Activation of the infralimbic cortex in a fear context enhances extinction learning

Activation of the infralimbic region (IL) of the medial prefrontal cortex (mPFC) reduces conditioned fear in a variety of situations, and the IL is thought to play an important role in the extinction of conditioned fear. Here we report a series of experiments using contextual fear conditioning in which the IL is activated with the GABAa antagonist picrotoxin (Ptx) during a single extinction session in the fear context. We investigate the impact of this manipulation on subsequent extinction sessions in which Ptx is no longer present. First, we demonstrate that a single treatment with intra-IL Ptx administered in a conditioned fear context greatly accelerates the rate of extinction on the following days. Importantly, IL-Ptx also enhances extinction to a different fear context than the one in which IL-Ptx was administered. Thus, IL-Ptx primes extinction learning regardless of the fear context in which the IL was initially activated. Second, activation of the IL must occur in conjunction with a fear context in order to enhance extinction; the extinction enhancing effect is not observable if IL-Ptx is administered in a neutral context. Finally, this extinction enhancing effect is specific to the IL for it does not occur if Ptx is injected into the prelimbic region (PL) of the mPFC. The results indicate a novel persisting control of fear induced by activation of the IL and suggest that IL activation induces changes in extinction-related circuitry that prime extinction learning.     

Prospects behind bars: Analyzing decisions under risk in a prison population

Criminal activity often involves considerable risks. It is therefore not surprising that criminals have been speculated to differ from noncriminals in risk attitude. Yet, few data exist to support this assumption. Moreover, the psychological underpinnings of differences in risk attitude are currently little understood. We presented prisoners and controls with sets of risky decision tasks and modeled their responses using cumulative prospect theory (CPT). The two groups showed several differences. Prisoners were more risk seeking than nonprisoners in lotteries involving losses, but they were less risk seeking in lotteries involving high-probability gains. Bestfitting CPT parameters indicated a reduced sensitivity to outcomes, for both gains and losses, and a stronger loss aversion among prisoners. In addition, prisoners showed a diminished sensitivity to the probability of gains. Our results contribute to a better understanding of prisoners’ risk attitudes and the underlying mechanisms that distinguish prisoners from nonprisoners and may thus help improve interventions designed to prevent crime.     

Psychotherapie von Kriegs- und Folteropfern

Within the context of worldwide migratory movements, numerous victims of war and torture are moving into western countries. Frequently, these patients are in need of psychotherapy, which is partly provided by specialized institutions. Psychotherapists of victims of war and torture have to deal with manifold additional physical, social, material, and legal problems of their clients. Therefore, such patients are best treated by multidisciplinary teams. The psychotherapy of such victims involves the classical methods for the treatment of PTSD; however, these methods may be of limited effect in these patients due to high comorbidity. Additional methods and concepts known from the treatment of complex PTSD and borderline personality disorders must be integrated into therapeutic strategies.     

The Reduced and Enhanced Impact of Shared Features on Individual Brand Evaluations

In 3 studies, consumers received information about products that had either positive or negative features in common. When they evaluated the products shortly afterward, the common features had little influence on their evaluations, and this was true regardless of whether they had made a preference rating, a similarity rating, or no rating at all before reporting these evaluations. In all cases, consumers apparently used one of the brands spontaneously as a standard of comparison for the other and, in doing so, discounted their common features. When their evaluation was delayed, however, shared features had greater impact. Two factors appear to be operating in the latter conditions. First, the alternative brand is less accessible and, therefore, is less likely to be used as a standard of comparison. Second, shared features are easier to recall than unique features, so they have a disproportional influence for this reason.     

Immunization of opioid analgesia: Effects of prior escapable shock on subsequent shock-induced and morphine-induced antinociception

In Experiment 1, it was shown that experience with escapable foot shock 4 hr prior to a session of 80 inescapable tail shocks prevented the occurrence of an analgesic response normally observed immediately following the tail shock. It has been suggested by J. W. Grau, R. L. Hyson, S. F. Maier, J. Madden, and J. D. Barchas (Science, 1981, 213, 1409–1411) that the analgesia that occurs following this number of inescapable tail shocks is mediated by endogenous opioid systems. To further explore the influence of escapable shock on opiate-mediated analgesia, Experiment 2 examined the effects of prior escapable shock on the long-term analgesia reaction that occurs upon brief exposure to shock 20 hr after morphine administration. Rats were given escapable shock, inescapable shock, or no shock 4 hr prior to a morphine injection. Twenty hours following the injection, all subjects received 5 brief foot shocks and were then immediately given tail-flick analgesia tests. Subjects which received inescapable shock or no shock prior to the morphine injection displayed a significant analgesic response. However, subjects which received escapable shock prior to morphine were not analgesic following brief exposure to shock. Thus, escapable shock seems to directly influence the activation of opioid analgesia systems.