Aging and medical adherence: the use of automatic processes to achieve effortful things

This research examined whether forming detailed implementation plans for achieving a goal improved older adults' adherence to a health behavior. Nondiabetic participants (N = 31) rehearsed, deliberated, or formed implementation intentions to perform home blood glucose monitoring, 4 times daily for 3 weeks. The implementation group performed tests nearly 50% more often than the 2 comparison groups. Results were not attributable to a priori differences in intentions to perform testing. Findings indicate that implementation intentions can facilitate older adults' performance of important medical self-care tasks in naturalistic settings over sustained periods of time and concur with previous research that implicates automatic cognitive processes that do not show age-related decline. These results support the utility of this technique for improving adherence to health behaviors in clinical populations.     

Smoking attenuates regular aerobic exercise benefits to episodic free recall immediately following strenuous physical activity

The present study was designed to evaluate the extent to which free recall performance is influenced by competing demands on physiological resources dependent on blood‐oxygen levels. Fifty‐six healthy young adults (mean age=20 years) were allocated to groups (n_1–4=14) according to their level of exercise (more than 6 h aerobic exercise per wk, or sedentary 1

1 Here sedentary refers to individuals with no regular exercise routines

.) and smoking (more than 10 cigarettes per day, or none) behaviour. Participants performed two free recall tasks, one under normal physically inactive conditions and the other immediately following strenuous physical exertion (a step‐up test for 2 min). We predicted that recall would suffer following strenuous physical activity among smoking aerobic exercisers. We reasoned this would be due to the oxygen‐carrying capacity of the blood being compromised in this group by higher levels of smoking‐related carbon monoxide in the blood stream. The results supported this prediction. We interpret our findings according to a resource model of cognitive function, mediated by physiological mechanisms. Copyright © 2004 John Wiley & Sons, Ltd.     

On the role of stimulus-response and stimulus-stimulus compatibility in the Stroop effect

Stroop effects might be due to differences in stimulus-response compatibility (SRC) and/or to differences in stimulus-stimulus compatibility (SSC). Recent evidence for the role of SSC is inconclusive, because there were no controls for effects of SRC that are based on short-term associations between stimuli and responses (i.e., associations set up as the result of task instructions). In two experiments, SRC effects were controlled for. Regardless of whether the irrelevant and the relevant stimulus features were separated (Experiment 1) or integrated in one stimulus (Experiment 2), the results revealed an effect of SSC and an effect of SRC that was based on short-term associations. The results thus confirm that both processes at the level of encoding and processes at the level of response selection contribute to the Stroop effect.     

Processing of temporal information: Evidence from eye movements

In two experiments, we recorded eye movements to study how readers monitor temporal order information contained in narrative texts. Participants read short texts containing critical temporal information in the sixth sentence, which could be either consistent or inconsistent with temporal order information given in the second sentence. In Experiment 1, inconsistent sentences yielded more regressions to the second sentence and longer refixations of it. In Experiment 2, this pattern of eye movements was shown only by readers who noticed the inconsistency and were able to report it. Theoretical and methodological implications of the results for research on text comprehension are discussed.     

Autocracy bias in informal groups under need for closure

Two experiments investigated the tendency of groups with members under high (vs. low) need for cognitive closure to develop an autocratic leadership structure in which some members dominate the discussion, constitute the "hubs" of communication, and influence the group more than other members. The first experiment found that high (vs. low) need for closure groups, as assessed via dispositional measure of the need for closure, manifested greater asymmetry of conversational floor control, such that members with autocratic interactional style were more conversationally dominant and influential than less autocratic members. The second experiment manipulated the need for closure via time pressure and utilized a social network analysis. Consistent with expectation, groups under time pressure (vs. no pressure) showed a greater asymmetry of participation, of centrality, and of prestige among the group members, such that the more focal members were perceived to exert the greater influence over the groups' decisions.     

Stressor exposure produces long-term reductions in antigen-specific T and B cell responses

Exposure to an acute laboratory stressor at the time of keyhole limpet hemocyanin (KLH) immunization results in a long-term suppression in circulating anti-KLH antibody. The mechanism for the stress-induced reduction in anti-KLH immunoglobulin (Ig) remains unknown. Given that the generation of anti-KLH antibody requires T cell help, we hypothesize that stress reduces the proliferation of anti-KLH T cells, thus leading to a reduction in anti-KLH antibody. The present studies examined the effect of tail shock stress (100, 1.6 mA, 5-s, 60 s ITI) on the KLH specific T cell response. Fischer F344 rats were immunized either intraperitoneally (i.p.) or subcutaneously (s.c.) at the base of the tail with 200 microg KLH, and exposed to inescapable tail shock (IS) or remained in their home cages (HCC). T cell proliferation after KLH restimulation, but not ConA, was markedly suppressed in IS animals in both the spleen after i.p. immunization and the draining lymph nodes after s.c. immunization. Other secondary lymphoid cells did not differ in their proliferative capacity. Anti-KLH IgG, IgG1 and IgG2a, but not anti-KLH IgM serum levels were significantly suppressed. These data support the conclusion that stress suppresses the generation of antigen specific T cells. In addition, the methods employed in the current study allow the isolation of the site of the acquired T cell immune response, making it possible to further elucidate the cellular mechanisms that contribute to stress-induced modulation of the antigen-specific acquired immune response.     

