Sleep deprivation selectively impairs memory consolidation for contextual fear conditioning

Many behavioral and electrophysiological studies in animals and humans have suggested that sleep and circadian rhythms influence memory consolidation. In rodents, hippocampus-dependent memory may be particularly sensitive to sleep deprivation after training, as spatial memory in the Morris water maze is impaired by rapid eye movement sleep deprivation following training. Spatial learning in the Morris water maze, however, requires multiple training trials and performance, as measured by time to reach the hidden platform is influenced by not only spatial learning but also procedural learning. To determine if sleep is important for the consolidation of a single-trial, hippocampus-dependent task, we sleep deprived animals for 0–5 and 5–10 h after training for contextual and cued fear conditioning. We found that sleep deprivation from 0–5 h after training for this task impaired memory consolidation for contextual fear conditioning whereas sleep deprivation from 5–10 h after training had no effect. Sleep deprivation at either time point had no effect on cued fear conditioning, a hippocampus-independent task. Previous studies have determined that memory consolidation for fear conditioning is impaired when protein kinase A and protein synthesis inhibitors are administered at the same time as when sleep deprivation is effective, suggesting that sleep deprivation may act by modifying these molecular mechanisms of memory storage.     

Executive and visuospatial sketchpad resources in euthymic bipolar disorder: Implications for visuospatial working memory architecture

Visuospatial working memory theory is used to interpret the cognitive impairment in euthymic bipolar disorder. Such patients show deficits in the Corsi Blocks Test (CBT) and executive control. To understand these deficits, 20 euthymic bipolar patients and controls were administered the CBT, Visual Patterns Test (VPT), and a new visual memory task designed to make minimal demands on executive resources. Initial analyses validated the visual memory task and implicated executive involvement in the CBT and VPT. Subsequent analyses on a number of tests confirmed CBT and executive deficits while performance was normal on the VPT and visual memory test. ANCOVA indicated that impaired executive function underpinned patients' CBT performance. Implications for the interface between executive and slave systems of working memory are discussed.     

Self- and other-reports of traits from the five-factor model: relations to personality disorder

The current study used a psychiatric sample (N = 69) to examine: (1) the correspondence between self- and other-reports of general personality, as measured by the Five-Factor Model (FFM; Costa & McCrae, 1990), and personality disorder (PD) traits, as measured by a structured interview, (2) the relations between these two sets of ratings (FFM and PD traits) and consensus ratings of PD and impairment, and (3) the incremental validity of other-rated personality scores. Agreement between raters for the five domains of the FFM ranged from .23 (agreeableness) to .71 (openness); for the PD traits agreement ranged from .37 (avoidant) to .69 (antisocial). At both the domain and facet level, the personality profiles reflected in the correlations between the FFM scores and PD criteria were consistent across raters with the exception of narcissistic PD. Substantial evidence was found for the incremental validity of other-rated personality scores, with these ratings accounting for an additional 8 to 20% of the overall variance in PD features. The other-rated FFM scores also accounted for more variance in consensus ratings of impairment in the domains of romance, work, and social relations.     

Self- and peer perspectives on pathological personality traits and interpersonal problems

This study compares the relationship between personality disorders and interpersonal problems as obtained by self-report and peer-report measures. Participants (N = 393) were administered self- and peer-report versions of the Peer Inventory for Personality Disorder and the Inventory of Interpersonal Problems-64. Canonical analyses demonstrated similar relationships between personality disorder features and interpersonal problems as measured by either self or peer. Analyses between self and peer found little shared variance across sources, indicating a large method variance. Results indicate that although similar constructs are identified by self and peers in their understanding of personality pathology and associated interpersonal problems, self-report information overlaps very little with information obtained from peers, underscoring the importance of obtaining multiple sources of information.     

Do lonely days invade the nights? Potential social modulation of sleep efficiency

Loneliness predicts morbidity and mortality from broad-based causes, but the reasons for this effect remain unclear. Few differences in traditional health behaviors (e.g., smoking, exercise, nutrition) have been found to differentiate lonely and nonlonely individuals. We present evidence that a prototypic restorative behavior—sleep—does make such a differentiation, not through differences in time in bed or in sleep duration, but through differences in efficacy: In the study we report here, lonely individuals evinced poorer sleep efficiency and more time awake after sleep onset than nonlonely individuals. These results, which were observed in controlled laboratory conditions and were found to generalize to the home, suggest that lonely individuals may be less resilient than nonlonely individuals in part because they sleep more poorly. These results also raise the possibility that social factors such as loneliness not only may influence the selection of health behaviors but also may modulate the salubrity of restorative behaviors.     

Search performance with discrete-cell stimulus arrays: filtered naturalistic images and probabilistic markers

In order to partially fill the gap between search studies with artificial and naturalistic stimuli, experiments with segmented and spatially filtered images of real stimuli in the discrete cells of search arrays were conducted. RT × set size functions obtained with the spatially filtered arrays were compared with those obtained with geometric and other types of arrays. With the aid of Fourier analysis, components of target certainty/uncertainty, target-distractor similarity/dissimilarity, and distractor homogeneity/heterogeneity were evaluated for their effects on search performance and efficiency. The comparative effects of valid/invalid and ambiguous/unambiguous markers of search items were included in the experiments to probe the potential contributions of top-down and bottom-up control to search with naturalistic stimuli. Visual coding in the form of spatial frequency passbands and top-down preferences for distractor search were used to explain the results.     

Toward an Analytical Model of Ethical Decision Making in Plagiarism

Plagiarism by students is a common and worldwide phenomenon with a significant impact on our society. Numerous studies on the pervasive nature of plagiarism among students have focused on the behavioral aspects of plagiarism and how to prevent it. Based on an empirical study of a sample of 463 eighth graders in Hong Kong, this article offers an analytical model to understand the ethical decision-making process in plagiarism among students. Using this model, students' plagiaristic behavior can be analyzed in terms of their moral judgment, moral intensity, and perceived risks.     

Measuring consciousness in dreams: The lucidity and consciousness in dreams scale

In this article, we present results from an interdisciplinary research project aimed at assessing consciousness in dreams. For this purpose, we compared lucid dreams with normal non-lucid dreams from REM sleep. Both lucid and non-lucid dreams are an important contrast condition for theories of waking consciousness, giving valuable insights into the structure of conscious experience and its neural correlates during sleep. However, the precise differences between lucid and non-lucid dreams remain poorly understood. The construction of the Lucidity and Consciousness in Dreams scale (LuCiD) was based on theoretical considerations and empirical observations. Exploratory factor analysis of the data from the first survey identified eight factors that were validated in a second survey using confirmatory factor analysis: INSIGHT, CONTROL, THOUGHT, REALISM, MEMORY, DISSOCIATION, NEGATIVE EMOTION, and POSITIVE EMOTION. While all factors are involved in dream consciousness, realism and negative emotion do not differentiate between lucid and non-lucid dreams, suggesting that lucid insight is separable from both bizarreness in dreams and a change in the subjectively experienced realism of the dream.