322 resultados para arousal


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A controlled trial was conducted of cue-exposure with dependent drinkers in treatment. All subjects were engaged in an insight-orientated therapy programme, and responses to an alcohol-associated, compared with a neutral, stimulus were assessed at the beginning and end of treatment. Compared with a control group, which did not receive intervening cue-exposure sessions, subjects who received such interventions manifested reductions in heart rate, salivation and arousal responses to the alcohol-associated, compared with the neutral, stimulus. They did not, however, show similar reductions in subjective estimates of craving and anxiety. These results and the desynchrony in reductions in cue-reactivity across response domains are discussed in terms of their implications for cue-exposure in treatment and recent theoretical conceptualizations of the relationship between autonomic reactivity, craving and drinking behaviour.

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Background This study aims to examine the relationship between how individuals with intellectual disabilities report their own levels of anger, and the ability of those individuals to recognize emotions. It was hypothesized that increased expression of anger would be linked to lower ability to recognize facial emotional expressions and increased tendency to interpret facial expressions in a hostile or negative manner. It was also hypothesized increased levels of anger may lead to the altered perception of a particular emotion.

Method A cross-sectional survey design was used. Thirty participants completed a test of facial emotion recognition (FER), and a self-report anger inventory (Benson & Ivins 1992) as part of a structured interview.

Results Individuals with higher self-reported anger did not show significantly reduced performance in FER, or interpret facial expressions in a more hostile manner compared with individuals with less self-reported anger. However, they were less accurate in recognizing neutral facial emotions.

Conclusions It is tentatively suggested that individuals with high levels of anger may be likely to perceive emotional content in a neutral facial expression because of their high levels of emotional arousal.

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Background: Emotional responding is sensitive to social context; however, little emphasis has been placed on the mechanisms by which social context effects changes in emotional responding.

Objective: We aimed to investigate the effects of social context on neural responses to emotional stimuli to inform on the mechanisms underpinning context-linked changes in emotional responding.

Design: We measured event-related potential (ERP) components known to index specific emotion processes and self-reports of explicit emotion regulation strategies and emotional arousal. Female Chinese university students observed positive, negative, and neutral photographs, whilst alone or accompanied by a culturally similar (Chinese) or dissimilar researcher (British).

Results: There was a reduction in the positive versus neutral differential N1 amplitude (indexing attentional capture by positive stimuli) in the dissimilar relative to alone context. In this context, there was also a corresponding increase in amplitude of a frontal late positive potential (LPP) component (indexing engagement of cognitive control resources). In the similar relative to alone context, these effects on differential N1 and frontal LPP amplitudes were less pronounced, but there was an additional decrease in the amplitude of a parietal LPP component (indexing motivational relevance) in response to positive stimuli. In response to negative stimuli, the differential N1 component was increased in the similar relative to dissimilar and alone (trend) context.

Conclusion: These data suggest that neural processes engaged in response to emotional stimuli are modulated by social context. Possible mechanisms for the social-context-linked changes in attentional capture by emotional stimuli include a context-directed modulation of the focus of attention, or an altered interpretation of the emotional stimuli based on additional information proportioned by the context.

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Several neurodevelopmental disorders are associated with preference for routine and challenging behavior following changes to routines. We examine individuals with Prader–Willi syndrome, who show elevated levels of this behavior, to better understand how previous experience of a routine can affect challenging behavior elicited by disruption to that routine. Play based challenges exposed 16 participants to routines, which were either adhered to or changed. Temper outburst behaviors, heart rate and movement were measured. As participants were exposed to routines for longer before a change (between 10 and 80 min; within participants), more temper outburst behaviors were elicited by changes. Increased emotional arousal was also elicited, which was indexed by heart rate increases not driven by movement. Further study will be important to understand whether current intervention approaches that limit exposure to changes, may benefit from the structured integration of flexibility to ensure that the opportunity for routine establishment is also limited.

