Habitual sleep duration and eating disorders in college students

To measure the relationship between habitual sleep duration and eating disorders, the responses of groups of 34 short- and 43 longer-sleeping college students to the EAT-26 Test were compared. The short-sleepers scored twice as high and were five times more likely to exhibit abnormal eating patterns than the longer-sleeping group.     

The repetition effect in time judgments is not a function of the intensity of the stimulus defining the interval: implications for an arousal theory

College students (N = 17 per group) estimated the durations of time intervals ranging from 8 to 20 sec. Intervals were defined by tones of 35, 55, and 75 db for each of three groups. The estimates of all groups declined across trials, but the degree of decline did not differ as a function of stimulus intensity. These data call into question the view that the repetition effect is attributable to a decrement in general arousal.     

Correlation between handedness and birth order: compilation of five studies

Bakan has suggested that left-handedness is the result of left hemishperic pyramidal motor dysfunction following perinatal hypoxia. To a degree support for the validity of this hypothesis rests on Bakan's (1971, 1977a) findings that left-handed college students were more likely the progeny of birth orders designated as "high-risk" than right-handed students. Attempts by others to replicate Bakan's data have been unsuccessful. To achieve a more powerful test of this relationship than has been provided by any single study, the data from the five studies which have considered it were pooled and tested. The resulting correlation between birth order and handedness was near zero.     

Task interference from prospective memories covaries with contextual associations of fulfilling them

One of the current issues in the field of prospective memory concerns whether having an intention produces a cost to other ongoing activities (called task interference). The evidence to date suggests that certain intentions held over the shorter term do interfere with other tasks. Because the cumulative effect of such costs would be prohibitively expensive in everyday life, the present study examined one means by which that interference may be reduced. Participants who formed a specific association to fulfilling an intention in a future context did not exhibit task interference over the intervening period until that context was encountered. This outcome was observed with both an event-based and a time-based prospective memory task. The results suggest that associating intention fulfillment with a specific context can eliminate task interference, and they emphasize the importance of studying intentions that are linked to future contexts versus those that are not.     

The effect of context variability on source memory

High-context-variability (HCV) items are experienced in many more preexperimental semantic contexts than are low-context-variability (LCV) items. LCV confers an advantage to recognition memory (Steyvers & Malmberg, 2003). In the present study, we tested whether or not that advantage could be causedby enhanced source memory. Both context variability and word frequency were manipulated, and both factors generally affected source monitoring. Accuracy was better for LCV items than for HCV items and better for low- than for high-word-frequency items. We also considered whether context variability exerts its influence at encoding or at retrieval. We concluded that better recognition memory for LCV items was due, in part, to better retrieval of contextual details that specify how an item was originally studied.     

Relations between psychopathy facets and externalizing in a criminal offender sample

The construct of psychopathy is viewed as comprising distinctive but correlated affective-interpersonal and social deviance facets. Here, we examined these facets of Hare's Psychopathy Checklist-Revised (PCL-R) in terms of their associations with the externalizing dimension of adult psychopathology, defined as the common factor underlying symptoms of conduct disorder, adult antisocial behavior, alcohol use/abuse, and drug abuse, along with disinhibitory personality traits. Correlational analyses revealed a strong relationship between this externalizing dimension and the social deviance facet of psychopathy (r = .84), and a lesser relationship with the emotional-interpersonal component (r = .44). Structural models controlling for the moderate overlap between the PCL-R factors revealed that externalizing was substantially related to the unique variance in the social deviance features of psychopathy, but unrelated to the unique variance of the emotional and interpersonal features whether modeled together or as separate factors. These results indicate that the social deviance factor of the PCL-R reflects the externalizing dimension of psychopathology, whereas the emotional-interpersonal component taps something distinct aside from externalizing. In addition, based on our finding of an association between PCL-R social deviance and externalizing, we were able to predict new relations between this facet of psychopathy and criterion variables, including nicotine use and gambling, that have previously been linked to externalizing. Implications for future research on the causes and correlates of psychopathy are discussed.     

Increase in Syntaxin 1B mRNA in Hippocampal and Cortical Circuits During Spatial Learning Reflects a Mechanism of Trans-synaptic Plasticity Involved in Establishing a Memory Trace

It has long been proposed that the cellular and molecular mechanisms responsible for LTP may well involve the mechanisms that lead to the type of synaptic modification that occurs during learning. However, it is also known that a single memory trace is encoded in spatially distributed networks; implying that alterations of synaptic strength occur at multiple sites along circuits of connected cells. Recent evidence suggests that regulation of the gene encoding syntaxin 1B, a presynaptic protein involved in exocytosis, plays an important role in the mediation of trans-synaptic LTP, a candidate mechanism for the propagation of plasticity in neural circuits during learning. Using in situ hybridization to measure the mRNA levels at different time points after learning a spatial working or reference memory task, we show that expression of the gene encoding this protein in the hippocampal and corticoprefrontal circuits increases linearly with performance at a critical window of learning when rats are reaching between 75% and 100% of their maximal performance. No changes were observed during the early phases of learning or when rats where overtrained. The correlational analysis indicates that coordinated increases in syntaxin 1B expression occurs in hippocampal circuits during working memory and in more widespread hippocampocortical circuits during reference memory. These results suggest that a form of trans-synaptic plasticity mediated in part by regulation of the expression of syntaxin 1B may play an active role in configuring specific spatially distributed circuits during the laying down of memories.     

Treating jealousy as a system dynamic in recovering alcoholic families: An application of the social network model of recovery

Jealousy often interferes with the recovery process for alcoholic families. Recovery for such families requires that external boundaries shift from rigid and closed to open and more permeable. Jealousy often erupts as families struggle with shifting boundaries. When jealousy is recognized as a system dynamic, necessary to the process of recovery, it is manageable. The key to the treatment of jealousy in recovering families is recognizing the crucial role of boundaries in both the development and recovery processes.     

The sleep-promoting behaviors of habitual short- and longer-sleeping adults

Consistent with the view that habitual longer-sleepers are more concerned with their sleep, this group (n = 25) reported engaging in twice as many sleep-promoting behaviors as a group of short-sleepers (n = 25). The longer sleepers tended to use alcohol and the short sleepers food to promote sleep.