Exploring memory in infancy: deferred imitation and the development of declarative memory

Imitation is an important means by which infants learn new behaviours. When infants do not have the opportunity to immediately reproduce observed actions, they may form a memory representation of the event which can guide their behaviour when a similar situation is encountered again. Imitation procedures can, therefore, provide insight into infant memory. The deferred imitation paradigm requires a modelled action to be reproduced following a delay, without prior motor practice. As such, deferred imitation procedures have been proposed to tap declarative memory abilities in non‐verbal populations such as infants. Contrary to the popular belief that infants form sparse or ill‐defined memories, deferred imitation research reveals that infants store and retrieve highly detailed memory representations. The specificity of detail encoded into the representation can, however, cause memory retrieval to fail at young ages. Developing the ability to identify event components which are central (the target stimulus) versus details which are peripheral (the exact context in which learning occurred) is therefore an important aspect of memory development. Using deferred imitation procedures to study the transition from constrained to flexible memory representations can thus facilitate our understanding of the development of declarative memory during the infancy period. Copyright © 2006 John Wiley & Sons, Ltd.     

Control beliefs and susceptibility to the promises of memory improvement

Brain training is increasingly popular, and many believe in the efficacy of such programs without empirical evidence. We examined whether instructions promising memory improvement would influence subjective and objective cognition. Participants (n = 145; age: M = 50.64) were randomly assigned to a memory improvement or memory task condition. Participants completed demographic and perceived control over cognition measures, in addition to cognitive tasks and subjective cognition items for 7 days. Participants in the improvement condition reported significantly greater memory increases than those in the memory task condition. This effect was moderated by perceived control over cognition; participants in the improvement condition with high control beliefs were significantly more likely than those with low control beliefs or those in the task condition to report better memory. Individuals with higher control beliefs may be more susceptible to the claims of brain training programs, which is significant given that such programs are increasingly popular and commercially available.     

Quality of written record following mock eyewitness testimony: Note taking should be a minimum standard!

By using a video‐based narrative (unidirectional) eyewitness statement of an alleged victim, participants were asked to imagine they were police officers. We compared the quality of mock police officer written records in a between‐subjects design comprising three conditions: (a) a free recall (n = 27), (b) a free recall by using recall strategies of the cognitive interview (n = 27), or (c) note taking while watching the video (n = 26). The quality of the reports was determined by the amount of correctly recalled details, omitted details, added details (commission errors), and changed details (confabulations). As predicted, the number of correct details was higher in the “Note Taking” condition whereas performance in the “Free Recall” and in the “Cognitive Interview” conditions did not differ. Higher verbal memory ability resulted in a better quality of the written records. Our results suggest that note taking facilitates the quality of written records.     

汉语短时序列回忆中的语音相似性和视觉相似性效应

语音相似性效应和视觉相似性效应是短时序列回忆中的两个典型性效应, 但前人很少探讨这两种效应的交互作用。本研究利用汉语字形和语音的属性, 观察汉字短时序列回忆中语音相似性效应、视觉相似性效应及两者的交互作用。研究结果发现当回忆项目在语音或视觉上单纯相似或不相似时, 视觉相似性效应及其与语音相似性的交互作用与混合词表条件下所发现的结果有很大的不同。这个研究结果为丰富和补充相关理论模型提供了进一步实证依据。     

Memories and anticipations control responding by rats (<Emphasis Type="Italic">Rattus norvegicus</Emphasis>) in a Pavlovian procedure

In Experiment 1 each rat received two different fixed series of three trials each. The unconditioned stimulus occurred on Trial 1 of one series and on Trial 3 of the other series, all other trials being nonreinforced. Previous Pavlovian investigations have shown that rats can remember the immediately prior reward outcome and anticipate the immediately subsequent reward outcome. Experiment 1 demonstrated that rats could remember and anticipate even more remote reward outcomes. In Experiment 2 two groups received a series of two nonrewarded trials followed by a rewarded trial. It was demonstrated that a change in the conditioned stimulus (CS) from Trial 2 to Trial 3, which occurred in one group, produced weaker responding than in the other group that did not experience such CS change. On the basis of these findings it was suggested that the rats organized the trials of a series into a unit or chunk. This was concluded for two reasons. First, remembering and anticipating remote reward outcomes strongly suggests that responding is being controlled by events extending beyond the current trial. Secondly, the experimental manipulations employed in the Pavlovian situation here are similar to those used in prior human learning and animal instrumental learning investigations concerned with chunking. Thus, it would appear that chunking is a ubiquitous phenomenon appearing in human serial learning (e.g., Bower and Winzenz 1969; Crowder 1976), in animal instrumental learning (e.g., Capaldi 1992; Hulse and Dorsky 1977; Terrace 1987), and now in Pavlovian learning.     

