Jalal Baland, McNally Richard J, Elias Jason A, Potluri Sriramya, Ramachandran Vilayanur S
Department of Psychiatry, Behavioural and Clinical Neuroscience Institute, University of Cambridge School of Clinical Medicine, Cambridge, United Kingdom.
Department of Psychology, Harvard University, Cambridge, MA, United States.
Front Hum Neurosci. 2020 Jan 9;13:414. doi: 10.3389/fnhum.2019.00414. eCollection 2019.
Obsessive-compulsive disorder (OCD) is a deeply enigmatic psychiatric condition associated with immense suffering worldwide. Efficacious therapies for OCD, like exposure and response prevention (ERP), are sometimes poorly tolerated by patients. As many as 25% of patients refuse to initiate ERP mainly because they are too anxious to follow exposure procedures. Accordingly, we proposed a simple and tolerable (immersive yet indirect) low-cost technique for treating OCD that we call "multisensory stimulation therapy." This method involves contaminating a rubber hand during the so-called "rubber hand illusion" (RHI) in which tactile sensations may be perceived as arising from a fake hand. Notably, Jalal et al. (2015) showed that such fake hand contamination during the RHI provokes powerful disgust reactions in healthy volunteers. In the current study, we explored the therapeutic potential of this novel approach. OCD patients ( = 29) watched as their hidden real hand was being stroked together with a visible fake hand; either synchronously (inducing the RHI; i.e., the experimental condition; = 16) or asynchronously (i.e., the control condition; = 13). After 5 min of tactile stimulation, the rubber hand was contaminated with fake feces, simulating conventional exposure therapy. Intriguingly, results suggested sensory assimilation of contamination sensations into the body image the RHI: patients undergoing synchronous stimulation did not report greater contamination sensations when the fake hand was initially contaminated relative to asynchronous stroking. But contrary to expectations, they did so after the rubber hand had been contaminated for 5 min, as assessed disgust facial expressions (a secondary outcome) and exposure (upon discontinuing the illusion). Further, to our surprise, synchronous and asynchronous stroking induced an equally vivid and fast-emerging illusion, which helps explain why both conditions initially (5 min after initiating tactile stimulation) provoked contamination reactions of equal magnitude. This study is the first to suggest heightened malleability of body image in OCD. Importantly, it may pave the way for a tolerable technique for the treatment of OCD-highly suitable for poorly resourced and emergency settings, including low-income and developing countries with minimal access to high-tech solutions like virtual reality.
强迫症（OCD）是一种极具谜团的精神疾病，在全球范围内给患者带来巨大痛苦。针对强迫症的有效疗法，如暴露与反应阻止疗法（ERP），有时患者耐受性较差。多达25%的患者拒绝开始接受ERP治疗，主要原因是他们过于焦虑而无法遵循暴露程序。因此，我们提出了一种简单且耐受性良好（沉浸式但间接）的低成本技术来治疗强迫症，我们称之为“多感官刺激疗法”。该方法涉及在所谓的“橡胶手错觉”（RHI）过程中弄脏一只橡胶手，在此过程中触觉感受可能被感知为来自一只假手。值得注意的是，贾拉尔等人（2015年）表明，在RHI过程中对假手的这种弄脏会在健康志愿者中引发强烈的厌恶反应。在本研究中，我们探索了这种新方法的治疗潜力。29名强迫症患者观看他们隐藏的真实手部与一只可见的假手一起被抚摸；要么同步进行（诱发RHI，即实验条件，16名患者），要么异步进行（即对照条件，13名患者）。在进行5分钟的触觉刺激后，橡胶手被假粪便弄脏，模拟传统的暴露疗法。有趣的是，结果表明污染感觉在身体意象中进行了感觉同化——在RHI中：相对于异步抚摸，接受同步刺激的患者在假手最初被弄脏时并未报告更强烈的污染感觉。但与预期相反，在橡胶手被弄脏5分钟后，根据厌恶面部表情（一个次要结果）和暴露情况（在错觉停止时）评估，他们报告了更强烈的污染感觉。此外，令我们惊讶的是，同步和异步抚摸诱发了同样生动且迅速出现的错觉，这有助于解释为什么两种条件在最初（开始触觉刺激5分钟后）引发了同等程度的污染反应。这项研究首次表明强迫症患者身体意象具有更高的可塑性。重要的是，它可能为一种耐受性良好的强迫症治疗技术铺平道路——这种技术非常适合资源匮乏和紧急情况的环境，包括那些难以获得虚拟现实等高科技解决方案的低收入和发展中国家。
