Environmental enrichment eliminates the anxiety phenotypes in a triple transgenic mouse model of Alzheimer’s disease

Although the impacts of environmental enrichment (EE) in several genetic models of Alzheimer’s disease (AD) have been documented, the focus has remained predominantly on cognition. Few have investigated the expression of emotional phenotypes that mimic the notable affective features in AD. Here, we studied the interaction between EE and the coexpression of three genetic risk factors (mutations) for AD. In a longitudinal design, 3×Tg-AD mutants and wild type controls were compared at 6–7 months and subsequently at 12–13 months of age. Under standard housing, phenotypes of heightened anxiety levels were identified in the 3×Tg-AD mice in the elevated plus maze and open-field tests. Such trait differences between genotypes were substantially diminished under EE housing, which was attributable to the anxiolytic impact of EE on the mutant mice as much as the anxiogenic impact of EE on the wild type mice. In contrast, the phenotypes in learned fear were not significantly modified by EE in the tests of Pavlovian freezing and conditioned active avoidance conducted at either age. Rearing under EE thus has uncovered a novel distinction between innate and acquired expressions of fear response in the 3×Tg-AD mouse model that might be relevant to the mental health management of AD.     

A Semantic Network Approach to the Creativity Quotient (CQ)

The Creativity Quotient (CQ) is a novel metric building on ideational fluency that accounts for both the number of novel ideas (ideation) and the number of distinct categories (fluency) these ideas fall into. Categories are, however, difficult to define unambiguously and objectively. We propose that the principal contribution of this article is an entirely algorithmic approach based on concept networks, and an information metric defined thereon. It requires only measures of the similarity between concepts, which may come from databases such as Wordnet, Wikipedia, Google, or corpus analysis tools. In the special case of strong, unique categories it reduces directly to CQ.     

The Wisdom of Sharing a Frame: Commentary on Papers by Anthony Bass and Ilana Laor

In this discussion I agree with Anthony Bass, who shows how the analytic frame has properties that involve both the process and the structure, and I suggest replacing the term structure with the term constraints. Bass considers analytic frames as contexts: Different frames organize different contexts of experience. He says that the frame is cocreated by patient and analyst and evolves over time. I think that Dafna's case presented by Ilana Laor is a good example of this aspect. I agree with Laor, who shows how the frame reflects the negotiation process between patient and analyst, emphasizing that this process itself is therapeutic. Following Bass I emphasize that a polarization between stability versus flexibility should be replaced by the dialectic between stability and flexibility. I conclude wondering how Bass's and Laor's “wisdom” regarding flexibility and elasticity can be passed over to younger psychoanalysts who are beginning their clinical work.     

Microstructural integrity of the corpus callosum linked with neuropsychological performance in adolescents

Background: Diffusion tensor imaging (DTI) has revealed microstructural aspects of adolescent brain development, the cognitive correlates of which remain relatively uncharacterized. Methods: DTI was used to assess white matter microstructure in 18 typically developing adolescents (ages 16–18). Fractional anisotropy (FA) and mean diffusion (MD) were evaluated within the splenium and body of the corpus callosum in relation to cognitive performance. Results: Visuospatial construction abilities were associated with white matter integrity in both the splenium and body of the corpus callosum, while only splenium integrity was associated with language and psychomotor function. Conclusion: Results suggest that, for typically developing adolescents, white matter coherence positively relates to visuospatial, psychomotor, and language skills. These findings may have implications for the cognitive functioning of clinical populations in which typical white matter development is altered.     

No Exception for Belief

This paper defends a principle I call Equal Treatment, according to which the rationality of a belief is determined in precisely the same way as the rationality of any other state. For example, if wearing a raincoat is rational just in case doing so maximizes expected value, then believing some proposition P is rational just in case doing so maximizes expected value. This contrasts with the popular view that the rationality of belief is determined by evidential support. It also contrasts with the common idea that in the case of belief, there are two different incommensurable senses of rationality, one of which is distinctively epistemic. I present considerations that favor Equal Treatment over these two alternatives, reply to objections, and criticize some arguments for Evidentialism. I also show how Equal Treatment opens the door to a distinctive kind of response to skepticism.