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.
Friday, January 16, 2009
ARTICLE UPDATE - Dissociable neural effects of stimulus valence and preceding context during the inhibition of responses to emotional faces.
Schulz KP, Clerkin SM, Halperin JM, Newcorn JH, Tang CY, Fan J.
Human Brain Mapping, in press
Socially appropriate behavior requires the concurrent inhibition of actions that are inappropriate in the context. This self-regulatory function requires an interaction of inhibitory and emotional processes that recruits brain regions beyond those engaged by either processes alone. In this study, we isolated brain activity associated with response inhibition and emotional processing in 24 healthy adults using event-related functional magnetic resonance imaging (fMRI) and a go/no-go task that independently manipulated the context preceding no-go trials (ie, number of go trials) and the valence (ie, happy, sad, and neutral) of the face stimuli used as trial cues. Parallel quadratic trends were seen in correct inhibitions on no-go trials preceded by increasing numbers of go trials and associated activation for correct no-go trials in inferior frontal gyrus pars opercularis, pars triangularis, and pars orbitalis, temporoparietal junction, superior parietal lobule, and temporal sensory association cortices. Conversely, the comparison of happy versus neutral faces and sad versus neutral faces revealed valence-dependent activation in the amygdala, anterior insula cortex, and posterior midcingulate cortex. Further, an interaction between inhibition and emotion was seen in valence-dependent variations in the quadratic trend in no-go activation in the right inferior frontal gyrus and left posterior insula cortex. These results suggest that the inhibition of response to emotional cues involves the interaction of partly dissociable limbic and frontoparietal networks that encode emotional cues and use these cues to exert inhibitory control over the motor, attention, and sensory functions needed to perform the task, respectively.
Human Brain Mapping, in press
Socially appropriate behavior requires the concurrent inhibition of actions that are inappropriate in the context. This self-regulatory function requires an interaction of inhibitory and emotional processes that recruits brain regions beyond those engaged by either processes alone. In this study, we isolated brain activity associated with response inhibition and emotional processing in 24 healthy adults using event-related functional magnetic resonance imaging (fMRI) and a go/no-go task that independently manipulated the context preceding no-go trials (ie, number of go trials) and the valence (ie, happy, sad, and neutral) of the face stimuli used as trial cues. Parallel quadratic trends were seen in correct inhibitions on no-go trials preceded by increasing numbers of go trials and associated activation for correct no-go trials in inferior frontal gyrus pars opercularis, pars triangularis, and pars orbitalis, temporoparietal junction, superior parietal lobule, and temporal sensory association cortices. Conversely, the comparison of happy versus neutral faces and sad versus neutral faces revealed valence-dependent activation in the amygdala, anterior insula cortex, and posterior midcingulate cortex. Further, an interaction between inhibition and emotion was seen in valence-dependent variations in the quadratic trend in no-go activation in the right inferior frontal gyrus and left posterior insula cortex. These results suggest that the inhibition of response to emotional cues involves the interaction of partly dissociable limbic and frontoparietal networks that encode emotional cues and use these cues to exert inhibitory control over the motor, attention, and sensory functions needed to perform the task, respectively.
ARTICLE UPDATE - Emotions in word and face processing: Early and late cortical responses.
Emotions in word and face processing: Early and late cortical responses.
Brain & Cognition, in press
Recent research suggests that emotion effects in word processing resemble those in other stimulus domains such as pictures or faces. The present study aims to provide more direct evidence for this notion by comparing emotion effects in word and face processing in a within-subject design. Event-related brain potentials (ERPs) were recorded as participants made decisions on the lexicality of emotionally positive, negative, and neutral German verbs or pseudowords, and on the integrity of intact happy, angry, and neutral faces or slightly distorted faces. Relative to neutral and negative stimuli both positive verbs and happy faces elicited posterior ERP negativities that were indistinguishable in scalp distribution and resembled the early posterior negativities reported by others. Importantly, these ERP modulations appeared at very different latencies. Therefore, it appears that similar brain systems reflect the decoding of both biological and symbolic emotional signals of positive valence, differing mainly in the speed of meaning access, which is more direct and faster for facial expressions than for words.
