Variation in working memory capacity and episodic memory: Examining the importance of encoding specificity

In the present study, we examined the extent to which encoding specificity influences the relation between individual differences in working memory capacity (WMC) and episodic recall. Participants performed a paired associates cued recall task in which a rhyme or a semantic judgment was made during encoding. During recall participants were presented with the cue word along with either a rhyme or semantic cue. Across both rhyme and semantic conditions, encoding and retrieval conditions either matched or mismatched. When encoding and retrieval conditions matched, high WMC individuals outperformed low WMC individuals. When encoding and retrieval conditions mismatched, high and low WMC individuals performed equivalently. Importantly, this occurred because high WMC individuals were hurt more than low WMC individuals when conditions mismatched. These results demonstrate the importance of encoding specificity in the relation between WMC and episodic recall as well as of unifying prior work that has demonstrated that high WMC individuals are hurt more in some recall conditions than are low WMC individuals.     

Extensive performance on the antisaccade task does not lead to negative transfer

Executive-control processes regulate thoughts, emotions, actions, and behaviors that are critical for everyday functioning. Recently, researchers have suggested that these processes can be flexibly modified by tasks that require executive control. Specifically, it has been argued that executive-control tasks can deplete these executive-control processes, which can in turn lead to negative transfer on subsequent task performance. Importantly, the degrees of malleability in executive-control processes and transfer to different tasks are of ongoing debate. The present study critically examined the hypothesis that executive-control processes can be exerted and whether or not this exertion would negatively transfer to performance on various subsequent tasks. Across a series of experiments, negative transfer effects from extensive performance on the antisaccade task were not found. Traditional hypothesis testing and Bayes factor computations were used to validate these findings. Collectively, the present results put in question the use of the antisaccade task to observe both near and far negative transfer from using executive-control processes.     

Functional categories and syntactic operations in (Ab)normal language acquisition

This article argues in favor of the hypothesis that computational complexity determines order of acquisition of functional categories by normal children and patterns of impairment vs. relative preservation of these categories in children with Specific Language Impairment. Complexity is defined in terms of the properties of functional categories of the language the (ab)normal child is acquiring. The results of a study on present/past tense production and comprehension, carried out with children with and without Specific Language Impairment confirm the predictions of the computational complexity hypothesis. It is shown that it is easier to compute kernel functional categories than those that introduce further semantic modifications in the sentence.     

Comparing recollective experience in true and false autobiographical memories

This study investigated whether true autobiographical memories are qualitatively distinct from false autobiographical memories using a variation of the interview method originally reported by E. F. Loftus and J. Pickrell (1995). Participants recalled events provided by parents on 3 separate occasions and were asked to imagine true and false unremembered events. True memories were rated by both participants and observers as more rich in recollective experience and were rated by participants as more important, more emotionally intense, as having clearer imagery, and as less typical than false memories. Rehearsal frequency was used as a covariate, eliminating these effects. Imagery in true memories was most often viewed from the field perspective, whereas imagery in false memories was most often viewed from the observer perspective. More information was communicated in true memories, and true memories contained more information concerning the consequences of described events. Results suggest repeated remembering can make false memories more rich in recollective experience and more like true memories. Differences between true and false memories suggest some potentially distinct characteristics of false memories and provide insight into the process of false memory creation.     

Individual differences in working memory capacity and search efficiency

In two experiments, we examined how various learning conditions impact the relation between working memory capacity (WMC) and memory search abilities. Experiment 1 employed a delayed free recall task with semantically related words to induce the buildup of proactive interference (PI) and revealed that the buildup of PI differentially impacted recall accuracy and recall latency for low-WMC and high-WMC individuals. Namely, the buildup of PI impaired recall accuracy and slowed recall latency for low-WMC individuals to a greater extent than what was observed for high-WMC individuals. To provide a circumstance in which previously learned information remains relevant over the course of learning, Experiment 2 required participants to complete a multitrial delayed free recall task with unrelated words. Results revealed that with increased practice with the same word list, WMC-related differences were eventually eliminated in interresponse times (IRTs) and recall accuracy, but not recall latency. Thus, despite still accumulating larger search sets, low-WMC individuals searched LTM as efficiently as high-WMC individuals. Collectively, these results are consistent with the notion that under normal free recall conditions, low-WMC individuals search LTM less efficiently than do high-WMC individuals because of their reliance on noisy temporal–contextual cues at retrieval. However, it appears that under conditions in which previously learned items remain relevant at recall, this tendency to rely on vague self-generated retrieval cues can actually facilitate the ability to accurately and quickly recall information.     