An improved algorithm for predicting free recalls

Laming [Laming, D. (2006). Predicting free recalls. Journal of Experimental Psychology: Learning, Memory, and Cognition, 32, 1146-1163] has shown that, in a free-recall experiment in which the participants rehearsed out loud, entire sequences of recalls could be predicted, to a useful degree of precision, from the prior sequences of stimuli and rehearsals. This article describes an improved predictive algorithm, which is then used to re-analyse two further sets of free-recall data. Prediction is compared, generically, with conventional modelling, represented here by three recent models of free recall that are concerned with recalls only, not with rehearsals. Some implications are drawn, from the use of rehearsal data by the predictive algorithm, for some of the constituent assumptions embodied in those three models.     

Maternal provision of structure in a deliberate memory task in relation to their preschool children's recall

Strategic remembering emerges gradually during the preschool years. Socialization practices, specifically mother–child social interactions, might provide the foundation for the development of skills necessary for effective organization of information in memory. In the current study, 48 mothers and their 40-month-olds were engaged in the process of remembering (i.e., study and recall) categorically related picture stimuli in a laboratory context. Children’s recall was reliably predicted by the way in which mothers structured both the study and recall periods of the deliberate memory task. Specifically, maternal verbal and physical behaviors that focused on organization of items, such as sorting items into distinct groups and providing the name of a category, were most beneficial in supporting children’s memory. Moreover, some mothers employed a number of different mnemonic techniques that emphasized categorical connections among items, suggesting systematic approaches in the manner in which mothers help children to learn effective ways of remembering.     

A Distributed Representation of Temporal Context

The principles of recency and contiguity are two cornerstones of the theoretical and empirical analysis of human memory. Recency has been alternatively explained by mechanisms of decay, displacement, and retroactive interference. Another account of recency is based on the idea of variable context (Estes, 1955; Mensink & Raaijmakers, 1989). Such notions are typically cast in terms of a randomly fluctuating population of elements reflective of subtle changes in the environment or in the subjects' mental state. This random context view has recently been incorporated into distributed and neural network memory models (Murdock, 1997; Murdock, Smith, & Bai, 2001). Here we propose an alternative model. Rather than being driven by random fluctuations, this formulation, the temporal context model (TCM), uses retrieval of prior contextual states to drive contextual drift. In TCM, retrieved context is an inherently asymmetric retrieval cue. This allows the model to provide a principled explanation of the widespread advantage for forward recalls in free and serial recall. Modeling data from single-trial free recall, we demonstrate that TCM can simultaneously explain recency and contiguity effects across time scales.     

Effects of Guided Notes on University Students' Responding and Recall of Information

The present study assessed the effects of guided notes on student responding and accuracy of recall of lecture material in an undergraduate psychology class using multi-element design. Guided notes were administered for approximately half of the class sessions on a random schedule. Data were collected on the frequency of student responses and daily quizzes were administered to assess accuracy of recall of information presented in the lecture. Results indicated higher mean quiz scores and response frequencies during the guided notes condition. Social validity questionnaires administered to participants revealed satisfaction with results and procedures.     

Sources of Bias in Memory for Emotions

How accurately can people remember how they felt in the past? Although some investigators hold that emotional memories are resistant to change, we review evidence that current emotions, appraisals, and coping efforts, as well as personality traits, are all associated with bias in recalling past emotions. Bias occurs as memories of emotional states are updated in light of subsequent experience and goals. Biased memories in turn influence future plans and emotions, and may contribute to the formation of enduring personality traits. People's memories for emotions provide highly condensed and accessible summaries of the relevance of past experiences to current goals.