Pupillary measurement and release from proactive inhibition.

One of the explanations of release from proactive inhibition in short-term memory is that the subjects re-attend to the items on the release trial because the items are different from the previous ones. It is further assumed that this increase in attention causes the relase items to be learned better than the preceding items. This experiment measured the pupils of the subjects' eyes while they were participating in a proactive-inhibition release-type task. The results showed no increase in attention, as indexed by pupil size, on the release trial. This did not support the attentional explanation of the proactive-inhibition release phenomenon.     

Speed and accuracy of accessing information in working memory: an individual differences investigation of focus switching

Three experiments examined the nature of individual differences in switching the focus of attention in working memory. Participants performed 3 versions of a continuous counting task that required successive updating and switching between counts. Across all 3 experiments, individual differences in working memory span and fluid intelligence were related to the accuracy of the counts, but not to the time cost associated with switching between counts. The authors suggest that working memory span and fluid intelligence measures partially index the ability to accurately switch information in and out of the focus of attention, but this variation is not related to the speed of switching.     

Individual differences in delay discounting: relation to intelligence, working memory, and anterior prefrontal cortex

Lower delay discounting (better self-control) is linked to higher intelligence, but the basis of this relation is uncertain. To investigate the potential role of working memory (WM) processes, we assessed delay discounting, intelligence (g), WM (span tasks, 3-back task), and WM-related neural activity (using functional magnetic resonance imaging) in 103 healthy adults. Delay discounting was negatively correlated with g and WM. WM explained no variance in delay discounting beyond that explained by g, which suggests that processes through which WM relates to delay discounting are shared by g. WM-related neural activity in left anterior prefrontal cortex (Brodmann's area 10) covaried with g, r= .26, and delay discounting, r=-.40, and partially mediated the relation between g and delay discounting. Overall, the results suggest that delay discounting is associated with intelligence in part because of processes instantiated in anterior prefrontal cortex, a region known to support the integration of diverse information.     

Individual differences in working memory capacity and dual-process theories of the mind

Dual-process theories of the mind are ubiquitous in psychology. A central principle of these theories is that behavior is determined by the interplay of automatic and controlled processing. In this article, the authors examine individual differences in the capacity to control attention as a major contributor to differences in working memory capacity (WMC). The authors discuss the enormous implications of this individual difference for a host of dual-process theories in social, personality, cognitive, and clinical psychology. In addition, the authors propose several new areas of investigation that derive directly from applying the concept of WMC to dual-process theories of the mind.     

Individual differences in working memory capacity and enumeration

Two experiments are reported in which subjects performed working memory and enumeration tasks. In the first experiment, subjects scoring low on the working memory task also performed poorly on the attention-demanding "counting" portion of the enumeration task. Yet no span differences were found for the non-attention-demanding "subitizing" portion. In Experiment 2, conjunctive and disjunctive distractors were added to the enumeration task. Although both high and low working memory span subjects were adversely affected by the addition of conjunctive distractors, the effect was much greater for the low-span subjects. Implications from these findings are that differences in working memory capacity correspond to differences in capability for controlled attention.     

Psychotropic placebos reduce the misinformation effect by increasing monitoring at test

A psychotropic placebo can help people resist the misinformation effect, an effect thought to be caused by a shift to more stringent source monitoring. When this shift occurs has been unclear. To address this issue we gave some people—but not others—a phoney cognitive-enhancing drug we called R273. Shortly afterwards, everyone took part in a misinformation effect experiment. To gather evidence about source monitoring we surreptitiously recorded time to read the misleading postevent narrative, and response time at test. Our findings suggest that people shifted to more stringent source monitoring at test. Moreover, people with higher working memory capacity (WMC) performed better than people with lower WMC—but only when they were told they had received R273, a finding that fits with research showing that WMC can confer advantages in situations demanding effortful control, but not when automatic heuristics suffice.     

