The factor structure of the Eysenck Personality Profiler in Russia

One hundred and seventy seven males and 399 females completed a translated short version of the Eysenck Personality Profiler (EPP-S). Two hundred and ninety four Ss also completed the EPQ. By means of item analysis, further shortening of the EPP was achieved, while retaining adequate psychometric characteristics and convergent validity with EPQ scales. Confirmatory factor analysis (CFA) confirmed the Eysenck hierarchical model of personality with three basic dimensions and showed stability of the EPP factor structure across genders and sub-samples of different origin. However, CFA showed that only E and P were independent, while N was correlated with E and P.     

Posttraumatic Growth in the Context of Heart Disease

The concept of positive consequences arising as a result of coping with traumatic experiences, such as life-threatening illness, represents an emerging area of empirical study in the stress and health literature. This study investigates three specific psychosocial variables (personality, social support, and coping) in relation to posttraumatic growth in a population of individuals coping with heart disease. The results indicate that Extraversion was the most significant predictor of growth, and there is evidence that Problem-Focused Coping partially mediated this relationship between Extraversion and posttraumatic growth. The role of Social Support Satisfaction in predicting growth remains unclear. Findings emphasize the importance of personal and environmental factors in psychological interventions aimed at improving the adjustment and posttraumatic growth of heart patients. Directions for future research are proposed.     

Close encounters of the distracting kind: Identifying the cause of visual tracking errors

Why can we track only so many objects? We addressed this question by asking when and how tracking errors emerge. To test the hypothesis that many tracking errors are target/nontarget confusions emerging from close encounters, we compared standard multiple-object tracking trials with trials on which a nontarget turned a random color whenever it approached within 4° of a target. This manipulation significantly improved performance by alleviating the correspondence challenge of a close encounter. Two control experiments showed that color change benefits were not merely due to target recovery. Follow-up experiments demonstrated that color change benefits did not accrue monotonically with distance but, instead, seemed to obey a step function; and an additional experiment demonstrated that, without color changes, the frequency of close encounters predicts tracking performance. Taken together, these experiments suggest that uncertainty about target location imposes the primary constraint on tracking, at times causing errors by leading to confusions between targets and nontargets.     

An observation on the spontaneous noticing of prospective memory event-based cues

In event-based prospective memory, current theories make differing predictions as to whether intention-related material can be spontaneously noticed (i.e., noticed without relying on preparatory attentional processes). In 2 experiments, participants formed an intention that was contextually associated to the final phase of the experiment, and lures that overlapped to differing degrees with the features of the intention-related cues were embedded in the initial phase. When participants were outside of the appropriate responding context (i.e., the initial phase), they exhibited slower latencies to lures that exactly matched the features of their intention compared with other types of lures and control words. In addition, on a final remember/know recognition test, participants reported having greater subjective recollection for the occurrence of the exact-match lures. These results suggest that exact-match lures were spontaneously noticed and differentially processed in the absence of any observable preparatory attentional processes. The findings have implications for the theoretical debate over whether preparatory attention must always be relied upon to notice intention-related material.     

Reevaluation of Piaget’s concept of egocentrism: New perspectives on a misunderstood idea

The paper states the goal of this special issue and briefly summarizes the topics of the papers addressed in this issue.     

Towards mouse models of perseveration: a heritable component in extinction of operant behavior in fourteen standard and recombinant inbred mouse lines

Extinction of instrumental responses is an essential skill for adaptive behavior such as foraging. So far, only few studies have focused on extinction following appetitive conditioning in mice. We studied extinction of appetitive operant lever-press behavior in six standard inbred mouse strains (A/J, C3H/HeJ, C57BL/6J, DBA/2J, BALB/cByJ and NOD/Ltj) and eight recombinant inbred mouse lines. From the response rates at the end of operant and extinction training we computed an extinction index, with higher values indicating better capability to omit behavioral responding in absence of reward. This index varied highly across the mouse lines tested, and the variability was partially due to a significant heritable component of 12.6%.To further characterize the relationship between operant learning and extinction, we calculated the slope of the time course of extinction across sessions. While many strains showed a considerable capacity to omit responding when lever pressing was no longer rewarded, we found a few lines showing an abnormally high perseveration in lever press behavior, showing no decay in response scores over extinction sessions.No correlation was found between operant and extinction response scores, suggesting that appetitive operant learning and extinction learning are dissociable, a finding in line with previous studies indicating that these forms of learning are dependent on different brain areas. These data shed light on the heritable basis of extinction learning and may help develop animal models of addictive habits and other perseverative disorders, such as compulsive food seeking and eating.     

High-fat diets impair spatial learning in the radial-arm maze in mice

It has been suggested that hyperglycemia and insulin resistance triggered by energy-dense diets can account for hippocampal damage and deficits of cognitive behaviour. We wonder if the impairment of learning and memory processes detected in diet-induced obese (DIO) mice is linked to diet composition itself. With this purpose we have evaluated learning performance in mice undergoing a short-term high-fat (HF) treatment, which leads to a pre-obese state characterized by increased adiposity without significant changes of glucose and insulin plasma levels. C57BL/6J mice were fed either a HF (45 kcal% from fat) or control diet (10 kcal% from fat) during 8 weeks. Learning performance was evaluated by using the four-arm baited version of the eight-arm radial maze test (RAM). Mice were trained to learn the RAM protocol and then memory was tested at different time-points. Time spent to consume food placed in baited arms and errors committed to find them were measured in all sessions. DIO mice significantly spent more time in learning the task and made a greater number of errors than controls. Moreover, retention tests revealed that both working and total memory errors were also more numerous in DIO mice. The current results show that short-term DIO impairs spatial learning and suggest that impairment of hippocampal learning elicited by HF diets might be perceptible before metabolic alterations linked to obesity develop.