发表时间：
2005-08-01
影响因子：
3.2
通讯作者：
Ries, AJ
中科院分区：
文献类型：
--
作者：
Hopfinger, JB;Ries, AJ
最近的研究已经产生了关于反射性注意机制是否是在一个纯粹的自动刺激驱动的方式触发的争论。行为学研究发现，一个非预测性的“线索”刺激会加速对同一位置的后续目标的手动反应，但前提是该线索与主动保持的用于目标检测的顶部小丑设置一致。当一个线索与顶级小丑的设置不一致时，反应时间不受影响，这被认为是反射性注意机制从未参与过这些条件的证据。但是，手动响应时间可能会掩盖对处理早期阶段的影响。在这里，我们使用事件相关电位来研究自下而上的感觉驱动机制和自上而下的控制设置在大脑处理的多个阶段的相互作用。我们的研究结果分离的感觉驱动的机制，自动偏见的早期阶段的视觉处理，后来的机制，是偶然的自上而下的控制。纹外视皮层中tat-get处理的早期增强（即，P1分量）由独特的明亮提示的出现触发，而不管自上而下的设置。然而，当线索与自上而下的设置一致时，视觉处理的增强延长。后颞顶叶区域的后期处理（即，同侧无效负性）在线索由单个新对象的突然出现组成时自动触发。然而，在提示显示期间出现多个对象的情况下，此处理阶段取决于自上而下的控制。这些发现提供了证据，表明视觉信息处理在大脑的多个层面上存在偏见，并且结果将自动触发的感觉驱动机制与那些取决于顶级小丑控制设置的机制区分开来。
Recent studies have generated debate regarding whether reflexive attention mechanisms are triggered in a purely automatic stimulus-driven manner. Behavioral studies have found that a nonpredictive "cue" stimulus will speed manual responses to subsequent targets at the same location, but only if that cue is congruent with actively maintained top-clown settings for target detection. When a cue is incongruent with top-clown settings, response times are unaffected, and this has been taken as evidence that reflexive attention mechanisms were never engaged in those conditions. However, manual response times may mask effects on earlier stages of processing. Here, we used event-related potentials to investigate the interaction of bottom-up sensory-driven mechanisms and top-down control settings at multiple stages of processing in the brain. Our results dissociate sensory-driven mechanisms that automatically bias early stages of visual processing from later mechanisms that are contingent on top-down control. An early enhancement of tat-get processing in the extrastriate visual cortex (i.e., the P1 component) was triggered by the appearance of a unique bright cue, regardless of top-down settings. The enhancement of visual processing was prolonged, however, when the cue was congruent with top-down settings. Later processing in posterior temporal-parietal regions (i.e., the ipsilateral invalid negativity) was triggered automatically when the cue consisted of the abrupt appearance of a single new object. However, in cases where more than a single object appeared during the Cue display, this stage of processing was contingent on top-down control. These findings provide evidence that visual information processing is biased at multiple levels in the brain, and the results distinguish automatically triggered sensory-driven mechanisms from those that are contingent on top-clown control settings.