Operant discrimination of an interoceptive stimulus in rhesus monkeys

Five rhesus macaques monkeys surgically prepared with Thiry small intestinal (jejunum) loops and implanted brain electrodes were restrained in primate chairs and kept on 23-hr deprivation-feeding cycle. After being trained to press a lever for sugar pills on an FR 25 schedule of reinforcement, a discrimination training procedure was established. Lever presses were reinforced during the S(D)-a non-aversive mechanical stimulus applied to the internal walls of the Thiry loop by rhythmic inflation-deflation of a small latex balloon by air at the rate of one cycle per sec at 100 mm Hg pressure. The S(Delta) was the absence of the visceral stimulation. The monkeys successfully discriminated between presence and absence of the internal stimulus. A discrimination reversal was attempted and completed on one monkey. The results clearly show operant discrimination based on an interoceptive stimulus. Cortical and subcortical EEG records reflected the onset but not termination of the visceral stimulation.     

Competition, cooperation, satisfaction, and the performance of complex tasks among air force cadets

Forty-eight U.S. Air Force Academy cadets were studied to examine the effects of individual attitudes and organizational reward structures on the performance of a complex, integrative task. An attitudinal survey was used to measure each subject’s preference for cooperative or competitive situations. Distinctly different group environments were created by giving four groups of six subjectscompetitive instructions and another four groupscooperative instructions. The performance criterion was the “sum” score across eight trials of a complex arcade-type computer game which required one subject to control horizontal movement and another to control vertical movement. Although neither attitude nor reward structure alone influenced performance, their interaction was found to be very significant; subjects performed poorly when the reward structure did not match their individual orientation. Implications for military and professional training programs are discussed.     

Predicting sugar-sweetened behaviours with theory of planned behaviour constructs: Outcome and process results from the SIPsmartER behavioural intervention

Objective: Guided by the theory of planned behaviour (TPB) and health literacy concepts, SIPsmartER is a six-month multicomponent intervention effective at improving SSB behaviours. Using SIPsmartER data, this study explores prediction of SSB behavioural intention (BI) and behaviour from TPB constructs using: (1) cross-sectional and prospective models and (2) 11 single-item assessments from interactive voice response (IVR) technology.

Design: Quasi-experimental design, including pre- and post-outcome data and repeated-measures process data of 155 intervention participants.

Main Outcome Measures: Validated multi-item TPB measures, single-item TPB measures, and self-reported SSB behaviours. Hypothesised relationships were investigated using correlation and multiple regression models.

Results: TPB constructs explained 32% of the variance cross sectionally and 20% prospectively in BI; and explained 13–20% of variance cross sectionally and 6% prospectively. Single-item scale models were significant, yet explained less variance. All IVR models predicting BI (average 21%, range 6–38%) and behaviour (average 30%, range 6–55%) were significant.

Conclusion: Findings are interpreted in the context of other cross-sectional, prospective and experimental TPB health and dietary studies. Findings advance experimental application of the TPB, including understanding constructs at outcome and process time points and applying theory in all intervention development, implementation and evaluation phases.     

Metatraits: Enhancing Criterion‐Related Validity Through the Assessment of Traitedness1

With the growing use of personality tests as predictors of job performance, the reliable measurement of these personality variables has become important to selection researchers and practitioners. Metatrait researchers have examined the possibility that personality traits are not equally relevant for all people. This study sought to examine whether considering the relevance of a trait to an individual (i.e., traitedness) would enhance the predictive validity of a measure. Specifically, traitedness was expected to moderate the relationship between predictor and criterion scores such that the predictor‐criterion relationship would be stronger for traited than for untraited individuals. Consistent with this hypothesis, a strong moderating effect was found for traitedness between a measure of personality and an objective criterion. Contrary to what was predicted, traitedness only provided incremental validity, above personality, for supervisor ratings of job performance.     

Prejudice and Racism,Year 2008—Still Going Strong: Research on Reducing Prejudice With Recommended Methodological Advances

This article addresses the origins, mechanisms, and expressions of prejudice. A selective review of research finds strong support for the validity of G. W. Allport's (1954) contact hypothesis conditions in reducing prejudice. Methodological advances in the study of prejudice are reviewed, and implications of research findings for counselors are explored.     

Memory for media: investigation of false memories for negatively and positively charged public events

Despite a large body of false memory research, little has addressed the potential influence of an event's emotional content on susceptibility to false recollections. The Paradoxical Negative Emotion (PNE) hypothesis predicts that negative emotion generally facilitates memory but also heightens susceptibility to false memories. Participants were asked whether they could recall 20 "widely publicised" public events (half fictitious) ranging in emotional valence, with or without visual cues. Participants recalled a greater number of true negative events (M=3.31/5) than true positive (M=2.61/5) events. Nearly everyone (95%) came to recall at least one false event (M=2.15 false events recalled). Further, more than twice as many participants recalled any false negative (90%) compared to false positive (41.7%) events. Negative events, in general, were associated with more detailed memories and false negative event memories were more detailed than false positive event memories. Higher dissociation scores were associated with false recollections of negative events, specifically.     

Effort during visual search and counting: insights from pupillometry

We investigated the processing effort during visual search and counting tasks using a pupil dilation measure. Search difficulty was manipulated by varying the number of distractors as well as the heterogeneity of the distractors. More difficult visual search resulted in more pupil dilation than did less difficult search. These results confirm a link between effort and increased pupil dilation. The pupil dilated more during the counting task than during target-absent search, even though the displays were identical, and the two tasks were matched for reaction time. The moment-to-moment dilation pattern during search suggests little effort in the early stages, but increasingly more effort towards response, whereas the counting task involved an increased initial effort, which was sustained throughout the trial. These patterns can be interpreted in terms of the differential memory load for item locations in each task. In an additional experiment, increasing the spatial memory requirements of the search evoked a corresponding increase in pupil dilation.These results support the view that search tasks involve some, but limited, memory for item locations, and the effort associated with this memory load increases during the trials. In contrast, counting involves a heavy locational memory component from the start.