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O presente trabalho pretende caracterizar a associação entre ansiedade social e assertividade na adolescência, bem como desenvolver um modelo compreensivo e de intervenção teórica e empiricamente fundamentado acerca desta problemática. A ansiedade social é definida por medo intenso em situações sociais, associado a crenças negativas predisponentes e comportamentos de segurança ou evitamento subsequentes de situações sociais. A assertividade consiste numa resposta comportamental de auto-expressão empática, fundamentada em crenças positivas e activação emocional reduzida. Assim, estes dois conceitos parecem estar em dissonância, uma vez que, por definição, a ansiedade social surge associada a défice de comportamentos sociais adequados e a assertividade a diminuída activação ansiosa em eventos sociais. Por outro lado, ansiedade social e défice assertivo poderão fundamentar-se em mecanismos psicológicos semelhantes. Para verificar estas duas premissas, o presente trabalho utilizou uma amostra de 679 adolescentes do ensino secundário público de ambos os sexos. Para avaliar a ansiedade social nas três dimensões do funcionamento psicológico foram utilizadas a Escala de Crenças e Pensamentos Sociais e a Escala de Ansiedade e Evitamento de Situações Sociais para Adolescentes. No caso da assertividade, foram utilizados o Questionário de Esquema Interpessoal Assertivo e Escala de Comportamento Interpessoal. A análise de dados permite verificar a existência de uma associação recíproca negativa entre ansiedade social e assertividade, em todos os níveis considerados. Igualmente, os resultados obtidos indicam que esta associação poderá ser fundamentada na existência de baixas crenças sociais positivas que activam pensamentos sociais negativos e subsequentemente ansiedade e desconforto em situações sociais e reduzida frequência de comportamento assertivo. Esta conclusão fundamentou uma intervenção integrada para a promoção da gestão de ansiedade social e da prática de competências assertivas. Esta intervenção foi construída, implementada e avaliada em dois ensaios clínicos junto a 6 adolescentes. Os resultados de significância clínica indicam que o programa tem eficácia terapêutica, ainda que este estudo preliminar não exclua a necessidade de uma avaliação mais aprofundada do benefício associado a esta intervenção. Estes trabalhos assumem, assim, implicações educativas e terapêuticas, ao permitir explicitar e clarificar a associação entre ansiedade social e assertividade, e ao contribuir para o desenvolvimento e avaliação de formas de intervenção adequadas junto ao adolescente social tímido ou inibido. A compreensão e intervenção preventiva para a promoção do ajustamento psicossocial do adolescente emergem como uma realidade possível, pertinente e acessível a todos os agentes educativos.

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A disfunção eréctil é actualmente considerada um problema de saúde pública que afecta muitos milhares de homens em todo o mundo. Para além dos factores de natureza médica, reconhecidamente implicados neste tipo de problemática sexual, a literatura empírica tem destacado um conjunto de variáveis de cariz psicológico envolvidas nas dificuldades. Não obstante, o estudo acerca da influência de variáveis disposicionais no funcionamento eréctil não tem merecido muita atenção da literatura científica nos últimos anos. Neste sentido, o conjunto de estudos apresentados no âmbito da presente dissertação procurou investigar de que forma variáveis disposicionais como as dimensões da personalidade, afecto-traço, auto-consciência sexual e mecanismos de excitação e inibição sexual, intervêm na resposta de excitação sexual masculina e são susceptíveis de se constituírem como factores de risco psicológico para o desenvolvimento e/ou manutenção da disfunção eréctil. Este trabalho envolveu a participação de um total de 1,274 indivíduos da população Portuguesa e os resultados obtidos indicaram a relevância das referidas variáveis no funcionamento eréctil de homens sexualmente funcionais da comunidade e também em homens diagnosticados com disfunção eréctil. Adicionalmente, os dados mostraram que as dimensões disposicionais avaliadas se encontram envolvidas na disfunção eréctil associada a diferentes factores etiológicos (factores psicológicos e/ou médicos), sublinhando a sua relevância para a generalidade das situações clínicas relacionadas com a perda da função eréctil e de forma independente dos factores precipitantes envolvidos. Ao demonstrar empiricamente que aspectos individuais de natureza psicológica são susceptíveis de interagir com factores de ordem médica no desenvolvimento e na manutenção da disfunção eréctil, o conjunto dos dados apresentados oferece uma perspectiva integrada para a conceptualização deste quadro clínico e encoraja a utilização de uma abordagem terapêutica multidisciplinar no tratamento das dificuldades erécteis.

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BACKGROUND: Researchers have tested the beliefs of sportspeople and sports medicine specialists that cognitive strategies influence strength performance. Few investigators have synthesised the literature. OBJECTIVES: The specific objectives were to review evidence regarding (a) the cognitive strategy-strength performance relationship; (b) participant skill level as a moderator; and (c) cognitive, motivational, biomechanical/physiological, and emotional mediators. METHOD: Studies were sourced via electronic databases, reference lists of retrieved articles, and manual searches of relevant journals. Studies had to be randomised or counterbalanced experiments with a control group or condition, repeated measures, and a quality control score above 0.5 (out of 1). Cognitive strategies included goal setting, imagery, self-talk, preparatory arousal, and free choice. Dependent variables included maximal strength, local muscular endurance, or muscular power. RESULTS: Globally, cognitive strategies were reliability associated with increased strength performance (results ranged from 61 to 65 %). Results were mixed when examining the effects of specific strategies on particular dependent variables, although no intervention had an overall negative influence. Indeterminate relationships emerged regarding hypothesised mediators (except cognitive variables) and participant skill level as a moderator. CONCLUSIONS: Although cognitive strategies influence strength performance, there are knowledge gaps regarding specific types of strength, especially muscular power. Cognitive variables, such as concentration, show promise as possible mediators.

