The effects of self-generated comparison targets, BMI, and social comparison tendencies on body image appraisal

Previous studies examining the association between social comparison processes and body image dissatisfaction have yielded inconsistent findings. This study examined whether such discrepancies are due to either the use of identical comparison targets for all subjects or variability in body mass. Specifically, 216 subjects were randomly assigned to one of three experimental conditions: self-generated upward comparison group, self-generated downward comparison group, or control group. Dependent variables were measures of body image. Results indicated that increasing body mass and trait comparison tendencies were associated with increased body dissatisfaction. However, the experimental manipulation did not affect body image ratings. Results suggest that social comparison processes may operate similarly over a range of body mass index (BMI) values.     

Attentional Bias in Posttraumatic Stress Disorder

This study investigated preferential encoding of threat material in subjects with posttraumatic stress disorder (PTSD) with a modified dot-probe paradigm. This paradigm indexes attentional bias by measuring response latency to name neutral target words that are presented adjacent to or distant from threat words. Motor vehicle accident survivors with PTSD (n = 15), subclinical PTSD (n = 15), and low anxiety (n = 15) were required to name target words that were presented either adjacent to or distant from strong threat, mild threat, positive, and neutral words. PTSD subjects named targets faster when they were in close proximity to mild threat words. Results suggested that PTSD subjects' attention was drawn to the mild threat stimuli and are discussed in the context of network models of PTSD.     

Learning and memory deficits in rats following exposure to 3,3'-iminodipropionitrile

Rats were examined using a learning and memory test battery 4 weeks following exposure to 3,3'-iminodipropionitrile (IDPN). Initial testing revealed deficits in olfactory discrimination and passive avoidance (PA) conditioning. In order to dissociate learning and performance effects, additional tests were conducted. First, to rule out the possibility that IDPN reduced the aversiveness of foot shock, rats were tested in a simple shock sensitivity paradigm. The results indicated no change in shock sensitivity produced by IDPN. Second, to determine if the hyperactivity produced by IDPN was responsible for deficits in conditioning, several additional tests were conducted including (a) repeated-trials active avoidance (AA) and PA conditioning, (b) a PA study which included both a 1- and 24-hr training-testing interval, and (c) long-delay flavor-aversion conditioning. Rats treated with IDPN required more conditioning trials to reach criterion on both AA and PA procedures suggesting that they were capable of performing the required response but acquired those responses at a much slower rate. The deficits in PA conditioning were similar at both the 1- and 24-hr training-testing interval. Finally, the effects of IDPN on flavor-aversion conditioning depended on the delay separating flavor intake and lithium administration during conditioning. Rats treated with IDPN demonstrated robust flavor aversions when trained with a 30-min but not with a 6-hr delay. In summary, the neurotoxic profile of effects produced by IDPN must be expanded to include a prominent cognitive component characterized by protracted deficits in learning and memory capacity. The present experiment illustrates how chemically induced disruption of learning and memory produced by IDPN can be experimentally dissociated from associate neurological symptoms using a simple, routine battery of neurobehavioral tests.     

Surfactant approach to the gastric mucosal barrier: protection of rats by banana even when acidified

Physical studies of their suspensions have shown bananas to be highly surface active at both liquid-air and solid-liquid interfaces which they render hydrophobic by adsorption of phospholipid detected by thin-layer chromatography and by staining. Electron microscopy of the fruit has demonstrated lamellar bodies--the same form in which phospholipid is so surface-active in the lung. When administered to intact rats and scored by two methods (ulcer length and area), banana imparted appreciable (75%) protection against acid insult (1 ml of 0.8 N HCl) in a dose-dependent manner not attributable to "bulking" or buffering as it was equally effective at a pH of 2. The best protection (89% by ulcer length) was obtained with banana vortexed with milk (1:1), this mixture offering the possibility of a simple foodstuff on which to maintain patients treated acutely by suppressing acid secretion pharmacologically. These studies support Davenport's original concept of a gastric mucosal barrier--but one whose physical reality is provided by an adsorbed layer of surface-active phospholipid (surfactant).