Single prolonged stress disrupts retention of extinguished fear in rats

Clinical research has linked post-traumatic stress disorder (PTSD) with deficits in fear extinction. However, it is not clear whether these deficits result from stress-related changes in the acquisition or retention of extinction or in the regulation of extinction memories by context, for example. In this study, we used the single prolonged stress (SPS) animal model of PTSD and fear conditioning procedures to examine the effects of prior traumatic stress on the acquisition, retention, and context-specificity of extinction. SPS administered one week prior to fear conditioning had no effect on the acquisition of fear conditioning or extinction but disrupted the retention of extinction memories for both contextual and cued fear. This SPS effect required a post-stress incubation period to manifest. The results demonstrate that SPS disrupts extinction retention, leading to enhanced fear renewal; further research is needed to identify the neurobiological processes through which SPS induces these effects.     

Unconditioned freezing is enhanced in an appetitive context: implications for the contextual dependency of unconditioned fear

It has been well established that expression of conditioned fear is context independent, but the context dependency of unconditioned fear expression has rarely been explored. A recent study reported that unconditioned freezing in rats is enhanced in a familiar context, which suggests that unconditioned fear expression can be modulated by contextual processing. In order to further explore this possibility we examined unconditioned freezing in novel, familiar, and appetitive contexts; and attempted to identify brain regions critical for context-related changes in unconditioned freezing by measuring c-Fos mRNA levels in emotional circuits. Unconditioned freezing was enhanced in the appetitive context, and this enhancement was accompanied by increased c-Fos mRNA expression in the medial amygdala and hippocampus, but attenuated expression in the medial prefrontal cortex. In the appetitive context, expectation of a reward coupled with detection of threat may have enhanced unconditioned fear expression, which suggests that unconditioned fear expression can be modulated by contextual factors. Context-related expectancy mismatch may explain the enhancement of unconditioned fear expression seen in this study and warrants further examination.     

Computational psychiatry

Computational ideas pervade many areas of science and have an integrative explanatory role in neuroscience and cognitive science. However, computational depictions of cognitive function have had surprisingly little impact on the way we assess mental illness because diseases of the mind have not been systematically conceptualized in computational terms. Here, we outline goals and nascent efforts in the new field of computational psychiatry, which seeks to characterize mental dysfunction in terms of aberrant computations over multiple scales. We highlight early efforts in this area that employ reinforcement learning and game theoretic frameworks to elucidate decision-making in health and disease. Looking forwards, we emphasize a need for theory development and large-scale computational phenotyping in human subjects.     

Model-based and model-free Pavlovian reward learning: Revaluation,revision, and revelation

Evidence supports at least two methods for learning about reward and punishment and making predictions for guiding actions. One method, called model-free, progressively acquires cached estimates of the long-run values of circumstances and actions from retrospective experience. The other method, called model-based, uses representations of the environment, expectations, and prospective calculations to make cognitive predictions of future value. Extensive attention has been paid to both methods in computational analyses of instrumental learning. By contrast, although a full computational analysis has been lacking, Pavlovian learning and prediction has typically been presumed to be solely model-free. Here, we revise that presumption and review compelling evidence from Pavlovian revaluation experiments showing that Pavlovian predictions can involve their own form of model-based evaluation. In model-based Pavlovian evaluation, prevailing states of the body and brain influence value computations, and thereby produce powerful incentive motivations that can sometimes be quite new. We consider the consequences of this revised Pavlovian view for the computational landscape of prediction, response, and choice. We also revisit differences between Pavlovian and instrumental learning in the control of incentive motivation.     

The Preliminary Employment Interview as a Predictor of Assessment Center Outcomes

The current study examined the relationships between personnel employment interview scores (PEI), cognitive ability test scores (CAT) and assessment center (AC) scores, as well as the potential to circumvent the costly AC method for some of the candidates by using these less expensive selection methods. A total of 423 Israeli police force candidates participated in the study. Their PEI and CAT scores were collected in the first stage of the selection process. They subsequently participated in an AC and a final decision was made regarding their acceptance to the police force. It was found that PEI and CAT scores significantly correlated with the AC scores and the recruitment decision, although the PEI scores demonstrated stronger correlations with the criteria. An actuarial analysis demonstrated the benefit of using the AC procedure for those achieving middle range scores on the PEI and CAT, circumventing the costly ACs for those achieving high and low scores. This strategy resulted in minor costs of both α and β errors. Organizations can adopt this economical strategy when the AC costs exceed the manpower costs incurred by disposing of the AC.     

