Directed forgetting of autobiographical memory in mild Alzheimer's disease

Using the autobiographical directed forgetting method (Barnier et al., 2007), the present paper addressed the intentional inhibitory processes of episodic and semantic autobiographical memory in Alzheimer's disease (AD). Mild AD patients and healthy elderly people were instructed to either forget or to continue remembering previously generated autobiographical events. In a later recall test they were asked to reconstruct the early-generated memories regardless of the forget/remember instruction. Autobiographical reconstruction was further distributed into episodic and semantic memories. Results showed no forget instruction effect on episodic or semantic autobiographical recall with AD patients, whereas healthy elderly people were able to inhibit only episodic autobiographical memories. The findings suggest an impairment of the intentional inhibitory processes in autobiographical memory with AD and a relative preservation of these mechanisms with normal ageing. They also demonstrate an earlier decline in the intentional inhibitory processes compared to the autobiographical deterioration in AD.     

RSK2 signaling in brain habenula contributes to place aversion learning

RSK2 is a Ser/Thr kinase acting in the Ras/MAPK pathway. Rsk2 gene deficiency leads to the Coffin-Lowry Syndrome, notably characterized by cognitive deficits. We found that mrsk2 knockout mice are unable to associate an aversive stimulus with context in a lithium-induced conditioned place aversion task requiring both high-order cognition and emotional processing. Virally mediated shRNA-RSK2 knockdown in the habenula, whose involvement in cognition is receiving increasing attention, also ablated contextual conditioning. RSK2 signaling in the habenula, therefore, is essential for this task. Our study reveals a novel role for RSK2 in cognitive processes and uncovers the critical implication of an intriguing brain structure in place aversion learning.     

Pre-training anandamide infusion within the basolateral amygdala impairs plus-maze discriminative avoidance task in rats

Endocannabinoids (eCBs) modulate a variety of brain functions via activation of the widely expressed CB1 receptor. One site of high density of this receptor is the basolateral amygdala (BLA), a structure involved in the formation of aversive memories. The activation and blockade of CB1 receptors by systemic or hippocampal drug administrations have been shown to modify memory processing. However, little is known about the role of the BLA endocannabinoid system in aversive memories. Additionally, BLA endocannabinoid transmission seems to be related to emotional states, but the relevance of these effects to memory formation is still unknown. In this study we investigated the effects of the eCB anandamide (AEA) and the CB1 antagonist/inverse agonist AM251 infused into the BLA on the acquisition of an aversive memory task, concomitantly evaluating basal anxiety levels in rats. Male rats received pre-training micro-injection of AEA, AM251 or vehicle bilaterally into the BLA, and were studied with the plus-maze discriminative avoidance task (a paradigm that allows concomitant and independent evaluation of anxiety-like behavior and the memory of an aversive task). Our results showed that AEA into the BLA before training prevented memory retrieval 24 h later, as evaluated by exploration of the aversive arm of the maze, while AM251 into the BLA did not interfere with animals' performance. In addition, AEA had no effect on anxiety-like behavior (as evaluated by open arm exploration and risk assessment), while AM251 induced an anxiogenic effect. Our data indicate an important role of BLA CB1 receptors in aversive memory formation, and suggest that this involvement is not necessarily related to a possible modulation of anxiety states.     

Integrative processing of perception and reward in an auditory localization paradigm

Under natural conditions, human beings routinely have to choose among multiple alternatives which are associated with specific outcomes of varying desirability. Typically, decisions are based upon the processing of perceptual input, which introduces additional noise to the system. Bayesian decision theory (BDT) allows us to formalize decision under risk and to predict statistically optimal choice behavior. In the present study, human observers performed a classification task characterized by an extensive amount of perceptual uncertainty (auditory localization). In addition, a spatial reward function was imposed on the task. We set up a BDT model with no free parameters to serve as a benchmark for statistically optimal choices, and tested it against a purely perceptual model and a hybrid, heuristic model. In addition, we tested these three models with free rather than fixed parameters for the perceptual uncertainty and the peak of the reward function. The log likelihoods of the models given the empirical data were determined by means of Monte Carlo simulations. Bayesian model comparison (BMC) revealed that the BDT model with two free parameters was the most plausible among the tested models. The fitted parameter values for the peak of the reward function were consistently smaller than the actual peak reward communicated to the participants. The results are discussed in the context of an internal underweighting of the reward function.     

