Exploring the within-person coupling of sleep and cognition in older African Americans

This study examined the within-person relationship between sleep and cognitive functioning. Fifty community-dwelling African Americans (age range = 50-80 years) were asked to report their sleep duration and quality the previous evening and to complete cognitive measures over 8 occasions within a 2-3 week period. A within-person daily change in sleep duration was significantly associated with worse global cognitive performance. The greater an individual deviated away from his or her average sleep duration on a particular day, the more likely his or her performance would decline. These results demonstrate that the sleep-cognition relationship can be observed at a within-person level of analysis.     

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.     

The communicative functions of touch in humans, nonhuman primates, and rats: a review and synthesis of the empirical research

Although touch is one of the most neglected modalities of communication, several lines of research bear on the important communicative functions served by the modality. The authors highlighted the importance of touch by reviewing and synthesizing the literatures pertaining to the communicative functions served by touch among humans, nonhuman primates, and rats. In humans, the authors focused on the role that touch plays in emotional communication, attachment, bonding, compliance, power, intimacy, hedonics, and liking. In nonhuman primates, the authors examined the relations among touch and status, stress, reconciliation, sexual relations, and attachment. In rats, the authors focused on the role that touch plays in emotion, learning and memory, novelty seeking, stress, and attachment. The authors also highlighted the potential phylogenetic and ontogenetic continuities and discussed suggestions for future research.