ELECTROCORTICAL DIFFERENTIATION OF EVALUATIVE AND NONEVALUATIVE CATEGORIZATIONS

Abstract— The evaluative categorizations that underlie affective and attitudinal judgments have often been equated with non-evaluative categorizations despite the central importance of evaluative processes for survival In the present experiment, a late positive potential (LPP) of the event-related brain potential elicited when participants evaluatively categorized food items as positive or nonpositive was compared with the LPP elicited when participants semantically (i e., nonevaluatively) categorized food items as vegetable or nonvegetable Results revealed that evaluative categorizations evoked an LPP that was relatively larger over the right than the left scalp regions compared with the LPP evoked by nonevaluative categorizations. This finding provides evidence regarding the differences in neural and cognitive processes involved in evaluative and nonevaluative categorizations.     

The interaction of stressful life events and chronic strains on community mental health

One of the possible adaptive costs of coping with stress is diminished capacity to respond to subsequent adaptive demands. This paper examined the complex interplay between major life events and one source of chronic strain. Residents of the greater Los Angeles metropolitan area exposed to higher levels of smog, who had also experienced a recent stressful life event, exhibited poorer mental health than those exposed to pollution who had not experienced a recent stressful life event. There were, however, no direct effects of smog levels on mental health. These patterns of results were replicated in both a cross-sectional and a longitudinal study. The interplay of psychosocial vulnerability and environmental conditions is discussed.     

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.

     

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.

     

A Voice Cursing in the Wilderness

Book reviewed in this article:
John Berkman and Michael Cartwright (eds), The Hauerwas Reader     

Individual differences in information order effects: The importance of right-hemisphere access in belief updating

The order in which information is received alters the evaluation of causal hypotheses. Specifically, research suggests that the last piece of information oftentimes has the greatest impact on the evaluation and that the difference in subjective value between two pieces of information is an important factor influencing the magnitude of this recency effect. The present paper extends this line of work by exploring individual differences in this phenomenon via one's degree of handedness. Two hundred and five participants were given two hypothetical scenarios and related causal hypotheses accompanied by two pieces of additional information and asked to revise their belief in each hypothesis as information accumulated. Results confirmed predictions that 1) inconsistent/mixed-handers (those who use their non-dominant hand for at least some activities) show a larger effect with two pieces of inconsistent weak or strong information, and 2) neither mixed-handers nor consistent/strong-handers (those who use their dominant hand for almost all activities) show an effect with strong and weak pieces of consistent information. Mixed-handers' susceptibility to persuasive arguments and Ramachandran’s (1995; Ramachandran and Blakeslee, 1998) belief-updating theory centered around communication between the two halves of the brain and functional access to the right hemisphere are used to account for these data.     

A longitudinal study of career success,embeddedness, and mobility of early career professionals

The study of voluntary job mobility has traditionally focused on how the present context and individual factors either support or constrain choice of blue and white collar workers. Less attention has been devoted to the relationships among career success, embeddedness, and mobility of early career professionals. How do past career success and job mobility affect job embeddedness, subsequent career success, and future mobility within and between organizations and occupations? Each of these constructs is often studied as a dependent variable, yet the relationships among them, over time, are rarely examined. We explore the effects of past objective career actions (promotions, % salary change, and job mobility) on current job embeddedness and subjective career success, and on job, organizational, and occupational mobility one year later. Results support the positive influence of past promotions, % salary change, and current job embeddedness on subjective career success, and a negative influence for past promotions, job embeddedness, and subjective career success on mobility one year later as people began to ‘settle in’. We also observed small positive relationships of past promotions and % salary change with job embeddedness, and of past job mobility with future mobility — indicating that objective career success contributes to embeddedness, yet those that move more often tend to keep doing so. There were no differences or interaction effects based on gender or years of work experience. We found significantly stronger negative relationships of embeddedness and subjective career success with mobility between occupations than for mobility within organizations. However, the same pattern of findings was observed for job, organization, and occupational mobility.     

Task-set reconfiguration with predictable and unpredictable task switches

Participants switched frequently between high/low and odd/even classification of a digit. The interval between a task cue and the next digit varied between blocks. In Experiment 1, the task switched predictably every two, four, or eight trials. In Experiment 2, switching predictably every four trials was compared with random switching. With predictable switching, the cost was limited to the first trial of a run. Random switching produced a more gradual approach to asymptotic performance. After one performance, control processes attenuate the resulting change in task-set bias if a further switch is likely, but this strategic modulation is soon overwhelmed by task-set priming through further performances. Preparation reduced switch costs but not interference from the irrelevant attribute: Control of interference appears to be reactive, not proactive. Switch costs did not increase with run length, suggesting that retrieval of the task set last associated with the stimulus did not contribute to switch costs.