Brain & Cognition, in press
Recent research suggests that emotion effects in word processing resemble those in other stimulus domains such as pictures or faces. The present study aims to provide more direct evidence for this notion by comparing emotion effects in word and face processing in a within-subject design. Event-related brain potentials (ERPs) were recorded as participants made decisions on the lexicality of emotionally positive, negative, and neutral German verbs or pseudowords, and on the integrity of intact happy, angry, and neutral faces or slightly distorted faces. Relative to neutral and negative stimuli both positive verbs and happy faces elicited posterior ERP negativities that were indistinguishable in scalp distribution and resembled the early posterior negativities reported by others. Importantly, these ERP modulations appeared at very different latencies. Therefore, it appears that similar brain systems reflect the decoding of both biological and symbolic emotional signals of positive valence, differing mainly in the speed of meaning access, which is more direct and faster for facial expressions than for words.
ARTICLE UPDATE - Functional connectivity of the human amygdala using resting state fMRI.
Roy AK, Shehzad Z, Margulies DS, Kelly AM, Uddin LQ, Gotimer K, Biswal BB, Castellanos FX, Milham MP.
Neuroimage, in press
The amygdala is composed of structurally and functionally distinct nuclei that contribute to the processing of emotion through interactions with other subcortical and cortical structures. While these circuits have been studied extensively in animals, human neuroimaging investigations of amygdala-based networks have typically considered the amygdala as a single structure, which likely masks contributions of individual amygdala subdivisions. The present study uses resting state functional magnetic resonance imaging (fMRI) to test whether distinct functional connectivity patterns, like those observed in animal studies, can be detected across three amygdala subdivisions: laterobasal, centromedial, and superficial. In a sample of 65 healthy adults, voxelwise regression analyses demonstrated positively-predicted ventral and negatively-predicted dorsal networks associated with the total amygdala, consistent with previous animal and human studies. Investigation of individual amygdala subdivisions revealed distinct differences in connectivity patterns within the amygdala and throughout the brain. Spontaneous activity in the laterobasal subdivision predicted activity in temporal and frontal regions, while activity in the centromedial nuclei predicted activity primarily in striatum. Activity in the superficial subdivision positively predicted activity throughout the limbic lobe. These findings suggest that resting state fMRI can be used to investigate human amygdala networks at a greater level of detail than previously appreciated, allowing for the further advancement of translational models.
Neuroimage, in press
The amygdala is composed of structurally and functionally distinct nuclei that contribute to the processing of emotion through interactions with other subcortical and cortical structures. While these circuits have been studied extensively in animals, human neuroimaging investigations of amygdala-based networks have typically considered the amygdala as a single structure, which likely masks contributions of individual amygdala subdivisions. The present study uses resting state functional magnetic resonance imaging (fMRI) to test whether distinct functional connectivity patterns, like those observed in animal studies, can be detected across three amygdala subdivisions: laterobasal, centromedial, and superficial. In a sample of 65 healthy adults, voxelwise regression analyses demonstrated positively-predicted ventral and negatively-predicted dorsal networks associated with the total amygdala, consistent with previous animal and human studies. Investigation of individual amygdala subdivisions revealed distinct differences in connectivity patterns within the amygdala and throughout the brain. Spontaneous activity in the laterobasal subdivision predicted activity in temporal and frontal regions, while activity in the centromedial nuclei predicted activity primarily in striatum. Activity in the superficial subdivision positively predicted activity throughout the limbic lobe. These findings suggest that resting state fMRI can be used to investigate human amygdala networks at a greater level of detail than previously appreciated, allowing for the further advancement of translational models.
ARTICLE UPDATE - Dissociable processes underlying decisions in the Iowa Gambling Task: A new integrative framework.
Stocco A, Fum D, Napoli A.
