Philipp Kazzer

Talking about Emotion: Prosody and Skin Conductance Indicate Emotion Regulation

Talking about emotion and putting feelings into words has been hypothesized to regulate emotion in psychotherapy as well as in everyday conversation. However, the exact dynamics of how different strategies of verbalization regulate emotion and how these strategies are reflected in characteristics of the voice has received little scientific attention. In the present study, we showed emotional pictures to 30 participants and asked them to verbally admit or deny an emotional experience or a neutral fact concerning the picture in a simulated conversation. We used a 2 × 2 factorial design manipulating the focus (on emotion or facts) as well as the congruency (admitting or denying) of the verbal expression. Analyses of skin conductance response (SCR) and voice during the verbalization conditions revealed a main effect of the factor focus. SCR and pitch of the voice were lower during emotion compared to fact verbalization, indicating lower autonomic arousal. In contradiction to these physiological parameters, participants reported that fact verbalization was more effective in down-regulating their emotion than emotion verbalization. These subjective ratings, however, were in line with voice parameters associated with emotional valence. That is, voice intensity showed that fact verbalization reduced negative valence more than emotion verbalization. In sum, the results of our study provide evidence that emotion verbalization as compared to fact verbalization is an effective emotion regulation strategy. Moreover, based on the results of our study we propose that different verbalization strategies influence valence and arousal aspects of emotion selectively.

A neural network reflecting individual differences in cognitive processing of emotions during perceptual decision making

Even simple perceptual decisions are influenced by the emotional content of a stimulus. Recent neuroimaging studies provide evidence about the neural mechanisms of perceptual decision making on emotional stimuli. However, the effect of individual differences in cognitive processing of emotions on perceptual decision making remains poorly understood. Here, we investigated how changes in the fMRI signal during perceptual decision making on facial stimuli covaried with individual differences in the ability to identify and communicate ones emotional state. Although this personality trait covaried with changes in activity in the dorsal anterior cingulate cortex (dACC) during gender decisions on facial expressions, there was no correlation during emotion decisions. Further, we investigated whether individual differences in the ability to cognitively process emotions depend on differences in the functional integration of emotional and cognitive brain regions. We therefore compared task-dependent changes in effective connectivity of dACC in individuals with good and with poor ability to cognitively process emotions using a psychophysiological interaction analysis. We found greater coupling of dACC with prefrontal regions in individuals with good ability to identify and communicate their emotional state. Conversely, individuals with poor ability in this domain showed greater coupling of dACC with the amygdala. Our data indicate that individual differences in the ability to identify and communicate ones emotional state are reflected by altered effective connectivity of the dACC with prefrontal and limbic regions. Thus, we provide neurophysiological evidence for a theoretical model that posits that a discommunication between limbic areas and the neocortex impairs cognitive processing of emotions.

Temporal dynamics of prediction error processing during reward-based decision making

Adaptive decision making depends on the accurate representation of rewards associated with potential choices. These representations can be acquired with reinforcement learning (RL) mechanisms, which use the prediction error (PE, the difference between expected and received rewards) as a learning signal to update reward expectations. While EEG experiments have highlighted the role of feedback-related potentials during performance monitoring, important questions about the temporal sequence of feedback processing and the specific function of feedback-related potentials during reward-based decision making remain. Here, we hypothesized that feedback processing starts with a qualitative evaluation of outcome-valence, which is subsequently complemented by a quantitative representation of PE magnitude. Results of a model-based single-trial analysis of EEG data collected during a reversal learning task showed that around 220ms after feedback outcomes are initially evaluated categorically with respect to their valence (positive vs. negative). Around 300ms, and parallel to the maintained valence-evaluation, the brain also represents quantitative information about PE magnitude, thus providing the complete information needed to update reward expectations and to guide adaptive decision making. Importantly, our single-trial EEG analysis based on PEs from an RL model showed that the feedback-related potentials do not merely reflect error awareness, but rather quantitative information crucial for learning reward contingencies.

Effects of intranasal oxytocin on pupil dilation indicate increased salience of socioaffective stimuli.

