Combining representations in working memory: A brief report

A task combining both digit and Corsi memory tests was administered to a group of 75 children. The task is shown to share variance with standardized reading and maths attainments, even after partialling out performance on component tasks separately assessed. The emergent task property may reflect coordination skills, although several different refinements can be made to this general conclusion

Synergies between processing and memory in children's reading span.

Previous research has established the relevance of working memory for cognitive development. Yet the factors responsible for shaping performance in the complex span tasks used to assess working memory capacity are not fully understood. We report a study of reading span in 7- to 11-year old children that addresses several contemporary theoretical issues. We demonstrate that both the timing and the accuracy of recall are affected by the presence or absence of a semantic connection between the processing requirement and the memoranda. Evidence that there can be synergies between processing and memory argues against the view that complex span simply measures the competition between these activities. We also demonstrate a consistent relationship between the rate of completing processing operations (sentence reading) and recall accuracy. At the same time, the shape and strength of this function varies with the task configuration. Taken together, these results demonstrate the potential for reconstructive influences to shape working memory performance among children

On the interpretation of working memory span in adults.

Experimental research into children’s working memory span has shown that retention duration contributes substantially to span performance, while processing efficiency need not be related to concurrent memory load (Towse, Hitch, & Hutton, 1998). These findings have been used to argue for a model of working memory span that emphasizes time-based forgetting rather than the popular resource-sharing or tradeoff framework. The present paper considers whether adults perform working memory span tasks in a qualitatively different way. Data from reading span and operation span tasks show that adults’ performance can be distinguished from that of children, but also that a task-switching model of working memory span can explain some important aspects of performance

With development, list recall includes more chunks, not just larger ones.

The nature of the childhood development of immediate recall has been difficult to determine. There could be a developmental increase in either the number of chunks held in working memory or the use of grouping to make the most of a constant capacity. In 3 experiments with children in the early elementary school years and adults, we show that improvements in the immediate recall of word and picture lists come partly from increases in the number of chunks of items retained in memory. This finding was based on a distinction between access to a studied group of items (i.e., recall of at least 1 item from the group) and completion of the accessed group (i.e., the proportion of the items recalled from the group). Access rates increased with age, even with statistical controls for completion rates, implicating development of capacity in chunks. (PsycINFO Database Record (c) 2010 APA, all rights reserved

On the nature of the relationship between processing activity and item retention in children.

The concept of working memory emphasizes the interrelationship between the transient retention of information and concurrent processing activity. Three experiments address this relationship in children between 8 and 17 years of age by examining forgetting when a processing task is interpolated between presentation and recall of the memory items. Unlike previous studies, delivery of interpolated stimuli was under computer control and responses to these stimuli were timed. There were consistent effects of the duration of the interpolated task, but no effects of either its difficulty or similarity to memory material and no qualitative developmental differences in task performance. The absence of an effect of difficulty provides no support for models of working memory in which limited capacity is shared between the dual functions of processing and storage, but is compatible with an alternative “task switching” account. However, task switching did not explain developmental differences in recall. Other aspects of the results suggest that there can be interactions between processing and storage but it is argued that these cannot be straightforwardly explained in terms of either task switching or resource sharing

What can we learn about immediate memory from the development of children's free recall?

We ask the question: Which aspects of immediate memory performance improve with age? In two studies, we reexamine the widely held view that primary memory capacity estimates derived from children's immediate free recall are age invariant. This was done by assessing children's immediate free-recall accuracy while also measuring the order in which they elected to recall items (Experiment 1) and by encouraging children to begin free recall with items from towards the end of the presented list (Experiment 2). Across samples aged between 5 and 8 years we replicated the previously reported age-related changes in free-recall serial position functions when aggregated across all trials of the standard task, including an absence of age differences in the recency portion of this curve. However, we also show that this does not reflect the fact that primary memory capacity is constant across age. Instead, when we incorporate order of report information, clear age differences are evident in the recall of list-final items that are output at the start of a participant's response. In addition, the total amount that individuals recalled varied little across different types of free-recall tasks. These findings have clear implications for the use of immediate free recall as a means of providing potential indices of primary memory capacity and in the study of the development of immediate memory

Email fraud: The search for psychological predictors of susceptibility

Decisions that we make about email legitimacy can result in a pernicious threat to security of both individuals and organisations. Yet user response to phishing emails is far from uniform; some respond while others do not. What is the source of this diversity in decision-making? From a psychological perspective, we consider cognitive and situational influences that might explain why certain users are more susceptible than others. Alongside an email judgment task employed as a proxy for fraud susceptibility, 224 participants completed a range of cognitive tasks. In addition, we manipulated time pressure for email legitimacy judgments. We identify cognitive reflection and sensation seeking as significant, albeit modest, predictors of susceptibility. Further to this, participants asked to make quicker responses made more judgment errors. We conclude there are cognitive signatures that partially contribute to email fraud susceptibility, with implications for efforts to limit online security breaches and train secure behaviors

The social value of a QALY : raising the bar or barring the raise?

Background: Since the inception of the National Institute for Health and Clinical Excellence (NICE) in England, there have been questions about the empirical basis for the cost-per-QALY threshold used by NICE and whether QALYs gained by different beneficiaries of health care should be weighted equally. The Social Value of a QALY (SVQ) project, reported in this paper, was commissioned to address these two questions. The results of SVQ were released during a time of considerable debate about the NICE threshold, and authors with differing perspectives have drawn on the SVQ results to support their cases. As these discussions continue, and given the selective use of results by those involved, it is important, therefore, not only to present a summary overview of SVQ, but also for those who conducted the research to contribute to the debate as to its implications for NICE. Discussion: The issue of the threshold was addressed in two ways: first, by combining, via a set of models, the current UK Value of a Prevented Fatality (used in transport policy) with data on fatality age, life expectancy and age-related quality of life; and, second, via a survey designed to test the feasibility of combining respondents’ answers to willingness to pay and health state utility questions to arrive at values of a QALY. Modelling resulted in values of £10,000-£70,000 per QALY. Via survey research, most methods of aggregating the data resulted in values of a QALY of £18,000-£40,000, although others resulted in implausibly high values. An additional survey, addressing the issue of weighting QALYs, used two methods, one indicating that QALYs should not be weighted and the other that greater weight could be given to QALYs gained by some groups. Summary: Although we conducted only a feasibility study and a modelling exercise, neither present compelling evidence for moving the NICE threshold up or down. Some preliminary evidence would indicate it could be moved up for some types of QALY and down for others. While many members of the public appear to be open to the possibility of using somewhat different QALY weights for different groups of beneficiaries, we do not yet have any secure evidence base for introducing such a system

Random number generation and working memory.

We demonstrate the close relationship that exists between random sequence generation and working memory functioning. We clarify the nature of this link by examining the impact of concurrent requirements for random sequence response quality. Experiments 1A and 1B show that marking specific response choices for differential treatment, either by requiring an ancillary behaviour or by suppressing these choices from output, impairs overall sequence quality. Contrasting with previous findings, these distinct concurrent tasks have comparable effects. We show that disruption is found only when concurrent demand is high. Experiment 2 demonstrates that increasing the dynamic working memory load by requiring the ancillary response to change during the task leads to additional disruption of randomisation. The results extend and refine our understanding of the contribution of active maintenance of representations in random generation