Working memory costs of task switching

Although many accounts of task switching emphasize the importance of working memory as a substantial source of the switch cost, there is a lack of evidence demonstrating that task switching actually places additional demands on working memory. The present study addressed this issue by implementing task switching in continuous complex span tasks with strictly controlled time parameters. A series of 4 experiments demonstrate that recall performance decreased as a function of the number of task switches and that the concurrent load of item maintenance had no influence on task switching. These results indicate that task switching induces a cost on working memory functioning. Implications for theories of task switching, working memory, and resource sharing are addressed.     

Learning correct responses and errors in the Hebb repetition effect: two faces of the same coin

In a serial recall task, the Hebb repetition effect occurs when recall performance improves for a sequence repeated throughout the experimental session. This phenomenon has been replicated many times. Nevertheless, such cumulative learning seldom leads to perfect recall of the whole sequence, and errors persist. Here the authors report evidence that there is another side to the Hebb repetition effect that involves learning errors produced in a repeated sequence. A learning measure based on past recalls (correct or incorrect) shows that the probability of a given response increases with the number of prior occurrences of that response. The pattern of results reveals another manifestation of the Hebb repetition effect and speaks to the nature of implicit learning.     

Time-related decay or interference-based forgetting in working memory?

The time-based resource-sharing model of working memory assumes that memory traces suffer from a time-related decay when attention is occupied by concurrent activities. Using complex continuous span tasks in which temporal parameters are carefully controlled, P. Barrouillet, S. Bernardin, S. Portrat, E. Vergauwe, & V. Camos (2007) recently provided evidence that any increase in time of the processing component of these tasks results in lower recall performance. However, K. Oberauer and R. Kliegl (2006) pointed out that, in this paradigm, increased processing times are accompanied by a corollary decrease of the remaining time during which attention is available to refresh memory traces. As a consequence, the main determinant of recall performance in complex span tasks would not be the duration of attentional capture inducing time-related decay, as Barrouillet et al. (2007) claimed, but the time available to repair memory traces, and thus would be compatible with an interference account of forgetting. The authors demonstrate here that even when the time available to refresh memory traces is kept constant, increasing the processing time still results in poorer recall, confirming that time-related decay is the source of forgetting within working memory.     

Do working-memory executive components mediate the effects of age on strategy selection or on strategy execution? Insights from arithmetic problem solving

Younger and older adults performed an inequality verification task (7+6 < 15, Yes/No?) in a control condition and in a dual-task condition where they simultaneously performed an executive-component task. Arithmetic-problem characteristics were manipulated in order to test strategy selection (i.e., choice of appropriate strategies in order to improve performance) and strategy execution (i.e., performance of the cognitive processes involved in each strategy). Results revealed that strategy selection changes with age: Older adults mainly selected one type of strategies in contrast to younger adults who used several types of strategies. These age-related changes were similar in the control and dual-task conditions. Strategy execution also changed with age, as shown by larger age-related differences on hardest problems. These age-related changes were larger in the dual-task condition, compared to the control condition. This impact of executive components as mediator of age-related changes depended on general age-related slowing. We discuss these findings in order to further understand the effects of age on arithmetic performance.     

Cognitive and linguistic skills in Swedish children with cochlear implants - measures of accuracy and latency as indicators of development

The purpose of the present study was to examine working memory (WM) capacity, lexical access and phonological skills in 19 children with cochlear implants (CI) (5;7-13;4 years of age) attending grades 0-2, 4, 5 and 6 and to compare their performance with 56 children with normal hearing. Their performance was also studied in relation to demographic factors. The findings indicate that children with CI had visuospatial WM capacities equivalent to the comparison group. They had lower performance levels on most of the other cognitive tests. Significant differences between the groups were not found in all grades and a number of children with CI performed within 1 SD of the mean of their respective grade-matched comparison group on most of the cognitive measures. The differences between the groups were particularly prominent in tasks of phonological WM. The results are discussed with respect to the effects of cochlear implants on cognitive development.     

Beyond the Class Norm: Bullying Behavior of Popular Adolescents and its Relation to Peer Acceptance and Rejection

This study examined to what extent bullying behavior of popular adolescents is responsible for whether bullying is more or less likely to be accepted or rejected by peers (popularity-norm effect) rather than the behavior of all peers (class norm). Specifically, the mean level of bullying by the whole class (class norm) was split into behavior of popular adolescents (popularity-norm) and behavior of non-popular adolescents (non-popularity-norm), and examined in its interaction with individual bullying on peer acceptance and peer rejection. The data stem from a peer-nominations subsample of TRAILS, a large population-based sample of adolescent boys and girls (N = 3312). The findings of multilevel regression analyses demonstrated that the negative impact of individual bullying on peer acceptance and the positive impact on peer rejection were particularly weakened by bullying by popular adolescents. These results place the class-norm effects found in previous person-group dissimilarity studies in a different light, suggesting that particularly bullying by popular adolescents is related to the social status attached to bullying.

