Effects of personal space intrusion in affective contexts: an fMRI investigation with women suffering from borderline personality disorder.

The amygdala and the parietal cortex play a key role in the neural representation of personal space. Although the concept of personal space is clinically very relevant for borderline personality disorder (BPD), especially in affective contexts, it has not been investigated thus far with functional magnetic resonance imaging (fMRI). In this fMRI study, 25 female BPD patients and 25 healthy women were exposed to photos of angry, disgusted and neutral facial expressions. All stimuli were once shown as still photos, and once were zoomed-in in order to simulate intrusion into one's own personal space. Approaching faces generally provoked activation of the amygdala and the somatosensory cortex. BPD patients showed an increased activation within both regions, but only toward approaching disgusted faces. Their amygdala activation in this specific condition positively correlated with self-disgust scores. Moreover, the clinical group indicated an enhanced personal distance preference, which was associated with parietal activation. The present study revealed altered personal space processing of BPD patients, especially in situations that relate to social contexts involving disgust. Future studies should focus on the temporal stability of personal space processing during the natural course of BPD as well as during therapy.

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.

Out of sight, but still in mind: electrocortical correlates of attentional capture in spider phobia as revealed by a 'dot probe' paradigm.

The current investigation focused on attentional processes in spider phobia. Twenty phobics and 20 controls performed a dot-probe task while event-related potentials were recorded. In each trial they viewed a picture pair (a spider or a generally disgust eliciting picture that was paired with a neutral picture) for either 100 or 1500 ms. After the offset a visual probe (a dot) was presented either at the previous position of the emotionally relevant or the neutral slide and participants were asked to indicate with a button press whether the dot had been presented on the left or the right side of the screen. Results revealed a modulation of the centro-parietal P300 (340-500 ms after picture onset). Amplitudes were higher when the dot replaced a spider than when it replaced a neutral picture. This was phobia-specific, as it was only present in phobics and did not appear in response to disgust pictures. Moreover, the modulation could only be shown for short presentation times. The results are interpreted to reflect motivated attention in spider phobia, if disorder-relevant and neutral pictures are shown simultaneously. As the modulation of the P300 was found after picture offset, attentional allocation seems to be persist after the phobic object is no longer present.

Electrocortical effects of directing attention during visual exposure in dentophobia.

Fear of pain is a main motivator for avoidance or delay of dental treatment in patients afflicted with dentophobia. Studies employing passive viewing paradigms found motivated attention to the phobic object to be associated with enhanced amplitudes of the late positive potential (LPP). The aim of the current study was to investigate, if explicit attention-guiding instructions are able to modify the LPP. Twenty-three patients suffering from dentophobia and 23 controls were presented with pictures showing disorder-relevant or neutral contents, which were combined with different instructions: to distract the attention away from the picture, to classify the content, or to decide whether the scene elicited fear of pain. Relative to controls, dentophobics displayed enhanced late positivity (300-1000 ms after picture onset) in the fear of pain condition at frontal and central recording sites, whereas there was no group difference during classification and distraction. Within patients, fear of pain elicited greater positivity than classification and distraction. The findings are discussed within the framework of attentional direction. Future studies could investigate whether psychotherapy differentially affects neural correlates of attention regulation.

Altered functional connectivity of basal ganglia circuitry in dental phobia.

Recent symptom provocation studies that compared patients suffering from dental phobia with healthy controls identified hyperactivation of basal ganglia structures, but none have assessed striatal functional connectivity. We reanalyzed data from a previous functional magnetic resonance imaging study on dental phobia. Patients (20 men, 25 women) and healthy controls (18 men, 23 women) had been exposed to pictures showing dental treatment, and neutral contents. We conducted connectivity analyses via psychophysiological interactions (PPIs). Relative to non-phobic controls, the patients showed decreased connectivity between prefrontal and basal ganglia regions. Moreover, the clinical group was characterized by increased internal basal ganglia connectivity, which was more pronounced in female compared with male patients. This study provides first evidence for an altered information flow within a fronto-striatal network in dentophobic individuals during visual symptom provocation, which can be considered a neuromarker of this disorder.

Disgust regulation via placebo: an fMRI study.

The present fMRI study investigated whether placebo treatment can change disgust feelings. Disgust-prone women underwent a retest design where they were presented with disgusting, fear-eliciting and neutral pictures once with and once without a placebo (inert pill presented with the suggestion that it can reduce disgust symptoms). The placebo provoked a strong decrease of experienced disgust, which was accompanied by reduced insula activation. Exploratory psychophysiological interaction analyses revealed decreased connectivity in a network consisting of the insula, the amygdala, the anterior cingulate cortex and the orbitofrontal cortex. Moreover, the placebo increased amygdala-DMPFC coactivation. Our findings suggest that placebo use can modulate a specific affective state and might be an option as a first therapy step for clinical samples characterized by excessive and difficult-to-control disgust feelings.

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.

Auditory symptom provocation in dental phobia: a near-infrared spectroscopy study.

The act of drilling a tooth belongs to the most feared situations of patients suffering from dental phobia. We presented 25 female patients and 24 nonphobic women with the sound of a dental drill, pleasant and neutral sounds. Brain activation was recorded via near infrared spectroscopy in fronto-parietal and premotor areas. The groups differed in supplementary motor area (SMA) recruitment. Relative to controls, the phobics displayed increased oxy hemoglobin while presented with the phobia-relevant sound, but showed comparable activation in the other conditions. As the SMA is engaged in the preparation of motor actions, the increased response in patients might mirror the priming of flight behavior during exposure. We found no indication of an emotional modulation of parietal and dorsomedial prefrontal cortex activation.