989 resultados para ABERRANT SALIENCE


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We investigated the roles of top-down task set and bottom-up stimulus salience for feature-specific attentional capture. Spatially nonpredictive cues preceded search arrays that included a color-defined target. For target-color singleton cues, behavioral spatial cueing effects were accompanied by cueinduced N2pc components, indicative of attentional capture. These effects were only minimally attenuated for nonsingleton target-color cues, underlining the dominance of top-down task set over salience in attentional capture. Nontarget-color singleton cues triggered no N2pc, but instead an anterior N2 component indicative of top-down inhibition. In Experiment 2, inverted behavioral cueing effects of these cues were accompanied by a delayed N2pc to targets at cued locations, suggesting that perceptually salient but task-irrelevant visual events trigger location-specific inhibition mechanisms that can delay subsequent target selection.

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Major Depressive Disorder (MDD) has been associated with biased processing and abnormal regulation of negative and positive information, which may result from compromised coordinated activity of prefrontal and subcortical brain regions involved in evaluating emotional information. We tested whether patients with MDD show distributed changes in functional connectivity with a set of independently derived brain networks that have shown high correspondence with different task demands, including stimulus salience and emotional processing. We further explored if connectivity during emotional word processing related to the tendency to engage in positive or negative emotional states. In this study, 25 medication-free MDD patients without current or past comorbidity and matched controls (n=25) performed an emotional word-evaluation task during functional MRI. Using a dual regression approach, individual spatial connectivity maps representing each subject’s connectivity with each standard network were used to evaluate between-group differences and effects of positive and negative emotionality (extraversion and neuroticism, respectively, as measured with the NEO-FFI). Results showed decreased functional connectivity of the medial prefrontal cortex, ventrolateral prefrontal cortex, and ventral striatum with the fronto-opercular salience network in MDD patients compared to controls. In patients, abnormal connectivity was related to extraversion, but not neuroticism. These results confirm the hypothesis of a relative (para)limbic-cortical decoupling that may explain dysregulated affect in MDD. As connectivity of these regions with the salience network was related to extraversion, but not to general depression severity or negative emotionality, dysfunction of this network may be responsible for the failure to sustain engagement in rewarding behavior.

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Background Recent evidence has shown that individuals with acute anorexia nervosa and those recovered have aberrant physiological responses to rewarding stimuli. We hypothesized that women recovered from anorexia nervosa would show aberrant neural responses to both rewarding and aversive disorder-relevant stimuli. Methods Using functional magnetic resonance imaging (fMRI), the neural response to the sight and flavor of chocolate, and their combination, in 15 women recovered from restricting-type anorexia nervosa and 16 healthy control subjects matched for age and body mass index was investigated. The neural response to a control aversive condition, consisting of the sight of moldy strawberries and a corresponding unpleasant taste, was also measured. Participants simultaneously recorded subjective ratings of “pleasantness,” “intensity,” and “wanting.” Results Despite no differences between the groups in subjective ratings, individuals recovered from anorexia nervosa showed increased neural response to the pleasant chocolate taste in the ventral striatum and pleasant chocolate sight in the occipital cortex. The recovered participants also showed increased neural response to the aversive strawberry taste in the insula and putamen and to the aversive strawberry sight in the anterior cingulate cortex and caudate. Conclusions Individuals recovered from anorexia nervosa have increased neural responses to both rewarding and aversive food stimuli. These findings suggest that even after recovery, women with anorexia nervosa have increased salience attribution to food stimuli. These results aid our neurobiological understanding and support the view that the neural response to reward may constitute a neural biomarker for anorexia nervosa.

