Category label and response location shifts in category learning

The category shift literature suggests that rule-based classification, an important form of explicit learning, is mediated by two separate learned associations: a stimulus-to-label association that associates stimuli and category labels, and a label-to-response association that associates category labels and responses. Three experiments investigate whether information–integration classification, an important form of implicit learning, is also mediated by two separate learned associations. Participants were trained on a rule-based or an information–integration categorization task and then the association between stimulus and category label, or between category label and response location was altered. For rule-based categories, and in line with previous research, breaking the association between stimulus and category label caused more interference than breaking the association between category label and response location. However, no differences in recovery rate emerged. For information–integration categories, breaking the association between stimulus and category label caused more interference and led to greater recovery than breaking the association between category label and response location. These results provide evidence that information–integration category learning is mediated by separate stimulus-to-label and label-to-response associations. Implications for the neurobiological basis of these two learned associations are discussed

The effects of acute tryptophan depletion on costly information sampling: impulsivity or aversive processing?

RATIONALE: The neurotransmitter serotonin (5-HT) has been implicated in both aversive processing and impulsivity. Reconciling these accounts, recent studies have demonstrated that 5-HT is important for punishment-induced behavioural inhibition. These studies focused on situations where actions lead directly to punishments. However, decision-making often involves making tradeoffs between small 'local' costs and larger 'global' losses. OBJECTIVE: We aimed to distinguish whether 5-HT promotes avoidance of local losses, global losses, or both, in contrast to an overall effect on reflection impulsivity. We further examined the influence of individual differences in sub-clinical depression, anxiety and impulsivity on global and local loss avoidance. METHODS: Healthy volunteers (N = 21) underwent an acute tryptophan depletion procedure in a double-blind, placebo-controlled crossover design. We measured global and local loss avoidance in a decision-making task where subjects could sample information at a small cost to avoid making incorrect decisions, which resulted in large losses. RESULTS: Tryptophan depletion removed the suppressive effects of small local costs on information sampling behaviour. Sub-clinical depressive symptoms produced effects on information sampling similar to (but independent from) those of tryptophan depletion. Dispositional anxiety was related to global loss avoidance. However, trait impulsivity was unrelated to information sampling. CONCLUSIONS: The current findings are consistent with recent theoretical work that characterises 5-HT as pruning a tree of potential decisions, eliminating options expected to lead to aversive outcomes. Our results extend this account by proposing that 5-HT promotes reflexive avoidance of relatively immediate aversive outcomes, potentially at the expense of more globally construed future losses

Effect of a Fatty Acid Additive on the Kinetic Friction and Stiction of Confined Liquid Lubricants

