Reinholdt-Dunne ML, Mogg K, Bradley BP.
Behavioral Research & Therapy, in press
This study investigated the role of executive attention control in modulating selective processing of emotional information in anxiety. It was hypothesized that the combination of high anxiety and poor attention control would be associated with greater difficulty in ignoring task-irrelevant threat-related information. The study included both faces and words as stimuli. Cognitive interference effects were assessed using two emotional Stroop tasks: one with angry, fearful, happy and neutral faces, and one with threat-related, positive, and neutral words. An objective measure of attention control was obtained from the Attention network task. There were four participant groups with high/low trait anxiety and high/low attention control. Results indicated that the combination of high anxiety and poor attention control was associated with greater cognitive interference by emotional faces (including angry faces), compared to neutral faces. This interference effect was not evident in participants with high anxiety and high attentional control, or in low-anxious individuals. There was no evidence of associations between anxiety, attention control, and the interference effect of emotional words. Results indicate that high anxiety and poor attention control together predict enhanced processing of emotionally salient information, such as angry facial expressions. Implications for models of emotion processing are discussed.
Saturday, February 28, 2009
ARTICLE UPDATE - Time course and task dependence of emotion effects in word processing.
Schacht A, Sommer W.
Cognitive, Affective and Behavioral Neuroscience, 8, 28-43
The emotional content of stimuli influences cognitive performance. In two experiments, we investigated the time course and mechanisms of emotional influences on visual word processing in various tasks by recording event-related brain potentials (ERPs). The stimuli were verbs of positive, negative, and neutral valence. In Experiment 1, where lexical decisions had to be performed on single verbs, both positive and negative verbs were processed more quickly than neutral verbs and elicited a distinct ERP component, starting around 370 msec. In Experiment 2, the verbs were embedded in a semantic context provided by single nouns. Likewise, structural, lexical, and semantic decisions for positive verbs were accelerated, and an ERP effect with a scalp distribution comparable to that in Experiment 1 now started about 200 msec earlier. These effects may signal an automatic allocation of attentional resources to emotionally arousing words, since they were not modulated by different task demands. In contrast, a later ERP effect of emotion was restricted to lexical and semantic decisions and, thus, appears to indicate more elaborated, task-dependent processing of emotional words.
Cognitive, Affective and Behavioral Neuroscience, 8, 28-43
The emotional content of stimuli influences cognitive performance. In two experiments, we investigated the time course and mechanisms of emotional influences on visual word processing in various tasks by recording event-related brain potentials (ERPs). The stimuli were verbs of positive, negative, and neutral valence. In Experiment 1, where lexical decisions had to be performed on single verbs, both positive and negative verbs were processed more quickly than neutral verbs and elicited a distinct ERP component, starting around 370 msec. In Experiment 2, the verbs were embedded in a semantic context provided by single nouns. Likewise, structural, lexical, and semantic decisions for positive verbs were accelerated, and an ERP effect with a scalp distribution comparable to that in Experiment 1 now started about 200 msec earlier. These effects may signal an automatic allocation of attentional resources to emotionally arousing words, since they were not modulated by different task demands. In contrast, a later ERP effect of emotion was restricted to lexical and semantic decisions and, thus, appears to indicate more elaborated, task-dependent processing of emotional words.
ARTICLE UPDATE - Noradrenergic enhancement of amygdala responses to fear.
Onur OA, Walter H, Schlaepfer TE, Rehme AK, Schmidt C, Keysers C, Maier W, Hurlemann R.
Social Cognitive & Affective Neuroscience, in press
Multiple lines of evidence implicate the basolateral amygdala (BLA) and the noradrenergic (norepinephrine, NE) system in responding to stressful stimuli such as fear signals, suggesting hyperfunction of both in the development of stress-related pathologies including anxiety disorders. However, no causative link between elevated NE neurotransmission and BLA hyperresponsiveness to fear signals has been established to date in humans. To determine whether or not increased noradrenergic tone enhances BLA responses to fear signals, we used functional magnetic resonance imaging (fMRI) and a strategy of pharmacologically potentiating NE neurotransmission in healthy volunteers. 18 subjects were scanned two times on a facial emotion paradigm and given either a single-dose placebo or 4 mg of the selective NE reuptake inhibitor reboxetine 2 h prior to an fMRI session. We found that reboxetine induced an amygdala response bias towards fear signals that did not exist at placebo baseline. This pharmacological effect was probabilistically mapped to the BLA. Extrapolation of our data to conditions of traumatic stress suggests that disinhibited endogenous NE signaling could serve as a crucial etiological contributor to post-traumatic stress disorder (PTSD) by eliciting exaggerated BLA responses to fear signals.
