Angelika Köchel

Source localization of late electrocortical positivity during symptom provocation in spider phobia: an sLORETA study.

This symptom provocation study on spider phobia investigated sources of late event-related potentials (ERPs) using sLORETA (standardized low resolution brain electromagnetic tomography). Twenty-five phobic female patients and 20 non-phobic controls were confronted with phobia-relevant, generally fear-inducing, disgust-inducing and affectively neutral pictures while an electroencephalogram was recorded. Mean amplitudes of ERPs were extracted in the time windows 340–500 ms (P300) and 550–770 ms (late positive potential, LPP). Phobics showed enhanced P300 and LPP amplitudes in response to spider pictures relative to controls. Sources were mainly located in areas engaged in visuo-attentional processing (occipital and parietal regions, ventral visual pathway). Moreover, there were sources in areas which are crucial for emotional processing and the representations of aversive bodily states (cingulate cortex, insula). Further sources were located in premotor areas reflecting the priming of flight behaviour. Our findings are in good accordance with existing brain imaging studies and underline that source localization is a useful alternative for identifying phobia-relevant cortical regions.

Psychophysiology of spider phobia in 8- to 12-year-old girls

The present investigation focused on late event-related potentials (ERPs) and facial electromyographic (EMG) activity in response to symptom provocation in 8- to 12-year-old spider phobic girls and compared results to those in non-fearful controls. Fourteen patients and 14 controls were presented with phobia-relevant, generally fear-inducing, disgust-inducing and affectively neutral pictures in an EEG/EMG session. ERPs were extracted in the time-windows 340-500ms (P300) and 550-770ms (late positive potential, LPP). Relative to controls, phobics showed enhanced amplitudes of P300 and LPP in response to spider pictures. This result is interpreted to reflect motivated attention to emotionally salient stimuli. Moreover, phobics showed enhanced average facial EMG activity of the levator labii and the corrugator supercilii in response to spider pictures, reflecting the negative valence and disgust relevance of spiders. Additionally, spider phobic girls relative to controls showed higher overall disgust proneness and heightened average facial EMG activity in both muscle regions in response to disgust stimuli, possibly revealing a disgust-based origin of spider phobia in children. These aspects should be considered in psychotherapeutic treatment of childhood spider phobia.

Exposure therapy leads to enhanced late frontal positivity in 8- to 13-year-old spider phobic girls

Highlights ► Spider phobic girls show enhanced late positivity after psychotherapy. ► Reduced overall disgust proneness after psychotherapy. ► Spider phobia should already be treated in childhood.

Disrupted response inhibition toward facial anger cues in children with attention-deficit hyperactivity disorder (ADHD): an event-related potential study.

This event-related potential study focused on neural correlates of inhibitory affective control in attention-deficit hyperactivity disorder (ADHD). Sixteen boys with ADHD and 16 healthy boys underwent an emotional Go/NoGo task with pictures of facial expressions from the categories anger, sadness, happiness, and neutral. The participants were instructed to execute or withhold a motor response to specific emotions. Patients relative to controls displayed a severe impairment in response inhibition toward anger cues, which was accompanied by a reduced P300 amplitude (positive voltage deflection about 300 ms after picture onset). The control group showed a P300 differentiation of the affective categories that was absent in the ADHD group. The pronounced anger-processing deficit in ADHD patients might be linked to their interpersonal difficulties and should be addressed in psychotherapy.

Frontal late positivity in dental phobia: A study on gender differences

Although dental phobia afflicts men and women, gender differences in neural correlates of this disorder have not been investigated thus far. We recorded event-related potential (ERPs) in 30 individuals with dental phobia (15 women, 15 men with comparable disorder severity) and 30 nonphobic controls (15 women, 15 men) while they passively viewed pictures depicting dental treatment, generally fear-eliciting, disgust-eliciting and neutral contents. Male and female individuals with dental phobia as compared with controls displayed an enlarged centro-parietal late positivity (300-1500 ms). Gender difference concerned prefrontal ERPs. Only men with dentophobia showed an enhanced positivity towards the phobic relative to the neutral pictures in the time window between 300 and 1500 ms. Such a differentiation was absent in the other groups (male controls, female phobics, female controls). This finding indicates a gender-dependent recruitment of frontal attention networks in dental phobia and might reflect that male and female sufferers of dentophobia differ with regard to controlled attention focusing and cognitive avoidance during exposure.

