Corrigendum: Does Transcranial Direct Current Stimulation (tDCS) Improve Disgust Regulation Through Imagery Rescripting?

[This corrects the article DOI: 10.3389/fnhum.2019.00192.].

Does Transcranial Direct Current Stimulation (tDCS) Improve Disgust Regulation Through Imagery Rescripting?

The first pilot studies have shown the potential of imagery rescripting (ImR) for reducing contamination-related pathological disgust, although the effects were rather small. The aim of the present study is to investigate whether the effects of ImR in reducing disgust can be further increased by transcranial direct current stimulation (tDCS). tDCS is a non-invasive method of brain stimulation that has been successfully used multiple times to support emotion-regulation strategies. In the present study, disgust was induced via images related to individualized sources of disgust. Fifty-eight healthy volunteers took part in two parallel experiments. The two groups were matched by age, highest educational level and gender, and were tested under two emotion-regulation conditions, namely an ImR condition and a control condition. Participants performed three trials on the first day and three trials on the second day. Across both days they performed three trials under each of the two emotion-regulation conditions in a randomized order. On one day active stimulation was applied, while on the other day participants were sham stimulated. The combination of emotion-regulation and stimulation condition was balanced across subjects. The only difference between the two groups was the localization of tDCS stimulation: one group was stimulated over the dorsolateral prefrontal cortex and the other group was stimulated over the visual cortex (VC). This experimental manipulation was implemented to gain further insights into the underlying neuropsychological mechanisms of imagery. ImR was conducted via a previously-recorded audio file. The results confirm the effect of ImR on the reduction of disgust. However, with the present experimental design we were not able to show that supplementary tDCS of the VC or the dorsolateral prefrontal cortex lead to improvement.

Changing disgust through imagery rescripting and cognitive reappraisal in contamination-based obsessive-compulsive disorder.

Contamination-related obsessive-compulsive disorder (C-OCD) is characterized by strongly experienced disgust and fear, in response to potentially contaminating stimuli. Both emotions differ in their susceptibility for change by habituation and extinction, which are important processes for the success of exposure therapy. Even though the response rates for exposure therapy for C-OCD are very good, it seems promising to test additional therapeutic techniques which target disgust more directly. Therefore, imagery rescripting and cognitive reappraisal were evaluated for their potential to change levels of disgust (within-subject), in the two-session laboratory study with 30 participants, with diagnosed C-OCD, and 30 matched, healthy controls (between-subject), presented. The results show that both emotion-regulation strategies reduced disgust better than a non-intervention control task (counting fishes), across all the participants. Therefore, both strategies seem to be applicable and effective for reducing disgust, in the short term, in participants with diagnosed C-OCD. The implications of these findings for the experimental approach and for the clinical treatment of C-OCD, are discussed.

Differential response patterns to disgust-related pictures.

In the present study, attentional bias was investigated as a potential predisposing mechanism for the contamination-related subtype of obsessive-compulsive disorder (C-OC disorder). Fifty healthy participants with varying degrees of subclinical C-OC symptoms performed a visual search task to measure differential attentional biases elicited by neutral, disgust-, and fear-specific pictorial material. Participants had to find a target picture within five neutral distractor pictures randomly presented on different locations in an array. The task was to decide whether the array contained an unpleasant target picture or not. In randomly-selected emotional trials, participants were further asked about the content of the picture and the confidence of their answer. The results show that the reaction times significantly differed between the emotional and neutral pictures. Participants were significantly more confident in answering questions referring to fear compared to disgust pictures. This effect was marginally amplified in participants with higher C-OC symptoms. We discuss the results within the framework of the cost and benefit hypothesis, which postulates that disgust evolutionarily elicits stronger uncertainty compared to fear, owing to the ambiguous nature of the stimuli. Increased uncertainty might be an important but underestimated factor for pathological disgust experience, such as in obsessive-compulsive disorder.

The impact of attentional and emotional demands on memory performance in obsessive-compulsive disorder.

Lower performance on memory tests in obsessive-compulsive disorder (OCD) has been repeatedly observed. However, the origins of these performance deficits are not sufficiently explained. In this study we tested if OCD-related extensive focus of attention on thoughts (heightened self-consciousness) could be an explanatory mechanism for lower memory performance. Heightened situational self-consciousness was manipulated by instructing participants to either monitor neutral thoughts or to monitor OCD-related thoughts. We included a Behavioral Avoidance Task based on individual obsessions and compulsions to induce OCD-related thoughts. Participants were asked to perform these monitoring tasks in parallel to a taxing verbal memory task, resulting in learning under divided attention. The two conditions of learning under divided attention were compared to a single-task condition. Twenty-four participants with OCD and 24 healthy controls took part in these three learning conditions. The results indicate that in both groups memory performance deteriorated in the two conditions with divided attention compared to the single task condition. In the OCD-related thought monitoring condition (OTM) self-consciousness and Behavioral Avoidance Task-induced stress and fear were particularly increased and memory performance further deteriorated in the OCD group. This finding highlights an important and underestimated mechanism (personal involvement) which might serve to better understand lower memory performance in OCD.

[Spinal epidural abscesses are rare and warrant fast intervention].

A spinal epidural abscess is a rare infectious disease that warrants urgent treatment. Symptoms involve a classic triad of fever, backache and neurological deficits but all the symptoms are rarely seen at the first contact. The low incidence and the non-specific symptoms can delay the diagnosis, resulting in grave neurological sequelae and death. Common risk factors are diabetes mellitus and intravenous drug abuse. Successful treatment relies on a multidisciplinary approach. We describe a case of spinal epidural abscesses in a previously healthy young man without known risk factors.

Basilar Artery Thrombosis in a Child Treated With Intravenous Tissue Plasminogen Activator and Endovascular Mechanical Thrombectomy.

Basilar artery occlusion in children is rare. It has a high mortality and morbidity if recanalization is not achieved before extensive brainstem infarction has occurred. An 11-year-old boy presented with a clinical and radiological "top-of-the-basilar" syndrome. Intravenous tissue plasminogen activator was administered, and the patient was immediately referred to the regional stroke center. Subsequent mechanical thrombectomy using a Solitaire stent (Solitaire FR stent; ev3, Irvine, CA, USA) resulted in clot removal and recanalization of the basilar artery 4 hours after stroke onset. The patient made a full clinical recovery. To the authors' knowledge this is the first report on basilar artery occlusion in a child treated with "bridging" therapy, the combination of intravenous thrombolysis and endovascular thrombectomy. If the diagnosis can be made within the time window for intravenous thrombolysis (4.5 hours), the present case suggests that bridging therapy in pediatric basilar artery occlusion can be safe and effective.