Estimating the validity of the guilty knowledge test from simulated experiments: the external validity of mock crime studies

This experiment was designed to examine the external validity of the standard mock-crime procedure used extensively to evaluate the validity of polygraph tests. The authors manipulated the type of mock-crime procedure (standard vs. a more realistic version) and the time of test (immediate vs. delayed) and examined their effects on the validity of the Guilty Knowledge Test (GKT) and the recall rate of the relevant items. The results indicated that only the type of mock-crime affected the 2 outcome variables. The realistic procedure was associated with a lower recall rate and weaker detection efficiency than the standard procedure. However, these effects were mediated by the type of GKT questions used. Practical implications of these results are discussed.     

Effects of social media use on desire for cosmetic surgery among young women

Current Psychology - A large body of research has documented the influence of traditional media formats (e.g. television programs, adverts) on young women’s consideration of cosmetic surgery....     

Flexible shaping: How learning in small steps helps

Humans and animals can perform much more complex tasks than they can acquire using pure trial and error learning. This gap is filled by teaching. One important method of instruction is shaping, in which a teacher decomposes a complete task into sub-components, thereby providing an easier path to learning. Despite its importance, shaping has not been substantially studied in the context of computational modeling of cognitive learning. Here we study the shaping of a hierarchical working memory task using an abstract neural network model as the target learner. Shaping significantly boosts the speed of acquisition of the task compared with conventional training, to a degree that increases with the temporal complexity of the task. Further, it leads to internal representations that are more robust to task manipulations such as reversals. We use the model to investigate some of the elements of successful shaping.     

Acculturation orientations towards Israeli Arabs and Jewish immigrants in Israel

The State of Israel can be characterized as having two integration policies: an assimilationist one towards “valued” Jewish immigrants and a somewhat ethnist one towards its “devalued” national minority, namely Israeli Arabs. Using the Host Community Acculturation Scale (HCAS), this study explored Jewish undergraduate (N = 153) acculturation orientations towards “valued” Jewish immigrants of Russian and Ethiopian background and towards “devalued” Israeli Arabs. Results showed that Jewish undergraduates mainly endorsed the integrationism and individualism acculturation orientations towards Jewish immigrants. However, they were more segregationist and exclusionist towards Israeli Arabs than towards Jewish immigrants of Russian and Ethiopian background. Assimilation was weakly endorsed towards both Jewish immigrants and Israeli Arabs. Based on an extensive questionnaire, multiple regression analyses showed that each acculturation orientation had a distinct psychological profile. The integrationism and individualism orientations were endorsed by undergraduates who were tolerant towards ethnic diversity, felt secure personally, culturally, and militarily, and did not endorse the social dominance orientation (SDO). In addition to not feeling threatened by the presence of Israeli Arabs, integrationists and individualists were identified as secular Israelis and Labour Party sympathizers rather than as religious Jews. In contrast, the assimilationism, segregationism, and exclusionism orientations were endorsed by undergraduates who felt insecure personally, religiously, culturally, and militarily, who tended to be less tolerant towards ethnic diversity, and who were more prone to endorse the SDO. In addition to feeling threatened by Israeli Arabs, they avoided close relations with Russian and Ethiopian immigrants. Segregationists and exclusionists were identified mainly as Jewish nationals. Orthodox Jews, and as Likud Party sympathizers. Exclusionists were distinctive in also feeling threatened by the presence Jewish immigrants of Russian and Ethiopian background. While taking into consideration the context of intergroup relations in Israel, results are discussed using the Interactive Acculturation Model (Bourhis, Moïse, Perreault, & Senecal, 1997).