The effect of perceptual load on gaze and EEG signals in multi-target visual search with free eye-movements
The effect of perceptual load on gaze and EEG signals in multi-target visual search with free eye-movements
复制标题
自由眼动多目标视觉搜索中感知负荷对凝视和脑电图信号的影响
DOI：
10.1167/19.10.273
复制
发表时间：
2019
影响因子：
1.8
通讯作者：
Harris A
中科院分区：
文献类型：
--
作者：
Harris A
并非所有搜索任务都是平等的。搜索任务的难度随着任务的感知负荷而显著变化（Lavie &考克斯，1997;罗珀等人，2013年）。知觉负荷的神经相关性通常被要求参与者保持中央固定的任务检查。然而，最近，人们越来越感兴趣的是在更自然的场景中研究注意力的神经相关性，例如自由观看，其中在参与者用他们的眼睛探索显示器的同时同时测量注视度量和神经反应（例如，Kamienkowski等人，2012年）。在这里，我们研究了知觉负荷与眼动跟踪和脑电图（EEG）的神经相关性，而参与者进行了自由观看多目标视觉搜索任务。参与者搜索形状特征（低负荷）或形状和颜色的连接（高负荷），并通过保持固定直到目标消失（500 ms后），然后继续搜索。参与者还检测到固定或扫视期间出现的罕见音调。音调检测显着受损的高（与低）负荷下，在固定和扫视，确认知觉负荷的操纵。眼动追踪显示，在高负荷参与者固定非目标更频繁，持续时间显着更长，也显着更短的扫视，比低负荷。EEG反应共同注册的发病非目标固定和匹配的潜在混淆固定参数在负载条件下，显示了一个显着较大的P300组件下高于低负载。高负荷搜索也与固定锁定~ 10 Hz振荡α功率降低显著大于低负荷相关。这些结果表明，与高知觉负荷（反映在P300; Kok，2001）增加的注意力需求招募阿尔法介导的注意过程中的凝视依赖的方式下自然的搜索条件。
All search tasks are not created equal. The difficulty of search tasks varies considerably with the perceptual load of the task (Lavie & Cox, 1997; Roper et al., 2013). The neural correlates of perceptual load have typically been examined with tasks that require participants to maintain central fixation. Recently, however, there has been growing interest in investigating the neural correlates of attention in more naturalistic scenarios, such as free viewing, where gaze metrics and neural responses are measured simultaneously while participants explore a display with their eyes (eg, Kamienkowski et al., 2012). Here we examined the neural correlates of perceptual load with eye-tracking and electroencephalography (EEG) while participants performed a free-viewing multi-target visual search task. Participants searched for either a shape feature (low load) or conjunctions of shape and colour (high load) and responded by holding fixation until the target disappeared (after 500ms), after which the search continued. Participants also detected an infrequent tone presented during fixation or saccade. Tone detection was significantly impaired under high (vs. low) load during both fixations and saccades, confirming the manipulation of perceptual load. Eye-tracking revealed that under high load participants fixated nontargets more often and for a significantly longer duration, and also made significantly shorter saccades, than under low load. EEG responses co-registered to the onset of nontarget fixations and matched for potentially confounding fixation parameters across load conditions, revealed a significantly larger P300 component under high than low load. High load search was also associated with significantly greater fixation-locked~ 10 Hz oscillatory alpha power reduction than low load. These results demonstrate that the increased attentional requirements associated with high perceptual load (as reflected in the P300; Kok, 2001) recruit alpha-mediated attentional processes in a gaze-dependent manner under naturalistic search conditions.