HIV+ participants demonstrated more difficulties

in learning the gambling task than did HIV- participants. Executive functioning and depression emerged as strong predictors of gambling task performance. Depression partially mediated the relationship between executive functioning and gambling performance. Our findings suggest that HIV infection, executive dysfunction, and depression place individuals at risk for poor decision-making. (The Journal of Neuropsychiatry and Clinical Neurosciences 2012; 24:340-348)”
“Intrinsic surface tension of nanoscale ferroelectric thin film tends to induce tensile stress in its surface layer, whereas the other portion of the film is subjected to compression to maintain mechanical balance. A continuum-based phase-field model accounting for such surface effect has been set up to investigate GW2580 molecular weight the evolution of domain structure and thickness-dependent HM781-36B research buy ferroelectric properties of free-standing BaTiO3 nano-thin films. It was observed that both remnant polarization and coercive

field decrease with a decrease of film thickness and increase of surface tension, and that, for film thickness ranging from 10-20 nm, both properties decreased sharply at the surface strain 2-3 epsilon(0) (epsilon(0) being the spontaneous strain). Further decrease in film thickness or increase in surface tension could result in loss of ferroelectricity. Such a critical state for the ferroelectric-to-paraelectric transition has also been established for the range of film thickness 4-20 nm. (C) 2011 American Institute of Physics. [doi:10.1063/1.3652906]“
“Hard-wired, Pavlovian, responses elicited MX69 cell line by predictions of rewards and punishments exert significant benevolent and malevolent influences over instrumentally-appropriate actions. These influences come in two main groups, defined along anatomical, pharmacological, behavioural and functional lines. Investigations of the influences have so far concentrated on the groups as a whole; here we take the critical step of looking inside each group, using a detailed reinforcement

learning model to distinguish effects to do with value, specific actions, and general activation or inhibition. We show a high degree of sophistication in Pavlovian influences, with appetitive Pavlovian stimuli specifically promoting approach and inhibiting withdrawal, and aversive Pavlovian stimuli promoting withdrawal and inhibiting approach. These influences account for differences in the instrumental performance of approach and withdrawal behaviours. Finally, although losses are as informative as gains, we find that subjects neglect losses in their instrumental learning. Our findings argue for a view of the Pavlovian system as a constraint or prior, facilitating learning by alleviating computational costs that come with increased flexibility.