Physiological responses of obese subjects to external stimuli

Physiological arousal was measured in 11 obese and 11 normal-weight subjects during presentation of emotive, food, and neutral stimuli. No differential arousal (heart rate, temperature, GSR, and EMG on frontalis muscle) between the groups was obtained for any of the three types of stimuli. Discrepancies between the present findings and earlier results are discussed.     

Physiological arousal of obese persons to food stimuli

Physiological arousal was measured in 20 obese and 20 normal-weight subjects during presentation of imagery tasks with food- and nonfood-related stimuli and during presentation and eating of food. No differential arousal, as measured by skin conductance, was obtained between the groups for any of the stimuli. Presentation and eating of the food did produce significant arousal in subjects.     

A Study of the affective responses elicited by occupational stimuli

In this study the semantic differential was used to assess the properties of affect elicited by occupational stimuli. Vocationally committed men studying medicine (N = 119), business (N = 120), and engineering (N = 83) responded to a semantic differential containing occupational concepts representing the fields of medicine, business, engineering, the clergy, and law enforcement. A factor analysis of the data yielded a semantic space for all three groups composed of three orthogonal dimensions of affect called Evaluation, Activity, and Potency, in that order of salience. Tests of factorial similarity indicated that the semantic spaces of the three groups were virtually identical. It was concluded that occupational stimuli elicit Evaluative, Activity, and Potency responses, and that all three affective dimensions should be used when predicting occupational behavior.     

The effects of anxiety upon attention allocation to affective stimuli

Pictures of emotionally aversive, neutral, and pleasant scenes were presented for 500 ms, followed by a probe presented in the same location (valid trials) or an alternate location (invalid trials) as the picture. Response-times to the probes were recorded in low (N=20) and high (N=27) trait anxious participants. Results revealed an overall negative cue validity effect of shorter reaction times (RTs) on invalid than valid trials, suggestive of an inhibition of return effect. Moreover, high trait anxious females showed a reduced negative cue validity effect for aversive pictures in comparison with neutral and pleasant pictures, suggestive of selective interference by the unpleasant material. By contrast, low trait anxious females showed an enhanced negative cue validity effect for aversive pictures relative to neutral and pleasant pictures, suggestive of attentional avoidance of the aversive content. The emotional content of picture cues did not significantly affect RTs in males, regardless of anxiety status. The results suggest that biased attention processes for aversive stimuli may contribute to the greater female propensity for anxiety disorders.     

Conflict monitoring and adaptation to affective stimuli as a function of ageing

The current study investigated whether preference for positive affect would be observed in the context of a higher order control process with increasing age given the premise of affective prioritization with ageing. The study examined how affect interacted with cognitive control mechanisms across young, middle-aged and older adults. Conflict monitoring and adaptation for affective stimuli was examined with a face-word Stroop task using happy and fearful facial expressions. The participants’ task was to detect the emotional expression (Happy or Fear) of the face shown with a distractor word (Happy or Fear) written across the face. Reaction time and accuracy data was analysed to compare adaptation effect and Stroop interference as a function of age, valence and previous trial congruence. The results demonstrated a stronger adaptation effect for negative affect in young adults and for positive affect in middle-aged adults and older adults. These results can be explained in terms of the socio-emotional selectivity theory of affective bias in the elderly and the involvement of attentional control mechanisms. This study empirically demonstrates shifts in affective bias towards positive affect with ageing through the implicit recruitment of cognitive control.

     

Effects of processing style on responsiveness to affective stimuli and processing fluency

In the present study, we provide direct evidence for effects of global versus local processing on responsiveness to and reliance on affective information in judgement and decision-making. Results of Experiments 1 and 2 showed an increased responsiveness to affective stimuli among participants in a global processing mode. Experiment 3 showed similar effects for processing fluency; participants adopting a global processing style showed an increased reliance on fluency. Experiment 4 replicated our findings in a more mundane judgement task in which participants judged apartments. We discuss our findings in relation to the distinction between intuitive versus deliberative modes of thinking.     

A pictorial version of the Extrinsic Affective Simon Task: sensitivity to generally affective and phobia-relevant stimuli in high and low spider fearful individuals

This study assessed whether a pictorial, rather than a verbal, Extrinsic Affective Simon Task (EAST: De Houwer, 2003) is, 1) sensitive to the affective valence of normatively positive, neutral, and negative pictures, 2) sensitive to interindividual differences pertaining to fear-relevant affective associations, and 3) a valid predictor for strategic and/or reflexive fear responses. High (n = 35) and low (n = 35) spider fearful individuals completed an EAST comprising of universal positive, negative, neutral, and spider pictures. The pictorial EAST was sensitive to normatively valenced stimuli, tended to differentiate between high and low fearful individuals with respect to spider pictures, and showed independent predictive validity for avoidance behavior.     

