تفاوت‌های آگاهی از قصدِ عمل و مولفه‌های پتانسیل آمادگی در حرکات خودآگاه ارادی در افراد دارای اختلال بولیمیا

مقدمه: در این پژوهش با اتکا به روشِ libet تفاوتِ وضعیت آمادگی یا پتانسیل آمادگی در یک عمل ارادی، همچنین زمان ادراک شده از قصدِ عمل و زمان ادراک شده از انجام آن عمل بین دو گروه مبتلا به اختلال بولیمیا و گروه عادی فاقد اختلال مورد مطالعه قرار گرفت. روش کار: 36 آزمودنی‌ (19 نفر دارای اختلال بولیمیا و 17 نفر عادی فاقد اختلال) در دو بلوک 40 تلاشی شرکت داده شدند. در هر دو بلوک از آزمودنی ‌ها خواسته می ‌شد با توجه به عقربۀ ساعت libet هر وقت که خواستند دکمه ای را فشار دهند. در بلوک اول آزمودنی‌ها زمان ادراک قصد برای عملِ فشار دادن کلید و در بلوک دوم زمان ادراک خود عمل فشار دادن کلید را گزارش دادند و همزمان اطلاعات مربوط به مولفه‌های قله و هِنگامه الکتروآنسفالوگرافیِ آنها برای 64 کانال ثبت گردید. یافته ‌ها: یافته‌ها نشان داد که هیچ گونه تفاوت معناداری بین دو گروه از لحاظ زمان ادراک قصد و میل فشار دادن کلید و زمان ادراکِ عملِ فشار دادن کلید وجود نداشت. اما نتایج حاصله از داده‌های الکتروآنسفالوگرافی در مولفه قلۀ بلوک ادراک قصد و میل در کانال‌های 1cp، 5cp و pz تفاوت معناداری بین دو گروه واجد اختلال بولیمیا و فاقد اختلال (عادی) نشان داد. نتیجه‌ گیری: با توجه به این که کانال‌های معنادار شده بین دو گروه، با بخش آهیانۀ مغز مرتبط هستند، این یافته‌ها نشان می‌دهند که آگاهی از قصد و میل انجام عمل در افراد مبتلا به اختلال بولیمیا در سطح عصب‌شناختی دچار اشکال است.

Differences on “Awareness of willing to act” and “Readiness Potential” components in voluntary actions in bulimia nervosa

Introduction: Voluntary actions are preceded by neuroelectrophysiological ldquo;Bereitschaftspotential (BP) or Readiness Potential rdquo; (RP). The Readiness Potential (RP) is a slow negative shift in neuroelectrical potential generated by the brain that begins at about a second or more before a selfpaced voluntary motor act. Benjamin Libet rsquo;s famous experimental findings led us to conclude that voluntary acts can be initiated by unconscious cerebral processes before any conscious ldquo;willing or intention to act rdquo; appears. This empirical finding strongly challenges the old notion of ldquo;free will rdquo; which argued that the conscious intention or free will initiates the onset of the specific cerebral processes that mediate the act. Later researchers have found that RPs were absent or reduced in brain illnesses like Parkinson disease and some mental disorders like Tourette rsquo;s syndrome. Based on Libet rsquo;s method, the present study aimed to examine the differences of Readiness Potential rsquo;s components (Peak and latency) among persons with bulimia Nervosa compared to the control (normal) group. Also, this research investigated and compared the perceived time of willing to action (W time) and the perceived time of action itself (M time) between the groups. Bulimia nervosa, as a mental health condition and an eating disorder, is characterized by eating much food and then taking inappropriate steps to prevent weight gain, such as vomiting or misusing laxatives. People living with bulimia feel that they are not in control of how much food they consume during an episode of binge eating and subsequent purging, which usually occurs at least once a week. Binge eating refers to eating a large amount of food in a short amount of time. Purging refers to the attempts to get rid of the food or calories consumed.Methods: Thirtysix subjects (19 with bulimia and 17 normal) participated in two 40 trial blocks. In the two blocks, subjects were asked to press a key at any time they felt the ldquo;willing rdquo; or desire to do so. In the first block, subjects reported the perceived time of will to act of pressing the key, (W) and in the second block, they reported the time of pressing the key itself (M). Reports of W time (in the first block) and M time (in the second block) depended upon the subject rsquo;s recall of the spatial Libet rsquo;s clock position of a revolving spot at the time of her/his initial awareness of doing (M)/intending (W) to press the key. During all procedures the 64channels EEG was recorded.Results: Results showed that no significant differences in ldquo;W time rdquo; and ldquo;M time rdquo; between the groups. Nevertheless, EEG data from the ldquo;W block rdquo; showed a significant difference between the bulimia and normal groups in the ldquo;peak component rdquo; of CP1, CP5 and PZ Channels. Peak components of these channels were more significant in the bulimia group than in the normal one.Conclusion: As these significant channels are related to the parietal lobe, and the parietal lobe is related to awareness of willing to act, the current study rsquo;s findings show that the awareness of will and intention to act among persons with bulimia nervosa is disturbed at the neuroscientific level.