Effects of d-amphetamine and strychnine on cycloheximide- and diethyldithiocarbamate-induced amnesia in mice.

Groups of C57BL/6J mice were administred cycloheximide (CYC) 30 min before or immediately after training on a passive avoidance task and tested 72 hr later. Some CYC-pretreated groups were given strychnine or d-amphetamine (d-amp) immediately after training and others were given d-amp 1 hr after training. Other groups were given diethyldithiocarbamate (DDC) at various times before or after training. Some DDC-pretreated groups were gived-amp or strychnine as described above for CYC groups. Immediate posttraining administration of 5 mg/kg d-amp, but not strychnine, prevented amnesia in CYC-pretreated mice. The DDC induced an apparent amnesia when administered from 30 min before training to 3 hr after training. Posttraining administration of d-amp or strychnine did not prevent DDC-induced amnesia. These results are discussed in relation to previous suggestions that CYC- and DDC-induced amnesia may be the result of a functional impairment of catecholamine neurotransmitter systems by these drugs.     

Self-punishment as a regulation strategy in borderline personality disorder

Studies using the Thought Control Questionnaire (TCQ; Wells & Davies, 1994) suggest that the tendency to use self-punishment (e.g., shouting at oneself) in order to control unpleasant internal experiences (e.g., cognitive and emotional) is associated with psychopathology. To evaluate the role of self-punishment in borderline personality disorder (BPD), we first examined whether TCQ scales, including Self-Punishment, were different among adults with BPD (n = 31) when compared to those with other personality disorders (OPD; n = 24), elevated symptoms of major depressive disorder (MDD; n = 24), and healthy controls (n = 105). Findings indicated that Self-Punishment was elevated in the BPD group relative to other groups. Next, Self-Punishment was examined as a potential mediator in the relationship between negative affectivity and BPD symptom severity in all participants. Results indicated that Self-Punishment did not mediate this relationship, but did account for significant variance in BPD symptoms over and above negative affectivity. Implications and future research directions are discussed.     

Two-component theory of the suffix effect: Contrary evidence

The suffix effect is the selective impairment in recall of the final items of a spoken list when the list is followed by a nominally irrelevant speech item, or suffix. It is widely assumed to comprise a bottom-up, or structural, effect restricted to the terminal item and a top-down, or conceptually sensitive, effect confined to the preterminal items. Reported here are eight experiments that challenge this view by demonstrating that the terminal suffix effect, as well as the preterminal suffix effect, is susceptible to conceptual influence. The entire suffix effect may be better conceived of as a phenomenon arising from perceptual grouping.     

Heightened sensitivity to facial expressions of emotion in borderline personality disorder

Individuals with borderline personality disorder (BPD) have been hypothesized to exhibit significant problems associated with emotional sensitivity. The current study examined emotional sensitivity (i.e., low threshold for recognition of emotional stimuli) in BPD by comparing 20 individuals with BPD and 20 normal controls on their accuracy in identifying emotional expressions. Results demonstrated that, as facial expressions morphed from neutral to maximum intensity, participants with BPD correctly identified facial affect at an earlier stage than did healthy controls. Participants with BPD were more sensitive than healthy controls in identifying emotional expressions in general, regardless of valence. These findings could not be explained by participants with BPD responding faster with more errors. Overall, results appear to support the contention that heightened emotional sensitivity may be a core feature of BPD.     

Comparison and contrast in perceptual categorization

People categorized pairs of perceptual stimuli that varied in both category membership and pairwise similarity. Experiments 1 and 2 showed categorization of 1 color of a pair to be reliably contrasted from that of the other. This similarity-based contrast effect occurred only when the context stimulus was relevant for the categorization of the target (Experiment 3). The effect was not simply owing to perceptual color contrast (Experiment 4), and it extended to pictures from common semantic categories (Experiment 5). Results were consistent with a sign-and-magnitude version of N. Stewart and G. D. A. Brown's (2005) similarity-dissimilarity generalized context model, in which categorization is affected by both similarity to and difference from target categories. The data are also modeled with criterion setting theory (M. Treisman & T. C. Williams, 1984), in which the decision criterion is systematically shifted toward the mean of the current stimuli.