Prediction of experimental pain sensitivity by attention to pain-related stimuli in healthy individuals

The aim of the present study was to assess the predictive power of the processing of pain-related information, comprising concepts of hypervigilance to pain, pain catastrophizing, and pain-related anxiety (questionnaires) as well as attentional processes related to pain-related stimuli (dot-probe task) in explaining individual differences in experimental pain sensitivity (pressure/thermal pain threshold). In 160 healthy participants (ages 13-61; 80 females), results of hierarchical multiple regression analyses showed that self-reported hypervigilance contributed significantly to the prediction of pain sensitivity, whereas pain catastrophizing and anxiety did not. However, inconsistent with prediction, the effect was in the opposite direction, indicating that vigilance to pain sensations or stimuli is associated with lower pain sensitivity in healthy individuals. Entering the attentional bias indices from the dot-probe task showed that an increased bias to pain words is related to higher experimental pain sensitivity, which confirms the hypothesis.     

Cross-modal attention capture by affective stimuli: Evidence from event-related potentials

The P3 component of the event-related potential (ERP) to an acoustic startle probe is modulated during picture viewing, with reduced P3 amplitude when participants view either pleasant or unpleasant, as opposed to neutral, pictures. We have interpreted this as reflecting capture of attentional resources by affective pictures, with fewer resources available for processing the secondary startle probe. In the present study, we tested this resource allocation hypothesis by presenting either pictures or sounds as foreground stimuli, with the prediction that P3 amplitude in response to secondary startle probes would be reduced for affectively engaging foregrounds regardless of modality. Using dense-array electroencephalography and a source estimation procedure, we observed that P3 amplitude was indeed smaller when startle probes were presented during emotional, as opposed to neutral, stimuli for both sound and picture foregrounds. Source modeling indicated a common frontocentral maximum of P3 modulation by affect. The data support the notion that emotionally arousing stimuli transmodally attract resources, leading to optimized processing of the affective stimuli at the cost of the processing of concurrent stimuli.     

Moray revisited: High-priority affective stimuli and visual search

Previous research offers conflicting suggestions about whether “high-priority” verbal stimuli such as an individual's own name or emotionally charged words automatically grab attention and/or can be detected without the usual capacity limitations. Nine experiments investigated this issue, using visual search through displays of words. In speeded search tasks, the subject's own name was detected more quickly than other targets, but in no case were search slopes flat enough to suggest parallel search or “pop-out”. Further, names were not found to be unusually potent distractors. Emotionally charged words were neither more readily detected as targets nor more potent as distractors than neutral words. Acomparison of observers' accuracy in searching briefly exposed simultaneous vs. successive displays provided further evidence that search for “high-priority” word targets is subject to the same severe capacity limitations as those that are found with search for neutral words.     

Anxiety-related differences in affective categorizations of lexical stimuli

Effects of emotional valence on attention have been shown to occur even when stimuli are presented outside awareness. The impact of negative valence on stimulus processing has been demonstrated to be particularly salient in anxiety. Therefore, it has been hypothesized that compared to nonanxious individuals, anxious individuals have an enhanced ability to detect the valence of negative stimuli. However, it remains unclear whether anxious individuals are better at identifying the valence of threatening stimuli or, rather, more likely to label ambiguous stimuli as threatening. To investigate these hypotheses, high and low anxious participants categorized lexical stimuli as "safe" or "dangerous." Stimuli were presented at durations that allowed for both conscious (unmasked) and nonconscious (masked) processing. Results show that on masked trials, anxious individuals evidenced an enhanced ability to correctly classify threatening information, whereas nonanxious participants demonstrated an enhanced ability to correctly classify neutral or positive information. Signal detection analyses indicated results were explained by a response bias, whereby anxious individuals were more likely than nonanxious individuals to categorize masked words as threatening and nonanxious individuals were more likely to categorize masked words as nonthreatening. No group differences for nonword stimuli emerged, suggesting that anxiety-related response bias tendencies are activated only after detection of a weak semantic signal.     