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Tese de mestrado, Neurociências, Faculdade de Medicina, Universidade de Lisboa, 2015

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The immediate and short-term chemosensory impacts of coffee and caffeine on cardiovascular activity. Introduction: Caffeine is detected by 5 of the 25 gustatory bitter taste receptors (hTAS2Rs) as well as by intestinal STC-1 cell lines. Thus there is a possibility that caffeine may elicit reflex autonomic responses via chemosensory stimulation. Methods: The cardiovascular impacts of double-espresso coffee, regular (130 mg caffeine) and decaffeinated, and encapsulated caffeine (134 mg) were compared with a placebocontrol capsule. Measures of four post-ingestion phases were extracted from a continuous recording of cardiovascular parameters and contrasted with pre-ingestion measures. Participants (12 women) were seated in all but the last phase when they were standing. Results: Both coffees increased heart rate immediately after ingestion by decreasing both the diastolic interval and ejection time. The increases in heart rate following the ingestion of regular coffee extended for 30 min. Encapsulated caffeine decreased arterial compliance and increased diastolic pressure when present in the gut and later in the standing posture. Discussion: These divergent findings indicate that during ingestion the caffeine in coffee can elicit autonomic arousal via the chemosensory stimulation of the gustatory receptors which extends for at least 30 min. In contrast, encapsulated caffeine can stimulate gastrointestinal receptors and elicit vascular responses involving digestion. Conclusion: Research findings on caffeine are not directly applicable to coffee and vice versa. The increase of heart rate resulting from coffee drinking is a plausible pharmacological explanation for the observation that coffee increases risk for coronary heart disease in the hour after ingestion.

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Empirical evidence supports the hypothesis that emotional states might contribute to cardiovascular disease and health through multiple pathways. To the extent that the acute cardiovascular response to emotional events plays a role in cardiovascular health and disease, an essential step in order to understand this possible link is to define the hemodynamic response to affective challenges. This was the aim of the present study. We assessed blood pressure (BP), heart rate (HR), stroke volume (SV), cardiac output, and total peripheral resistance (TPR) in response to 13 picture series in 18 men and 19 women (mean age 26) in order to investigate their hemodynamic responses associated with activation of the appetitive and defensive motivational systems underlying emotional experience. The hemodynamic parameters were recorded by finger-cuff photoplethysmography with Finometer™ (FMS Finapres Medical Systems, Amsterdam) and electrocardiography with the Lifeshirt system (VivoMetrics Inc., Ventura, California). Participants rated self-perceived pleasantness and arousal for each series. In men, BP and SV, but not TPR, increased with increasing self-rated arousal both for appetitive and defensive activation, whereas in women these relationships were almost absent, especially, for defensive activation. HR decelerated more in response to negative than positive and neutral pictures, and more so in men than women. These findings indicate striking sex differences. In particular, it is suggested that the sympathetic inotropic effect to the heart increases with increasing self-rated arousal strongly in men but only weakly in women. Regardless of sex differences, the modulation of the cardiovascular response to affective pictures along the dimensions of pleasantness and arousal is primarily myocardial, and the pattern of cardiovascular response is consistent with a configuration of cardiac sympathetic-parasympathetic coactivation. One possible implication of the observed sex differences concerns the link between affective states and cardiovascular health and disease. Men have a higher incidence of cardiovascular diseases than premenopausal women, and exaggerated sympathetic reactivity to emotional events is a potential pathophysiological mechanism. These findings extend current knowledge showing that under several acute behavioral challenges men demonstrate stronger cardiovascular reactivity than women.

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The transition from wakefulness to sleep represents the most conspicuous change in behavior and the level of consciousness occurring in the healthy brain. It is accompanied by similarly conspicuous changes in neural dynamics, traditionally exemplified by the change from "desynchronized" electroencephalogram activity in wake to globally synchronized slow wave activity of early sleep. However, unit and local field recordings indicate that the transition is more gradual than it might appear: On one hand, local slow waves already appear during wake; on the other hand, slow sleep waves are only rarely global. Studies with functional magnetic resonance imaging also reveal changes in resting-state functional connectivity (FC) between wake and slow wave sleep. However, it remains unclear how resting-state networks may change during this transition period. Here, we employ large-scale modeling of the human cortico-cortical anatomical connectivity to evaluate changes in resting-state FC when the model "falls asleep" due to the progressive decrease in arousal-promoting neuromodulation. When cholinergic neuromodulation is parametrically decreased, local slow waves appear, while the overall organization of resting-state networks does not change. Furthermore, we show that these local slow waves are structured macroscopically in networks that resemble the resting-state networks. In contrast, when the neuromodulator decrease further to very low levels, slow waves become global and resting-state networks merge into a single undifferentiated, broadly synchronized network.