Public Attitudes on the Ethics of Deceptively Planting False Memories to Motivate Healthy Behavior

Researchers have proposed that planting false memories could have positive behavioral consequences. The idea of deceptively planting ‘beneficial’ false memories outside of the laboratory raises important ethical questions, but how might the general public appraise this moral dilemma? In two studies, participants from the USA and UK read about a fictional ‘false‐memory therapy’ that led people to adopt healthy behaviors. Participants then reported their attitudes toward the acceptability of this therapy, via scale‐rating (both studies) and open‐text (study 2) responses. The data revealed highly divergent responses to this contentious issue, ranging from abject horror to unqualified enthusiasm. Moreover, the responses shed light on conditions that participants believed would make the therapy less or more ethical. Whether or not deceptively planting memories outside the lab could ever be justifiable, these studies add valuable evidence to scientific and societal debates on neuroethics, whose relevance to memory science is increasingly acute. Copyright © 2016 The Authors Applied Cognitive Psychology Published by John Wiley & Sons Ltd.     

Asymptotic confidence intervals for the Pearson correlation via skewness and kurtosis

When bivariate normality is violated, the default confidence interval of the Pearson correlation can be inaccurate. Two new methods were developed based on the asymptotic sampling distribution of Fisher's z′ under the general case where bivariate normality need not be assumed. In Monte Carlo simulations, the most successful of these methods relied on the (Vale & Maurelli, 1983, Psychometrika, 48, 465) family to approximate a distribution via the marginal skewness and kurtosis of the sample data. In Simulation 1, this method provided more accurate confidence intervals of the correlation in non-normal data, at least as compared to no adjustment of the Fisher z′ interval, or to adjustment via the sample joint moments. In Simulation 2, this approximate distribution method performed favourably relative to common non-parametric bootstrap methods, but its performance was mixed relative to an observed imposed bootstrap and two other robust methods (PM1 and HC4). No method was completely satisfactory. An advantage of the approximate distribution method, though, is that it can be implemented even without access to raw data if sample skewness and kurtosis are reported, making the method particularly useful for meta-analysis. Supporting information includes R code.     

On the division of short-term and working memory: an examination of simple and complex span and their relation to higher order abilities

Research has suggested that short-term memory and working memory (as measured by simple and complex span tasks, respectively) are separate constructs that are differentially related to higher order cognitive abilities. This claim is critically evaluated by reviewing research that has compared simple and complex span tasks in both experimental and correlational studies. In addition, a meta-analysis and re-analyses of key data sets were conducted. The review and analyses suggest that simple and complex span tasks largely measure the same basic subcomponent processes (e.g., rehearsal, maintenance, updating, controlled search) but differ in the extent to which these processes operate in a particular task. These differences largely depend on the extent to which phonological processes are maximized and variability from long list lengths is present. Potential methodological, psychometric, and assessment implications are discussed and a theoretical account of the data is proposed.     

There’s more to the working memory capacity—fluid intelligence relationship than just secondary memory

The present study examined the claim that secondary memory processes account for the correlation between working memory capacity and fluid intelligence via a latent variable analysis. In the present study, participants performed multiple measures of secondary memory, working memory capacity, and fluid intelligence. Structural equation modeling suggested that both secondary memory and working memory capacity account for unique variance in fluid intelligence. These results are inconsistent with recent claims that working memory capacity does not account for variance in fluid intelligence over and above what is accounted for by secondary memory. Rather, the results are consistent with models of working memory capacity that suggest that both maintenance and retrieval processes are needed to account for the substantial relation between working memory capacity and fluid intelligence.     

Facing away from the interviewer: Evidence of little benefit to eyewitnesses' memory performance

Averting gaze from another person's face generally improves cognitive performance, yet, little is known about how witnesses' gaze direction affects their recall during investigative interviews. Here, participants witnessed a video-recorded incident, and were interviewed via free recall and closed questions following a short delay. In Experiment 1, participants either faced the interviewer or faced away during the interview. In Experiment 2, alongside this manipulation, the interviewer also either faced the witness or faced away. In Experiment 3, witness gaze direction was manipulated alongside rapport-building. In Experiment 4, the effect of facing away was directly compared with that of eye-closure. Mini meta-analysis of all four experiments showed that the effect of witness gaze direction on memory performance was minimal. Furthermore, neither aversion of interviewer's gaze nor rapport-building magnified this effect. Added to the cumulative literature on eyewitness gaze aversion, these findings afford better estimates of the likely size of these effects.