Effects of incidental positive emotion and cognitive reappraisal on affective responses to negative stimuli

Previous studies have identified two powerful ways to regulate emotional responses to a stressor: experiencing incidental positive emotions and using cognitive reappraisal to reframe the stressor. Several cognitive and motivational theories of positive emotion support the formulation that incidental positive emotions may facilitate cognitive reappraisal. To test the separate and interacting effects of positive emotions and cognitive reappraisal, we first adapted an established picture-based reappraisal paradigm by interspersing blocks of positive emotion inducing and neutral pictures. Across two pre-registered studies (Studies 1, 2), reappraisal effectively decreased self-reported negative emotions and increased self-reported positive emotions; however, experiencing incidental positive emotions did not facilitate reappraisal success. In another preregistered study (Study 3), we employed a more powerful positive emotion induction via virtual reality (VR), used a social stress anticipation task, and instructed participants to reappraise the anticipated stressor positively. Although there was a robust effect of the positive emotion induction (relative to the neutral induction) on feeling more positive emotions throughout stress anticipation, the results again indicated that incidental positive emotions did not facilitate cognitive reappraisal. We propose that incidental positive emotions and cognitive reappraisal may constitute separate pathways of influence when regulating one's responses to negative events.     

Hypervigilance to rejecting stimuli in rejection sensitive individuals: Behavioral and neurocognitive evidence

Individuals who are high in rejection sensitivity are vigilant toward social cues that signal rejection, and they exhibit attention biases towards information that confirms expectations of rejection. Little is known, however, about the neural correlates of rejection sensitivity. The present study examined whether rejection sensitivity is associated with individuals’ neural responses to rejection-relevant information. Female participants, classified as high or average in rejection sensitivity, completed a modified dot-probe task in which a neutral face was paired with either another neutral face or a gaze-averted (“rejecting”) face while EEG was collected and ERP components were computed. Behavioral results indicated that average rejection sensitive participants showed an attention bias away from rejecting faces, while high rejection sensitive participants were equally vigilant to neutral and rejecting faces. High rejection sensitivity was associated with ERP components signaling elevated attention and arousal to faces. These findings suggest that rejection sensitivity shapes behavioral and neurocognitive responses to faces.     

Investigating the dynamics of affect: Psychological mechanisms of affective habituation to pleasurable stimuli

Affective habituation (i.e., reductions in stimulus-evoked affective reactions as a result of previous exposure) may serve a functional purpose. However, little is know about the psychological mechanisms underlying this process. To elucidate the characteristics of affective habituation, two experiments that examined affective reactions to repeated exposures of pleasurable stimuli were conducted. Results of these experiments indicated that habituation trajectories are characterized by linear decreases in affect. Results also demonstrated that habituation can be slowed by the introduction of novel stimuli (i.e., “novelty effects”), effects that are dimensional (rather than taxonic) in nature. Experiment 2 demonstrated that habituation is mediated by conceptual rather than perceptual processes. Depressed and anhedonic individuals were not more susceptible to habituation in either experiment. The current findings and previous theorizing suggest that habituation may be an important component of an adaptive affective processing system that promotes effective responses to salient stimuli and prevents compulsive reward-seeking behavior.

Neurocognitive effects of phobia-related stimuli in animal-fearful individuals

Two experiments were conducted to explore neurocognitive effects of phobia-related stimuli. Contingency assessments and event-related potentials (ERPs) were collected from animalearful individuals during probabilistic classification learning in diverse motivational—affective contexts. As revealed by ERPs, attentional amplification of cortical sensory processing occurred in response to phobiarelated stimuli. In particular, the posterior selection negativity in the ERPs to phobiaelated stimuli had its origin in a bottom-up route, probably the amygdaloid—extrastriate cortex path. No evidence for top-down modulation of phobia-related attentional amplification was obtained. The covariation bias occurred only when aversive motivational—affective expectancies prevailed, suggesting a role of retrieval from associative emotional memory. Finally, phobia-related cue competition was probably related to the disruption of elaboration in memory of neutral and aversive stimulus pairings that was induced by belonging pairings of phobia-related and aversive stimuli. The findings have far-reaching implications for the interface between cognition and emotion.     

Processing affective stimuli in children with attention-deficit hyperactivity disorder.

Neuropsychological investigations have suggested a contribution of right hemisphere dysfunction in attention-deficit hyperactivity disorder (ADHD). Right hemisphere dysfunction has been implicated in deficits of attention, motor impersistence, and processing emotion-laden stimuli. The current study investigated the ability of ADHD children to perceive emotional stimuli in the form of facial expressions and speech intonation. The subjects consisted of 37 ADHD and 37 control children aged 7 to 12 years. ANCOVA analysis indicated that ADHD children demonstrate mild-to-moderate deficits in the perception of affect. Furthermore, deficits in attention may contribute to inaccurate or incomplete encoding of stimulus properties. The results lend tentative support for the notion that the right cerebral hemisphere may play a critical role in ADHD.