Neural correlates of intolerance of uncertainty

Many future events are unpredictable, which is considered unacceptable by individuals with an intolerance of uncertainty (IU). We investigated the influence of two related personality traits, IU and habitual worrying on neural correlates of affective uncertainty with functional magnetic resonance imaging. Thirty females viewed a warning cue that always preceded an aversive picture, a safety cue that always preceded a neutral picture and an uncertainty cue that signaled that an aversive or a neutral picture might be shown (probability: 50%:50%). The processing of uncertainty was associated with activation of the posterior frontomedian cortex (PFMC), the dorsolateral prefrontal cortex, and the anterior cingulate cortex. IU and habitual worrying were positively correlated with amygdala activity during experienced uncertainty. Moreover, IU correlated negatively with PFMC activity. This response pattern might reflect that uncertainty is threatening to individuals high in IU and that they lack adequate cognitive mechanism to cope with the uncertainty.

Affective perception and imagery: A NIRS study.

The activation of cortical attention networks during affective picture processing has been extensively studied, whereas little is known about affective imagery. It is still unclear whether differences in emotional stimulus content are able to modulate visual cortex activation during imagery. Moreover, individual differences in emotional reactivity and imagery ability have not been investigated. The aim of this experiment was to examine these processes by means of near-infrared spectroscopy (NIRS). Thirty-five healthy adults were instructed to look at affective (disgust and happy) and neutral pictures and afterwards visualize them during multi-channel NIRS recording. Our main results indicated a differential involvement of parietal and occipital areas in the perception and imagery of affective pictures. In general, picture perception provoked increased oxygenated hemoglobin in occipital regions, whereas imagery was associated with an increase in parietal areas. Emotional content modulated activation of the left occipital cortex during both picture perception and imagery. Affective pictures (disgust and happy) provoked greater activation compared to neutral ones. Additionally, the self-rated imagery ability of the participants was positively correlated with their occipital activation during affective imagery. Thus, occipital activation might be crucial for the quality of imagery. In contrast, all correlations with emotional traits (e.g. trait disgust) and oxygenation were nonsignificant, which might be due to the fact that those personality factors predominantly modulate the activation of subcortical limbic structures which are not accessible with NIRS.

Cortical activation during auditory elicitation of fear and disgust: A near-infrared spectroscopy (NIRS) study

This near infrared spectroscopy study investigated whether nonverbal human sounds representing different basic emotions are able to specifically modulate temporo-parietal cortices, involved in auditory processing and attention. Forty-three adults (19 females and 24 males) were presented with sounds from the categories fear, disgust, and neutral. The stimuli were able to elicit the target emotions with sufficient specificity. The listening to fear-relevant sounds (e.g., screams of fear and pain) led to increased activation of the right superior temporal gyrus and the bilateral supramarginal gyrus. The hemodynamic responses to disgusting sounds (e.g., sniffing, diarrhea) were smaller. Our findings point to a differential neuronal sensitivity of the human brain to two basic emotion elicitors in the auditory domain.

Affective inhibitory control in adults with attention deficit hyperactivity disorder: Abnormalities in electrocortical late positivity

Boys afflicted with ADHD (Attention-deficit/hyperactivity disorder) are characterized by deficient response inhibition and reduced electrocortical late positivity when presented with facial expressions of anger. This deficit might contribute to their problems in social interactions. We conducted the present event-related potential study with 15 men suffering from ADHD and 15 healthy controls in order to investigate whether similar dysfunctions are present in adult ADHD. The participants underwent an emotional version of a Go/NoGo task while event-related potentials (ERPs) were recorded. They were instructed to inhibit a motor response to one of four facial emotional expressions: anger, fear, sadness, or happiness. There were no behavioral differences in inhibitory control between the ADHD and the control group. However, the patients showed a reduced right parietal late positivity when instructed to inhibit a response to negative emotions. Obviously, the patients have learned to compensate for their deficit on a behavioral level, while it is still visible on the electrocortical level in this relatively simple task. Interestingly, the reduced positivity correlated with lowered self-reported emotional intelligence in the ADHD group.

Processing of affective prosody in boys suffering from attention deficit hyperactivity disorder: A near-infrared spectroscopy study

Neurobiological studies on facial affect recognition have demonstrated reduced response amplitudes to anger cues in patients suffering from attention deficit hyperactivity disorder (ADHD). It is still unclear whether a similar deficit exists in the auditory domain. Therefore, this near-infrared spectroscopy study focused on neuronal correlates of affective prosody processing. Fourteen boys suffering from ADHD and fourteen healthy boys were exposed to emotionally intoned, standardized sentences of the categories anger, sadness, happiness, and to affectively neutral sentences. Relative to controls, the patients displayed a diminished activation of the right superior temporal gyrus (STG) when processing anger prosody, which was correlated with aggressive behavior. There were no group differences for the other emotions. Additionally, the ADHD group showed increased supramarginal gyrus (SMG) activation in the anger condition. This might mirror compensatory attention allocation. In summary, we identified a selectively lowered STG activation to auditory anger cues in ADHD patients. Consequently, STG recruitment during anger exposure might be used for evaluation of psychotherapy effects.