Specific temporal-lobe signs and enhanced delayed cross-modal matching performance

Structural damage to the amygdala severely retards delayed cross-modal (tactile-to-sight) matching in primates. Conversely, we hypothesized that people who display signs suggestive of specific temporal lobe lability should show enhanced delayed cross-modal matching performance. The hypothesis was supported. In a single experiment involving 25 subjects, significant negative correlations obtained between the numbers of errors on the cross-modal matching task and numbers of affirmative responses within clusters of items that contained themes of meaningfulness, religious beliefs or ictal, complex partial epileptic (limbic) states. On the other hand, the numbers of errors were not significantly correlated with either clusters of control items or items that are presumed to reflect the function of other temporal-lobe structures. Both matching and questionnaire data were collected under double-blind conditions.     

Stress as a state of anticipatory vigilance

The pituitary-adrenocortical system is activated in stressful situations, and the adrenocortical hormones have been implicated by Selye in the diseases of stress. Evidence indicates that the adrenocortical hormones peak during the period of anticipation of stressful events, not during actual confrontation with them. The circadian cortisol rhythm shows peaks before waking, not during active periods of the day, and cortisol does not appear to be required during physical activity. The role of these hormones appears to be to suppress ongoing physiological activity in order to increase vigilance and to get the organism ready to take action before the impact of dangers.     

The Effects of Flavor-Aversion Learning on Instrumental Performance

Two experiments investigated the role of lithium-mediated environmental conditioning on instrumental performance. Experiment 1 demonstrated that a novel taste consumed in one arm of a T maze prior to lithium-induced toxicosis reduced performance in this environment whereas similar aversions conditioned in the home cage failed to alter maze performance. Experiment 2 showed that maze performance in a straight alleyway was decremented during extinction only in a group that actually traversed the alley prior to drinking saccharin and receiving lithium injections. This demonstrated that the instrumental decrement observed in Experiment 1 was due not only to the presence of an unpalatable flavor in the goalbox during the test.

     

Book Reviews

The Psychological Record -     

Galef’s Transfer-of-Information Effect Occurs in a Free-Foraging Situation

Galef and his colleagues have repeatedly shown that one rat may transfer information regarding the type of food it has consumed to other conspecifics. Such experiments typically have been conducted in wire-mesh cages or a wooden maze. The present experiments sought to extend this paradigm to the open-field foraging situation having six food patches to choose from. Following interaction with a demonstrator that had consumed either a cocoa or a cinnamon diet, single observers (Experiment 1) were tested in the foraging situation. Food-consumption scores indicated that observers consumed significantly more of their specific demonstrator’s diet than a second diet that was available also. Experiment 2 involved the simultaneous testing of two observers in the foraging laboratory. In Experiment 3 two observers were once again tested, but each had been provided a different food-type message prior to foraging. Positive results, mirroring those of Experiment 1, were obtained in both Experiments 2 and 3. The results of these three experiments underscore the robustness of this phenomenon and its generalizability to other testing conditions.

     

Linking person and context in the daily stress process

In this study we combined daily diary data with interview data to investigate individual differences in the impact of stressful daily events on mood. Using a sample of 96 women in an urban community, we examined perceived neighborhood quality and major life events as possibly potentiating the effects of stressful daily events, and we viewed social supports as potentially buffering this daily process. Results confirmed that the presence of chronic ecologic stress (neighborhood perceptions) exacerbated the immediate effects of stressful daily events on mood and also increased the likelihood of enduring effects of daily stressors on next day's mood. Contrary to expectations, previous exposure to major life events decreased the impact of stressful daily events. The availability of social supports, although not buffering the impact of stressful daily events on mood, did mitigate the enduring effects of these events on next day's mood. This study also presents a method for analyzing daily time-series data, while correcting for potential problems of autocorrelated error terms. As such, this study represents a significant advance over previous analytic approaches to time-series data in the study of the stress process.