In the single-store model of memory, the enhanced recall for the last items in a free-recall task (i.e., the recency effect) is understood to reflect a general property of memory rather than a separate short-term store. This interpretation is supported by the finding of a long-term recency effect under conditions that eliminate the contribution from the short-term store. In this article, evidence is reviewed showing that recency effects in the short and long terms have different properties, and it is suggested that 2 memory components are needed to account for the recency effects: an episodic contextual system with changing context and an activation-based short-term memory buffer that drives the encoding of item-context associations. A neurocomputational model based on these 2 components is shown to account for previously observed dissociations and to make novel predictions, which are confirmed in a set of experiments.

Neurofeedback has begun to attract the attention and scrutiny of the scientific and medical mainstream. Here, neurofeedback researchers present a consensus-derived checklist that aims to improve the reporting and experimental design standards in the field.

We report three correlation studies, which investigate the hypothesis that individual differences in the capacity of a semantic short-term memory (STM) component in working memory (WM) predict performance on complex language tasks. To measure the capacity of semantic STM, we devised a storage-only measure, the conceptual span, which makes use of a category-cued recall procedure. In the first two studies, where the conceptual span was administered with randomized words (not blocked by categories), we found that conceptual span predicted single-sentence and text comprehension, semantic anomaly detection and verbal problem solving, explaining unique variance beyond non-word and word span. In some cases, the conceptual span explained unique variance beyond the reading span. Conceptual span correlated better with verbal problem solving than reading span, suggesting that a storage-only measure can outperform a storage-plus-processing measure. In Study 3, the conceptual span was administered with semantically clustered lists. The clustered span correlated with the comprehension measures as well as the non-clustered span, indicating that the critical process is memory maintenance and not semantic clustering. Moreover, we found an interaction between subjectsÕ performance on the conceptual span and the effect of the distance between critical words in anomaly detection, supporting the proposal that semantic STM maintains unintegrated word meanings. Ó 2002 Elsevier Science (USA). All rights reserved.Keywords: Short term memory; Working memory; Reading comprehension; Individual differences; Conceptual span; Reading span It is widely recognized that a limited-capacity working memory (WM) system plays an important role in complex cognition, supporting both the temporary storage and processing of information (for a review see Kintsch, Healy, Hegarty, Pennington, & Salthouse, 1999). A seminal study by Daneman and Carpenter (1980) demonstrated the importance of WM in the domain of language processing. Its major finding was that a storage-plus-processing measure of WM, the reading span, predicted accuracy of text comprehension (see also Baddeley, Logie, Nimmo-Smith, & Brereton, 1985;Budd, Whitney, & Turley, 1995;Daneman & Carpenter, 1983;Dixon, Le Fevre, & Twilley, 1989;Engle, Cantor, & Carullo, 1992;LaPointe & Engle, 1990;Masson & Miller, 1983), while a storage-only measure, the word span, did not (see also Turner & Engle, 1989). Moreover, when a statistically significant correlation between word span and comprehension is obtained, it tends to be smaller than the correlation between reading span and comprehension (LaPointe & Engle, 1990). The reading span test determines the number of sentence-final words a person can recall immediately after reading aloud a set of sentences and thus emphasizes both storage and processing of words. By contrast, the word span is a storage-only measure, which determines the number of 0749-596X/02/$ -see front matter Ó 2002 Elsevier Science (USA). All rights reserved. PII: S 0 7 4 9 -5 9 6 ...

Memory suppression is investigated with the no-think paradigm, which produces forgetting following repeated practice of not thinking about a memory [Anderson MC, Green C (2001) Nature 410:366 -369]. Because the forgotten item is not retrieved even when tested with an independent, semantically related cue, it has been assumed that this forgetting is due to an inhibition process. However, this conclusion is based on a single stage to recall, whereas global memory models, which produce forgetting through a process of interference, include both a sampling and a recovery stage to recall. By assuming that interference exists during recovery, these models can explain cue-independent forgetting. We tested several predictions of this interference explanation of cue-independent forgetting by modifying the think/nothink paradigm. We added a condition where participants quickly pressed enter rather than not thinking. We also manipulated initial memory strength and tested recognition memory. Most importantly, learning to quickly press enter produced as much cueindependent forgetting as no-think instructions. Demonstrating the adequacy of two-stage recall, a simple computational model (SAM-RI) simultaneously captured the original cue, independent cue, and recognition results.cued recall ͉ inhibition ͉ recall ͉ recognition ͉ computational model