Apresentamos neste texto parte das produções de pesquisa que acompanhou a construção de corpos inseridos num Centro de Atenção Psicossocial para Álcool e outras Drogas, em cidade do nordeste brasileiro, focando de modo mais acentuado em arranjos de masculinidades. Especial atenção é dada à tensão entre normalização de corpos e tentativas de (re)existências. A argumentação se desenvolve no campo da saúde pública, em particular o da saúde mental, e alicerçada nos estudos de gênero e sexualidade. A produção de dados se valeu de observações registradas em diário de campo, acompanhamento itinerante, composição de um coletivo de pesquisa, entrevistas, grupos focais em que, dentre outras coisas, se discutia trechos de diários de campo, rodas de conversa e oficinas com profissionais e usuári*s. A aposta metodológica foi a de forjar um modo de narrar coletivo que agenciasse experimentação e desaprendizagens corporais, junto a modos de produzir cuidado em saúde e de fazer pesquisa.Apresentamos neste texto parte das produções de pesquisa que acompanhou a construção de corpos inseridos num Centro de Atenção Psicossocial para Álcool e outras Drogas, em cidade do nordeste brasileiro, focando de modo mais acentuado em arranjos de masculinidades. Especial atenção é dada à tensão entre normalização de corpos e tentativas de (re)existências. A argumentação se desenvolve no campo da saúde pública, em particular o da saúde mental, e alicerçada nos estudos de gênero e sexualidade. A produção de dados se valeu de observações registradas em diário de campo, acompanhamento itinerante, composição de um coletivo de pesquisa, entrevistas, grupos focais em que, dentre outras coisas, se discutia trechos de diários de campo, rodas de conversa e oficinas com profissionais e usuári*s. A aposta metodológica foi a de forjar um modo de narrar coletivo que agenciasse experimentação e desaprendizagens corporais, junto a modos de produzir cuidado em saúde e de fazer pesquisa.Apresentamos neste texto parte das produções de pesquisa que acompanhou a construção de corpos inseridos num Centro de Atenção Psicossocial para Álcool e outras Drogas, em cidade do nordeste brasileiro, focando de modo mais acentuado em arranjos de masculinidades. Especial atenção é dada à tensão entre normalização de corpos e tentativas de (re)existências. A argumentação se desenvolve no campo da saúde pública, em particular o da saúde mental, e alicerçada nos estudos de gênero e sexualidade. A produção de dados se valeu de observações registradas em diário de campo, acompanhamento itinerante, composição de um coletivo de pesquisa, entrevistas, grupos focais em que, dentre outras coisas, se discutia trechos de diários de campo, rodas de conversa e oficinas com profissionais e usuári*s. A aposta metodológica foi a de forjar um modo de narrar coletivo que agenciasse experimentação e desaprendizagens corporais, junto a modos de produzir cuidado em saúde e de fazer pesquisa.Apresentamos neste texto parte das produções de pesquisa que acompanhou a construção de corpos inseridos num Centro de Atenção Psicossocial para Álcool e outras Drogas, em cidade do nordeste brasileiro, focando de modo mais acentuado em arranjos de masculinidades. Especial atenção é dada à tensão entre normalização de corpos e tentativas de (re)existências. A argumentação se desenvolve no campo da saúde pública, em particular o da saúde mental, e alicerçada nos estudos de gênero e sexualidade. A produção de dados se valeu de observações registradas em diário de campo, acompanhamento itinerante, composição de um coletivo de pesquisa, entrevistas, grupos focais em que, dentre outras coisas, se discutia trechos de diários de campo, rodas de conversa e oficinas com profissionais e usuári*s. A aposta metodológica foi a de forjar um modo de narrar coletivo que agenciasse experimentação e desaprendizagens corporais, junto a modos de produzir cuidado em saúde e de fazer pesquisa.Apresentamos neste texto parte das produções de pesquisa que acompanhou a construção de corpos inseridos num Centro de Atenção Psicossocial para Álcool e outras Drogas, em cidade do nordeste brasileiro, focando de modo mais acentuado em arranjos de masculinidades. Especial atenção é dada à tensão entre normalização de corpos e tentativas de (re)existências. A argumentação se desenvolve no campo da saúde pública, em particular o da saúde mental, e alicerçada nos estudos de gênero e sexualidade. A produção de dados se valeu de observações registradas em diário de campo, acompanhamento itinerante, composição de um coletivo de pesquisa, entrevistas, grupos focais em que, dentre outras coisas, se discutia trechos de diários de campo, rodas de conversa e oficinas com profissionais e usuári*s. A aposta metodológica foi a de forjar um modo de narrar coletivo que agenciasse experimentação e desaprendizagens corporais, junto a modos de produzir cuidado em saúde e de fazer pesquisa.Apresentamos neste texto parte das produções de pesquisa que acompanhou a construção de corpos inseridos num Centro de Atenção Psicossocial para Álcool e outras Drogas, em cidade do nordeste brasileiro, focando de modo mais acentuado em arranjos de masculinidades. Especial atenção é dada à tensão entre normalização de corpos e tentativas de (re)existências. A argumentação se desenvolve no campo da saúde pública, em particular o da saúde mental, e alicerçada nos estudos de gênero e sexualidade. A produção de dados se valeu de observações registradas em diário de campo, acompanhamento itinerante, composição de um coletivo de pesquisa, entrevistas, grupos focais em que, dentre outras coisas, se discutia trechos de diários de campo, rodas de conversa e oficinas com profissionais e usuári*s. A aposta metodológica foi a de forjar um modo de narrar coletivo que agenciasse experimentação e desaprendizagens corporais, junto a modos de produzir cuidado em saúde e de fazer pesquisa.The paper presents part of the research productions that accompanied the construction of bodies inserted in a Psychosocial Care Center for Alcohol and Other Drugs (CAPS-AD) of a city in the northern region of Brasil, focusing more sharply on masculinities arrangements. Special attention is given to the tension between normalized bodies and attempts at resistance and (re) exist. The argument is in the field of public health, particularly mental health, and rooted in gender and sexuality studies. The data production methodology made use of observations recorded in a diary, itinerant follow-up of a collective of research, interviews, focus groups where, among other things, was discussed diary topics, conversation circles and workshops. The attempt was to produce a way of collective narrating strategy, combining up experience and body (un)learn well as ways of producing health care and doing research

Effects of dopaminergic modulation on electrophysiological brain response to affective stimuli

Introduction: Several theoretical accounts of the role of dopamine suggest that dopamine has an influence on the processing of affective stimuli. There is some indirect evidence for this from studies showing an association between the treatment with dopaminergic agents and self-reported affect. Materials and methods: We addressed this issue directly by examining the electrophysiological correlates of affective picture processing during a single-dose treatment with a dopamine D2 agonist (bromocriptine), a dopamine D2 antagonist (haloperidol), and a placebo. We compared early and late event-related brain potentials (ERPs) that have been associated with affective processing in the three medication treatment conditions in a randomized double-blind crossover design amongst healthy males. In each treatment condition, subjects attentively watched neutral, pleasant, and unpleasant pictures while ERPs were recorded. Results: Results indicate that neither bromocriptine nor haloperidol has a selective effect on electrophysiological indices of affective processing. In concordance with this, no effects of dopaminergic modulation on self-reported positive or negative affect was observed. In contrast, bromocriptine decreased overall processing of all stimulus categories regardless of their affective content. Discussion: The results indicate that dopaminergic D2 receptors do not seem to play a crucial role in the selective processing of affective visual stimuli

