Searching night and day: a dissociation of effects of circadian phase and time awake on visual selective attention and vigilance

How does sleepiness affect selective attention? We studied the effect of circadian phase and time awake on visual search. The generalized-cognitive-slowing hypothesis predicts that search rate will be slower, feature guidance less effective, and response time (RT) lengthened when observers are sleepy. Observers performed spatial-configuration (finding a 5 among 2s) and conjunction (finding red vertical among red horizontal and green vertical) search tasks during 38 hr of wakefulness under constant conditions. Adverse circadian phases and elapsed time awake did lead to increased RT (corrected for errors). However, contrary to the hypothesis, search rates (indexed by RT x Set Size slopes) were constant across the protocol. This was true for conjunction as well as for spatial-configuration search, indicating that feature guidance was also insensitive to sleepiness. The locus of sleepiness effects on search is probably downstream from the bottleneck of attentional selection. Observers did trade accuracy for speed when sleepy. This implicates decision-stage impairments.     

Strategy-dependent changes in memory: Effects on behavior and brain activity

In the present study, an implicit strategy manipulation was used to explore the contribution of memory strategy to brain activation and behavioral performance. Participants were biased to use either a short-term (maintenance-focused) or long-term (retrieval-focused) memory strategy within a single memory task through manipulation of task context. In comparing directly matched trials across the different task contexts, we observed clear changes in both behavioral performance and brain activity across a network of regions located primarily within lateral and medial frontal cortex. These effects of the memory strategy manipulation suggest that when a retrieval-focused strategy is induced, mnemonic processes are preferentially engaged during the encoding period. In contrast, when a maintenance-focused strategy is induced, mnemonic processes are preferentially engaged during the delay and response periods. Taken together, the results imply that covert cognitive strategies play an important role in modulating brain activation and behavior during memory tasks.     

Predicting outcome of military basic training for individuals referred for psychological evaluation.

We examined outcome data for 632 U.S. Air Force personnel who were referred for psychological evaluation during Basic Military Training (BMT) but who were subsequently returned to BMT to determine what proportion graduated. We analyzed motivational, biographical, and psychological testing variables, using logistic regression to develop a model predictive of training outcome. The results demonstrated that a relatively small number of variables could predict outcome with close to 70% accuracy. Level of optimism regarding training, history of physical abuse, and frequency of visits to the trainee health clinic were major contributors to the model. MMPI-2 (Hathaway & McKinley, 1989) Scales D and Sc also remained in the model but added little to its power. The findings are generally consistent with prior research on normal military populations, except that some factors previously linked to adjustment, such as sex and ethnicity, were found to be unrelated to training outcome in this population.     

Promoting Novelty in Vision: Inhibition of Return Modulates Perceptual-Level Processing

To facilitate visual search of complex scenes, information arising from recently attended locations is subject to a selective inhibition in processing known as inhibition of return (IOR). Although the mechanisms of IOR remain unresolved, both motor and perceptual influences have been proposed based on reaction time (RT) studies. Here we report the results of two reflexive cuing studies in which signal detection methodology was employed to directly examine the effects of IOR on perception. IOR was found to be associated with a significant reduction in the accuracy of target discriminations at recently attended locations. Further, these effects of IOR on response accuracy were independent of whether emphasis was placed on the speed of responding. These results provide the first direct evidence that IOR can affect the perceptual quality of visual processing.     

Testing the buffering hypothesis: Perceptions of coach support and pre-competitive anxiety among male and female high school athletes

Research suggests that social support moderates or “buffers” the impact of stress on the individual and thus indirectly affects emotional well-being (Cohen and Wills, 1985). The present study sought to extend the “buffering hypothesis” to competitive sport by examining the influence of perceived coach support on competitive state anxiety among young athletes (N = 270). Results from confirmatory factor analyses (CFA) substantiated the validity of the sport-modified Social Provisions Scale (Russell and Cutrona, 1984; Ryska and Yin, 1994). Structural equation modeling analyses revealed a significant support-anxiety effect in the high trait-anxious model only (r =-.27, p .05). The present results suggest that perceived coach support represents an important mediating factor in the sport stress process among highly anxious athletes.     

Differences in Parental Investment Contribute to Important Differences Between Men and Women

Parental investment theory addresses sex differences that result from the trade-off between parenting effort and mating effort. For example, relative to men, women spend more time caring for offspring, are more selective in assenting to sexual intercourse, are more upset by a partner's emotional infidelity than by a partner's sexual infidelity, and are better able to inhibit their behaviors in certain situations. These and other sex differences are attributable to evolved mechanisms that work in interaction with the physical and social environments.     

Reading “glasses” will prime “vision,” but reading a pair of “glasses” will not

In a lexical decision task with two primes and a target, the target was preceded 300 msec by the second prime (P2) which in turn was preceded by a brief forward and backward masked first prime (P1). When P1 and P2 were unrelated, reaction times were faster when the target was related to P2 (e.g.,wave SALT ... pepper) than when the target was unrelated to P2 (and P1—e.g.,wave LOAN ... pepper). However, this semantic priming effect was reduced to statistically nonsignificant levels when P1 and P2 were repetitions of the same word. That is, priming did not occur forsalt SALT ... pepper relative toloan LOAN ... pepper. This reduction in priming was observed whether P2 and the target were strongly or weakly related. These findings raise problems for current accounts of semantic priming.     

Effects of trait and situational self-handicapping on competitive anxiety among athletes

Initial evidence suggests that the employment of self-handicapping strategies has a beneficial effect on negative affective states associated with the perceived threat of evaluative contexts (Harris & Snyder, 1986; Leary, 1986). The present study sought to describe the type of self-handicapping behaviors demonstrated by youth athletes (N=238) as well as to assess the stress-buffering role of athlete self-handicapping on indices of competitive state anxiety. Specifically, it was hypothesized that among high trait-handicapping athletes, those who report a greater degree of performance-debilitating obstacles prior to competition would demonstrate lowered cognitive and somatic state anxiety as well as greater state self-confidence than nonhandicapping athletes. However, MANOVA results indicated that both high trait and situational self-handicappers demonstrate elevated state anxiety immediately prior to competition. Results are discussed in relation to the possible role of state anxiety as a salient self-handicapping strategy within competitive sport.