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Most of the human population in the western world has access to unlimited calories and leads an increasingly sedentary lifestyle. The propensity to undertake voluntary exercise or indulge in spontaneous physical exercise, which might be termed "exercise salience", is drawing increased scientific attention. Despite its genetic aspects, this complex behaviour is clearly modulated by the environment and influenced by physiological states. Inflammation is often overlooked as one of these conditions even though it is known to induce a state of reduced mobility. Chronic subclinical inflammation is associated with the metabolic syndrome; a largely lifestyle-induced disease which can lead to decreased exercise salience. The result is a vicious cycle that increases oxidative stress and reduces metabolic flexibility and perpetuates the disease state. In contrast, hormetic stimuli can induce an anti-inflammatory phenotype, thereby enhancing exercise salience, leading to greater biological fitness and improved functional longevity. One general consequence of hormesis is upregulation of mitochondrial function and resistance to oxidative stress. Examples of hormetic factors include calorie restriction, extreme environmental temperatures, physical activity and polyphenols. The hormetic modulation of inflammation, and thus, exercise salience, may help to explain the highly heterogeneous expression of voluntary exercise behaviour and therefore body composition phenotypes of humans living in similar obesogenic environments.

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AbstractBackground Depression in adolescence is debilitating with high recurrence in adulthood, yet its pathophysiological mechanism remains enigmatic. To examine the interaction between emotion, cognition and treatment, functional brain responses to sad and happy distractors in an affective go/no-go task were explored before and after Cognitive Behavioural Therapy (CBT) in depressed female adolescents, and healthy participants. Methods Eighty-two Depressed and 24 healthy female adolescents, aged 12 to 17 years, performed a functional magnetic resonance imaging (fMRI) affective go/no-go task at baseline. Participants were instructed to withhold their responses upon seeing happy or sad words. Among these participants, 13 patients had CBT over approximately 30 weeks. These participants and 20 matched controls then repeated the task. Results At baseline, increased activation in response to happy relative to neutral distractors was observed in the orbitofrontal cortex in depressed patients which was normalized after CBT. No significant group differences were found behaviourally or in brain activation in response to sad distractors. Improvements in symptoms (mean: 9.31, 95% CI: 5.35-13.27) were related at trend-level to activation changes in orbitofrontal cortex. Limitations In the follow-up section, a limited number of post-CBT patients were recruited. Conclusions To our knowledge, this is the first fMRI study addressing the effect of CBT in adolescent depression. Although a bias toward negative information is widely accepted as a hallmark of depression, aberrant brain hyperactivity to positive distractors was found and normalised after CBT. Research, assessment and treatment focused on positive stimuli could be a future consideration. Moreover, a pathophysiological mechanism distinct from adult depression may be suggested and awaits further exploration.

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Since its inception in 2006, the United Nations-backed Principles for Responsible Investment (PRI) have grown to over 1300 signatories representing over $45 trillion. This growth is not slowing down. In this paper, we argue that there is a set of attributes which make the PRI salient as a stakeholder and its claim to sign the six PRI important to institutional investors. We use Mitchell et al.’s (Acad Manag Rev 22:853–886, 1997) theoretical framework of stakeholder salience, as extended by Gifford (J Bus Eth 92:79–97, 2010). We use as evidence confidential data from the annual survey of signatories carried out by the PRI in a 5-year period between 2007 and 2011. The findings highlight pragmatic and organizational legitimacy, normative and utilitarian power, and management values as the attributes that contribute most to the salience of the PRI as a stakeholder.

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One of the most fascinating aspects of plant morphology is the regular geometric arrangement of leaves and flowers, called phyllotaxy. The shoot apical meristem (SAM) determines these patterns, which vary depending on species and developmental stage. Auxin acts as an instructive signal in leaf initiation, and its transport has been implicated in phyllotaxy regulation in Arabidopsis (Arabidopsis thaliana). Altered phyllotactic patterns are observed in a maize (Zea mays) mutant, aberrant phyllotaxy1 (abph1, also known as abphyl1), and ABPH1 encodes a cytokinin-inducible type A response regulator, suggesting that cytokinin signals are also involved in the mechanism by which phyllotactic patterns are established. Therefore, we investigated the interaction between auxin and cytokinin signaling in phyllotaxy. Treatment of maize shoots with a polar auxin transport inhibitor, 1-naphthylphthalamic acid, strongly reduced ABPH1 expression, suggesting that auxin or its polar transport is required for ABPH1 expression. Immunolocalization of the PINFORMED1 (PIN1) polar auxin transporter revealed that PIN1 expression marks leaf primordia in maize, similarly to Arabidopsis. Interestingly, maize PIN1 expression at the incipient leaf primordium was greatly reduced in abph1 mutants. Consistently, auxin levels were reduced in abph1, and the maize PIN1 homolog was induced not only by auxin but also by cytokinin treatments. Our results indicate distinct roles for ABPH1 as a negative regulator of SAM size and a positive regulator of PIN1 expression. These studies highlight a complex interaction between auxin and cytokinin signaling in the specification of phyllotactic patterns and suggest an alternative model for the generation of altered phyllotactic patterns in abph1 mutants. We propose that reduced auxin levels and PIN1 expression in abph1 mutant SAMs delay leaf initiation, contributing to the enlarged SAM and altered phyllotaxy of these mutants.

