认知负荷对网页广告加工过程的影响

利用眼动记录技术,以33名大学生为被试,探讨了认知负荷对网页广告加工过程的影响。结果发现：（1）不同认知负荷水平下被试对网页广告的再认率存在显著差异,低认知负荷条件下的再认率较高,高认知负荷条件下的再认率较低;（2）与高认知负荷条件相比,被试在低认知负荷条件下对网页广告的注视次数更多,凝视时间更长。实验表明,认知负荷影响网页广告的加工过程。     

Stereotype strength and attentional bias: Preference for confirming versus disconfirming information depends on processing capacity

In two experiments, we investigated the relationships among stereotype strength, processing capacity, and the allocation of attention to stereotype-consistent versus stereotype-inconsistent information describing a target person. The results of both experiments showed that, with full capacity, greater stereotype strength was associated with increased attention toward stereotype-consistent versus stereotype-inconsistent information. However, when capacity was diminished, greater stereotype strength was associated with increased attention toward inconsistent versus consistent information. Thus, strong stereotypes may act as self-confirming filters when processing capacity is plentiful, but as efficient information gathering devices that maximize the acquisition of novel (disconfirming) information when capacity is depleted. Implications for models of stereotyping and stereotype change are discussed.     

外语焦虑、紧张情绪与认知负荷对外语说谎的影响：来自中-英双语者的证据

采用错误陈述范式探究中-英双语者用母语和外语说真话和说谎时的认知神经差异, 涉及外语焦虑、认知负荷和说谎诱发的紧张情绪。对P200和CNV观察发现：(1)中-英双语者用英语说真话的P200波幅比用母语大, 说明被试用英语说话时受外语焦虑情绪影响; (2)中-英双语者用英语说谎与说真话的P200波幅无显著差异, 但用母语说谎和讲真话的P200波幅差异显著, 说明被试用外语说谎没有用母语说谎诱发的紧张情绪大; (3)中-英双语者说谎时的CNV波幅比说真话时大, 说明被试说谎比说真话的认知负荷更大; (4)中-英双语者用英语说谎时的CNV波幅比用汉语说谎时大, 说明被试用外语说谎比用母语说谎产生了更大的认知负荷。相关分析表明, 英语熟练程度是影响中-英双语者用母语和外语说谎时的认知神经差异的重要变量。     

快速与慢速读者的中央凹加工对副中央凹预视的影响

在中文阅读中, 预视量是否存在个体差异及其是否受中央凹加工调节, 尚不清楚。本研究采用眼动技术和边界范式, 通过操纵前目标词的加工负荷(高、低)与目标词的预视(相同、假字)来考察快速与慢速读者的中央凹加工对副中央凹预视的影响。结果显示, 中央凹负荷主效应显著; 快速读者对低负荷词的首次和单次注视短于高负荷词, 而慢速读者对两种负荷词的首次和单次注视无差异, 表明快速读者能更快利用词汇特性加工中央凹词汇。预视主效应显著, 即与假字预视相比, 相同预视使两组读者都对目标词的注视更短、向前眼跳更长、跳读率更高; 而且该效应与中央凹负荷没有交互作用。这表明快速读者与慢速读者提取了等量预视, 且不受其中央凹加工的调节。E-Z读者模型和SWIFT模型不能完全解释当前结果。     

Examining the effects of memory specificity and perceptual load on susceptibility to misleading information

Our study aimed to examine the role of perceptual load in eyewitness memory and susceptibility to misinformation and establish whether trait-based memory specificity protects against misinformation. Participants (n = 264) viewed a video depicting a crime and completed a memory questionnaire immediately afterwards and 1 week later. Memory specificity was measured using the Autobiographical Memory Test (AMT). Higher AMT scores were associated with better memory accuracy. Performance was worse in the high load compared to the low load condition at immediate recall. However, this effect was not seen for every question and load did not influence eyewitness identifications. To test the possibility that load effects were not fully captured by the questionnaire in experiment 1, we conducted a second experiment (n = 120) where we systematically manipulated misinformation about central and peripheral details. We found no effects. Our findings suggest that high perceptual load enhances eyewitness suggestibility, while specific autobiographical memory protects against misinformation.     

