Changing the rate and hippocampal dependence of trace eyeblink conditioning: slow learning enhances survival of new neurons

Trace eyeblink conditioning in which a conditioned stimulus and unconditioned stimulus are separated by a gap, is hippocampal dependent and can rescue new neurons in the adult dentate gyrus from death (e.g., Beylin et al., 2001; Gould et al., 1999). Tasks requiring more training trials for reliable expression of the conditioned response are most effective in enhancing survival of neurons (Waddell & Shors, 2008). To dissociate hippocampal dependence from acquisition rate, we facilitated hippocampal-dependent trace eyeblink conditioning in two ways: a shorter trace interval and signaling the intertrial interval with a post-US cue. Trace conditioning with a shorter trace interval (250ms) requires an intact hippocampus, and acquisition is faster relative to rats trained with a 500ms trace interval (e.g., Weiss et al., 1999). Using excitotoxic hippocampal lesions, we confirmed that eyeblink conditioning with the 250 or 500ms trace interval is hippocampal dependent. However, training with the post-US cue was not hippocampal dependent. The majority of lesion rats in this condition reached criterion of conditioned responding. To determine whether hippocampal dependence is sufficient to rescue adult-generated neurons in the dentate gyrus, rats were injected with BrdU and trained in one of the three trace eyeblink arrangements one week later. Of these training procedures, only the 500ms trace interval enhanced survival of new cells; acquisition of this task proceeded slowly relative to the 250ms and post-US cue conditions. These data demonstrate that rate of acquisition and not hippocampal dependence determines the impact of learning on adult neurogenesis.     

Examination of psychiatric symptoms in student athletes

In the present study, the authors examined the severity of psychiatric symptoms in undergraduate recreational (noncompetitive) athletes (n = 64) and National Collegiate Athletic Association (NCAA; competitive) athletes (n = 72). The results indicated that the 2 groups were similar in the severity of psychiatric symptoms. The recreational and NCAA athletes combined (n = 136) showed less severe global psychiatric symptoms when they were compared with an undergraduate control group (n = 435). The implications of the study are discussed in the context of those findings.     

The interpersonal circumplex as a model of interpersonal capabilities

In this study, we sought to challenge the existing conceptualization of interpersonal capabilities as a distinct construct from interpersonal traits by explicitly taking into account the general factor inherent within most models of circumplexes. A sample of 206 college students completed a battery of measures including the Battery of Interpersonal Capabilities (BIC; Paulhus & Martin, 1987). Principal components analysis and the randomization test of hypothesized order relations demonstrated that contrary to previous findings, the BIC adhered to a circular ordering. Joint analysis of the BIC with the Interpersonal Adjective Scale (Wiggins, 1995) using principal components analysis and structural equation modeling demonstrated that the 2 measures represented similar constructs. Furthermore, the general factor in the BIC was not correlated with measures of general self-competence, satisfaction with life, or general pathology.     

Mothers' and fathers' behaviors toward their 3- to 4-month-old infants in lower, middle, and upper socioeconomic African American families

African American mothers' and fathers' availability, caregiving, and social behaviors toward their infants in and around their homes were examined. Twenty lower, 21 middle, and 21 upper socioeconomic families and their 3- to 4-month-old infants were observed for 4 3-hr blocks between 8:00 a.m. and 8:00 p.m. on 4 different weekdays. With increasing economic resources, children's exposure to multiple caregivers and nonresident fathers declined. Mothers were more available to infants than fathers were, regardless of socioeconomic status. Mothers fed infants more than fathers did, whereas fathers vocalized more and displayed more affection to infants than mothers did when they were examined in proportion to caregiver presence. Mothers and fathers interacted with male and female infants quite similarly, although, in the upper socioeconomic families, fathers of daughters were more available than fathers of sons. Fathers and mothers in the different socioeconomic groups held, displayed affection to, and soothed their infants differently.     

Learning during stressful times

Stressful life events can have profound effects on our cognitive and motor abilities, from those that could be construed as adaptive to those not so. In this review, I discuss the general notion that acute stressful experience necessarily impairs our abilities to learn and remember. The effects of stress on operant conditioning, that is, learned helplessness, as well as those on classical conditioning procedures are discussed in the context of performance and adaptation. Studies indicating sex differences in learning during stressful times are discussed, as are those attributing different responses to the existence of multiple memory systems and nonlinear relationships. The intent of this review is to highlight the apparent plasticity of the stress response, how it might have evolved to affect both performance and learning processes, and the potential problems with interpreting stress effects on learning as either good or bad. An appreciation for its plasticity may provide new avenues for investigating its underlying neuronal mechanisms.     

Predicting performance times from deliberate practice hours for triathletes and swimmers: what, when, and where is practice important?

