Older adults’ associative deficit in episodic memory: Assessing the role of decline in attentional resources

In this study, we evaluated an associative deficit hypothesis. This hypothesis suggests that the deficit seen in the episodic memory performance of older adults is due, in considerable part, to older adults’ difficulty in binding together unrelated components of an episode into a cohesive entity (Naveh-Benjamin, 2000). The study extended the conditions under which older adults show a differential deficit in tests requiring associations among the episode components to situations in which the item and the associative recognition tests are equated on the response mode used and on the amount of information displayed. In addition, we tested the potential role of a decrease in attentional resources in the associative deficit of older adults by comparing their performance to that of younger adults under conditions of reduced attentional resources. The results of the study, which indicate that younger adults under divided attention do not show an associative deficit, are interpreted as indicating that the associative deficit of older adults is due to factors other than depleted attentional resources.     

Obsessive-compulsive disorder subtypes: an attempted replication and extension of a symptom-based taxonomy

A symptom-based subgroup taxonomy for obsessive-compulsive disorder (OCD) was evaluated and refined. The Yale-Brown Obsessive-Compulsive Scale symptom checklist was scored and cluster analysis was conducted with a sample of OCD patients (N = 114). Results were compared to Calamari et al.'s (Behaviour Research and Therapy 37 (1999) 113) five subgroup model. Rules for determining the number of subgroups supported a more complex model. In between sample comparisons, a stable contamination subgroup was found in both a five and seven subgroup taxonomy. Between sample stability was not as strong for Harming, Obsessionals, Symmetry, and Certainty subgroups. Hoarding, as a distinctive subgroup, was unstable in separate samples. When the Calamari et al. sample and the present sample were combined (N = 220), we found a reliable Hoarding subgroup. More interpretable and stable models emerged with the combined samples suggesting that large clinical samples are needed to identify OCD subgroups. Greater support was found for a seven subgroup taxonomy based subgroup interpretability and validation measure differences. The potential utility of symptom-based subgroup models of OCD and alternative approaches are discussed. Identification of reliable and valid OCD subtypes may advance theory and treatment.     

Self-reported attachment, interpersonal aggression, and personality disorder in a prospective community sample of adolescents and adults

Anxious and avoidant attachment were assessed in the Children in the Community (CIC) Study during adolescence and adulthood using self-report scales developed for this prospective study. The convergent and discriminant validity of the new CIC attachment scales were evaluated and their stability was assessed across a 17-year interval. Attachment scales predicted DSM-IV personality disorders in theoretically coherent and clinically meaningful ways, especially when supplemented with a separate measure of interpersonal aggression. Cluster B and C personality disorder symptoms were associated with elevated anxious attachment. Avoidant attachment was positively associated with Cluster A symptoms and inversely associated with Cluster B and C symptoms. Interpersonal aggression was higher in Cluster B symptoms and lower in Cluster C symptoms, thus differentiating between these symptom clusters.     

Behavioral interference and C/EBPbeta expression in the insular-cortex reveal a prolonged time period for taste memory consolidation

Memory consolidation is defined as the time window during which the memory trace is susceptible to behavioral, electrical, or pharmacological interventions. Here, we presented rats with two novel tastes at consecutive time intervals. Clear interference was evident when a novel taste formed the second taste input whereby, surprisingly, the time window for interference was found to last more than 10 h. In addition, we detected an increase of C/EBPbeta protein expression in the gustatory cortex 18 h after novel taste learning. This modulation was attenuated by a subsequent novel taste. Our findings reveal temporal constraints and a lingering nature of taste memory consolidation.     

Cross-language lexical connections in the mental lexicon: evidence from a case of trilingual aphasia

Despite anecdotal data on lexical interference among the languages of multilingual speakers, little research evidence about the lexical connections among multilinguals' languages exists to date. In the present paper, two experiments with a multilingual speaker who had suffered aphasia are reported. The first experiment provides data about inter-language activation during natural conversations; the second experiment examines performance on a word-translation task. Asymmetric patterns of inter-language interference and translation are evident. These patterns are influenced by age of language learning, degree of language recovery and use, and prevalence of shared lexical items. We conclude that whereas age of language learning plays a role in language recovery following aphasia, the degrees of language use prior to the aphasia onset and of shared vocabulary determine the ease with which words are accessed. The findings emphasize the importance of patterns of language use and the relations between the language pair under investigation in understanding lexical connections among languages in bilinguals and multilinguals.     