Behavioral and Brain Functions, in press
ABSTRACT: BACKGROUND: The Iowa Gambling Task (IGT) is a common paradigm used to study the interactions between emotions and decision making, yet little consensus exists on the cognitive process determining participants' decisions, what affects them, and how these processes interact with each other. A novel conceptual framework is proposed according to which behavior in the IGT reflects a balance between two dissociable processes; a cognitively demanding process that tracks each option's long-term payoff, and a lower-level, automatic process that is primarily sensitive to loss frequency and magnitude. METHODS: A behavioral experiment was carried out with a modified version of IGT. In this modified version, participants went through an additional phase of interaction, designed to measure performance without further learning, in which no feedback on individual decisions was given. A secondary distractor task was presented in either the first or the second phase of the experiment. Behavioral measures of performance tracking both payoff and frequency sensitivity in choices were collected throughout the experiment. RESULTS: Consistent with our framework, the results confirmed that: (a) the two competing cognitive processes can be dissociated; (b) that learning from decision outcomes requires central cognitive resources to estimate long-term payoff; and (c) that the decision phase itself can be carried out during an interfering task once learning has occurred. CONCLUSIONS: The experimental results support our novel description of the cognitive processes underlying performance in the Iowa Gambling Task. They also suggest that patients' impairments in this and other gambling paradigms can originate from a number of different causes, including a failure in allocating resources among cognitive strategies. This latter interpretation might be particularly useful in explaining the impairments of patients with ventromedial prefrontal cortex lesions and, by extension, the contribution of this brain region to human decision making.
Behavioral and Brain Functions, in press
ABSTRACT: BACKGROUND: The Iowa Gambling Task (IGT) is a common paradigm used to study the interactions between emotions and decision making, yet little consensus exists on the cognitive process determining participants' decisions, what affects them, and how these processes interact with each other. A novel conceptual framework is proposed according to which behavior in the IGT reflects a balance between two dissociable processes; a cognitively demanding process that tracks each option's long-term payoff, and a lower-level, automatic process that is primarily sensitive to loss frequency and magnitude. METHODS: A behavioral experiment was carried out with a modified version of IGT. In this modified version, participants went through an additional phase of interaction, designed to measure performance without further learning, in which no feedback on individual decisions was given. A secondary distractor task was presented in either the first or the second phase of the experiment. Behavioral measures of performance tracking both payoff and frequency sensitivity in choices were collected throughout the experiment. RESULTS: Consistent with our framework, the results confirmed that: (a) the two competing cognitive processes can be dissociated; (b) that learning from decision outcomes requires central cognitive resources to estimate long-term payoff; and (c) that the decision phase itself can be carried out during an interfering task once learning has occurred. CONCLUSIONS: The experimental results support our novel description of the cognitive processes underlying performance in the Iowa Gambling Task. They also suggest that patients' impairments in this and other gambling paradigms can originate from a number of different causes, including a failure in allocating resources among cognitive strategies. This latter interpretation might be particularly useful in explaining the impairments of patients with ventromedial prefrontal cortex lesions and, by extension, the contribution of this brain region to human decision making.
ARTICLE UPDATE - The emotional blink: Adult age differences in visual attention to emotional information.
Langley LK, Rokke PD, Stark AC, Saville AL, Allen JL, Bagne AG.
Psycholoyg & Aging, 23, 873-885
To assess age differences in attention-emotion interactions, the authors asked young adults (ages 18-33 years) and older adults (ages 60-80 years) to identify target words in a rapid serial visual presentation (RSVP) task. The second of two target words was neutral or emotional in content (positive in Experiment 1, negative in Experiment 2). In general, the ability to identify targets from a word stream declined with age. Age differences specific to the attentional blink were greatly reduced when baseline detection accuracy was equated between groups. With regard to emotion effects, older adults showed enhanced identification of both positive and negative words relative to neutral words, whereas young adults showed enhanced identification of positive words and reduced identification of negative words. Together these findings suggest that the nature of attention-emotion interactions changes with age, but there was little support for a motivational shift consistent with emotional regulation goals at an early stage of cognitive processing.
Psycholoyg & Aging, 23, 873-885
To assess age differences in attention-emotion interactions, the authors asked young adults (ages 18-33 years) and older adults (ages 60-80 years) to identify target words in a rapid serial visual presentation (RSVP) task. The second of two target words was neutral or emotional in content (positive in Experiment 1, negative in Experiment 2). In general, the ability to identify targets from a word stream declined with age. Age differences specific to the attentional blink were greatly reduced when baseline detection accuracy was equated between groups. With regard to emotion effects, older adults showed enhanced identification of both positive and negative words relative to neutral words, whereas young adults showed enhanced identification of positive words and reduced identification of negative words. Together these findings suggest that the nature of attention-emotion interactions changes with age, but there was little support for a motivational shift consistent with emotional regulation goals at an early stage of cognitive processing.
