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Many people find it difficult to practice progressive muscle relaxation (PMR) regularly. We attempted to improve relaxation quantity (i.e. adherence), and relaxation quality via placebo. A total of 100 women were randomly assigned to a standard group, which practiced PMR at home every day for two weeks, or a placebo group, which practiced PMR for two weeks with additional daily placebo treatment. To monitor adherence to relaxation practice, we used a smartphone app. The placebo group practiced more often than the standard group. Both groups did not differ in their reported relaxation level after the daily exercises.

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BACKGROUND: Millions of people enjoy watching videos of pimple treatments. The underlying neural mechanisms of this enjoyment have not been investigated so far. METHOD: We administered a total of 96 video clips from three categories: Pimple Popping (PP), Water Fountains (WF), and Steam Cleaning (SC). The PP videos showed a pimple or blackhead that was opened to squeeze out the pus or sebum. The female participants (mean age: 24 years) were assigned to one of two groups: females who reported to enjoy watching PP (PPE_high; n = 38) and those with little enjoyment (PPE_low; n = 42). We analyzed brain activity in regions of interest (ROI) involved in the encoding of pleasure and aversion (e.g., nucleus accumbens (NAc), insula). RESULTS: The PPE_high group showed less deactivation of the NAc (ROI finding), more frontopolar activation (whole-brain finding), and stronger accumbens-insula coupling than the PPE_low group. CONCLUSIONS: A specific pattern of brain activity and connectivity that involves the NAc and insula (coding of aversion/pleasure) and the frontopolar region (prediction of outcomes of motor decisions) is associated with the enjoyment of PP videos.

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BACKGROUND: Individuals with reduced olfactory function (anosmia, hyposmia) have reported changes in disgust perception and disgust experience compared to normosmic controls. The current functional magnetic resonance imaging (fMRI) study investigated the neural underpinnings of the altered disgust processing. METHOD: Twenty-four patients with anosmia or hyposmia and 26 normosmic controls were presented with images depicting facial expressions and scenes from the categories disgust and neutral. The disgusting scenes depicted stimuli that typically smell repulsive (spoiled food, excrements). Brain activity and structure in the primary olfactory cortex (POC) and in a region that processes affective/motivational olfactory-related information (insula, orbitofrontal cortex, basal ganglia) were compared between the two groups. RESULTS: The anosmic/hyposmic participants were characterized by greater activation in the POC while looking at disgusting scenes. The POC can be activated by olfactory imagery and holds predictive templates of olfactory stimuli. The neural processing of the facial stimuli did not differ between the two groups. Additionally, group differences in functional connectivity and brain structure were not present or only minor. CONCLUSION: The increased POC activation in anosmic/hyposmic patients might reflect a compensatory process that helps to compensate for their olfactory deficit. However, in general, this study identified only small adaptations in the neural disgust system as a consequence of reduced olfactory function.

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Background: The emotion disgust is typically directed toward stimuli in the external environment, but sometimes people develop self-directed disgust responses. Aims: The current questionnaire study focused on the role of self-disgust in lifetime suicidal ideation and behavior. Method: A total of 1,167 individuals participated in an Internet-based survey containing self-report measures of self-disgust, externally directed disgust proneness, coping styles, diagnoses of mental disorders, and suicide risk. Hierarchical regression analyses as well as mediation analyses were computed. Results: Self-disgust was the most relevant predictor of suicide risk among the assessed variables. Self-disgust was negatively associated with the use of support by others, and positively associated with evasive coping (self-blame, venting, denial), which in turn was positively associated with suicidality. Limitations: This cross-sectional study provided information on the relationship between self-disgust and suicidality in a self-selected sample. Longitudinal studies are warranted. Conclusion: Future studies are required to replicate these findings. Additionally, stronger research designs are needed in order to investigate whether self-disgust should be targeted in suicide prevention programs and interventions.

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BACKGROUND: It has been shown that particular religious beliefs and practices are associated with brain function and structure. The present voxel-based morphometry study investigated the correlation between the belief in the miracles of Lourdes (a major Catholic pilgrimage site) and gray matter volume in specific brain regions associated with theory of mind (ToM). METHOD: Structural brain data from 84 women (mean age: 25 years; no current somatic illness; 80% Roman-Catholic) were correlated with self-report measures on belief in miracles, religious-spiritual well-being, and psychological problems. Selected brain regions of the ToM network included the temporoparietal junction (TPJ), hippocampus, amygdala, and medial prefrontal cortex (MPFC). RESULTS: The belief in the miracles of Lourdes was positively correlated with general religiousness and with feelings of connectedness; there was no association with psychological problems. Belief in miracles of Lourdes correlated positively with TPJ volume and negatively with MPFC volume. CONCLUSION: Belief in the miracles was associated with brain volume in regions involved in mentalizing and self-control.

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Background: Placebo and nocebo effects on visual attention are still poorly understood. This eye-tracking study directly compared effects of sham transcranial magnetic stimulation (sTMS) that was administered along with the verbal suggestion that the treatment would either increase (placebo) or decrease (nocebo) left-sided visual attention. Method: Twenty women who had reported decreased attention (nocebo responders) and 20 women who had reported increased attention (placebo responders) following sTMS completed a visual search task with three visual load levels. The task was conducted once with and once without the placebo or the nocebo (sTMS). Left-sided fixations and reaction times for left-sided targets (in comparison with right-sided targets) were analyzed. Results: Contrary to the verbal suggestion, the nocebo responders showed more left-sided fixations in the nocebo condition (compared with the control condition) and responded faster to left-sided targets in the high-load condition. The placebo had no effect on fixations and reaction times. Conclusion: These results indicate a more beneficial effect of a nocebo compared with a placebo for the first time. Limits and possibilities of placebo and nocebo interventions are discussed.

