en رويكرد عصب زيست شناختي Approach to biological neural پژوهشي Original Research Article <p dir="ltr" style="text-align: justify"><strong style="text-align: justify line-height: 20.8px">Objective:</strong><span style="text-align: justify line-height: 20.8px">&nbsp;Recent studies on treating obsessive compulsive disorder (OCD) have investigated&nbsp;noninvasive brain stimulation techniques such as transcranial direct current stimulation (tDCS)&nbsp;to improve patients&rsquo; impaired emotion and cognition. However, such experiments have yielded&nbsp;mixed results, especially with respect to cognition. This study aimed to investigate whether&nbsp;anodal and cathodal tDCS applied over the dorsolateral prefrontal cortex (DLPFC) would&nbsp;improve decision making and reduce obsession symptoms in patients with OCD.</span><br style="text-align: justify line-height: 20.8px" > <strong style="text-align: justify line-height: 20.8px">Methods:</strong><span style="text-align: justify line-height: 20.8px">&nbsp;the current study is analysis of variance. In this regard, 20 patients with obsessive&nbsp;compulsive disorder (n=20) were randomly assigned to receive either experimental (active) or&nbsp;control (sham) tDCS. To measure cognitive functions, the participants underwent a series of&nbsp;decision making neuropsychological tasks to measure obsession symptoms, the Yale-brown</span><br style="text-align: justify line-height: 20.8px" > <span style="text-align: justify line-height: 20.8px">obsessive compulsive and Beck anxiety scale (BAI) were used. The parameters of active&nbsp;tDCS included administration of 2 mA for 20 minutes per day for 15 consecutive days, anode&nbsp;electrode over the right DLPFC (F4), and cathode electrode over the left DLPFC (F3) region.</span><br style="text-align: justify line-height: 20.8px" > <strong style="text-align: justify line-height: 20.8px">Results:</strong><span style="text-align: justify line-height: 20.8px">&nbsp;After 10 sessions of anodal and cathodal tDCS, patients showed significant&nbsp;improvement in decision making tasks. The same results were observed for obsession&nbsp;symptoms.</span><br style="text-align: justify line-height: 20.8px" > <strong style="text-align: justify line-height: 20.8px">Conclusion:</strong><span style="text-align: justify line-height: 20.8px">&nbsp;The data were analyzed by SPSS 18.0.0 software, using analysis of variance&nbsp;methods.This study demonstrated that anodal tDCS over left DLPFC, concurrent with cathodal&nbsp;tDCS over right DLPFC, improved cognitive impairment and reduced obsession symptoms in&nbsp;patients with OCD.</span></p> Obsessive compulsive disorder, Decision making, Transcranial direct current stimulation (tDCS) 185 194 http://jpcp.uswr.ac.ir/browse.php?a_code=A-10-259-2&slc_lang=en&sid=1 Mehrnaz Yekta mehrnaz.yekta@gmail.com Yes Department of Psychology, Faculty of Psychology and Education, University of Tehran, Tehran, Iran. Reza Rostami rrostami@ut.ac.ir No Organization Elham Fayyaz fayyazelham@ gmail.com No Organization