ARTICLE UPDATE - Behavioral triggers of skin conductance responses and their neural correlates in the primate amygdala.
Laine CM, Spitler KM, Mosher CP, Gothard KM.
Journal of Neurophysiology, in press
The amygdala plays a crucial role in evaluating the emotional significance of stimuli and in transforming the results of this evaluation into appropriate autonomic responses. Lesion and stimulation studies suggest involvement of the amygdala in the generation of the skin conductance response (SCR), which is an indirect measure of autonomic activity that has been associated with both emotion and attention. It is unclear if this involvement marks an emotional reaction to an external stimulus, or sympathetic arousal regardless of its origin. We recorded skin conductance in parallel with single unit activity from the right amygdala of two rhesus monkeys during a rewarded image viewing task, and while the monkeys sat alone in a dimly lit room, drifting in and out of sleep. In both experimental conditions, we found similar SCR-related modulation of activity at the single unit and population level. This suggests that the amygdala contributes to the production or modulation of SCRs regardless of the source of sympathetic arousal.
Journal of Neurophysiology, in press
The amygdala plays a crucial role in evaluating the emotional significance of stimuli and in transforming the results of this evaluation into appropriate autonomic responses. Lesion and stimulation studies suggest involvement of the amygdala in the generation of the skin conductance response (SCR), which is an indirect measure of autonomic activity that has been associated with both emotion and attention. It is unclear if this involvement marks an emotional reaction to an external stimulus, or sympathetic arousal regardless of its origin. We recorded skin conductance in parallel with single unit activity from the right amygdala of two rhesus monkeys during a rewarded image viewing task, and while the monkeys sat alone in a dimly lit room, drifting in and out of sleep. In both experimental conditions, we found similar SCR-related modulation of activity at the single unit and population level. This suggests that the amygdala contributes to the production or modulation of SCRs regardless of the source of sympathetic arousal.
Sunday, December 21, 2008
ARTICLE UPDATE - Decoding face information in time, frequency and space from direct intracranial recordings of the human brain.
Tsuchiya N, Kawasaki H, Oya H, Howard MA 3rd, Adolphs R.
PLoS One, in press
Faces are processed by a neural system with distributed anatomical components, but the roles of these components remain unclear. A dominant theory of face perception postulates independent representations of invariant aspects of faces (e.g., identity) in ventral temporal cortex including the fusiform gyrus, and changeable aspects of faces (e.g., emotion) in lateral temporal cortex including the superior temporal sulcus. Here we recorded neuronal activity directly from the cortical surface in 9 neurosurgical subjects undergoing epilepsy monitoring while they viewed static and dynamic facial expressions. Applying novel decoding analyses to the power spectrogram of electrocorticograms (ECoG) from over 100 contacts in ventral and lateral temporal cortex, we found better representation of both invariant and changeable aspects of faces in ventral than lateral temporal cortex. Critical information for discriminating faces from geometric patterns was carried by power modulations between 50 to 150 Hz. For both static and dynamic face stimuli, we obtained a higher decoding performance in ventral than lateral temporal cortex. For discriminating fearful from happy expressions, critical information was carried by power modulation between 60-150 Hz and below 30 Hz, and again better decoded in ventral than lateral temporal cortex. Task-relevant attention improved decoding accuracy more than 10% across a wide frequency range in ventral but not at all in lateral temporal cortex. Spatial searchlight decoding showed that decoding performance was highest around the middle fusiform gyrus. Finally, we found that the right hemisphere, in general, showed superior decoding to the left hemisphere. Taken together, our results challenge the dominant model for independent face representation of invariant and changeable aspects: information about both face attributes was better decoded from a single region in the middle fusiform gyrus.
