Evidence for the involvement of brain GABA and serotonin systems in the anticonflict effects of chlordiazepoxide in rats

Using male hooded Lister rats the effects of GABAergic and serotonergic treatments alone and with chlordiazepoxide (CDP) were compared with the behavioral effects of CDP in a conditioned conflict procedure with three components; Reward, Time Out, and Conflict. CDP (2.5, 5.0, and 10.0 mg/kg ip) dose- relatedly increased punished and time out responding, but increased rewarded responding in an inversely dose-related manner. Punished responding was enhanced by chronic treatment to a rate which remained stable between 9 and 19 injections. The GABA transaminase inhibitor ethanolamine-O-sulfate (EOS), given chronically in drinking water (5.0 mg/ml), increased punished responding linearly to a high stable level after 2-3 weeks. Rewarded and time out responding were less substantially increased. CDP given with EOS dose- relatedly increased time out and punished responding substantially above the rates found with either treatment alone. The GABA antagonist picrotoxin blocked the increase in punished and time out responding found with EOS and CDP alone. The tryptophan hydroxylase inhibitor p-chlorophenylalanine (PCPA; 100 mg/kg x 3) linearly increased punished responding for the first week of treatment. CDP with PCPA selectively and significantly increased punished responding above the rates for either treatment alone, but the increases were not as substantial as those with EOS + CDP. The serotonin reuptake inhibitor Wy 25093 reduced increases in time out and punished responding under CDP, and the precursor 5-hydroxytryptophan (5-HTP) counteracted increases in punished responding under PCPA but also substantially reduced rewarded responding. These results provide evidence that both increased GABA and decreased serotonin transmission are involved in the anticonflict effects of CDP, as EOS and PCPA both mimicked and potentiated effects of CDP, while picrotoxin, Wy 25093, and 5-HTP counteracted them.(ABSTRACT TRUNCATED AT 250 WORDS)     

Logic and Existence: Timothy Williams

The paper defends the intelligibility of unrestricted quantification. For any natural number n , 'There are at least n individuals' is logically true, when the quantifier is unrestricted. In response to the objection that such sentences should not count as logically true because existence is contingent, it is argued by consideration of cross-world counting principles that in the relevant sense of 'exist' existence is not contingent. A tentative extension of the upward Löwenheim–Skolem theorem to proper classes is used to argue that a sound and complete axiomatization of the logic of unrestricted universal quantification results from adding all sentences of the form 'There are at least n individuals' as axioms to a standard axiomatization of the first-order predicate calculus.
Of the many questions on which logic is neutral, one is usually supposed to be this: 'How many individuals are there?' On the alternative view defended below, truths about the number of individuals are logically true. They are not contingent logical truths, for it is not contingent what individuals there are.     

Process demands of rejection mechanisms of recognition memory

A surge of research has been conducted to examine memory editing mechanisms that help distinguish accurate from inaccurate memories. In the present experiment, the authors examined the ability of participants to use novelty detection, recollection rejection, and plausibility judgments to reject lures presented on a recognition memory test. Participants studied a list of word pairs that were arranged in a category relationship (both words from the same category) or an unrelated relationship (both words from different categories) under full or divided attention. At test, participants were given a yes/no recognition test in which they were to respond after seeing the test items for 400 ms or 2,800 ms. Some of the test items were rearranged word pairs that were consistent with the study relationship, whereas others were inconsistent with the study relationship. The results demonstrate that the participants required full attention at study to use novelty detection, recollection rejection, and plausibility judgments to reject lures. Moreover, the results indicate that a long response deadline at test was needed for participants to use both recollection rejection and plausibility judgments to reject lures.     

Mixed-effects logistic regression for estimating transitional probabilities in sequentially coded observational data

This article demonstrates the use of mixed-effects logistic regression (MLR) for conducting sequential analyses of binary observational data. MLR is a special case of the mixed-effects logit modeling framework, which may be applied to multicategorical observational data. The MLR approach is motivated in part by G. A. Dagne, G. W. Howe, C. H. Brown, & B. O. Muthén (2002) advances in general linear mixed models for sequential analyses of observational data in the form of contingency table frequency counts. The advantage of the MLR approach is that it circumvents obstacles in the estimation of random sampling error encountered using Dagne and colleagues' approach. This article demonstrates the MLR model in an analysis of observed sequences of communication in a sample of young adult same-sex peer dyads. The results obtained using MLR are compared with those of a parallel analysis using Dagne and colleagues' linear mixed model for binary observational data in the form of log odds ratios. Similarities and differences between the results of the 2 approaches are discussed. Implications for the use of linear mixed models versus mixed-effects logit models for sequential analyses are considered.     

Counter‐intuitive moral judgement following traumatic brain injury

Several neurological patient populations, including traumatic brain injury (TBI), appear to produce an abnormally ‘utilitarian’ pattern of judgements to moral dilemmas; they tend to make judgements that maximize the welfare of the majority, rather than deontological judgements based on the following of moral rules (e.g., do not harm others). However, this patient research has always used extreme dilemmas with highly valued moral rules (e.g., do not kill). Data from healthy participants, however, suggest that when a wider range of dilemmas are employed, involving less valued moral rules (e.g., do not lie), moral judgements demonstrate sensitivity to the psychological intuitiveness of the judgements, rather than their deontological or utilitarian content (Kahane et al., Social Cognitive and Affective Neuroscience, 7, 2011, 393). We sought the moral judgements of 30 TBI participants and 30 controls on moral dilemmas where content (utilitarian/deontological) and intuition (intuitive/counter‐intuitive) were measured concurrently. Overall TBI participants made utilitarian judgements in equal proportions to controls; disproportionately favouring utilitarian judgements only when they were counter‐intuitive, and deontological judgements only when they were counter‐intuitive. These results speak against the view that TBI causes a specific utilitarian bias, suggesting instead that moral intuition is broadly disrupted following TBI.