Mood and cognition in healthy older European adults: the Zenith study

YesBackground: The study aim was to determine if state and trait intra-individual measures of everyday affect predict cognitive functioning in healthy older community dwelling European adults (n = 387), aged 55-87 years. Methods: Participants were recruited from centres in France, Italy and Northern Ireland. Trait level and variability in positive and negative affect (PA and NA) were assessed using self-administered PANAS scales, four times a day for four days. State mood was assessed by one PANAS scale prior to assessment of recognition memory, spatial working memory, reaction time and sustained attention using the CANTAB computerized test battery. Results: A series of hierarchical regression analyses were carried out, one for each measure of cognitive function as the dependent variable, and socio-demographic variables (age, sex and social class), state and trait mood measures as the predictors. State PA and NA were both predictive of spatial working memory prior to looking at the contribution of trait mood. Trait PA and its variability were predictive of sustained attention. In the final step of the regression analyses, trait PA variability predicted greater sustained attention, whereas state NA predicted fewer spatial working memory errors, accounting for a very small percentage of the variance (1-2%) in the respective tests. Conclusion: Moods, by and large, have a small transient effect on cognition in this older sample

Analysis of the piggyBac transposase reveals a functional nuclear targeting signal in the 94 c-terminal residues

<p>Abstract</p> <p>Background</p> <p>The <it>piggyBac</it> transposable element is a popular tool for germ-line transgenesis of eukaryotes. Despite this, little is known about the mechanism of transposition or the transposase (TPase) itself. A thorough understanding of just how <it>piggyBac</it> works may lead to more effective use of this important mobile element. A PSORTII analysis of the TPase amino acid sequence predicts a bipartite nuclear localization signal (NLS) near the c-terminus, just upstream of a putative ZnF (ZnF).</p> <p>Results</p> <p>We fused the <it>piggyBac</it> TPase upstream of and in-frame with the enhanced yellow fluorescent protein (EYFP) in the <it>Drosophila melanogaster</it> inducible metallothionein protein. Using Drosophila Schneider 2 (S2) cells and the deep red fluorescent nuclear stain Draq5, we were able to track the pattern of <it>piggyBac</it> localization with a scanning confocal microscope 48 hours after induction with copper sulphate.</p> <p>Conclusion</p> <p>Through n and c-terminal truncations, targeted internal deletions, and specific amino acid mutations of the <it>piggyBac</it> TPase open reading frame, we found that not only is the PSORTII-predicted NLS required for the TPase to enter the nucleus of S2 cells, but there are additional requirements for negatively charged amino acids a short length upstream of this region for nuclear localization.</p

Effects of the cannabinoid CB1 receptor antagonist rimonabant on distinct measures of impulsive behavior in rats

Rationale Pathological impulsivity is a prominent feature in several psychiatric disorders, but detailed understanding of the specific neuronal processes underlying impulsive behavior is as yet lacking. Objectives As recent findings have suggested involvement of the brain cannabinoid system in impulsivity, the present study aimed at further elucidating the role of cannabinoid CB1 receptor activation in distinct measures of impulsive behavior. Materials and methods The effects of the selective cannabinoid CB1 receptor antagonist, rimonabant (SR141716A) and agonist WIN55,212-2 were tested in various measures of impulsive behavior, namely, inhibitory control in a five-choice serial reaction time task (5-CSRTT), impulsive choice in a delayed reward paradigm, and response inhibition in a stop-signal paradigm. Results In the 5-CSRTT, SR141716A dose-dependently improved inhibitory control by decreasing the number of premature responses. Furthermore, SR141716A slightly improved attentional function, increased correct response latency, but did not affect other parameters. The CB1 receptor agonist WIN55,212-2 did not change inhibitory control in the 5-CSRTT and only increased response latencies and errors of omissions. Coadministration of WIN55,212-2 prevented the effects of SR141716A on inhibitory control in the 5-CSRTT. Impulsive choice and response inhibition were not affected by SR141716A at any dose, whereas WIN55,212-2 slightly impaired response inhibition but did not change impulsive choice. Conclusions The present data suggest that particularly the endocannabinoid system seems involved in some measures of impulsivity and provides further evidence for the existence of distinct forms of impulsivity that can be pharmacologically dissociated

Dopamine and inhibitory action control: evidence from spontaneous eye blink rates

The inhibitory control of actions has been claimed to rely on dopaminergic pathways. Given that this hypothesis is mainly based on patient and drug studies, some authors have questioned its validity and suggested that beneficial effects of dopaminergic stimulants on response inhibition may be limited to cases of suboptimal inhibitory functioning. We present evidence that, in carefully selected healthy adults, spontaneous eyeblink rate, a marker of central dopaminergic functioning, reliably predicts the efficiency in inhibiting unwanted action tendencies in a stop-signal task. These findings support the assumption of a modulatory role for dopamine in inhibitory action control