Using electrophysiology to demonstrate that cueing affects long-term memory storage over the short term

Retrospective cue benefits in visual working memory are limited to a single location at a time

Working memory (WM) performance can be improved by an informative cue presented during storage. This effect, termed a retrocue benefit, can be used to study limits on how human observers prioritize information stored in WM for behavioral output. There is disagreement about whether retrocue benefits extend to multiple WM locations. Here, we hypothesized that multiple retrocues may improve some aspects of memory performance (e.g., a reduction in random guessing) while worsening others (e.g., an increase in the probability of reporting a feature presented at a non-probed location). We tested this possibility in three experiments. Participants remembered arrays of four orientations or colors over a brief delay, and spatial retrocues instructed participants to prioritize zero, one, two, or all four remembered orientations for possible report. At the end of the trial, participants recalled the orientation that appeared at one location. The results of this study revealed that participants' recall errors were lower during cue-one relative to cue-two and cue-four trials, and this benefit was driven primarily by a reduction in random guessing during cue-one trials. We found no evidence suggesting that multiple spatial cues (i.e., during cue-two trials) induced a trade-off between memory precision, random guessing, and non-target reports compared to neutral trials (i.e., cue-zero or cue-four). Thus, cuing participants to prioritize information appearing at multiple unique spatial positions led to no improvement in memory performance compared to neutral or no-cue trials, providing additional support for the view that retrocue benefits on WM performance are limited to a single spatial location at a time.

Induced Forgetting Is the Result of True Forgetting, Not Shifts in Decision-making Thresholds

Induced forgetting occurs when accessing an item in memory appears to harm memory representations of categorically related items. However, it is possible that the actual memory representations are unharmed. Instead, people may just change how they make decisions. Specifically, signal detection theory suggests this apparent forgetting may be due to participants shifting their decision criterion. Here, we used behavioral and electrophysiological measures to determine whether induced forgetting is truly due to changes in how items are represented or simply due to a shifting criterion. Participants' behavior and brain activity showed that induced forgetting was due to changes in the strength of the underlying representations, weighing against a criterion shift explanation of induced forgetting.

In search of the focus of attention in working memory: 13 years of the retro-cue effect

The concept of attention has a prominent place in cognitive psychology. Attention can be directed not only to perceptual information, but also to information in working memory (WM). Evidence for an internal focus of attention has come from the retro-cue effect: Performance in tests of visual WM is improved when attention is guided to the test-relevant contents of WM ahead of testing them. The retro-cue paradigm has served as a test bed to empirically investigate the functions and limits of the focus of attention in WM. In this article, we review the growing body of (behavioral) studies on the retro-cue effect. We evaluate the degrees of experimental support for six hypotheses about what causes the retro-cue effect: (1) Attention protects representations from decay, (2) attention prioritizes the selected WM contents for comparison with a probe display, (3) attended representations are strengthened in WM, (4) not-attended representations are removed from WM, (5) a retro-cue to the retrieval target provides a head start for its retrieval before decision making, and (6) attention protects the selected representation from perceptual interference. The extant evidence provides support for the last four of these hypotheses.