Reconciling conflicting electrophysiological findings on the guidance of attention by working memory

Abstract Maintaining a representation in working memory has been proposed to be sufficient for the execution of topdown attentional control. Two recent electrophysiological studies that recorded event-related potentials (ERPs) during similar paradigms have tested this proposal, but have reported contradictory findings. The goal of the present study was to reconcile these previous reports. To this end, we used the stimuli from one stud

What not to look for: Electrophysiological evidence that searchers prefer positive templates

To-be-attended information can be specified either with positive cues (I'll be wearing a blue shirt) or with negative cues (I won't be wearing a red shirt). Numerous experiments have found that positive cues help search more than negative cues. Given that negative cues produce smaller benefits compared to positive cues, it stands to reason that searchers may choose to use positive templates instead of negative templates if given the opportunity. Here, we evaluate this possibility with behavioral measures as well as by directly measuring the formation of positive and negative templates with event-related potentials. Analysis of the contralateral delay activity (CDA) elicited by cues revealed that positive and negative templates relied on working memory to the same extent, even when negative working memory templates could have been circumvented by relying on long-term memories of target colors. Whereas the CDA did not discriminate positive and negative templates, a CNV-like potential did, suggesting cognitive differences between positive and negative templates beyond visual working memory. However, when both positive and negative information were presented in each cue, participants preferred to make use of the positive cues, as indicated by a CDA contralateral to the positive color in negative cue blocks, and a lack of search benefits for positive- and negative-color cues relative to positive-color cues alone. Our results show that searchers elect to selectively encode only positive information into visual working memory when both positive and negative information are available

Distractor Ignoring: Strategies, Learning, and Passive Filtering

Our sensory environments contain more information than we can processes and successful behaviors require the ability to separate task-relevant information from task-irrelevant information. While much research on attention has focused on the mechanisms that result in selection of desired information, much less is known about how distracting information is ignored. Here we describe evidence that strategic, learned, and passive information can all contribute to better distractor ignoring. The evidence suggests that there are multiple ways in which distractor ignoring is supported that may be different than those of target selection. Future work will need to identify the mechanisms by which each source of information adjusts attentional priority such that irrelevant information is better ignored

Visual working memory gives up attentional control early in learning: Ruling out interhemispheric cancellation

Abstract Current research suggests that we can watch visual working memory surrender the control of attention early in the process of learning to search for a specific object. This inference is based on the observation that the contralateral delay activity (CDA) rapidly decreases in amplitude across trials when subjects search for the same target object. Here, we tested the alternative explanation that the role of visual working memory does not actually decline across learning, but instead lateralized representations accumulate in both hemispheres across trials and wash out the lateralized CDA. We show that the decline in CDA amplitude occurred even when the target objects were consistently lateralized to a single visual hemifield. Our findings demonstrate that reductions in the amplitude of the CDA during learning are not simply due to the dilution of the CDA from interhemispheric cancellation