Effects of task interdependence and communication technologies synchrony on performance in virtual teams

Effects of task interdependence and communication technologies synchrony on performance in virtual teams. Survey results of 197 employees from 41 work groups in a large multinational software firm were used to investigate the effects of within-group task interdependence and the degree of communication synchrony on performance in virtual teams (VTs). The analyses revealed a moderating effect of task interdependence on the relationship between the degree of communications synchrony and performance in VT. We found that superior VTs performance is contingent on the fit between the nature of the task (i.e., task interdependence) and the choice of communications modality. This study complements previous research providing additional evidence of how task-technology interaction affects VTs performance, and extends previous findings obtained with ad-hoc groups in laboratory settings to natural, organizational teams.     

Contextual knowledge reduces demands on working memory during reading

An experiment is reported in which young, middle-aged, and older adults read and recalled ambiguous texts either with or without the topic title that supplied contextual knowledge. Within each of the age groups, the participants were divided into those with high or low working memory (WM) spans, with available WM capacity further manipulated by the presence or absence of an auditory target detection task concurrent with the reading task. Differences in reading efficiency (reading time per proposition recalled) between low WM span and high WM span groups were greater among readers who had access to contextual knowledge relative to those who did not, suggesting that contextual knowledge reduces demands on WM capacity. This position was further supported by the finding that increased age and attentional demands, two factors associated with reduced WM capacity, exaggerated the benefits of contextual knowledge on reading efficiency. The relative strengths of additional potential predictors of reading efficiency (e.g., interest, effort, and memory beliefs), along with knowledge, WM span, and age, are reported. Findings showed that contextual knowledge was the strongest predictor of reading efficiency even after controlling for the effects of all of the other predictors.     

The physics of optimal decision making: a formal analysis of models of performance in two-alternative forced-choice tasks

In this article, the authors consider optimal decision making in two-alternative forced-choice (TAFC) tasks. They begin by analyzing 6 models of TAFC decision making and show that all but one can be reduced to the drift diffusion model, implementing the statistically optimal algorithm (most accurate for a given speed or fastest for a given accuracy). They prove further that there is always an optimal trade-off between speed and accuracy that maximizes various reward functions, including reward rate (percentage of correct responses per unit time), as well as several other objective functions, including ones weighted for accuracy. They use these findings to address empirical data and make novel predictions about performance under optimality.     

The role of perceived similarity in supportive responses to victims of negative life events

The authors examined whether participants' perceived similarity to an ostensible victim of a negative life event influenced their supportiveness during a live interaction. Two competing models were considered: (a) increased similarity would be associated with increased supportiveness through attraction to the target and (b) increased similarity would be associated with decreased supportiveness through anxiety (due to heightened vulnerability). Participants (N = 241) met individually with a confederate posing as a cancer patient. Reactions were assessed, including verbal and nonverbal behaviors, both before and after the interaction, by participants themselves and by observers of the interaction. Results supported a model based on the classic similarity/attraction paradigm: Perceived similarity indirectly predicted participant-reported supportiveness/warmth and smiling through its relationship to attraction. Results extend the literature on similarity and attraction to the stress and coping arena and suggest that emphasizing perceived similarities to victims would be beneficial.     

Group morality and intergroup relations: cross-cultural and experimental evidence

An observational, cross-cultural study and an experimental study assessed behaviors indicative of a moral code that condones, and even values, hostility toward outgroups. The cross-cultural study, which used data from the Standard Cross-Cultural Sample (Murdock & White, 1969), found that for preindustrial societies, as loyalty to the ingroup increased the tendency to value outgroup violence more than ingroup violence increased, as did the tendencies to engage in more external than internal warfare, and enjoy war. The experimental study found that relative to guilt-prone group members who were instructed to remain objective, guilt-prone group members who were instructed to be empathic with their ingroup were more competitive in an intergroup interaction. The findings from these studies suggest that group morality is associated with intergroup conflict.