To investigate the mechanisms by which oxytocin improves socioaffective processing, we measured behavioral and pupillometric data during a dynamic facial emotion recognition task. In a double-blind between-subjects design, 47 men received either 24 IU intranasal oxytocin (OXT) or a placebo (PLC). Participants in the OXT group recognized all facial expressions at lower intensity levels than did participants in the PLC group. Improved performance was accompanied by increased task-related pupil dilation, indicating an increased recruitment of attentional resources. We also found increased pupil dilation during the processing of female compared with male faces. This gender-specific stimulus effect diminished in the OXT group, in which pupil size specifically increased for male faces. Results suggest that improved emotion recognition after OXT treatment might be due to an intensified processing of stimuli that usually do not recruit much attention.

Transcranial Direct Current Stimulation Enhances Cognitive Control During Emotion Regulation

BACKGROUND The ability to cognitively control emotions is critical for mental health. Previous studies have identified the dorsolateral prefrontal cortex (dlPFC) as a core region in cognitive reappraisal. However, there is only scarce evidence whether directly modulating dlPFC activity results in improved capacities for cognitive reappraisal. OBJECTIVE In this study, we used anodal transcranial direct current stimulation (tDCS) over the right dlPFC to investigate the effects of increased dlPFC excitability on cognitive reappraisal as indexed by subjective emotional arousal ratings and skin conductance responses. METHODS The study was designed as a double-blind, between-subjects, sham-controlled trial. Half of the healthy participants were randomly assigned to receive either active tDCS (n = 21, 1.5 mA for 20 min over the right dlPFC) or sham stimulation (n = 21). Participants viewed negative and neutral pictures from the International Affective Picture System while they were instructed to either downregulate, upregulate or maintain their emotions. After each picture presentation, participants rated the intensity of emotional arousal. Skin conductance responses and gaze fixation were assessed. RESULTS Our results revealed that anodal prefrontal tDCS during downregulation resulted in decreased skin conductance responses and decreased emotional arousal ratings. The opposite pattern was observed for the upregulation condition in which anodal tDCS resulted in higher arousal ratings accompanied by marginally enhanced skin conductance responses. CONCLUSION Our data indicates that tDCS facilitates cognitive reappraisal in both directions by either increasing or decreasing emotional responsiveness depending on the regulatory goal. This provides further evidence for the potential use of tDCS as a tool to modulate cognitive reappraisal. However, given the limitations of the present study, our findings need to be replicated and complimented by further studies.

Investigating socio-cognitive processes in deception: A quantitative meta-analysis of neuroimaging studies

Recent neuroimaging studies have found a broad network of brain regions involved in deception, including the prefrontal cortex, insula, anterior cingulate cortex (ACC), and inferior parietal lobule (IPL). Although deception can be conceptualized as the attempt to deliberately cause another person to accept a false belief, research to date has mainly focused on executive control processes when participants are instructed to lie under certain conditions. Recently, more ecologically valid and interactive experimental paradigms have been used in which subjects were also requested to take the perspective of another person, read his or her intentions, and make a self-determined decision to deceive that person and break a moral rule. To investigate the influence of these socio-cognitive processes on the neural network of deception, we performed a quantitative meta-analysis combining the data from 416 participants across 22 fMRI and two PET studies. Based on the description of the experimental paradigm, studies were divided in social interactive and non-interactive deception studies. Increased activation in the dorsal ACC, the right temporo-parietal junction (TPJ)/angular gyrus, and the bilateral temporal pole (TP) was found to be greater in social interactive than in non-interactive deception. These results demonstrate the important role of perspective taking, theory of mind, and moral reasoning processes in deception as well as conflict processing. In addition to the role of executive control processes determined by previous meta-analyses, our findings show the importance of these socio-cognitive processes in deception and give new insight into the function and interpretation of the brain regions involved.

