Steady-state Signatures of Visual Perceptual Load, Multimodal Distractor Filtering, and Neural Competition
Steady-state Signatures of Visual Perceptual Load, Multimodal Distractor Filtering, and Neural Competition
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DOI：
10.1162/jocn.2010.21460
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发表时间：
2011-05-01
影响因子：
3.2
通讯作者：
Corballis, Paul M.
中科院分区：
文献类型：
--
作者：
Parks, Nathan A.;Hilimire, Matthew R.;Corballis, Paul M.
注意力的知觉负荷理论认为，当一项任务对知觉要求很高时，注意力选择发生在处理的早期，而当另一项任务对知觉要求很高时，注意力选择发生在处理的晚期。我们使用了一个频率标记的稳态诱发电位范式来研究知觉负荷引起的分心物过滤的模态特异性和任务和分心物刺激之间的神经竞争相互作用的性质。EEG数据被记录，而参与者监测流的刺激发生在快速串行视觉呈现（RSVP）的外观以前分配的目标。知觉负荷的操纵分配的目标，可识别的颜色单独（低负荷）或颜色和方向的结合（高负荷）。RSVP任务单独进行，并在任务无关的视觉和听觉干扰。RSVP刺激，视觉干扰和听觉干扰被“标记”，通过调制每个在一个独特的频率（分别为2.5，8.5，和40.0 Hz），这使得每个被单独分析在频域。我们报告三个重要的发现知觉负荷的神经机制。首先，我们复制了以前的研究结果内的模态干扰过滤，并证明了减少视觉干扰信号与高感知负荷。第二，听觉稳态干扰信号不受视觉感知负荷的操纵，这与感知负荷引起的干扰过滤是模态特异性的想法一致。第三，任务相关信号的分析表明，视觉干扰与任务刺激的代表性和增加知觉负荷的竞争似乎解决了这种竞争，有利于任务刺激。
The perceptual load theory of attention posits that attentional selection occurs early in processing when a task is perceptually demanding but occurs late in processing otherwise. We used a frequency-tagged steady-state evoked potential paradigm to investigate the modality specificity of perceptual load-induced distractor filtering and the nature of neural-competitive interactions between task and distractor stimuli. EEG data were recorded while participants monitored a stream of stimuli occurring in rapid serial visual presentation (RSVP) for the appearance of previously assigned targets. Perceptual load was manipulated by assigning targets that were identifiable by color alone (low load) or by the conjunction of color and orientation (high load). The RSVP task was performed alone and in the presence of task-irrelevant visual and auditory distractors. The RSVP stimuli, visual distractors, and auditory distractors were "tagged" by modulating each at a unique frequency (2.5, 8.5, and 40.0 Hz, respectively), which allowed each to be analyzed separately in the frequency domain. We report three important findings regarding the neural mechanisms of perceptual load. First, we replicated previous findings of within-modality distractor filtering and demonstrated a reduction in visual distractor signals with high perceptual load. Second, auditory steady-state distractor signals were unaffected by manipulations of visual perceptual load, consistent with the idea that perceptual load-induced distractor filtering is modality specific. Third, analysis of task-related signals revealed that visual distractors competed with task stimuli for representation and that increased perceptual load appeared to resolve this competition in favor of the task stimulus.