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'Super smellers' are those individuals who show a heightened sense of smell. Data on the structural neuroanatomy of this phenomenon are still missing. A voxel-based morphometry study was conducted in order to compare gray matter volume (GMV) in specific brain regions of the olfactory network (piriform/entorhinal cortex, orbitofrontal cortex, insula, hippocampus) between 25 male 'super smellers' and 20 normosmic men. Participants were assigned to these groups based on their scores on a standardized olfactory performance test. Relative to normosmic men, 'super smellers' showed increased GMV in the anterior insula and in the hippocampus (dentate gyrus). These regions are crucial for the integration of olfactory information as well as odor learning and odor memory. Moreover, positive correlations between hippocampal volume and olfactory performance were detected in both groups. Future research should elaborate on how much of the observed neuroanatomical pattern of 'super smellers' is genetic and how much of it reflects experienced-based GMV increase.

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The knowledge about effects of placebos and nocebos on specific visual attention processes is still very limited. In the present eye-tracking study, it was analyzed if a nocebo (sham transcranial magnetic stimulation) is able to elicit left-sided attentional deficits (pseudo-neglect). Fifty-two healthy participants performed a search task on the computer, once with and once without the nocebo. Indicators of left-biased search behavior (e.g. fixation count, reaction times for left vs. right-sided target detection) and affective state (e.g., valence, arousal) were assessed. The sample was divided into two groups (nocebo responder, non-responder) based on the experienced effectiveness of the nocebo. The nocebo treatment was associated with a positive and calm affective state. Contrary to the verbal suggestion, the nocebo increased the number of fixations and the dwell time on the left side of the computer screen. Moreover, the nocebo decreased the detection time for targets on the left side. These paradoxical nocebo effects were restricted to nocebo responders. Possible implications of nocebo-related compensatory behaviors for neuropsychological therapy are discussed.

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Several eye-tracking studies have revealed that spider phobic patients show a typical hypervigilance-avoidance pattern when confronted with images of spiders. The present experiment investigated if this pattern can be changed via placebo treatment. We conducted an eye-tracking experiment with 37 women with spider phobia. They looked at picture pairs (a spider paired with a neutral picture) for 7 s each in a retest design: once with and once without a placebo pill presented along with the verbal suggestion that it can reduce phobic symptoms. The placebo was labelled as Propranolol, a beta-blocker that has been successfully used to treat spider phobia. In the placebo condition, both the fixation count and the dwell time on the spider pictures increased, especially in the second half of the presentation time. This was associated with a slight decrease in self-reported symptom severity. In summary, we were able to show that a placebo was able to positively influence visual avoidance in spider phobia. This effect might help to overcome apprehension about engaging in exposure therapy, which is present in many phobic patients.

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There is growing evidence that placebos are able to influence visual perception. A previous functional magnetic resonance imaging study on the processing of disgust images demonstrated that a ''disgust placebo'' (inert pill administered with the verbal suggestion of an anti-nausea medication) reduced visual cortex activity and connectivity. In the present functional magnetic resonance imaging investigation, visual effects corresponding to a ''disgust nocebo'' (an odorless substance introduced as an aversive smell that enhances disgust feelings) were examined. Data from 29 females were reanalyzed. They viewed disgusting, fear-eliciting, and neutral images once with and once without the nocebo. In the nocebo condition with disgusting images disgust experienced that significantly increased fusiform gyrus activation, which also showed enhanced coupling with the amygdala and several (extra)striate cortex regions. The nocebo changed the affective value and motivational relevance of the stimuli as well the perception of basic visual features. These findings demonstrate that nocebo-related expectations can have a strong influence on the experience of sensory input.

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The neurobiological mechanisms of nocebos are still poorly understood. Thirty-eight women participated in a 'smell study' using functional magnetic resonance imaging. They were presented with an odorless stimulus (distilled water) together with the verbal suggestion that this fluid has an aversive odor which enhances disgust feelings. The nocebo was presented while the participants viewed disgusting, fear-inducing, and neutral images. Participants' affective and neuronal responses during nocebo administration were compared with those in a control condition without nocebo. Twenty-nine women (76%) reported perceiving a slightly unpleasant and arousing odor. These 'nocebo responders' experienced increased disgust during the presentation of disgusting images in combination with the nocebo and showed enhanced left orbitofrontal cortex (OFC) activation. It has been suggested that the OFC is involved in the generation of placebo/nocebo-related expectations and appraisals. This region showed increased functional connectivity with areas involved in interoception (insula), autobiographical memories (hippocampus), and odor imagery (piriform cortex) during nocebo administration. The nocebo-induced change in brain activation was restricted to the disgust condition. Implications for psychotherapy are discussed.

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Blood can be easily recognized in situations involving injury. However, very little is known about the ability of humans to identify blood without such context information. We investigated the blood detection capacity and associated electrocortical correlates (event-related potentials) in 20 women with blood phobia and 20 non-phobic females. The participants viewed images depicting droplets of pig blood, and water with pink or red food coloring. They were asked to decide, whether the pictures showed real blood or not. Blood provoked enhanced P100 amplitudes (90-140 ms) in blood phobics. Late positivity (P300: 340-500 ms) as well as classification accuracy did not differ between the groups. However, blood elicited a general P300 enhancement (relative to red and pink fluids) possibly reflecting elevated visual attention to blood as a general characteristic in humans. The P100 augmentation in blood phobics very likely reflects enhanced early selective attention. Patients with BII phobia showed prioritized visual processing of blood without having to rely on contextual information.

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