Lleras Alejandro, Levinthal Brian R, Kawahara Jun
Department of Psychology, University of Illinois at Urbana-Champaign, Champaign, IL, USA.
Prog Brain Res. 2009;176:195-213. doi: 10.1016/S0079-6123(09)17611-2.
When an observer is searching through the environment for a target, what are the consequences of not finding a target in a given environment? We examine this issue in detail and propose that the visual system systematically tags environmental information during a search, in an effort to improve performance in future search events. Information that led to search successes is positively tagged, so as to favor future deployments of attention toward that type of information, whereas information that led to search failures is negatively tagged, so as to discourage future deployments of attention toward such failed information. To study this, we use an oddball-search task, where participants search for one item that differs from all others along one feature or belongs to a different visual category, from the other stimuli in the display. We find that when participants perform oddball-search tasks, the absence of a target delays identification of future targets containing the feature or category that was shared by all distractors in the target-absent trial. We interpret this effect as reflecting an implicit assessment of performance: target-absent trials can be viewed as processing "failures" insofar as they do not provide the visual system with the information needed to complete the task. Here, we study the goal-oriented nature of this bias in three ways. First, we show that the direction of the bias is determined by the experimental task. Second, we show that the effect is independent of the mode of presentation of stimuli: it happens with both serial and simultaneous stimuli presentation. Third, we show that, when using categorically defined oddballs as the search stimuli (find the face among houses or vice versa), the bias generalizes to unseen members of the "failed" category. Together, these findings support the idea that this inter-trial attentional biases arise from high-level, task-constrained, implicit assessments of performance, involving categorical associations between classes of stimuli and behavioral outcomes (success/failure), which are independent of attentional modality (temporal vs. spatial attention).
当观察者在环境中搜索目标时，在给定环境中未找到目标会有什么后果？我们详细研究了这个问题，并提出视觉系统在搜索过程中会系统地标记环境信息，以提高未来搜索事件中的表现。导致搜索成功的信息会被正向标记，以便在未来将注意力优先部署到该类信息上；而导致搜索失败的信息则会被负向标记，从而抑制未来对这类失败信息的注意力部署。为了研究这一点，我们使用了一个异常球搜索任务，参与者要在一组刺激物中搜索一个在某一特征上与其他所有刺激物不同或属于不同视觉类别的项目。我们发现，当参与者执行异常球搜索任务时，目标缺失会延迟对未来包含在无目标试验中所有干扰项所共有的特征或类别的目标的识别。我们将这种效应解释为反映了对表现的一种隐性评估：无目标试验可被视为处理上的“失败”，因为它们没有为视觉系统提供完成任务所需的信息。在此，我们通过三种方式研究这种偏差的目标导向性质。首先，我们表明偏差的方向由实验任务决定。其次，我们表明这种效应与刺激物的呈现方式无关：无论是串行还是同时呈现刺激物时都会出现这种效应。第三，我们表明，当使用按类别定义的异常球作为搜索刺激物（在房屋中找出人脸，反之亦然）时，这种偏差会推广到“失败”类别的未见过的成员上。总之，这些发现支持了这样一种观点，即这种试验间的注意力偏差源于对表现的高级、任务受限的隐性评估，涉及刺激物类别与行为结果（成功/失败）之间的类别关联，且与注意力模式（时间注意力与空间注意力）无关。
