mTOR signaling in the hippocampus is necessary for memory formation

It is widely accepted that the formation of long-term memory (LTM) requires mRNA translation, but little is known about the cellular mechanisms in the brain that regulate this process. Mammalian target of rapamycin (mTOR) is a key regulator of translational efficacy and capacity. Here, we show that LTM formation of one-trial inhibitory avoidance (IA) in rats, a hippocampus-dependent fear-motivated learning task, requires mTOR activation. IA training is specifically associated with a rapid increase in the phosphorylation state of mTOR and its substrate ribosomal S6 kinase (p70S6K). Bilateral intra-CA1 infusion of rapamycin, a selective mTOR inhibitor, 15 min before, but not immediately after training completely hinders IA LTM without affecting short-term memory (STM) retention. Therefore, our findings indicate that the regulation of hippocampal mRNA translation is a major control step in memory consolidation.     

Moral judgments, emotions and the utilitarian brain

The investigation of the neural and cognitive mechanisms underlying the moral mind is of paramount importance for understanding complex human behaviors, from altruism to antisocial acts. A new study on patients with prefrontal damage provides key insights on the neurobiology of moral judgment and raises new questions on the mechanisms by which reason and emotion contribute to moral cognition.     

Is the attribution of cultural differences to minorities an expression of racial prejudice?

The social psychological literature considers two main perspectives on the study of perceived cultural differences between majorities and minorities: one proposes that perception of cultural differences is an antecedent of prejudice and another states that the attribution of cultural differences to minorities is already a hidden expression of racial prejudice. This paper offers further support to this latter perspective. One hundred and ninety-four participants answered a questionnaire measuring (1) general racist belief; (2) cultural differences attributed to Black people (hetero-ethnicization); (3) the asymmetric attribution of secondary and primary emotions to the in-group and to Black people (infra-humanization); (4) the asymmetric attribution of natural and cultural traits to in-group members and to Black people (ontologization); and (5) negative evaluation of this social category. The general racist belief scale was not anchored in a specific group and measured the belief in the inferiority of certain social groups or peoples based on biological or cultural factors. Relationships between the scales were analysed through a set of Structural Equation Models. According to the predictions, results showed that the attribution of cultural differences is a dimension of prejudice. Results also showed that attribution of cultural differences, negative evaluation of Black people, ontologization, and infra-humanization were different dimensions of a common latent factor that can be identified as racial prejudice; and that prejudice was predicted by general racist belief. Results are discussed in the light of the study of the impact of perceived cultural differences on intergroup relations and in the light of the "new racism" approaches.     

Role of the Disease in the Psychological Impact of Pre-Symptomatic Testing for SCA2 and FAP ATTRV30M: Experience with the Disease, Kinship and Gender of the Transmitting Parent

To identify possible factors affecting the psychological impact of pre-symptomatic testing for spinocerebellar ataxia type 2 (SCA2) and familial amyloid polyneuropathy (FAP ATTRV30M), we studied (1) the effect of previous experience with the disease in the family, (2) kinship with the closest affected relative and (3) gender of affected parent, when adapting to test results; as well as (4) differences in the course of psychological wellbeing in 63 subjects ( 28 at-risk for FAP ATTRV30M, and 35 at risk for SCA2), who pursued predictive testing for these diseases, in Cuba and in Portugal. Our research shows that individuals with little or no experience with the disease in their family exhibited more anxiety; at-risk subjects for SCA2 or FAP ATTRV30M who had a first degree relative with the disease showed lower levels of anxiety and depression during pre-symptomatic testing. Also those with an affected mother had lower levels of depression, either immediately, or one year after receipt of test results. Adaptation to pre-symptomatic testing results differed for subjects at-risk for the two different conditions. Unlike the FAP ATTRV30M families, carriers for SCA2 reported pathological levels of depression immediately after-testing (3 weeks), although those levels had returned to normal levels at 6 months. Subjects at-risk for FAP ATTRV30M tended to have less anxiety than those tested for SCA2, at the one-year follow-up. Overall, depression levels improved over time, while anxiety remained more constant. A longer awareness of the disease in the family, closer kinship, and a transmitting mother all lessened the impact of pre-symptomatic testing, as expressed by the post-test levels of anxiety and depression.     

The formation of structurally relevant units in artificial grammar learning

A total of 78 adult participants were asked to read a sample of strings generated by a finite state grammar and, immediately after reading each string, to mark the natural segmentation positions with a slash bar. They repeated the same task after a phase of familiarization with the material, which consisted, depending on the group involved, of learning items by rote, performing a shortterm matching task, or searching for the rules of the grammar. Participants formed the same number of cognitive units before and after the training phase, thus indicating that they did not tend to form increasingly large units. However, the number of different units reliably decreased, whatever the task that participants had performed during familiarization. This result indicates that segmentation was increasingly consistent with the structure of the grammar. A theoretical account of this phenomenon, based on ubiquitous principles of associative memory and learning, is proposed. This account is supported by the ability of a computer model implementing those principles, PARSER, to reproduce the observed pattern of results. The implications of this study for developmental theories aimed at accounting for how children become able to parse sensory input into physically and linguistically relevant units are discussed.     

Implicit learning shapes new conscious percepts and representations

We present here the lineaments of a new account of implicit learning, an account that does not rely on the notion of “implicit knowledge.” In this account, improved performance depends on the action of unconscious mechanisms that structure the phenomenal, conscious experience of the world. This integrative view makes groundless the search for dissociations between conscious and unconscious influences that has been at the core of the research on implicit learning and memory. We contrast this view, on the one hand, to Dienes and Berry’s (1997) proposal, which defines implicit learning by analogy with subliminal perception, and, on the other, to Neal and Hesketh’s (1997) episodic account, in which subjective experience is a starting point for inquiry, rather than the phenomenon requiring explanation.     

Decrease of Precurrent Behavior as Training Increases: Effects of Task Complexity

The Psychological Record - When someone is described as memorizing a phone number, part of what is being asserted is that the person is capable of dialing the number without looking it up in the...