Ontogeny of the adrenal response to (+)-methamphetamine in neonatal rats: the effect of prior drug exposure

We examined the ontogeny of the corticosterone response to (+)-methamphetamine in neonatal rats. In experiment-1, animals were injected with 10 mg/kg of (+)-methamphetamine or saline and plasma corticosterone levels were examined in separate groups 30 or 105 min later on postnatal day (P) 1, 3, 5, 7, 9, 11, 13, 15, 17, or 19. The adrenal response to methamphetamine was best described by a U-shaped function with the nadir of corticosterone release occurring between P7 and P13. Experiment-2 was similar except that the effect of four consecutive days of exposure to (+)-methamphetamine (four times daily at 2 h intervals with 10 mg/kg) was assessed with a single final dose early on the fifth day (i.e. P1-5, 3-7, 5-9, 7-11, 9-13, 11-15, 13-17, 15-19). The 30 min corticosterone response after multiple methamphetamine doses was augmented compared to single exposures, with the exception of the two earliest dosing intervals ending on P5 and P7, where the responses were lower. In addition, at 105 min, the levels of corticosterone were attenuated relative to a single drug administration. With the exception of animals receiving methamphetamine from P15 to P19, thymus weights were unaffected. The data demonstrate that (+)-methamphetamine is a robust activator of corticosterone release in developing animals and this release is extensively modified by age and previous drug exposure.     

Individual differences in imagery and reports of aversions

Recent theoretical models highlighting the role of imagery in trauma and aversion learning focus on the role of images in memory (e.g., Brewin, Dalgleish, & Joseph, 1996) and images as substitute stimuli in aversive conditioning (Dadds, Bovbjerg, Redd, & Cutmore, 1997). An unanswered question is whether individual differences in imagery are associated with different rates of traumatisation and aversion states (fear and avoidance of various stimuli). We examine one aspect of this: does high imagery ability correlate with the frequency with which people report aversions? Three samples of university students were tested on the Betts Questionnaire Upon Mental Imagery, the Tellegen Absorption Scale, and a new measure we designed to sample of range of aversions. As hypothesised, vividness of imagery showed positive correlations with number of aversions reported. This relationship held after controlling for general neuroticism and proneness to disgust. Results for absorption showed no relationship. The results are unable to disentangle causal paths but suggest a focus on individual differences in imagery vividness may be fruitful for understanding individual differences in aversion learning.     

TV or not TV? Does the immediacy of viewing images of a momentous news event affect the quality and stability of flashbulb memories?

The flashbulb accounts of 38 participants concerning the September 11th 2001 terrorist attack reported at both 28 hours and 6 months following the event were examined for quantity, quality, and consistency as a function of the time lapse between first learning of the event and initial viewing of media images. The flashbulb accounts of those who reported seeing images at least an hour after learning of the event differed qualitatively, but not quantitatively, from accounts of participants who reported seeing images at the same time as or within minutes of learning of the event. Delayed viewing of images resulted in less elaborate and generally less consistent accounts across the 6-month interval. The results are discussed in terms of factors affecting flashbulb memory formation and individual differences in connectedness to the event.     

Psychometric evaluation of the eating disorder inventory (edi) in a clinical group

Abstract

This study examined the psychometric properties of the Eating Disorder Inventory (EDI) with a clinical sample of 79 female clients seen at an outpatient eating disorder program. The means and standard deviations for the bulimia nervosa subgroup in this study (n = 48) compared favorably with the bulimia group in the EDI Manual Supplement (1986) on all eight subscales, except Drive for Thinness. The present non-student sample had significantly lower scores on this particular subscale than did the norm group (mostly students). Another difference was that the local bulimic subgroup had significantly higher present and minimum weights (as a percentage of the expected average weight according to height). The EDI subscales also displayed respectable internal consistency reliability with this sample. In contrast to previous research, however, only five factors were found in a factor analysis rather than eight corresponding to the original subscales for the EDI. Differences between bulimic and a not-otherwise-specified (NOS) diagnostic groups were also found on both the EDI Ineffectiveness and Bulimia subscales (NOS had lower scores). The results of this study are discussed in terms of the importance of undertaking local standardization of tests in clinical settings.     

Toupee or not toupee? The role of instructional set,centrality, and relevance in change blindness

The influence of instructional set, centrality, and relevance on change blindness was examined. In a one-shot paradigm, participants reported alterations of items across pairs of driving scenes under two different instructional conditions. Alterations involved either relocations or disappearances of the same items and included driving-relevant and driving-irrelevant alterations to items of central and marginal interest. Three main findings emerged: Centrality was not a function of driving relevance/meaningfulness, disappearances of central interest items were identified significantly more often than positional changes to them, and instructions highlighting the importance of the task to driving attenuated change blindness. The possible role of a simple listing strategy in mediating successful identification of alterations is discussed. Together, the findings demonstrate that cognitive factors play an important role in change blindness.     

IN DEFENSE OF THE BODY: THE EFFECT OF MORTALITY SALIENCE ON FEMALE BODY OBJECTIFICATION

Previous research has illustrated the negative psychological consequences of female body objectification. The present study explores how female body objectification may serve as a defense against unconscious existential fears. Drawing from terror management theory, an experiment was designed to test the potential functionality of female body objectification. Men and women were primed to think about either their own mortality or an aversive control topic, and levels of body objectification were then assessed for both self- and other (women)-objectification. Findings supported the hypothesis that priming mortality would increase both self- and other-objectification among women, and self-objectification among those who derive self-esteem from their body. Implications for this research are discussed.     

The assessment of subjective probability distributions: A training experiment

For this experiment 22 Ss were especially trained to assess subjective probability distributions for proportions concerning student characteristics. Two different assessment techniques were used. There were four experimental sessions. From the second session on, Ss received feedback about their performance in the previous session(s). While Ss' associated by far too much confidence with their assessments at the beginning, they learned to assess more realistic distributions. Furthermore, discrepancies between techniques were reduced.Some considerations for a more effective training procedure are made and the concept of giving feedback only according to the tightness of the assessed distribution is critically discussed.     

Brain Function Associated with Cooccurring Trauma and Depression Symptoms in College Students

The goal of this pilot study was to determine if functional brain differences are present among individuals with high and low cooccurring trauma and depression symptoms. This pilot study examined how the P300 latency component of event-related potentials (ERPs), measured using electroencephalography (EEG) while participants performed a go/no-go task, might be associated with cooccurring self-report of trauma and depression symptoms in a sample of college students (N = 38). Alpha-corrected independent sample t tests revealed statistically significant differences in ERP P300 peak latencies between those in the high cooccurring trauma and depression symptoms group (n = 12) and those in the low group (n = 26) for all 3 midline electrode sites (Fz, Cz, and Pz). This pilot study provides preliminary evidence of differential brain functioning in individuals experiencing cooccurring trauma and depression symptoms. Accordingly, these findings support future research examining brain functioning in cooccurring symptoms.