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.     

Body dysmorphic symptoms: phenomenology and ethnicity

Differences in the presentation of clinical features of body dysmorphic disorder (BDD) across ethnic groups have received little investigation. The current study assessed BDD symptoms in an ethnically diverse sample of adults (n=401) using an online survey. Participants completed self-report measures assessing BDD symptoms, body parts of concern and BDD behaviors. Compared to Caucasian participants, no significant differences were found in body parts or behaviors reported by Latino or African American participants. Significant group differences did emerge between Asian and Caucasian participants. Specifically, Asians reported more concern with straight hair and dark skin and fewer body shape concerns than Caucasians. Asians also endorsed lower rates of grooming, touching body parts, and camouflaging and higher rates of exercise compared to Caucasians. Although most clinical features of BDD appear similar across ethnic groups, results showed some differences in body parts and behaviors between Caucasians and Asian Americans with BDD symptoms.     

Adaptation of the "Recovery Experience Questionnaire" in a Spanish sample

The aim of this work was to examine the psychometric properties of the Spanish version of the "Recovery Experience Questionnaire" developed by Sonnentag and Fritz. The sample was made up of 941 professionals from the security sector. Results from the exploratory factor analysis suggested the possibility of considering a four-factor structure. Confirmatory factor analysis showed that the four-factor model with three correlated items each provided the best fit to the data (CFI=0.97, GFI=0.96, NNFI=0.96, RMSEA=0.05 y AIC=171.76). Therefore, the questionnaire maintains the four recovery experiences -psychological detachment from work, relaxation, mastery experiences and control over leisure time--but with 12 items instead of 16 items as in the original scale. Reliability analysis showed good internal consistency for this scale with Cronbach alpha coefficients for the factors ranging from .75 to .88. Significant correlations were found between the recovery experiences and various external variables, providing evidence of construct validity. Thus, this Spanish version shows adequate psychometric properties and may help to achieve a better understanding of this topic.     

Professional efficacy,exhaustion, and work characteristics among police officers: A longitudinal test of the learning‐related predictions of the demand—control model

The present study addressed the relationships among professional efficacy, emotional exhaustion, and job characteristics (job demands and job control) in the context of a two‐wave panel study among 828 Dutch police officers. Based on the demand–control model, we expected that high demands/high control would be positively related to professional efficacy, and that high demands/low control would be related to high levels of exhaustion. Moreover, we hypothesized that high levels of exhaustion would lead to lower levels of professional efficacy and that high levels of efficacy would lead to low levels of exhaustion. Structural equation modelling largely supported these predictions. High demands were longitudinally related to high levels of efficacy and high levels of exhaustion; high control was longitudinally related to high levels of efficacy. Further, efficacy and exhaustion were indeed mutually related. Finally, high levels of exhaustion were longitudinally related to high levels of demands. We conclude that there are complex, yet theoretically, and practically interpretable relations among efficacy, strain and work characteristics.     

Connecting Information with Scientific Method: Darwin’s Significance for Epistemology

Theories of epistemology make reference—via the perspective of an observer—to the structure of information transfer, which generates reality, of which the observer himself forms a part. It can be shown that any epistemological approach which implies the participation of tautological structural elements in the information transfer necessarily leads to an antinomy. Nevertheless, since the time of Aristotle the paradigm of mathematics—and thus tautological structure—has always been a hidden ingredient in the various concepts of knowledge acquisition or general theories of information transfer. We hold that Darwin’s Evolutionary Theory is the first scientific theory which consistently presupposes a non-tautological structure for the information transfer and, at the same time, keeps it strictly distinct from the tautological metric of scientific observation. The consequences of this technique—namely the dissociation of information from intentionality—have not yet been fully drawn.     

Can the irrelevant speech effect turn into a stimulus suffix effect?

The irrelevant sound effect (ISE) and the stimulus suffix effect (SSE) are two qualitatively different phenomena, although in both paradigms irrelevant auditory material is played while a verbal serial recall task is being performed. Jones, Macken, and Nicholls (2004) have proposed the effect of irrelevant speech on auditory serial recall to switch from an ISE to an SSE mechanism, if the auditory-perceptive similarity of relevant and irrelevant material is maximized. The experiment reported here (n = 36) tested this hypothesis by exploring auditory serial recall performance both under irrelevant speech and under speech suffix conditions. These speech materials were spoken either by the same voice as the auditory items to be recalled or by a different voice. The experimental conditions were such that the likelihood of obtaining an SSE was maximized. The results, however, show that irrelevant speech—in contrast to speech suffixes—affects auditory serial recall independently of its perceptive similarity to the items to be recalled and thus in terms of an ISE mechanism that crucially extends to recency. The ISE thus cannot turn into an SSE.     

When Do Employees Identify? An Analysis of Cross‐Sectional and Longitudinal Predictors of Training Group and Organizational Identification1

Organizational research has shown the impact of organizational identification on employees' attitudes and behavior, and its relevance for economic success ( Haslam, 2004 ). Furthermore, the necessity to differentiate levels of identification within organizations has been emphasized ( van Knippenberg & van Schie, 2000 ). Little is known, however, about predictors of different identification levels within organizations and their influence on the development of identification. In a longitudinal study with training groups of flight attendants, we investigated how foci of identification (training group, organization) were differentially predicted by cross‐sectional and longitudinal variables. Interpersonal attraction related to training group identification, whereas professional motivation related to organizational identification. Furthermore, expected job circumstances and professional motivation were longitudinal predictors for training group identification and organizational identification, respectively.     

Rumor Has It: The Moderating Effect of Identification on Rumor Impact and the Effectiveness of Rumor Refutation1

Two studies were undertaken to examine the moderating effect of identification with a rumor target on rumor impact and refutation effectiveness. We show that identification and its opposite, disidentification, bias the way individuals react to a rumor. That is, as identification with the rumor target increased from disidentification to neutral to identification, belief in an aversive rumor declined. Furthermore, the effectiveness of a refutation was moderated by an individual's level of identification. People with a neutral identification level processed a refutation heuristically and were persuaded by it, whether it contained strong or weak arguments. Disidentifiers, who engaged in systematic processing, believed the rumor less only when the refutation contained strong arguments. Identifiers, processing heuristically, remained unbelieving in the rumor.     

Structural and functional MRI- findings in children and adolescents with antisocial behavior

BACKGROUND: The developmental course of children with conduct disorder (CD) is heterogeneous. Especially children who exhibit symptoms early in their lifetimes are characterized by a negative outcome. Neurobiological aspects of CD have been investigated in these children but little is known about structural and functional brain aberrations. METHODS: We describe the developmental taxonomy of children with CD and focus on those with the early onset subtype. Structural MRI data of these children and antisocial adults are recapitulated. The impact of investigating neurobiological underpinnings of antisocial behavior and how this might contribute to future forensic and psychiatric assessments is discussed. RESULTS/ CONCLUSION: Children display similar structural aberrations of fronto-limbic structures to adults with antisocial behavior, and amygdala dysfunction might be closely related to dysregulated emotions. Though the investigation of biological factors in antisocial subjects has made great progress in recent years, today MRI is still a rather complex, expensive and indistinct method for forensic assessment.