PLoS One, in press
Faces are processed by a neural system with distributed anatomical components, but the roles of these components remain unclear. A dominant theory of face perception postulates independent representations of invariant aspects of faces (e.g., identity) in ventral temporal cortex including the fusiform gyrus, and changeable aspects of faces (e.g., emotion) in lateral temporal cortex including the superior temporal sulcus. Here we recorded neuronal activity directly from the cortical surface in 9 neurosurgical subjects undergoing epilepsy monitoring while they viewed static and dynamic facial expressions. Applying novel decoding analyses to the power spectrogram of electrocorticograms (ECoG) from over 100 contacts in ventral and lateral temporal cortex, we found better representation of both invariant and changeable aspects of faces in ventral than lateral temporal cortex. Critical information for discriminating faces from geometric patterns was carried by power modulations between 50 to 150 Hz. For both static and dynamic face stimuli, we obtained a higher decoding performance in ventral than lateral temporal cortex. For discriminating fearful from happy expressions, critical information was carried by power modulation between 60-150 Hz and below 30 Hz, and again better decoded in ventral than lateral temporal cortex. Task-relevant attention improved decoding accuracy more than 10% across a wide frequency range in ventral but not at all in lateral temporal cortex. Spatial searchlight decoding showed that decoding performance was highest around the middle fusiform gyrus. Finally, we found that the right hemisphere, in general, showed superior decoding to the left hemisphere. Taken together, our results challenge the dominant model for independent face representation of invariant and changeable aspects: information about both face attributes was better decoded from a single region in the middle fusiform gyrus.
ARTICLE UPDATE - EEG-MEG evidence for early differential repetition effects for fearful, happy and neutral faces.
Morel S, Ponz A, Mercier M, Vuilleumier P, George N.
Brain Research, in press
To determine how emotional information modulates subsequent traces for repeated stimuli, we combined simultaneous electro-encephalography (EEG) and magneto-encephalography (MEG) measures during long-lag incidental repetition of fearful, happy, and neutral faces. Repetition effects were modulated by facial expression in three different time windows, starting as early as 40-50 ms in both EEG and MEG, then arising at the time of the N170/M170, and finally between 280-320 ms in MEG only. The very early repetition effect, observed at 40-50 ms over occipito-temporo-parietal regions, showed a different MEG topography according to the facial expression. This differential response to fearful, happy and neutral faces suggests the existence of very early discriminative visual processing of expressive faces, possibly based on the low-level physical features typical of different emotions. The N170 and M170 face-selective components both showed repetition enhancement selective to neutral faces, with greater amplitude for emotional than neutral faces on the first but not the second presentation. These differential repetition effects may reflect valence acquisition for the neutral faces due to repetition, and suggest a combined influence of emotion- and experience-related factors on the early stage of face encoding. Finally, later repetition effects consisted in enhanced M300 (MEG) between 280 and 320 ms for fearful relative to happy and neutral faces that occurred on the first presentation, but levelled out on the second presentation. This effect may correspond to the higher arousing value of fearful stimuli that might habituate with repetition. Our results reveal that multiple stages of face processing are affected by the repetition of emotional information.
Brain Research, in press
To determine how emotional information modulates subsequent traces for repeated stimuli, we combined simultaneous electro-encephalography (EEG) and magneto-encephalography (MEG) measures during long-lag incidental repetition of fearful, happy, and neutral faces. Repetition effects were modulated by facial expression in three different time windows, starting as early as 40-50 ms in both EEG and MEG, then arising at the time of the N170/M170, and finally between 280-320 ms in MEG only. The very early repetition effect, observed at 40-50 ms over occipito-temporo-parietal regions, showed a different MEG topography according to the facial expression. This differential response to fearful, happy and neutral faces suggests the existence of very early discriminative visual processing of expressive faces, possibly based on the low-level physical features typical of different emotions. The N170 and M170 face-selective components both showed repetition enhancement selective to neutral faces, with greater amplitude for emotional than neutral faces on the first but not the second presentation. These differential repetition effects may reflect valence acquisition for the neutral faces due to repetition, and suggest a combined influence of emotion- and experience-related factors on the early stage of face encoding. Finally, later repetition effects consisted in enhanced M300 (MEG) between 280 and 320 ms for fearful relative to happy and neutral faces that occurred on the first presentation, but levelled out on the second presentation. This effect may correspond to the higher arousing value of fearful stimuli that might habituate with repetition. Our results reveal that multiple stages of face processing are affected by the repetition of emotional information.
ARTICLE UPDATE - Dissociable neural effects of stimulus valence and preceding context during the inhibition of responses to emotional faces.
Schulz KP, Clerkin SM, Halperin JM, Newcorn JH, Tang CY, Fan J.