The Five-Factor Model of Personality at the Facet Level: Association with Antisocial Personality Disorder Symptoms and Prediction of Antisocial Behavior

The association between the Five-Factor Model of personality (FFM) and antisocial personality disorder (APD) symptoms was investigated in a sample of young males with a history of severe antisocial behavior. Results were compared against those of an expert-consensus study (Lynam and Widiger Journal of Abnormal Psychology 110:401–412, 2001) and those of a recent meta-analysis (Samuel and Widiger Clinical Psychology Review 28:1326–1342, 2008) based primarily on non-antisocial samples. A high degree of similarity was observed across the three. Multivariate analysis indicated two FFM facets, Compliance and Activity, to be associated with APD symptoms. The contribution of these facets to the prospective prediction of antisocial behavior over and above that of APD symptoms and past antisocial behavior was evaluated. Compliance alone explained 8.7% of the unique variance in future antisocial behavior.     

Multiculturalism as a dimension of school climate: the impact on the academic achievement of Asian American and Hispanic youth

Multiculturalism constitutes an important element of school climate, but the relation between perceived multiculturalism and academic achievement has not been widely studied. This study examined the influence of students' perceptions of school support for multiculturalism on academic achievement among 280 Asian American and Hispanic youth, including ethnic identity and ethnocultural empathy as potential mediators. Results of structural equation modeling revealed that perceived multiculturalism was significantly positively related to ethnocultural empathy for Asian Americans and Hispanics, and that ethnocultural empathy, in turn, was predictive of academic achievement for Hispanics only. Results of bootstrapping to test for mediation effects revealed ethnocultural empathy to be a salient mediator for Hispanic youth. Although ethnic identity did not mediate the link between multiculturalism and academic achievement, ethnic identity was significantly predictive of achievement for Hispanics. On the whole, these findings suggest that fostering a school climate supportive of multiculturalism may improve empathy toward ethnic out-groups. Furthermore, schools that promote compassion and tolerance for diverse ethnic groups may achieve better academic outcomes among Hispanic youth.     

多元企业认同的身份构建及其张力调和机理

基于认同驱动的营销关系视角, 系统地探讨了基于多元企业认同的企业身份构建及其张力调和机理。具体地, 通过定性和定量相结合的方法, 首先基于社会认同理论和身份理论, 探索多元企业认同的结构; 其次, 从社会心理学和文化创新的视角, 描绘多元企业认同形成及演化过程; 最后, 探究多元企业认同的身份构建以及身份张力调和机制。在理论上将消费者-企业认同扩展到多个利益相关者与企业的认同, 探索多元企业认同的身份构建及调和过程, 揭示其背后深层作用机理。实践上为企业与客户保持长期、和谐、多赢关系提供重要依据。     

Epistemic means and ends: a reply to Hofmann

How is epistemic justification related to knowledge? Is it, as widely thought, constitutive of knowledge? Is it merely a means to knowledge, or merely a means to something else, such as truth? In a recent article in this journal, Hofmann (2005, Synthese, 146(3), 357–369) addresses these questions in attempting to defend an important argument articulated by Sartwell (1992, The Journal of Philosophy, 89(4), 167–180) and reconstructed and criticized by Le Morvan (2002, Erkenntnis: An International Journal of Analytic Philosophy, 56(2), 151–168). This Sartwellian argument purported to show that, since epistemic justification is of merely instrumental value, it is not constitutive of knowledge. In this paper, I argue that Hofmann’s defense of Sartwell fails, but that its failure brings to light some important lessons concerning the nature of justification and its relationship to truth and knowledge.