Completeness of a Branching-Time Logic with Possible Choices

In this paper we present BTC, which is a complete logic for branchingtime whose modal operator quantifies over histories and whose temporal operators involve a restricted quantification over histories in a given possible choice. This is a technical novelty, since the operators of the usual logics for branching-time such as CTL express an unrestricted quantification over histories and moments. The value of the apparatus we introduce is connected to those logics of agency that are interpreted on branching-time, as for instance Stit Logics.     

Post Traumatic Stress,Context, and the Lingering Effects of the Hurricane Katrina Disaster among Ethnic Minority Youth

This study examined the stability of post traumatic stress disorder (PTSD) symptoms in a predominantly ethnic minority sample of youth exposed to Hurricane Katrina. Youth (n = 191 grades 4th thru 8th) were screened for exposure to traumatic experiences and PTSD symptoms at 24 months (Time 1) and then again at 30 months (Time 2) post-disaster. PTSD symptoms did not significantly decline over time and were higher than rates reported at earlier time points for more ethnically diverse samples. Younger age, female sex, and continued disrepair to the child’s home predicted stable elevated PTSD symptoms. Findings are consistent with predictions from contextual theories of disaster exposure and with epidemiological data from adult samples suggesting that the incidence of PTSD post Katrina is showing an atypical pattern of remittance. Theoretical, applied, and policy implications are discussed.     

Neural mechanisms of sensitivity to peer information in young adult cannabis users

Though social influence is a critical factor in the initiation and maintenance of marijuana use, the neural correlates of influence in those who use marijuana are unknown. In this study, marijuana-using young adults (MJ; n = 20) and controls (CON; n = 23) performed a decision-making task in which they made a perceptual choice after viewing the choices of unknown peers via photographs, while they underwent functional magnetic resonance imaging scans. The MJ and CON groups did not show differences in the overall number of choices that agreed with versus opposed group influence, but only the MJ group showed reaction time slowing when deciding against group choices. Longer reaction times were associated with greater activation of frontal regions. The MJ goup, compared to CON, showed significantly greater activation in the caudate when presented with peer information. Across groups, caudate activation was associated with self-reported susceptibility to influence. These findings indicate that young adults who use MJ may exhibit increased effort when confronted with opposing peer influence, as well as exhibit greater responsivity of the caudate to social information. These results not only better define the neural basis of social decisions, but also suggest that marijuana use is associated with exaggerated neural activity during decision making that involves social information.     

The extra credit effect in interpersonal attraction

An experiment was conducted in which three levels of personal evaluation (positive, mixed, or negative) were crossed with two levels of dependence of the evaluator (high or low) and two levels of accuracy of the evaluation (high or low). Liking for the evaluator was expected to increase linearly with the favorableness of the evaluation, with two possible exceptions: When a positive evaluation from a dependent evaluator was inaccurate, and when a negative evaluation from a dependent evaluator was accurate. In the former case, the obvious inaccuracy of the positive evaluation in the face of the temptation to ingratiate was expected to elicit a decrement in liking (an “ingratiation effect”) by the person being evaluated. In the latter case, the honesty of the evaluator in the face of the temptation to ingratiate was expected to elicit an increment of linking (an “extra credit effect”) by the person being evaluated. Only the second of these two possibilities was supported.     

Does Ontology Rest on a Mistake?: Andre Gallois

I discuss Steve Yablo's defence of Carnap's distinction between internal and external questions. In the first section I set out what I take that distinction, as Carnap draws it, to be, and spell out a central motivation Carnap has for invoking it. In the second section I endorse, and augment, Yablo's response to Quine's arguments against Carnap. In the third section I say why Carnap's application of the distinction between internal and external questions runs into trouble. In the fourth section I spell out what I take to be Yablo's version of Carnap. In the last I say why that version is especially vulnerable to the objection raised in the second.