Stress and Cytokine Effects on Learning: What Does Sex Have to Do With It?

Many studies have alluded to sexually dimorphic changes in behavior following stress. Although many have suggested that these changes are a function of stress-induced changes in learning and memory, there are questions regarding whether performance in those learning and memory tasks are influenced by stress-induced changes in drive more than in actual learning and memory processes. We used the classically conditioned eyeblink response (CCER) to determine whether slowed learning following stress in females can be explained by changes in unconditional response (UR) amplitude, a sign of a stress-induced shift in sensory reactivity. In addition, we had a second treatment group injected with the pro-inflammatory cytokine IL-1beta to serve as an interoceptive stress condition, a physiological stressor with minimal stimulation to the animal. Replicating the work by Shors and colleagues, we found that stressed female rats had slower acquisition of the conditioned response (CR), but we also found that an IL-1beta injection leads to a slowing of CR acquisition. However, in both cases, UR amplitude was lower in the treatment groups. We followed up these results by testing sensory reactivity through the acoustic startle response (ASR), where the magnitude of the ASR was marginally, but nonsignificantly, reduced by the same dose regimen of IL-1beta. Together, these experiments suggest that tailshock stress and immune signaling (IL-1beta) reduce sensory reactivity and the saliency of the stimuli used in the CCER, leading to slower learning in female rats.     

Presurgical MMPI-2 Cluster Profiles Predict 1-Year Low-Back Surgery Outcomes

The primary purpose of this study was to examine whether empirically derived cluster profiles based on scores from the Minnesota Multiphasic Personality Inventory-2 (MMPI-2) predicted outcomes of surgery at 1 year for patients with low-back pain. On the basis of hierarchical cluster analysis of presurgery MMPI-2 scores for 60 patients, three interpretable and significant subgroups were formed. These consisted of a pathological/neurotic type, a double V-code type, and a normal type. The patents in the normal type were significantly more likely to report beneficial outcomes of surgery in terms of disability and pain than those in the other 2 types. These findings extend previous research and suggest (1) low-back surgery candidates are heterogeneous in their psychological profiles, and (2) MMPI-2 profiles are predictive of low-back surgery outcome. Future research should focus on identifying physiological substrates for these distinct profiles and investigating the effectiveness of presurgical psychological interventions based on profile type.     

Is Political Cognition Like Riding a Bicycle? How Cognitive Neuroscience Can Inform Research on Political Thinking

Our understanding of political phenomena, including political attitudes and sophistication, can be enriched by incorporating the theories and tools of cognitive neuroscience—in particular, the cognitive neuroscience of nonconscious habitual cognition (akin to bicycle riding). From this perspective, different types of informational "building blocks" can be construed from which different types of political attitudes may arise. A reflection-reflexion model is presented that describes how these blocks combine to produce a given political attitude as a function of goals, primes, expertise, and inherent conflict in considerations relevant to the attitude. The ways in which neuroimaging methods can be used to test hypotheses of political cognition are reviewed.     

Staff survey results and characteristics that predict assault and injury to personnel working in mental health facilities

The purpose of this study was to complete a mental health staff opinion survey to identify patient and staff characteristics associated with staff assault and injury in psychiatric treatment settings and to develop a model of prediction for staff assault and injury utilizing these survey variables. The data consisted of opinion surveys sent to staff of 15 child, adolescent, and adult psychiatry inpatient units in the United States. Multivariate logistic regression was used to determine the level of assault and staff‐reported injury prediction that could be obtained from the staff‐completed opinion survey. Responses indicated a high prevalence of reported aggression, with 62.3% of staff endorsing verbal and physical aggression, property destruction, and self‐injurious behavior as being prevalent at their site, whereas only 4.1% rated none of these as prevalent. Staff working with children and adolescents in settings with high rates of psychiatric diagnoses reported increased frequency of assault and injury compared with those working with adults. Younger, less experienced staff reported higher rates of assault and injury. Staff working with female patients reported similar rates of assault and injury to those working with males. A logistic regression analysis using staff‐reported survey results of both staff and patient characteristics predicted assault correctly 73.7% of the time and injury 66.1% of the time. Resources for violence prevention and staff training programs in violence prevention are needed in child and adolescent psychiatry wards. Results are consistent with theories emphasizing the importance of negative emotions and affects, impulsivity, and frustration in goal‐directed activities in human aggression. Aggr. Behav. 29:31–40, 2003. © 2003 Wiley‐Liss, Inc.     

Refining Measurement of Career Indecision Types: A Validity Study

The authors conducted this study to address some of the limitations in previous indecision typology research and to provide validity evidence for the indecision types that were derived. The participants were 566 first‐semester, undecided students enrolled in a career exploration course. Career indecision, personality, and ability measures were used to derive career indecision types through cluster analysis. Four distinct career indecision types were identified. Subsequently, the effect of indecision type on response to a career exploration course was examined. Level of career indecision, the criterion variable, was not differentially affected by indecision type. Implications of the findings for career counseling are discussed.     

Memory conformity: can eyewitnesses influence each other's memories for an event?

The current study investigated memory conformity effects between individuals who witness and then discuss a criminal event, employing a novel procedure whereby each member of a dyad watches a different video of the same event. Each video contained unique items that were thus seen only by one witness. Dyads in one condition were encouraged to discuss the event before each witness (individually) performed a recall test, while in a control condition dyads were not allowed to discuss the event prior to recall. A significant proportion (71%) of witnesses who had discussed the event went on to mistakenly recall items acquired during the discussion. There were no age‐related differences in susceptibility to these memory conformity effects in younger (18–30 years) as compared to older (60–80 years) participants. Possible social and cognitive mechanisms underlying the distortions of memory due to conformity are discussed. Copyright © 2003 John Wiley & Sons, Ltd.     

Thomas P. Kasulis,Intimacy or Integrity: Philosophy and Cultural Difference

International Journal for Philosophy of Religion -     

Why Higher Working Memory Capacity May Help You Learn: Sampling,Search, and Degrees of Approximation

Algorithms for approximate Bayesian inference, such as those based on sampling (i.e., Monte Carlo methods), provide a natural source of models of how people may deal with uncertainty with limited cognitive resources. Here, we consider the idea that individual differences in working memory capacity (WMC) may be usefully modeled in terms of the number of samples, or “particles,” available to perform inference. To test this idea, we focus on two recent experiments that report positive associations between WMC and two distinct aspects of categorization performance: the ability to learn novel categories, and the ability to switch between different categorization strategies (“knowledge restructuring”). In favor of the idea of modeling WMC as a number of particles, we show that a single model can reproduce both experimental results by varying the number of particles—increasing the number of particles leads to both faster category learning and improved strategy‐switching. Furthermore, when we fit the model to individual participants, we found a positive association between WMC and best‐fit number of particles for strategy switching. However, no association between WMC and best‐fit number of particles was found for category learning. These results are discussed in the context of the general challenge of disentangling the contributions of different potential sources of behavioral variability.