Callahan-Flintoft Chloe, Wyble Brad
404 Moore Building, The Pennsylvania State University, University Park, PA 16802, USA.
404 Moore Building, The Pennsylvania State University, University Park, PA 16802, USA.
Vision Res. 2017 Nov;140:106-119. doi: 10.1016/j.visres.2017.06.013. Epub 2017 Sep 18.
The visual system is able to detect targets according to a variety of criteria, such as by categorical (letter vs digit) or featural attributes (color). These criteria are often used interchangeably in rapid serial visual presentation (RSVP) studies but little is known about how rapidly they are processed. The aim of this work was to compare the time course of attentional selection and memory encoding for different types of target criteria. We conducted two experiments where participants reported one or two targets (T1, T2) presented in lateral RSVP streams. Targets were marked either by being a singleton color (red letter among black letters), being categorically distinct (digits among letters) or non-singleton color (target color letter among heterogeneously colored letters). Using event related potential (ERPs) associated with attention and memory encoding (the N2pc and the P3 respectively), we compared the relative latency of these two processing stages for these three kinds of targets. In addition to these ERP measures, we obtained convergent behavioral measures for attention and memory encoding by presenting two targets in immediate sequence and comparing their relative accuracy and proportion of temporal order errors. Both behavioral and EEG measures revealed that singleton color targets were attended much more quickly than either non-singleton color or categorical targets, and there was very little difference between attention latencies to non-singleton color and categorical targets. There was however a difference in the speed of memory encoding for non-singleton color and category latencies in both behavioral and EEG measures, which shows that encoding latency differences do not always mirror attention latency differences.
视觉系统能够根据多种标准检测目标，例如通过类别（字母与数字）或特征属性（颜色）。这些标准在快速序列视觉呈现（RSVP）研究中经常互换使用，但对于它们的处理速度知之甚少。这项工作的目的是比较不同类型目标标准的注意力选择和记忆编码的时间进程。我们进行了两个实验，让参与者报告在横向RSVP流中呈现的一个或两个目标（T1、T2）。目标通过以下方式标记：成为单一颜色（黑色字母中的红色字母）、类别不同（字母中的数字）或非单一颜色（异类颜色字母中的目标颜色字母）。使用与注意力和记忆编码相关的事件相关电位（ERP，分别为N2pc和P3），我们比较了这三种目标在这两个处理阶段的相对潜伏期。除了这些ERP测量，我们通过立即依次呈现两个目标并比较它们的相对准确性和时间顺序错误比例，获得了注意力和记忆编码的趋同行为测量。行为和脑电图测量均显示，单一颜色目标的被关注速度比非单一颜色或类别目标快得多，并且非单一颜色目标和类别目标的注意力潜伏期之间差异很小。然而，在行为和脑电图测量中，非单一颜色目标和类别目标的记忆编码速度存在差异，这表明编码潜伏期差异并不总是反映注意力潜伏期差异。