Investment in body image for self-definition results in greater vulnerability to the thin media than does investment in appearance management

This study investigated the effect of thin images according to two dimensions of body-image (BI) investment. Ninety-five females were classified as high or low investors based on the Appearance Schemas Inventory-Revised Self-Evaluative Salience (SES) and Motivational Salience (MS) subscales. Participants viewed advertisements portraying either the thin ideal or products. Results indicated that both women high in SES and MS reported lowered appearance self-esteem but greater BI importance following thin exposures. However, only the high SES group reported greater BI dissatisfaction and importance of current-ideal discrepancies after seeing thin images. Although highly invested women (regardless of their motivation for investment) are more responsive to thin media images than are women low in investment, those invested for self-definition are affected on more dimensions than are those invested for appearance management.     

Graphical representation fosters discovery in the 2-4-6 task

In the 2-4-6 rule discovery task, reasoners seek to discover a rule that governs the arrangement of three numbers (or triple). The to-be-discovered rule is “ascending numbers”. Upon being given the triple 2-4-6 as an initial example, however, reasoners tend to formulate algebraically specific hypotheses. Traditionally, this task is conducted primarily from an internal representation of the triples and candidate hypotheses. More recently, substantial representational effects have been demonstrated wherein an external representation of the dimensions of the problem space facilitated successful rule discovery. In the two experiments reported here, an interactive graphical representation was created by concurrently plotting each triple produced by the participants. In Experiment 1, participants who performed the task with this external representation were more likely to discover the rule than were a group of control participants. Experiment 2 replicated the effect but also assessed participants' hypotheses for each triple generated. Results indicated that a graphical representation of the triples fostered the development of hypotheses that were less constrained by the implied algebraic specificity of the initial triple.     

Spatial associations in relational reasoning: evidence for a SNARC-like effect

Relational reasoning (A > B, B > C, therefore A > C) shares a number of similarities with numerical cognition, including a common behavioural signature, the symbolic distance effect. Just as reaction times for evaluating relational conclusions decrease as the distance between two ordered objects increases, people need less time to compare two numbers when they are distant (e.g., 2 and 8) than when they are close (e.g., 3 and 4). Given that some remain doubtful about such analogical representations in relational reasoning, we determine whether numerical cognition and relational reasoning have other overlapping behavioural effects. Here, using relational reasoning problems that require the alignment of six items, we provide evidence showing that the subjects' linear mental representation affects motor performance when evaluating conclusions. Items accessible from the left part of a linear representation are evaluated faster when the response is made by the left, rather than the right, hand and the reverse is observed for items accessible from the right part of the linear representation. This effect, observed with the prepositions to the left of and to the right of as well as with above and below, is analogous to the SNARC (Spatial Numerical Association of Response Codes) effect, which is characterized by an interaction between magnitude of numbers and side of response.     

Quality of Life in Patients with Recurrent Vasovagal or Unexplained Syncope: Influence of Sex, Syncope Type and Illness Representations

Health-related quality of life (QoL) is reduced in patients with recurrent vasovagal (VVS) or unexplained (US) syncope. Little is known regarding these patients’ QoL as pertains to their capacity to attain their life goals. Factors influencing QoL, such as sex, syncope type and illness representations have not been studied. Our objective is to examine the relationship between illness representations and QoL, as well as possible sex and syncope type differences. One hundred and four patients undergoing tilt-table testing (TTT) for recurrent syncope were interviewed one month before TTT, using questionnaires. Data were analysed using ANCOVAs, a-priori Helmert contrasts for illness representations, and regressions. Patients with US had a poor QoL compared to those with VVS [F(1, 91) = 10.46; p < 0.01], particularly in men (p < 0.01). Patients with higher perceived syncope severity showed an impoverished QoL relative to those with less severe perceptions [F(1, 91) = 5.47; p < 0.05]. A hierarchical regression revealed that illness representations mediate the impact of lifetime number of syncope on QoL. In conclusion, QoL is reduced in these patients, and is influenced by illness representations. Helping patients change their perceptions about their syncope may be an efficient way to promote QoL.