Social Support Mediates Loneliness and Human Herpesvirus Type 6 (HHV-6) Antibody Titers

The current study investigated the impact of a severe environmental stressor and the role that declining social integration played in mediating its effect on loneliness and immune status. Increased loneliness and decreased social support in the months following the stressor (storm) were significantly associated with increased HHV-6 antibody liters, reflecting poorer control over the virus. Poorer social integration mediated the relationship between loneliness and HHV-6, even after controlling for nonspecific polyclonal B-cell activation, disease status (CD3+CD4+ cell counts), living arrangements, acute social losses (bereavement), and potential disruptions in social-support resources. These findings suggest that specific elements of social support may explain the oft-noted negative effects of loneliness on the immune system, and generalized to a medically vulnerable population.     

Hebb repetition effects in visual memory: the roles of verbal rehearsal and distinctiveness

A version of the Hebb repetition task was used with faces to explore the generality of the effect in a nonverbal domain. In the baseline condition, a series of upright faces was presented, and participants were asked to reconstruct the original order. Performance in this condition was compared to another in which the same stimuli were accompanied by concurrent verbal rehearsal to examine whether Hebb learning is dependent on verbal processing. Baseline performance was also compared to a condition in which the same faces were presented inverted. This comparison was used to determine the importance in Hebb learning of being able to visually distinguish between the list items. The results produced classic serial position curves that were equivalent over conditions with Hebb repetition effects being in evidence only for upright faces and verbal suppression as having no effect. These findings are interpreted as posing a challenge to current models derived from verbal-domain data.     

Chickadees discriminate contingency reversals presented consistently,but not frequently

Chickadees are high-metabolism, non-migratory birds, and thus an especially interesting model for studying how animals follow patterns of food availability over time. Here, we studied whether black-capped chickadees (Poecile atricapillus) could learn to reverse their behavior and/or to anticipate changes in reinforcement when the reinforcer contingencies for each stimulus were not stably fixed in time. In Experiment 1, we examined the responses of chickadees on an auditory go/no-go task, with constant reversals in reinforcement contingencies every 120 trials across daily testing intervals. Chickadees did not produce above-chance discrimination; however, when trained with a procedure that only reversed after successful discrimination, chickadees were able to discriminate and reverse their behavior successfully. In Experiment 2, we examined the responses of chickadees when reversals were structured to occur at the same time once per day, and chickadees were again able to discriminate and reverse their behavior over time, though they showed no reliable evidence of reversal anticipation. The frequency of reversals throughout the day thus appears to be an important determinant for these animals’ performance in reversal procedures.     

Electrophysiological and behavioral evidence reveals the effects of trait anxiety on contingent attentional capture

Few studies have investigated the effects of anxiety on contingent attentional capture. The present study examined contingent attentional capture in trait anxiety by applying a rapid serial visual presentation (RSVP) paradigm during electroencephalographic recording. Overall, the behavioral and electrophysiological results showed a larger capture effect when a distractor was the same color as the target compared to when the distractor was not of the target color. Moreover, high-anxiety individuals showed a larger N2pc in the target colored distractor condition and nontarget colored distractor condition compared to the distractor-absent condition. In addition, the reaction time was slower when distractors were presented in the left visual field compared to when they were in the right visual field. This pattern was not seen in low-anxiety individuals. The findings may indicate that high-anxiety individuals allocate attention to the target less efficiently and have reduced suppression of distractors compared to low-anxiety individuals who could suppress attention to the distractors more efficiently. Future work could valuably investigate the consequences of such differences in terms of benefits and disruption associated with attentional capture differences in a range of anxious populations in different risk monitoring situations.     

Generation and memory for contextual detail

Generation enhances item memory but may not enhance other aspects of memory. In 12 experiments, the author investigated the effect of generation on context memory, motivated in part by the hypothesis that generation produces a trade-off in encoding item and contextual information. Participants generated some study words (e.g., hot-c__) and read others (e.g., hot-cold). Generation consistently enhanced item memory but did not enhance context memory. More specifically, generation disrupted context memory for the color of the target word but did not affect context memory for location, background color, and cue-word color. The specificity of the negative generation effect in context memory argues against a general item-context trade-off. A processing account of generation meets greater success. In addition, the results provide no evidence that generation enhances recollection of contextual details.     

Memory for actions: Enactment and source memory

Enacting simple action phrases enhances item memory but may not enhance other aspects of memory. The present experiment examines the effects of enactment on source memory. During the study phase, participants performed some actions (subject-performed tasks, SPTs) and observed the experimenter perform other actions (experimenter-performed tasks, EPTs). One group performed the SPTs with eyes closed, one group with eyes open (the standard condition), and one group performed SPTs facing a mirror (EPT presentation was constant across groups). As expected, item memory was better for SPTs than for EPTs. More importantly, source memory for SPTs was affected by the amount of visual feedback. As predicted by the source-monitoring framework, source memory for SPTs decreased as the amount of visual feedback increased from none (eyes closed) to moderate (standard condition) to maximal (mirror condition). In addition, SPT encoding failed to increase source memory and in one condition actually decreased source memory, relative to EPT encoding. Thus, enactment dissociated item and source memory, enhancing the former but not the latter.     

A construct-driven investigation of gender differences in a leadership-role assessment center

This study examined gender differences in a large-scale assessment center for officer entry in the British Army. Subgroup differences were investigated for a sample of 1,857 candidates: 1,594 men and 263 women. A construct-driven approach was chosen (a) by examining gender differences at the construct level, (b) by formulating a priori hypotheses about which constructs would be susceptible to gender effects, and (c) by using both effect size statistics and latent mean analyses to investigate gender differences in assessment center ratings. Results showed that female candidates were rated notably higher on constructs reflecting an interpersonally oriented leadership style (i.e., oral communication and interaction) and on drive and determination. These results are discussed in light of role congruity theory and of the advantages of using latent mean analyses.     

Measures of sensitivity based on a single hit rate and false alarm rate: the accuracy, precision, and robustness of d', Az, and A'

Signal detection theory offers several indexes of sensitivity (d', Az, and A') that are appropriate for two-choice discrimination when data consist of one hit rate and one false alarm rate per condition. These measures require simplifying assumptions about how target and lure evidence is distributed. We examine three statistical properties of these indexes: accuracy (good agreement between the parameter and the sampling distribution mean), precision (small variance of the sampling distribution), and robustness (small influence of violated assumptions on accuracy). We draw several conclusions from the results. First, a variety of parameters (sample size, degree of discriminability, and magnitude of hits and false alarms) influence statistical bias in these indexes. Comparing conditions that differ in these parameters entails discrepancies that can be reduced by increasing N. Second, unequal variance of the evidence distributions produces significant bias that cannot be reduced by increasing N-a serious drawback to the use of these sensitivity indexes when variance is unknown. Finally, their relative statistical performances suggest that Az is preferable to A'.