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In this article I challenge the claim that nuclearity is a central principle in the organization of texts. I propose the Framework for the Relational Analysis of Texts (FARS) which accounts for the paratactic and hypotactic realization of coherence relations. Within this framework, the taxis of coherence relations is co-textually dictated. I consider the writer choices in the distribution of discoursal salience and the intertextual and intercultural variation of these choices. It is suggested that divergence between approaches that perceive text as exhibiting both hypotactic and paratactic organization and those that see nuclearity as a basic characteristic of text structure arises from differences in the linguistic corpora examined during the construction of respective theoretical frameworks.

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This paper reports on a replication of Alba and Chattopadhyay’s (1986) study of the effects of substantially heightened brand salience upon the recall of competing brand names. Heightened salience was consistently shown to have an inhibiting effect on recall across a variety of experimental conditions. However, in the replication study this salience effect was not observed. Instead a trend in the reverse direction was found. This new finding is congruent with associative network model of memory and its prediction that subjects concentrating on a brand should trigger links in memory to the brand and other brands in the category.

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The concept of brand salience, or brand accessibility in memory, has been prevalent in the area of brand research for several decades. Brand salience has been driven by memory theory and psychological research, but debate has continued over the structure of memory systems, the way in which consumers undertake memory search, and what they do with brand information once it is retrieved. With the rise to prominence of brand equity, brand salience has been subsumed into the awareness category, as an operationalisation of recalling information. This paper looks at redefining brand salience and proposes new methods for measuring brand salience.

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The research reported in this paper proposed and tested a model of brand salience for banking services, which incorporates knowledge and brand image as antecedents. A full model of brand salience has not been tested previously, nor has a model of brand salience for services been tested. A quasi-experimental method was utilised. Respondents undertook a free recall exercise using category cues, and then completed multi-item measures of brand knowledge, brand associations, and purchase likelihood. Past purchase was tested via a recall exercise. A usable sample of 270 respondents was gained, and the data were analysed using Structural Equation Modelling (SEM). Analysis of the data found support for a model of brand salience for the banking services category, and found a relationship between brand salience and most recent brand purchased. This paper contributes to the field of branding by proposing and testing a model of brand salience. The research reported in this paper may suggest that advertisers need to design their communications to increase accessibility of brands in the memory of consumers, and that the last brand purchased by consumers will have an effect on their next purchase decision, especially in the consumer banking category.

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Many studies have shown that regular drinkers react to alcohol-related stimuli (i.e., cue reactivity) with a variety of appetitive responses, in particular, increased urge to drink. Recent research has focused on accounting for variability in responses to alcohol-related stimuli by examining drinking histories and personality. The aim of the current study was to extend this line of work by investigating the role of reinforcement expectancies (‘cue reward salience’) in alcohol cue reactivity research. In this study, ‘cue reward salience’ refers to the notion that appetitive responses will only ensue if the individual finds the stimulus to be equal to or more rewarding than initial expectations. Sixty-one regular drinkers completed a standard cue reactivity assessment whereby reactions (i.e., urge to drink and affect) to the sight, smell and taste of alcohol are measured and compared to a control condition. Results indicated significant increases in positive urge to drink but no changes in affect. Analyses revealed that drinking level and trait reward sensitivity were significant predictors of the urge to drink response. In addition, ‘cue reward salience’ accounted for significant additional variance in predicting urge to drink alcohol. Discussion focuses on the importance of measuring reinforcement expectancies when conducting cue reactivity studies.

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