Data from: The competitive influences of perceptual load and working memory guidance on selective attention

The perceptual load theory in selective attention literature proposes that the interference from task-irrelevant distractor is eliminated when perceptual capacity is fully consumed by task-relevant information. However, the biased competition model suggests that the contents of working memory (WM) can guide attentional selection automatically, even when this guidance is detrimental to visual search. An intriguing but unsolved question is what will happen when selective attention is influenced by both perceptual load and WM guidance. To study this issue, behavioral performances and event-related potentials (ERPs) were recorded when participants were presented with a cue to either identify or hold in memory and had to perform a visual search task subsequently, under conditions of low or high perceptual load. Behavioural data showed that high perceptual load eliminated the attentional capture by WM. The ERP results revealed an obvious WM guidance effect in P1 component with invalid trials eliciting larger P1 than neutral trials, regardless of the level of perceptual load. The interaction between perceptual load and WM guidance was significant for the posterior N1 component. The memory guidance effect on N1 was eliminated by high perceptual load. Standardized Low Resolution Electrical Tomography Analysis (sLORETA) showed that the WM guidance effect and the perceptual load effect on attention can be localized into the occipital area and parietal lobe, respectively. Merely identifying the cue produced no effect on the P1 or N1 component. These results suggest that in selective attention, the information held in WM could capture attention at the early stage of visual processing in the occipital cortex. Interestingly, this initial capture of attention by WM could be modulated by the level of perceptual load and the parietal lobe mediates target selection at the discrimination stage.

选择性注意领域的知觉负载理论（perceptual load theory）提出：当知觉容量被任务相关信息完全占用时，任务无关干扰物引发的干扰会被消除。然而，竞争偏向模型（biased competition model）则指出，工作记忆（working memory, WM）的内容可自动引导注意选择，即便该引导会对视觉搜索产生不利影响。一个尚未解决且颇具研究价值的问题是：当选择性注意同时受到知觉负载与工作记忆引导的双重影响时，会产生何种结果？为探究该问题，本研究在高低知觉负载条件下开展实验：向被试呈现需识别或暂存于记忆中的线索，随后要求其完成视觉搜索任务，同时记录行为表现与事件相关电位（event-related potentials, ERPs）。行为数据结果显示，高知觉负载可消除工作记忆引发的注意捕获效应。事件相关电位结果表明，P1成分存在显著的工作记忆引导效应：无论知觉负载水平如何，无效试次引发的P1波幅均大于中性试次。后部N1成分的知觉负载与工作记忆引导的交互效应显著，高知觉负载可消除N1成分上的记忆引导效应。标准化低分辨率脑电断层扫描分析（Standardized Low Resolution Electrical Tomography Analysis, sLORETA）结果显示，工作记忆引导效应与知觉负载对注意的影响分别定位于枕叶区域与顶叶。仅识别线索并未对P1或N1成分产生显著影响。上述结果表明，在选择性注意过程中，工作记忆中存储的信息可在视觉加工的早期阶段（枕叶皮层）捕获注意。值得注意的是，工作记忆引发的这一初始注意捕获可受知觉负载水平调控，而顶叶则在辨别阶段介导目标选择。