Effects of 1 mA and 2 mA transcranial direct current stimulation on working memory performance in healthy participants

Anodal transcranial current stimulation (tDCS) to the left dorsolateral prefrontal cortex (DLPFC) has been shown to enhance working memory (WM) in neuropsychiatric patients. In healthy populations, however, tDCS obtains inconclusive results, mostly due to heterogeneous study and stimulation protocols. Here, we approached these issues by investigating effects of tDCS intensity on simultaneous WM performance with three cognitive loads by directly comparing findings of two double-blind, cross-over, sham-controlled experiments. TDCS was administrated to the left DLPFC at intensity of 1 mA (Experiment 1) or 2 mA (Experiment 2), while participants completed a verbal n-back paradigm (1-, 2-, 3-back). Analysis showed no overall effects of tDCS on WM, but a significant interaction with cognitive load. The present study suggests that cognitive load rather than tDCS intensity could be a decisive factor for effects on WM. Moreover, it emphasizes the need of thorough investigation on study parameters to develop more efficient stimulation protocols.     

BOLD response to semantic and syntactic processing during hypoglycemia is load-dependent

This study investigates how syntactic and semantic load factors impact sentence comprehension and BOLD signal under moderate hypoglycemia. A dual session, whole brain fMRI study was conducted on 16 healthy participants using the glucose clamp technique. In one session, they experienced insulin-induced hypoglycemia (plasma glucose at ∼50 mg/dL); in the other, plasma glucose was maintained at euglycemic levels (∼100 mg/dL). During scans subjects were presented with sentences of contrasting syntactic (embedding vs. conjunction) and semantic (reversibility vs. irreversibility) load. Semantic factors dominated the overall load effects on both performance (p < 0.001) and BOLD response (p < 0.01, corrected). Differential BOLD signal was observed in frontal, temporal, temporo-parietal and medio-temporal regions. Hypoglycemia and syntactic factors significantly impacted performance (p = 0.002) and BOLD response (p < 0.01, corrected) in the reversible clause conditions, more extensively in reversible-embedded than in reversible-conjoined clauses. Hypoglycemia resulted in a robust decrease in performance on reversible clauses and exerted attenuating effects on BOLD unselectively across cortical circuits.The dominance of reversibility in all measures underscores the distinction between the syntactic and semantic contrasts. The syntactic is based in a quantitative difference in algorithms interpreting embedded and conjoined structures. We suggest that the semantic is based in a qualitative difference between algorithmic mapping of arguments in reversible clauses and heuristic linking in irreversible clauses. Because heuristics drastically reduce resource demand, the operations they support would resist the load-dependent cognitive consequences of hypoglycemia.     

Performance Benefits of Spatially Distributed Versus Stacked Information on Integration Tasks

Understanding the best way to present information has been an issue of interest to many researchers. Regardless of the content of the information, purely physical elements such as spatial organization may also influence performance. Across two studies with 111 undergraduates (78 in Study 1 and 33 in Study 2), we compared spatially distributed (i.e. when information sources are presented side‐by‐side) against stacked displays (i.e. when information sources are sitting on top of one another with only the top source fully visible). A distributed display time advantage was consistently observed. As potential explanations, a memory strategy selection hypothesis was examined along with other procedural alternative explanations. Copyright © 2011 John Wiley & Sons, Ltd.     

The effects of perceptual load in central and peripheral regions of the visual field

The perceptual load model claims that attentional selectively depends on perceptual load. Selectivity is high with high load, but low with low load. Previous studies only manipulated load levels at task-relevant regions. In this study, perceptual load was orthogonally manipulated in both relevant (central) and nonrelevant (peripheral) regions, by varying the similarity between the target and nontarget letters and the nontarget letters' heterogeneity. The participants had to identify a target-letter appearing in a central circle of letters. A distractor-letter, appearing in a peripheral circle, was compatible, neutral, or incompatible with the target. As expected, increasing peripheral load deteriorated performance, but only with low levels of central load. The pattern of distractor interference did not follow the model's predictions because distractor interference under high load levels was occasionally found. The expected pattern of results emerged only when the spatial uncertainty regarding the distractor position was low, implying that spatial uncertainty plays an important role in attentional selectivity.