Complex working memory span tasks and higher-order cognition: A latent-variable analysis of the relationship between processing and storage

Complex span tasks, assumed by many to measure an individual's working memory capacity, are predictive of several aspects of higher-order cognition. However, the underlying cause of the relationships between “processing-and-storage” tasks and cognitive abilities is still hotly debated nearly 30 years after the tasks were first introduced. The current study utilised latent constructs across verbal, numerical, and spatial content domains to examine a number of questions regarding the predictive power of complex span tasks. In particular, the relations among processing time, processing accuracy, and storage accuracy from the complex span tasks were examined, in combination with their respective relationships with fluid intelligence. The results point to a complicated pattern of unique and shared variance among the constructs. Implications for various theories of working memory are discussed.     

Presence and quality of kindergarten children's friendships: concurrent and longitudinal associations with child adjustment in the early school years

The presence and quality of friendships are posited to have developmental significance, yet little is known about the extent to which children without friends versus low‐quality friendships compare on socioemotional adjustment. The current study utilized data from a subsample of 567 children (289 boys) participating in the NICHD Study of Early Child Care and Youth Development. Based on maternal reports at kindergarten, four friendship groups were formed: no friends, low quality, average quality, and high quality, and these groups were used to predict teacher‐reported behaviour problems and social skills concurrently (in kindergarten) and longitudinally (in first and third grade). Concurrently, low‐quality friendships were associated with greater externalizing behaviour, whereas high‐quality friendships were associated with greater social skills. Longitudinally, having no friends in kindergarten was associated with higher levels of externalizing behaviour for boys, but lower levels for girls. Children without friends also showed more internalizing problems at first grade. Lastly, having a high‐quality friendship in kindergarten was associated with greater social skills in first and third grades, but only for boys. Results underscore high‐quality friendship as a context for the development of social skills and indicate different trajectories of problem behaviour for kindergarten children with no friends versus low‐quality friendships. Copyright © 2010 John Wiley & Sons, Ltd.     

Integrating working memory capacity and context-processing views of cognitive control

Individuals low in working memory capacity (WMC) exhibit impaired performance on a variety of cognitive control tasks. The executive-attention theory of WMC (Engle & Kane, 2004) accounts for these findings as failures of goal maintenance and response conflict resolution. Similarly, the context-processing view (Braver et al., 2001) provides an explanation of cognitive control deficits observed in schizophrenia patients and older adults that is based on the ability to maintain context information. Instead of maintenance deficits, the inhibition view (Hasher, Lustig, & Zacks, 2007) states that older adults and individuals low in WMC primarily have an impairment in the ability to inhibit information. In the current experiment, we explored the relationships among these theories. Individuals differing in performance on complex span measures of WMC performed the AX-Continuous Performance Test to measure context-processing performance. High-WMC individuals were predicted to maintain the context afforded by the cue, whereas low-WMC individuals were predicted to fail to maintain the context information. Low-WMC individuals made more errors on AX and BX trials and were slower to respond correctly on AX, BX, and BY trials. The overall pattern of results is most consistent with both the executive-attention and context-processing theories of cognitive control.     

Child anger proneness moderates associations between child-mother attachment security and child behavior with mothers at 33 months

Child-mother attachment security, assessed via a modified Strange Situation procedure (Cassidy & Marvin, with the MacArthur Attachment Working Group, 1992), and parent-reported child proneness to anger were examined as correlates of observed child behavior toward mothers during a series of interactive tasks (N = 120, 60 girls). Controlling for maternal sensitivity and child gender and expressive language ability, greater attachment security, and lower levels of anger proneness were related to more child responsiveness to maternal requests and suggestions during play and snack sessions. As hypothesized, anger proneness also moderated several security-behavior associations. Greater attachment security was related to (a) more committed compliance during clean-up and snack-delay tasks for children high on anger proneness, (b) more self-assertiveness during play and snack for children moderate or high on anger proneness, and (c) more help-seeking during play and snack for children moderate or low on anger proneness. Findings further our understanding of the behavioral correlates of child-mother attachment security assessed during late toddlerhood via the Cassidy-Marvin system and underscore child anger proneness as a moderator of attachment-related differences in child behavior during this developmental period.