Social Cognitive & Affective Neuroscience, in press
Multiple lines of evidence implicate the basolateral amygdala (BLA) and the noradrenergic (norepinephrine, NE) system in responding to stressful stimuli such as fear signals, suggesting hyperfunction of both in the development of stress-related pathologies including anxiety disorders. However, no causative link between elevated NE neurotransmission and BLA hyperresponsiveness to fear signals has been established to date in humans. To determine whether or not increased noradrenergic tone enhances BLA responses to fear signals, we used functional magnetic resonance imaging (fMRI) and a strategy of pharmacologically potentiating NE neurotransmission in healthy volunteers. 18 subjects were scanned two times on a facial emotion paradigm and given either a single-dose placebo or 4 mg of the selective NE reuptake inhibitor reboxetine 2 h prior to an fMRI session. We found that reboxetine induced an amygdala response bias towards fear signals that did not exist at placebo baseline. This pharmacological effect was probabilistically mapped to the BLA. Extrapolation of our data to conditions of traumatic stress suggests that disinhibited endogenous NE signaling could serve as a crucial etiological contributor to post-traumatic stress disorder (PTSD) by eliciting exaggerated BLA responses to fear signals.
Saturday, February 21, 2009
ARTICLE UPDATE - The set switching function of nonclinical dissociators under negative emotion.
Chiu CD, Yeh YY, Huang YM, Wu YC, Chiu YC.
Journal of Abnormal Psychology, 118, 214-222
Rapid switching may underlie the disruption of some integrated thought processes that characterize dissociation in both nonclinical and clinical populations. We investigated the set switching function under negative emotion with three groups of nonclinical participants that had different degrees of dissociation proneness. In the experiment, participants judged whether the digit in a predefined target color was odd or even on the preswitch trials. In a perseverance condition, participants were required to switch to a new target color while the previous target color became the distractor color. In a learned irrelevance condition, the previously ignored color became the new target color. The results showed that the three groups did not differ in focusing attention in the preswitch trials, for set switching in the baseline condition (in which emotion was not engaged), or for switching in the learned irrelevance condition under negative emotion. However, high dissociators under negative emotion showed faster switching in the perseverance condition. This enhanced ability to divert attention to a new mental set under negative emotion may be a coping strategy related to cognitive symptoms in dissociative disorders.
Journal of Abnormal Psychology, 118, 214-222
Rapid switching may underlie the disruption of some integrated thought processes that characterize dissociation in both nonclinical and clinical populations. We investigated the set switching function under negative emotion with three groups of nonclinical participants that had different degrees of dissociation proneness. In the experiment, participants judged whether the digit in a predefined target color was odd or even on the preswitch trials. In a perseverance condition, participants were required to switch to a new target color while the previous target color became the distractor color. In a learned irrelevance condition, the previously ignored color became the new target color. The results showed that the three groups did not differ in focusing attention in the preswitch trials, for set switching in the baseline condition (in which emotion was not engaged), or for switching in the learned irrelevance condition under negative emotion. However, high dissociators under negative emotion showed faster switching in the perseverance condition. This enhanced ability to divert attention to a new mental set under negative emotion may be a coping strategy related to cognitive symptoms in dissociative disorders.
Friday, February 13, 2009
ARTICLE UPDATE - Influence of intermixed emotion-relevant trials on the affective Simon effect.
Zhang Y, Proctor RW.
Experimental Psychology, 55, 409-416
"Good" and "bad" vocal responses are faster when an irrelevant emotional stimulus feature corresponds with the response than when it does not, a phenomenon known as the affective Simon effect. Two experiments investigated how this effect was influenced by an intermixed emotion-relevant evaluation task. In Experiment 1, four schematic faces (friendly, happy, hostile, sad) were used for the affective Simon task and four different images (bird, heart, gun, ghost) for the evaluation task, whereas in Experiment 2 the schematic faces were used for both tasks. Mixed-compatible emotion-relevant trials increased the affective Simon effect in both experiments, but mixed-incompatible emotion-relevant trials did not influence it. Also, the advantage of the compatible mapping over the incompatible mapping increased in mixed conditions rather than decreased. These results differ from those obtained when visual-manual tasks for which location is relevant and irrelevant are mixed. They confirm that enhancement of the affective Simon effect when the Simon task is mixed with a compatible emotion-relevant task is due to increased salience of the affective valence.