Human Brain Mapping, in press
Socially appropriate behavior requires the concurrent inhibition of actions that are inappropriate in the context. This self-regulatory function requires an interaction of inhibitory and emotional processes that recruits brain regions beyond those engaged by either processes alone. In this study, we isolated brain activity associated with response inhibition and emotional processing in 24 healthy adults using event-related functional magnetic resonance imaging (fMRI) and a go/no-go task that independently manipulated the context preceding no-go trials (ie, number of go trials) and the valence (ie, happy, sad, and neutral) of the face stimuli used as trial cues. Parallel quadratic trends were seen in correct inhibitions on no-go trials preceded by increasing numbers of go trials and associated activation for correct no-go trials in inferior frontal gyrus pars opercularis, pars triangularis, and pars orbitalis, temporoparietal junction, superior parietal lobule, and temporal sensory association cortices. Conversely, the comparison of happy versus neutral faces and sad versus neutral faces revealed valence-dependent activation in the amygdala, anterior insula cortex, and posterior midcingulate cortex. Further, an interaction between inhibition and emotion was seen in valence-dependent variations in the quadratic trend in no-go activation in the right inferior frontal gyrus and left posterior insula cortex. These results suggest that the inhibition of response to emotional cues involves the interaction of partly dissociable limbic and frontoparietal networks that encode emotional cues and use these cues to exert inhibitory control over the motor, attention, and sensory functions needed to perform the task, respectively.
Human Brain Mapping, in press
Socially appropriate behavior requires the concurrent inhibition of actions that are inappropriate in the context. This self-regulatory function requires an interaction of inhibitory and emotional processes that recruits brain regions beyond those engaged by either processes alone. In this study, we isolated brain activity associated with response inhibition and emotional processing in 24 healthy adults using event-related functional magnetic resonance imaging (fMRI) and a go/no-go task that independently manipulated the context preceding no-go trials (ie, number of go trials) and the valence (ie, happy, sad, and neutral) of the face stimuli used as trial cues. Parallel quadratic trends were seen in correct inhibitions on no-go trials preceded by increasing numbers of go trials and associated activation for correct no-go trials in inferior frontal gyrus pars opercularis, pars triangularis, and pars orbitalis, temporoparietal junction, superior parietal lobule, and temporal sensory association cortices. Conversely, the comparison of happy versus neutral faces and sad versus neutral faces revealed valence-dependent activation in the amygdala, anterior insula cortex, and posterior midcingulate cortex. Further, an interaction between inhibition and emotion was seen in valence-dependent variations in the quadratic trend in no-go activation in the right inferior frontal gyrus and left posterior insula cortex. These results suggest that the inhibition of response to emotional cues involves the interaction of partly dissociable limbic and frontoparietal networks that encode emotional cues and use these cues to exert inhibitory control over the motor, attention, and sensory functions needed to perform the task, respectively.
Saturday, December 06, 2008
ARTICLE UPDATE - Working memory capacity and the self-regulation of emotional expression and experience.
Schmeichel BJ, Volokhov RN, Demaree HA.
Journal of Personality and Social Psychology, 95, 1526-1540
This research examined the relationship between individual differences in working memory capacity and the self-regulation of emotional expression and emotional experience. Four studies revealed that people higher in working memory capacity suppressed expressions of negative emotion (Study 1) and positive emotion (Study 2) better than did people lower in working memory capacity. Furthermore, compared to people lower in working memory capacity, people higher in capacity more capably appraised emotional stimuli in an unemotional manner and thereby experienced (Studies 3 and 4) and expressed (Study 4) less emotion in response to those stimuli. These findings indicate that cognitive ability contributes to the control of emotional responding.
Journal of Personality and Social Psychology, 95, 1526-1540
This research examined the relationship between individual differences in working memory capacity and the self-regulation of emotional expression and emotional experience. Four studies revealed that people higher in working memory capacity suppressed expressions of negative emotion (Study 1) and positive emotion (Study 2) better than did people lower in working memory capacity. Furthermore, compared to people lower in working memory capacity, people higher in capacity more capably appraised emotional stimuli in an unemotional manner and thereby experienced (Studies 3 and 4) and expressed (Study 4) less emotion in response to those stimuli. These findings indicate that cognitive ability contributes to the control of emotional responding.
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