Histidine-decarboxylase knockout mice show deficient nonreinforced episodic object memory, improved negatively reinforced water-maze performance, and increased neo- and ventro-striatal dopamine turnover

The brain's histaminergic system has been implicated in hippocampal synaptic plasticity, learning, and memory, as well as brain reward and reinforcement. Our past pharmacological and lesion studies indicated that the brain's histamine system exerts inhibitory effects on the brain's reinforcement respective reward system reciprocal to mesolimbic dopamine systems, thereby modulating learning and memory performance. Given the close functional relationship between brain reinforcement and memory processes, the total disruption of brain histamine synthesis via genetic disruption of its synthesizing enzyme, histidine decarboxylase (HDC), in the mouse might have differential effects on learning dependent on the task-inherent reinforcement contingencies. Here, we investigated the effects of an HDC gene disruption in the mouse in a nonreinforced object exploration task and a negatively reinforced water-maze task as well as on neo- and ventro-striatal dopamine systems known to be involved in brain reward and reinforcement. Histidine decarboxylase knockout (HDC-KO) mice had higher dihydrophenylacetic acid concentrations and a higher dihydrophenylacetic acid/dopamine ratio in the neostriatum. In the ventral striatum, dihydrophenylacetic acid/dopamine and 3-methoxytyramine/dopamine ratios were higher in HDC-KO mice. Furthermore, the HDC-KO mice showed improved water-maze performance during both hidden and cued platform tasks, but deficient object discrimination based on temporal relationships. Our data imply that disruption of brain histamine synthesis can have both memory promoting and suppressive effects via distinct and independent mechanisms and further indicate that these opposed effects are related to the task-inherent reinforcement contingencies.     

Reality monitoring and metacognitive beliefs related to cognitive confidence in obsessive-compulsive disorder

The present study investigated general reality monitoring ability, and selective reality monitoring ability for anxiety relevant actions in a group of individuals with obsessive-compulsive disorder (OCD) and a group of non-anxious controls. In addition, reality monitoring confidence was assessed, as well as specific meta-cognitive beliefs related to cognitive confidence (by means of the Meta-Cognitions Questionnaire (MCQ)). No differences were found between both groups in actual reality monitoring ability. Unlike previous studies, the reality monitoring task included actions that were related to the individual concerns of the OCD patients and were ideographically selected. Nevertheless, no differential reality monitoring effect was observed for the anxiety relevant stimuli. Data from the MCQ, however, revealed that OCD patients had less overall confidence in their memory for actions and their reality monitoring ability. Analysis of the confidence ratings of the reality monitoring task showed that this reduced confidence was restricted to the neutral actions. No differences were observed for patients that reported low or high frequencies of checking behaviour. The whole of these data do not support memory deficit models of OCD, but are in line with recent emphasis on the importance of memory confidence and other meta-cognitive beliefs in OCD.     

Task versus relationship conflict,team performance,and team member satisfaction: a meta-analysis

This study provides a meta-analysis of research on the associations between relationship conflict, task conflict, team performance, and team member satisfaction. Consistent with past theorizing, results revealed strong and negative correlations between relationship conflict, team performance, and team member satisfaction. In contrast to what has been suggested in both academic research and introductory textbooks, however, results also revealed strong and negative (instead of the predicted positive) correlations between task conflict team performance, and team member satisfaction. As predicted, conflict had stronger negative relations with team performance in highly complex (decision making, project, mixed) than in less complex (production) tasks. Finally, task conflict was less negatively related to team performance when task conflict and relationship conflict were weakly, rather than strongly, correlated.     

Effects of slow-release caffeine and a nap on driving simulator performance after partial sleep deprivation

A driving simulator was used to evaluate the effectiveness of a 30-min. nap and 300-mg slow-release caffeine as countermeasures to drivers' sleepiness induced by partial sleep deprivation. 12 participants were allowed 45 hr. time in bed at the laboratory. Driving performance then was measured twice--at 9 a.m. and at 1 p.m.--by a 45-min. driving task on a simulator. Subjective sleepiness/alertness and mood were assessed four times on the Stanford Sleepiness Scale and the Profile of Mood States. Driving performance was assessed as Lane Drifting, Speed Deviation, and Accident Liability. A 30-min. nap opportunity and 300 mg of slow-release caffeine both were successful in counteracting drivers' sleepiness. The remedial effect of slow-release caffeine lasted longer than that of the nap, that is, it was also effective in the afternoon session. This suggests that slow-release caffeine represents a valuable countermeasure that, in the case of partial sleep deprivation, is preferred to a nap when sleepiness has to be counteracted for a longer time.