The Stroop task is a central experimental paradigm used to probe cognitive control by measuring the ability of participants to selectively attend to task-relevant information and inhibit automatic task-irrelevant responses. Research has revealed variability in both experimental manipulations and individual differences. Here, we focus on a particular source of Stroop variability, the reverse-facilitation (RF; faster responses to nonword neutral stimuli than to congruent stimuli), which has recently been suggested as a signature of task conflict. We first review the literature that shows RF variability in the Stroop task, both with regard to experimental manipulations and to individual differences. We suggest that task conflict variability can be understood as resulting from the degree of proactive control that subjects recruit in advance of the Stroop stimulus. When the proactive control is high, task conflict does not arise (or is resolved very quickly), resulting in regular Stroop facilitation. When proactive control is low, task conflict emerges, leading to a slow-down in congruent and incongruent (but not in neutral) trials and thus to Stroop RF. To support this suggestion, we present a computational model of the Stroop task, which includes the resolution of task conflict and its modulation by proactive control. Results show that our model (a) accounts for the variability in Stroop-RF reported in the experimental literature, and (b) solves a challenge to previous Stroop models-their ability to account for reaction time distributional properties. Finally, we discuss theoretical implications to Stroop measures and control deficits observed in some psychopathologies. (PsycINFO Database Record

Performance on the Stroop task reflects two types of conflict-informational (between the incongruent word and font color) and task (between the contextually relevant color-naming task and the irrelevant, but automatic, word-reading task). According to the dual mechanisms of control theory (DMC; Braver, 2012), variability in Stroop performance can result from variability in the deployment of a proactive task-demand control mechanism. Previous research has shown that when proactive control (PC) is diminished, both increased Stroop interference and a reversed Stroop facilitation (RF) are observed. Although the current DMC model accounts for the former effect, it does not predict the observed RF, which is considered to be behavioral evidence for task conflict in the Stroop task. Here we expanded the DMC model to account for Stroop RF. Assuming that a concurrent working memory (WM) task reduces PC, we predicted both increased interference and an RF. Nineteen participants performed a standard Stroop task combined with a concurrent n-back task, which was aimed at reducing available WM resources, and thus overloading PC. Although the results indicated common Stroop interference and facilitation in the low-load condition (zero-back), in the high-load condition (two-back), both increased Stroop interference and RF were observed, consistent with the model's prediction. These findings indicate that PC is modulated by concurrent WM load and serves as a common control mechanism for both informational and task Stroop conflicts.

Searching through semantic memory may involve the use of several retrieval cues. In a verbal fluency task, the set of available cues is limited and every candidate word is a target. Individuals exhibit clustering behavior as predicted by optimal foraging theory. In another semantic search task, the remote associates task (RAT), three cues are presented and a single target word has to be found. Whereas the task has been widely studied as a task of creativity or insight problem solving, in this article, the RAT is treated as a semantic retrieval task and assessed from the perspective of information foraging theory. Experiments are presented that address the superadditive combination of cues and the anti-clustering behavior in the recall sequence. A new type of search behavior in the RAT is put forward that involves maximizing the difference in activation between target and distractors. This type of search is advantageous when the target is weak and cue patches are contaminated with strong competitors.

The Eriksen flanker task (Eriksen & Eriksen, 1974) has been frequently used to investigate attentional control processes. The basic task requires a fast response to a centrally presented target stimulus, which is flanked by several distractor stimuli that also activate response channels. A congruent trial is one in which the flankers are associated with the same response as the target (e.g., ), whereas in an incongruent trial, the flankers are associated with a competing response (e.g., ). Reaction times (RTs) are faster for congruent than for incongruent trials. The dominant explanation for this finding is that the presentation of flankers results in automatic activation of the response channel associated with the flanker stimuli (Gratton, Coles, & Donchin, 1992;Gratton, Coles, Sirevaag, Eriksen, & Donchin, 1988), leading to fast correct responses in the congruent condition (i.e., the flankers are identical to the target and facilitate a correct and fast response). In the incongruent condition, the automatic activation leads to fast incorrect responses, necessitating attentional control processes to overrule the incorrect automatic activation, resulting in slow correct responses.This generally accepted view has been implemented in sophisticated computational models to investigate the dynamics of the control processes. One such model is the conflict-monitoring theory of Botvinick, Braver, Barch, Carter, and Cohen (2001), in which the automatic activation of the incorrect response channel competes with activation of the correct response channel at the level of response selection. Resolving this response competition requires time and thus underlies the main effect of congruency-the flanker effect.One of the important contributions made by the Botvinick et al. (2001) model is that the amount of response competition, or conflict, is monitored and used to adjust top-down attentional control-the more conflict, the more control. In the case of the flanker task, increased control results in an increased attentional focus to the central target stimulus. Botvinick et al. proposed that conflict monitored on the previous trial is used to modulate cognitive control on the current trial and that this sequential dependency across trials underlies the so-called Gratton effect (Gratton et al., 1992). This effect is an interaction between the trial type (congruent vs. incongruent) of the current trial and the trial type of the previous trial (see Figure 1). In this article, we will use the notation xX, where the first letter-in lowercase-indicates the congruency of the previous trial and the second letter-in uppercaseindicates the congruency of the current trial. The Gratton effect is a pattern of slower RTs for congruent trials that follow incongruent trials (iC), as compared with those that follow congruent trials (cC), and faster RTs for incongruent trials that follow incongruent trials (iI), as compared with those that follow congruent trials (cI). To prime the reader, the RT difference between cI and iI trials tends to be la...