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Knockout mice lacking the alpha-1b adrenergic receptor were tested in behavioral experiments. Reaction to novelty was first assessed in a simple test in which the time taken by the knockout mice and their littermate controls to enter a second compartment was compared. Then the mice were tested in an open field to which unknown objects were subsequently added. Special novelty was introduced by moving one of the familiar objects to another location in the open field. Spatial behavior and memory were further studied in a homing board test, and in the water maze. The alpha-1b knockout mice showed an enhanced reactivity to new situations. They were faster to enter the new environment, covered longer paths in the open field, and spent more time exploring the new objects. They reacted like controls to modification inducing spatial novelty. In the homing board test, both the knockout mice and the control mice seemed to use a combination of distant visual and proximal olfactory cues, showing place preference only if the two types of cues were redundant. In the water maze the alpha-1b knockout mice were unable to learn the task, which was confirmed in a probe trial without platform. They were perfectly able, however, to escape in a visible platform procedure. These results confirm previous findings showing that the noradrenergic pathway is important for the modulation of behaviors such as reaction to novelty and exploration, and suggest that this is mediated, at least partly, through the alpha-1b adrenergic receptors. The lack of alpha-1b adrenergic receptors in spatial orientation does not seem important in cue-rich tasks but may interfere with orientation in situations providing distant cues only.

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The purpose ofthis study was to investigate the emotion assumptions underlying just-world theory. This theory proposes that people have a need to believe in a just world - a world where people get what they deserve. The first emotion assumption is that people, therefore, find injustices (Le., undeserved outcomes) threatening and thus emotionally arousing. Second, it is this arousal that is assumed to drive subsequent strategies for maintaining the belief in a just world. One strategy an individual may use to maintain this belief is derogating victims of injustice, or seeing their character in a more negative light. To test these two assumptions, 102 participants viewed a video depicting either a victim who presumably presented a high threat to people's belief in ajust world (she was innocent and, therefore, undeserving of her fate) or low threat (she was not innocent and, therefore, more deserving of her fate) while their heart rate and EDA was measured. Half of the participants were then given the opportunity to help the victim whereas the other half were not given this opportunity. The manipulations were followed by both explicit and indirect measures of evaluations ofthe victim as well as self-report measures of affect experienced while watching the victim video, and an individual difference scale assessing the strength of participants' just-world beliefs (as well as other measures that were part ofa larger study). Results indicated that participants did report feeling more threatened by the innocent victim. Although there was some evidence of victim derogation on the implicit measure of victim evaluation, there was no evidence that emotional arousal drove the negative evaluations of the victim who could not be helped. Some interaction effects with individual differences in just-world beliefs did occur, but these were not entirely consistent with the rationale behind the individual difference scales. These results provide only weak support for the first emotion assumption ofjust-world theory. Implications of these findings as well as limitations of the study and future directions concerning just-world theory are discussed.

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The purpose of the current undertaking was to study the electrophysiological properties of the sleep onset period (SOP) in order to gain understanding into the persistent sleep difficulties of those who complain of insomnia following mild traumatic brain injury (MTBI). While many believe that symptoms of post concussion syndrome (PCS) following MTBI resolve within 6 to 12 months, there are a number of people who complain of persistent sleep difficulty. Two models were proposed which hypothesize alternate electrophysiological presentations of the insomnia complaints of those sustaining a MTBI: 1) Analyses of standard polysomnography (PSG) sleep parameters were conducted in order to determine if the sleep difficulties of the MTBI population were similar to that of idiopathic insomniacs (i.e. greater proportion ofREM sleep, reduced delta sleep); 2) Power spectral analysis was conducted over the SOP to determine if the sleep onset signature of those with MTBI would be similar to psychophysiological insomniacs (characterized by increased cortical arousal). Finally, exploratory analyses examined whether the sleep difficulties associated with MTBI could be explained by increases in variability of the power spectral data. Data were collected from 9 individuals who had sustained a MTBI 6 months to 5 years earlier and reported sleep difficulties that had arisen within the month subsequent to injury and persisted to the present. The control group consisted of 9 individuals who had experienced neither sleep difficulties, nor MTBI. Previous to spending 3 consecutive uninterrupted nights in the sleep lab, subjects completed questionnaires regarding sleep difficulties, adaptive functioning, and personality.