Experimental Psychology, 55, 409-416
"Good" and "bad" vocal responses are faster when an irrelevant emotional stimulus feature corresponds with the response than when it does not, a phenomenon known as the affective Simon effect. Two experiments investigated how this effect was influenced by an intermixed emotion-relevant evaluation task. In Experiment 1, four schematic faces (friendly, happy, hostile, sad) were used for the affective Simon task and four different images (bird, heart, gun, ghost) for the evaluation task, whereas in Experiment 2 the schematic faces were used for both tasks. Mixed-compatible emotion-relevant trials increased the affective Simon effect in both experiments, but mixed-incompatible emotion-relevant trials did not influence it. Also, the advantage of the compatible mapping over the incompatible mapping increased in mixed conditions rather than decreased. These results differ from those obtained when visual-manual tasks for which location is relevant and irrelevant are mixed. They confirm that enhancement of the affective Simon effect when the Simon task is mixed with a compatible emotion-relevant task is due to increased salience of the affective valence.
ARTICLE UPDATE - Motivated and controlled attention to emotion: Time-course of the late positive potential.
Hajcak G, Dunning JP, Foti D.
Clinical Neurophysiology, in press
OBJECTIVE: The present study examined the time-course of automatic and controlled modulation of the late positive potential (LPP) during emotional picture viewing. METHODS: Participants (N=32) viewed neutral and unpleasant stimuli for 6000ms; at 3000ms, one of two tones signaled participants to attend either to a more or less arousing portion of the picture. The time-course of the LPP was examined both during the passive viewing and directed attention portions of the trial using the method proposed by Guthrie and Buchwald [Guthrie D, Buchwald JS. Significance testing of difference potentials. Psychophysiology 1991;28(2):240-4]. RESULTS: During passive viewing, the LPP became reliably larger following the presentation of unpleasant pictures from 160ms onward; the magnitude of the LPP became reliably smaller beginning 620ms after participants were instructed to attend to the less arousing aspects of unpleasant pictures - and this difference was maintained throughout the duration of the trial. CONCLUSIONS: The LPP reflects relatively automatic attention to emotional visual stimuli, but is also sensitive to manipulations of directed attention toward arousing versus neutral aspects of such stimuli. SIGNIFICANCE: These results shed further light on the time-course of emotional and cognitive modulation of the LPP, and suggest that the LPP reflects the relatively rapid and dynamic allocation of increased attention to emotional stimuli.
Clinical Neurophysiology, in press
OBJECTIVE: The present study examined the time-course of automatic and controlled modulation of the late positive potential (LPP) during emotional picture viewing. METHODS: Participants (N=32) viewed neutral and unpleasant stimuli for 6000ms; at 3000ms, one of two tones signaled participants to attend either to a more or less arousing portion of the picture. The time-course of the LPP was examined both during the passive viewing and directed attention portions of the trial using the method proposed by Guthrie and Buchwald [Guthrie D, Buchwald JS. Significance testing of difference potentials. Psychophysiology 1991;28(2):240-4]. RESULTS: During passive viewing, the LPP became reliably larger following the presentation of unpleasant pictures from 160ms onward; the magnitude of the LPP became reliably smaller beginning 620ms after participants were instructed to attend to the less arousing aspects of unpleasant pictures - and this difference was maintained throughout the duration of the trial. CONCLUSIONS: The LPP reflects relatively automatic attention to emotional visual stimuli, but is also sensitive to manipulations of directed attention toward arousing versus neutral aspects of such stimuli. SIGNIFICANCE: These results shed further light on the time-course of emotional and cognitive modulation of the LPP, and suggest that the LPP reflects the relatively rapid and dynamic allocation of increased attention to emotional stimuli.
ARTICLE UPDATE - Mood influences supraspinal pain processing separately from attention.
Villemure C, Bushnell MC.