In Studies 1 and 2, the authors evaluated deliberate practice theory through analyses of the relationship between practice and performance for 2 populations of athletes: triathletes and swimmers, respectively. In Study 3, the authors obtained evaluations of practice from athletes' diaries. Across athletes, length of time involved in fitness activities was not related to performance. For the triathletes, a significant percentage of variance in performance was captured by practice. This was not so for sprint events for the swimmers, in which gender was a significant predictor. In the diaries, physical activities were perceived as enjoyable. In contrast to the results obtained from questionnaires, enjoyment did not covary with an activity's relevance to improving performance. Although these findings highlight the importance of sport-specific practice, the authors question a domain-independent account of expertise based on deliberate practice.     

The psychology of telling murder stories: do we think in scripts,exemplars, or prototypes?

According to the story model of Pennington and Hastie, jurors collect information at trial and modify it with general knowledge to create case stories. Schank and Ableson argue that human memory is organized to tell and understand stories. However, Finkel and Groscup questioned the use of manipulated, experimenter-constructed narratives to demonstrate the existence of multiple prototypical crime stories. We interviewed 76 jury eligible, death qualified citizens and asked them to imagine a first-degree murder scenario, describing the events that led to the killing. We coded the presence of dichotomous variables in the resulting stories and identified at least three shared story prototypes using cluster and profile analysis. We conclude that people do not store crime stories as simple prototypes and comment on the implications of this finding for legal decision-making.     

Neurogenesis and learning: acquisition and asymptotic performance predict how many new cells survive in the hippocampus

Previous research has shown that some associative learning tasks prevent the death of new neurons in the adult hippocampus. However, it is unclear whether it is mere exposure to the training stimuli that rescues neurons or whether successful learning of the task is required for enhanced neuronal survival. If learning is the important variable, then animals that learn better given the same amount of training should retain more of the new cells after learning than animals that do not learn as well. Here, we examined the effects of training versus learning on cell survival in the adult hippocampus. Animals were injected with BrdU to label a population of cells and trained one week later on one of two trace conditioning tasks, one of which depends on the hippocampus and one that does not. Increases in cell number occurred only in animals that acquired the learned response, irrespective of the task. There were significant correlations between acquisition and cell number, as well as between asymptotic performance and cell number. These data support the idea that learning and not simply training increases the survival of the new cells in the hippocampus.     

The interaction of perfectionism, perceived weight status, and self-esteem to predict bulimic symptoms: the role of 'benign' perfectionism

The present study sought to replicate an interactive model of global perfectionism, perceived weight status, and self-esteem in predicting bulimic symptom development in a sample of young women [Bardone-Cone, et al. (2006). Predicting bulimic symptoms: An interactive model of self-efficacy, perfectionism, and perceived weight status. Behaviour Research and Therapy, 44, 27-42; Vohs, K. D., et al. (1999). Perfectionism, perceived weight status, and self-esteem interact to predict bulimic symptoms: A model of bulimic symptom development. Journal of Abnormal Psychology, 108, 695-700; Vohs, K. D., et al. (2001). Perfectionism, body dissatisfaction, and self-esteem: An interactive model of bulimic symptom development. Journal of Social and Clinical Psychology, 20, 476-497]. The aim was to investigate the role of 'problematic' and 'benign' perfectionism within this model, using data from 95 female university students over a 3-month period. Contrary to hypotheses, multivariate analyses revealed a significant three-way interaction only between 'benign' perfectionism, perceived weight status and self-esteem in predicting change in bulimic symptoms over a 3-month period. The predictive effect of the interaction between 'benign' perfectionism and perceived weight status on bulimic symptoms was strongest for women with high self-esteem, for whom feeling overweight and having perfectionistic attitudes preceded increased bulimic symptoms. These findings suggest that high self-esteem is insufficient to protect against the development of bulimic symptoms when both the perception of oneself as being overweight, and high levels of perfectionistic standards, are present. It would appear that the role of perfectionism within the context of disordered eating is complex.     

Career Decision Ambiguity Tolerance Scale: Construction and initial validations

The Career Decision Ambiguity Tolerance Scale (CDAT) measures individual evaluations of and responses to ambiguity encountered in career decision making. It was developed and initially validated through two studies of college students. An exploratory and confirmatory factor analysis consistently showed a three-factor structure for career decision ambiguity tolerance, consisting of preference, tolerance, and aversion. In addition to support for construct validity and subscale reliabilities, the findings also support the scale's incremental validity in predicting career indecision, career decision-making self-efficacy, and career adaptability over and beyond general ambiguity tolerance. The theoretical meaning and practical application of the CDAT were discussed along with its limitations and suggestions for future research.