Mulckhuyse Manon, Dalmaijer Edwin S
Donders Institute for Brain, Cognition and Behavior, Affective Neuroscience, Radboud University, Kapittelweg 29, Nijmegen, The Netherlands.
Department of Experimental Psychology, University of Oxford, Oxford, UK.
Cogn Affect Behav Neurosci. 2016 Apr;16(2):315-24. doi: 10.3758/s13415-015-0391-2.
Threatening stimuli are known to influence attentional and visual processes in order to prioritize selection. For example, previous research showed faster detection of threatening relative to nonthreatening stimuli. This has led to the proposal that threatening stimuli are prioritized automatically via a rapid subcortical route. However, in most studies, the threatening stimulus is always to some extent task relevant. Therefore, it is still unclear if threatening stimuli are automatically prioritized by the visual system. We used the additional singleton paradigm with task-irrelevant fear-conditioned distractors (CS+ and CS-) and indexed the time course of eye movement behavior. The results demonstrate automatic prioritization of threat. First, mean latency of saccades directed to the neutral target was increased in the presence of a threatening (CS+) relative to a nonthreatening distractor (CS-), indicating exogenous attentional capture and delayed disengagement of covert attention. Second, more error saccades were directed to the threatening than to the nonthreatening distractor, indicating a modulation of automatically driven saccades. Nevertheless, cumulative distributions of the saccade latencies showed no modulation of threat for the fastest goal-driven saccades, and threat did not affect the latency of the error saccades to the distractors. Together these results suggest that threatening stimuli are automatically prioritized in attentional and visual selection but not via faster processing. Rather, we suggest that prioritization results from an enhanced representation of the threatening stimulus in the oculomotor system, which drives attentional and visual selection. The current findings are interpreted in terms of a neurobiological model of saccade programming.
已知威胁性刺激会影响注意力和视觉过程,以便进行优先选择。例如,先前的研究表明,相对于非威胁性刺激,对威胁性刺激的检测更快。这导致了一种观点,即威胁性刺激通过快速的皮层下途径自动被优先处理。然而,在大多数研究中,威胁性刺激在某种程度上总是与任务相关的。因此,尚不清楚威胁性刺激是否由视觉系统自动优先处理。我们使用了带有与任务无关的恐惧条件分心物(CS+和CS-)的额外单例范式,并对眼动行为的时间进程进行了索引。结果表明威胁会自动被优先处理。首先,相对于非威胁性分心物(CS-),在存在威胁性(CS+)分心物的情况下,指向中性目标的扫视平均潜伏期增加,这表明外源性注意力捕获以及隐蔽注意力的脱离延迟。其次,指向威胁性分心物的错误扫视比指向非威胁性分心物的更多,这表明自动驱动的扫视受到了调制。然而,扫视潜伏期的累积分布显示,对于最快的目标驱动扫视,威胁没有调制作用,并且威胁也不影响对分心物的错误扫视潜伏期。这些结果共同表明,威胁性刺激在注意力和视觉选择中会自动被优先处理,但不是通过更快的处理方式。相反,我们认为优先处理是由于眼动系统中威胁性刺激表征的增强,这驱动了注意力和视觉选择。当前的研究结果是根据扫视编程的神经生物学模型来解释的。