Journal of Neuroscience, 29, 705 - 715
Studies show that inducing a positive mood or diverting attention from pain decreases pain perception. Nevertheless, induction manipulations, such as viewing interesting movies or performing mathematical tasks, often influence both emotional and attentional states. Imaging studies have examined the neural basis of psychological pain modulation, but none has explicitly separated the effects of emotion and attention. Using odors to modulate mood and shift attention from pain, we previously showed that the perceptual consequences of changing mood differed from those of altering attention, with mood primarily altering pain unpleasantness and attention preferentially altering pain intensity. These findings suggest that brain circuits involved in pain modulation provoked by mood or attention are partially separable. Here we used functional magnetic resonance imaging to directly compare the neurocircuitry involved in mood- and attention-related pain modulation. We manipulated independently mood state and attention direction, using tasks involving heat pain and pleasant and unpleasant odors. Pleasant odors, independent of attentional focus, induced positive mood changes and decreased pain unpleasantness and pain-related activity within the anterior cingulate (ACC), medial thalamus, and primary and secondary somatosensory cortices. The effects of attentional state were less robust, with only the activity in anterior insular cortex (aIC) showing possible attentional modulation. Lateral inferior frontal cortex [LinfF; Brodmann's area (BA) 45/47] activity correlated with mood-related modulation, whereas superior posterior parietal (SPP; BA7) and entorhinal activity correlated with attention-related modulation. ACC activity covaried with LinfF and periacqueductal gray activity, whereas aIC activity covaried with SPP activity. These findings suggest that separate neuromodulatory circuits underlie emotional and attentional modulation of pain.
Journal of Neuroscience, 29, 705 - 715
Studies show that inducing a positive mood or diverting attention from pain decreases pain perception. Nevertheless, induction manipulations, such as viewing interesting movies or performing mathematical tasks, often influence both emotional and attentional states. Imaging studies have examined the neural basis of psychological pain modulation, but none has explicitly separated the effects of emotion and attention. Using odors to modulate mood and shift attention from pain, we previously showed that the perceptual consequences of changing mood differed from those of altering attention, with mood primarily altering pain unpleasantness and attention preferentially altering pain intensity. These findings suggest that brain circuits involved in pain modulation provoked by mood or attention are partially separable. Here we used functional magnetic resonance imaging to directly compare the neurocircuitry involved in mood- and attention-related pain modulation. We manipulated independently mood state and attention direction, using tasks involving heat pain and pleasant and unpleasant odors. Pleasant odors, independent of attentional focus, induced positive mood changes and decreased pain unpleasantness and pain-related activity within the anterior cingulate (ACC), medial thalamus, and primary and secondary somatosensory cortices. The effects of attentional state were less robust, with only the activity in anterior insular cortex (aIC) showing possible attentional modulation. Lateral inferior frontal cortex [LinfF; Brodmann's area (BA) 45/47] activity correlated with mood-related modulation, whereas superior posterior parietal (SPP; BA7) and entorhinal activity correlated with attention-related modulation. ACC activity covaried with LinfF and periacqueductal gray activity, whereas aIC activity covaried with SPP activity. These findings suggest that separate neuromodulatory circuits underlie emotional and attentional modulation of pain.
ARTICLE UPDATE - Attentional control of emotional distraction in rapid serial visual presentation.
Peers PV, Lawrence AD.
Emotion, 9, 140 - 145
Temperament research has highlighted the importance of attentional control in both emotion regulation and as a predictor of psychopathology. Enhanced susceptibility to emotional distraction is a key feature of mood disturbance. Whereas many studies have examined the influence of individual differences in anxiety on the disruptive effects of emotional distractors, individual differences in attentional control have been largely neglected. Here we examine, within healthy volunteers, the relative contributions of individual differences in self-reported anxiety and attentional control to distractibility caused by emotional or neutral faces distractors occurring prior to neutral face targets during rapid serial visual presentation. Participants with good attentional control were less affected by both neutral and emotional distractors than participants with poorer attentional control. More pronounced distraction deficits were seen for emotional relative to neutral distractors in individuals with poor attentional control. In contrast state anxiety was not associated with increased emotional distraction. Our findings suggest a protective role of attentional control mechanisms in minimizing the influence of emotional distraction.
Emotion, 9, 140 - 145
Temperament research has highlighted the importance of attentional control in both emotion regulation and as a predictor of psychopathology. Enhanced susceptibility to emotional distraction is a key feature of mood disturbance. Whereas many studies have examined the influence of individual differences in anxiety on the disruptive effects of emotional distractors, individual differences in attentional control have been largely neglected. Here we examine, within healthy volunteers, the relative contributions of individual differences in self-reported anxiety and attentional control to distractibility caused by emotional or neutral faces distractors occurring prior to neutral face targets during rapid serial visual presentation. Participants with good attentional control were less affected by both neutral and emotional distractors than participants with poorer attentional control. More pronounced distraction deficits were seen for emotional relative to neutral distractors in individuals with poor attentional control. In contrast state anxiety was not associated with increased emotional distraction. Our findings suggest a protective role of attentional control mechanisms in minimizing the influence of emotional distraction.
