The difference engine: A model of diversity in speeded cognition

A theory of diversity in speeded cognition, the difference engine, is proposed, in which information processing is represented as a series of generic computational steps. Some individuals tend to perform all of these computations relatively quickly and other individuals tend to perform them all relatively slowly, reflecting the existence of a general cognitive speed factor, but the time required for response selection and execution is assumed to be independent of cognitive speed. The difference engine correctly predicts the positively accelerated form of the relation between diversity of performance, as measured by the standard deviation for the group, and task difficulty, as indexed by the mean response time (RT) for the group. In addition, the difference engine correctly predicts approximately linear relations between the RTs of any individual and average performance for the group, with the regression lines for fast individuals having slopes less than 1.0 (and positive intercepts) and the regression lines for slow individuals having slopes greater than 1.0 (and negative intercepts). Similar predictions are made for comparisons of slow, average, and fast subgroups, regardless of whether those subgroups are formed on the basis of differences in ability, age, or health status. These predictions are consistent with evidence from studies of healthy young and older adults as well as from studies of depressed and age-matched control groups.     

Family transactions and relapse in bipolar disorder

This study examined whether patient symptoms and relatives' affective behavior, when expressed during directly observed family interactions, are associated with the short-term course of bipolar disorder. Twenty-seven bipolar patients and their relatives participated in two 10-minute family interactions when patients were discharged after a manic episode. Results indicated that patients who showed high levels of odd and grandiose thinking during the interactions were more likely to relapse during a 9-month followup period than patients who did not show these symptoms during the family discussions. Relapse was also associated with high rates of harshly critical and directly supportive statements by relatives. Patients' odd thinking and relatives' harsh criticism were significantly more likely to be correlated when patients relapsed (r = .53) than when they did not relapse (r = .12). Results suggest that bipolar patients who show increased signs of residual symptomatology during family transactions during the post-hospital period are at increased relapse risk. The data also suggest that relatives of relapsing patients cope with these symptoms by increasing both positive and negative affective behaviors. Moreover, a bidirectional, interactional relationship between patients' symptoms and relatives' coping style seems to capture best the role of the family in predicting relapse in bipolar disorder.     

A Computational Evaluation of Sentence Processing Deficits in Aphasia

Individuals with agrammatic Broca's aphasia experience difficulty when processing reversible non‐canonical sentences. Different accounts have been proposed to explain this phenomenon. The Trace Deletion account (Grodzinsky, 1995, 2000, 2006) attributes this deficit to an impairment in syntactic representations, whereas others (e.g., Caplan, Waters, Dede, Michaud, & Reddy, 2007; Haarmann, Just, & Carpenter, 1997) propose that the underlying structural representations are unimpaired, but sentence comprehension is affected by processing deficits, such as slow lexical activation, reduction in memory resources, slowed processing and/or intermittent deficiency, among others. We test the claims of two processing accounts, slowed processing and intermittent deficiency, and two versions of the Trace Deletion Hypothesis (TDH), in a computational framework for sentence processing (Lewis & Vasishth, 2005) implemented in ACT‐R (Anderson, Byrne, Douglass, Lebiere, & Qin, 2004). The assumption of slowed processing is operationalized as slow procedural memory, so that each processing action is performed slower than normal, and intermittent deficiency as extra noise in the procedural memory, so that the parsing steps are more noisy than normal. We operationalize the TDH as an absence of trace information in the parse tree. To test the predictions of the models implementing these theories, we use the data from a German sentence—picture matching study reported in Hanne, Sekerina, Vasishth, Burchert, and De Bleser (2011). The data consist of offline (sentence‐picture matching accuracies and response times) and online (eye fixation proportions) measures. From among the models considered, the model assuming that both slowed processing and intermittent deficiency are present emerges as the best model of sentence processing difficulty in aphasia. The modeling of individual differences suggests that, if we assume that patients have both slowed processing and intermittent deficiency, they have them in differing degrees.     

A Gender Analysis of Theories of Coping with Stress

In this article, various feminist theories are used to critique selected psychological theories of coping with stress, a reformulated coping theory is outlined, and recommendations for future research are made. To date, theories of coping often portray women as less able copers than the samples of men with whom they are compared. A reformulated theory, based on different women's experiences, explicitly examines the role of social forces (sexism, racism) and access to power as variables in the coping process rather than solely focusing on the individual. Selected examples of research that contribute to such a revision are given. Revised theories and methodologies will encourage the more accurate appraisal of women's coping abilities and generate information vital to the creation of more inclusive and representative theories of coping.     

Inducing a Rule in Wason's 2-4-6 Task: A Test of the Information-Quantity and Goal-Complementarity Hypotheses

In the standard 2-4-6 induction task, subjects are instructed to discover the rule generating sequences of three numbers by inventing number triples for which they receive immediate feedback. The rule is “ascending numbers”. Performance is greatly aided with Dual Goal (DG) instructions that ask subjects to discover two rules, one that generates “Dax” triples (equivalent to “yes” instances with Single Goal [SG] instructions) and another that generates “Med” triples (equivalent to “no” instances). The present study eliminates two explanations for this effect suggested by Wharton, Cheng, and Wickens (1993). Experiment 1 tested their Information-Quantity hypothesis that the effect results simply from the DG subjects testing more triples prior to proposing a rule. Our DG subjects were more likely to solve the problem and produced more “negative” triples than SG subjects when both groups generated exactly 15 triples. Two further groups received feedback only after generating all 15 triples, and again DG subjects were more likely to solve the problem and to generate more “negative” triples. Experiment 2 tested Wharton et al.'s Goal-Complementarity hypothesis that success under DG instructions hinges on preserving the complementary representation of the two rules. We compared SG instructions with three types of DG instructions that suggested different types of triples (Dax, Med, both Dax and Med, neither Dax nor Med). DG instructions were more effective in promoting successful rule discovery regardless of differences in rule complementarity. Our analysis of the heterogeneity of the examplars generated with DG instructions in both experiments suggest that success on the 2-4-6 task is as much a consequence of the breadth of hypotheses that subjects entertain as it is a consequence of the testing strategy.     

Off-task Behaviours and Outcomes: An Exploratory Investigation of a Neglected Domain in Organisational Behaviour

Bien que les travailleurs s'adonnent à la fois à nombre de tâches formelles et informelles, les recherches centrées sur le comportement organisationnel s'intéressent préférentiellement aux conduites formelles et à leur produit. Quand l'attention se porte sur les comportements informels, c'est généralement pour les atténuer ou les éliminer. On soutient dans cet article que les comportements informels doivent être pris en considération même si c'est la tâche à accomplir qui est l'objet de la problématique. On a, dans deux recherches exploitant des échantillons de 133 et 137 individus, relevé une série de comportements informels et étudié la relation entre leur fréquence d'apparition et la satisfaction. Les implications des comportements informels sont analysées du point de vue de la nature changeante du travail.
Although people at work engage in a number of on-task and off-task behaviours, the preponderance of behavioural research in organisations is directed towards on-task behaviours and the outcomes resulting from them. When attention is paid to off-task behaviours, it is usually directed at decreasing or eliminating such behaviours. The position taken here is that off-task behaviours must be understood even if our concern is with task behaviour. Two studies, with samples of 137 and 133 persons, identified a subset of off-task behaviours and explored the relationship of their reported occurrence to job satisfaction. Implications of off-task behaviour at work are discussed with respect to the changing nature of work.