Neural mechanisms underlying the integration of emotion and working memory

The present study aimed at investigating the behavioral effects and neuronal correlates of emotional content and emotional components, i.e. valence and arousal, in the context of a verbal working memory task. Our findings in twenty healthy male subjects demonstrate that (1) word valence has no impact on performance in the verbal working memory task, and (2) that emotion leads to an increase of activation in cognition-related lateral prefrontal regions, whereas cognitive effort yields enhanced deactivation in emotion-related cortical midline regions. The stronger dorsolateral prefrontal recruitment during emotional stimuli may reflect an arousal effect or higher cognitive effort due to interference with emotion.

Transcranial direct current stimulation of the prefrontal cortex: a means to modulate fear memories.

Targeting memory processes by noninvasive interventions is a potential gateway to modulate fear memories as shown by animal and human studies in recent years. Modulation of fear memories by noninvasive brain stimulation techniques might be an attractive approach, which, however, has not been examined so far. We investigated the effect of transcranial direct current stimulation (tDCS) applied to the right dorsolateral prefrontal cortex and left supraorbital region on fear memories in humans. Seventy-four young, healthy individuals were assigned randomly to two groups, which underwent fear conditioning with mild electric stimuli paired with a visual stimulus. Twenty-four hours later, both groups were shown a reminder of the conditioned fearful stimulus. Shortly thereafter, they received either tDCS (right prefrontal – anodal, left supraorbital – cathodal) for 20 min at 1 mA current intensity or sham stimulation. A day later, fear responses of both groups were compared by monitoring skin conductance. On day 3, during fear response assessment, the tDCS group had a significantly (P<0.05) higher mean skin conductance in comparison with the sham group. These results suggest that tDCS (right prefrontal – anodal, left supraorbital – cathodal) enhanced fear memories, possibly by influencing the prefrontal cortex–amygdala circuit underlying the memory for fear.

Insular activity during passive viewing of aversive stimuli reflects individual differences in state negative affect

People differ with regard to how they perceive, experience, and express negative affect. While trait negative affect reflects a stable, sustained personality trait, state negative affect represents a stimulus limited and temporally acute emotion. So far, little is known about the neural systems mediating the relationship between negative affect and acute emotion processing. To address this issue we investigated in a healthy female sample how individual differences in state negative affect are reflected in changes in blood oxygen level-dependent responses during passive viewing of emotional stimuli. To assess autonomic arousal we simultaneously recorded changes in skin conductance level. At the psychophysiological level we found increased skin conductance level in response to aversive relative to neutral pictures. However, there was no association of state negative affect with skin conductance level. At the neural level we found that high state negative affect was associated with increased left insular activity during passive viewing of aversive stimuli. The insula has been implicated in interoceptive processes and in the integration of sensory, visceral, and affective information thus contributing to subjective emotional experience. Greater recruitment of the insula in response to aversive relative to neutral stimuli in subjects with high state negative affect may represent increased processing of salient aversive stimuli.

Effects of Empathic Paraphrasing – Extrinsic Emotion Regulation in Social Conflict

In the present study, we investigated the effects of empathic paraphrasing as an extrinsic emotion regulation technique in social conflict. We hypothesized that negative emotions elicited by social conflict can be regulated extrinsically in a conversation by a listener following the narrator’s perspective and verbally expressing cognitive empathy. Twenty participants were interviewed on an ongoing or recently self-experienced social conflict. The interviewer utilized 10 standardized open questions inviting participants to describe their perception of the conflict. After each of the 10 descriptions, the interviewer responded by either paraphrasing or taking notes (control condition). Valence ratings pertaining to the current emotional state were assessed during the interview along with psychophysiological and voice recordings. Participants reported feeling less negative after hearing the interviewer paraphrase what they had said. In addition, we found a lower sound intensity of participants’ voices when answering to questions following a paraphrase. At the physiological level, skin conductance response, as well as heart rate, were higher during paraphrasing than during taking notes, while blood volume pulse amplitude was lower during paraphrasing, indicating higher autonomic arousal. The results show that demonstrating cognitive empathy through paraphrasing can extrinsically regulate negative emotion on a short-term basis. Paraphrasing led to enhanced autonomic activation in recipients, while at the same time influencing emotional valence in the direction of feeling better. A possible explanation for these results is that being treated in an empathic manner may stimulate a more intense emotion processing helping to transform and resolve the conflict.