ARTICLE UPDATE - The effects of emotional intensity on ERP correlates of recognition memory
Schaefer A, Fletcher K, Pottage CL, Alexander K, Brown C.
Neuroreport, 20, 319 - 324
The effects of negative emotional intensity on memory-related brain activity were tested by using human scalp event-related potentials (ERP). A neural index of memory function - the electrophysiological 'Old-New' effect - was obtained from participants undertaking a memory recognition test of previously studied ('old') and unstudied ('new') pictures of variable levels of negative emotional intensity. The magnitude of the old-new effect was compared across four different levels of linearly increasing stimulus emotional intensity. Results revealed an inverted-U-shaped effect of emotional intensity on the magnitude of ERP old-new differences starting at 300 ms after stimulus onset. These results suggest that moderate negative emotions can enhance memory brain function, whereas extreme levels of emotional intensity have the potential of inhibiting memory function. Results are discussed in terms of their implications for neurobiological and psychological models of emotion-memory interactions.
Neuroreport, 20, 319 - 324
The effects of negative emotional intensity on memory-related brain activity were tested by using human scalp event-related potentials (ERP). A neural index of memory function - the electrophysiological 'Old-New' effect - was obtained from participants undertaking a memory recognition test of previously studied ('old') and unstudied ('new') pictures of variable levels of negative emotional intensity. The magnitude of the old-new effect was compared across four different levels of linearly increasing stimulus emotional intensity. Results revealed an inverted-U-shaped effect of emotional intensity on the magnitude of ERP old-new differences starting at 300 ms after stimulus onset. These results suggest that moderate negative emotions can enhance memory brain function, whereas extreme levels of emotional intensity have the potential of inhibiting memory function. Results are discussed in terms of their implications for neurobiological and psychological models of emotion-memory interactions.
ARTICLE UPDATE- Orienting to threat: faster localization of fearful facial expressions and body postures revealed by saccadic eye movements.
Bannerman RL, Milders M, de Gelder B, Sahraie A.
Proceedings in Biological Science, in press
Most studies investigating speeded orientation towards threat have used manual responses. By measuring orienting behaviour using eye movements a more direct and ecologically valid measure of attention can be made. Here, we used a forced-choice saccadic and manual localization task to investigate the speed of discrimination for fearful and neutral body and face images. Fearful/neutral body or face pairs were bilaterally presented for either 20 or 500ms. Results showed faster saccadic orienting to fearful body and face emotions compared with neutral only at the shortest presentation time (20ms). For manual responses, faster discrimination of fearful bodies and faces was observed only at the longest duration (500ms). More errors were made when localizing neutral targets, suggesting that fearful bodies and faces may have captured attention automatically. Results were not attributable to low-level image properties as no threat bias, in terms of reaction time or accuracy, was observed for inverted presentation. Taken together, the results suggest faster localization of threat conveyed both by the face and the body within the oculomotor system. In addition, enhanced detection of fearful body postures suggests that we can readily recognize threat-related information conveyed by body postures in the absence of any face cues.
Proceedings in Biological Science, in press
Most studies investigating speeded orientation towards threat have used manual responses. By measuring orienting behaviour using eye movements a more direct and ecologically valid measure of attention can be made. Here, we used a forced-choice saccadic and manual localization task to investigate the speed of discrimination for fearful and neutral body and face images. Fearful/neutral body or face pairs were bilaterally presented for either 20 or 500ms. Results showed faster saccadic orienting to fearful body and face emotions compared with neutral only at the shortest presentation time (20ms). For manual responses, faster discrimination of fearful bodies and faces was observed only at the longest duration (500ms). More errors were made when localizing neutral targets, suggesting that fearful bodies and faces may have captured attention automatically. Results were not attributable to low-level image properties as no threat bias, in terms of reaction time or accuracy, was observed for inverted presentation. Taken together, the results suggest faster localization of threat conveyed both by the face and the body within the oculomotor system. In addition, enhanced detection of fearful body postures suggests that we can readily recognize threat-related information conveyed by body postures in the absence of any face cues.
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