List-method directed forgetting: Do critical findings generalize from short to long retention intervals?

People can purposefully forget information that has become irrelevant, as is demonstrated in list-method directed forgetting (LMDF). In this task, participants are cued to intentionally forget an already studied list (list 1) before encoding a second list (list 2); this induces forgetting of the first-list items. Most research on LMDF has been conducted with short retention intervals, but very recent studies indicate that such directed forgetting can be lasting. We examined in two experiments whether core findings in the LMDF literature generalize from short to long retention intervals. The focus of Experiment 1 was on the previous finding that, with short retention interval, list-2 encoding is necessary for list-1 forgetting to arise. Experiment 1 replicated the finding after a short delay of 3 min between study and test and extended it to a longer delay of 20 min. The focus of Experiment 1 was on the absence of list-1 forgetting in item recognition, previously observed after short retention interval. Experiment 1 replicated the finding after a short delay of 3 min between study and test and extended it to longer delays of 20 min and 24 h. Implications of the results for theoretical explanations of LMDF are discussed.

Affective Modulation of Working Memory Maintenance: The Role of Positive and Negative Emotions

The present study investigated the impact of task-irrelevant emotional images on the retention of information in spatial working memory (WM). Two experiments employed a delayed matching to-sample task where participants had to maintain the locations of four briefly presented squares. After a short retention interval, a probe item appeared and participants were required to indicate whether the probe position matched one of the previously occupied square positions. During the retention interval, task-irrelevant negative, positive, or neutral emotional pictures were presented. The results revealed a dissociation between negative and positive affect on the participants’ ability to hold spatial locations in WM. While negative affective pictures reduced WM capacity, positive pictures increased WM capacity relative to the neutral images. Moreover, the specific valence and arousal of a given emotional picture was also related to WM performance: While higher valence enhanced WM capacity, higher levels of arousal in turn reduced WM capacity. Together, our findings suggest that emotions up- or down-regulate attention to items in WM and thus modulate the short-term storage of visual information in memory.

The Role of Emotional Landmarks in Embodied and Not-Embodied Tasks

The role of emotional landmarks in navigation has been scarcely studied. Previous findings showed that valence and arousal of landmarks increase landmark’s salience and improve performance in navigational memory tasks. However, no study has directly explored the interplay between valence and arousal of emotionally laden landmarks in embodied and not-embodied navigational tasks. At the aim, 115 college students have been subdivided in five groups according to the landmarks they were exposed (High Positive Landmarks HPL; Low Positive Landmarks LPL; High Negative Landmarks HNL; Low Negative Landmarks LNL and Neutral Landmarks NeuL). In the embodied tasks participants were asked to learn a path in a first-person perspective and to recall it after five minutes, whereas in the not-embodied tasks participants were asked to track the learned path on a silent map and to recognize landmarks among distractors. Results highlighted firstly the key role of valence in the embodied task related to the immediate learning, but not to the delayed recall of the path, probably because of the short retention interval used. Secondly, results showed the importance of the interplay between valence and arousal in the non-embodied tasks, specifically, neutral and high negative emotional landmarks yielded the lowest performance probably because of the avoidance learning effect. Implications for future research directions are discussed.

The Influence of Retrieval Practice Versus Delayed Judgments of Learning on Memory

The positive effect of delayed retrieval practice on subsequent test performance is robust; by contrast, making delayed judgments of learning (JOLs) encourages covert retrieval but has a minor influence on final test performance. In three experiments, we experimentally established and explored this memory-metamemory paradox. After initial study of paired associates (e.g., husky – ram), participants either were explicitly tested (husky – ?) or made a JOL. In Experiment 1, we adopted the standard JOL method, using a short retention interval, whereas in Experiments 2 and 3, we used a common testing-effect method involving a longer retention interval. Delayed JOLs did not boost test performance, but explicit delayed tests boosted memory after a longer retention interval. As important, participants spent less time to make JOLs than to retrieve responses. These data indicate that differences in the dynamics of retrieval for practice tests versus delayed JOLs are responsible for the paradox.

Influence of Amount of Training and Retention Interval Length on Long-Term Perceptual Memory in Normal and Educable-Retarded Children

The influence of perceptual memory on the perception of apparent movement was found to be the same for educable-retarded children and normals of the same MA following a short retention interval. However, in order for the memory effects to endure 24 hr., the EMRs needed much more training than did normals. The results are discussed with respect to those reported in an earlier paper (Raskin, 1969b) and interpreted in terms of association perceptual learning.