بررسی و مقایسهٔ توانایی کنترل بازداری در کودکان دارای لکنت و همسالان طبیعی

زمینه و هدف: بازداری به معنای توانایی فعالانهٔ متوقف کردن یا تاخیر فعالیتی است. چندین محقق به نقش ممکن فرایندهای خودتنظیمی و فرایندهای کنترل توجه و به ویژه کنترل بازداری در رشد لکنت اشاره کرده اند. هدف این پژوهش بررسی تفاوت ها در عملکرد کنترل بازداری بین کودکان لکنتی و غیرلکنتی بود. روش بررسی: در این پژوهش مقطعی مقایسه ای، توانایی کنترل بازداری 30 کودک 7تا13سالهٔ شهر تهران با تشخیص لکنت رشدی و 30 کودک غیرلکنتی رشدیافتهٔ طبیعی که به لحاظ سن و جنس با کودکان لکنتی تطابق داشته با استفاده از تکلیف بروبایست شنیداری ارزیابی شد. تحلیل اطلاعات ازطریق آمار توصیفی تحلیلی ازجمله آزمون تی مقایسهٔ میانگین های دو گروه مستقل و آزمون من ویتنی و آزمون همبستگی پیرسون با نرم افزار spss نسخهٔ 24 صورت گرفت. در تمامی آزمون ها سطح معناداری کمتر از 0٫05در نظر گرفته شد. یافته ها: تفاوت های بین گروهی برای خطاهای ارتکاب و خطاهای بازداری نشان داد میانگین درصد خطاهای ارتکاب و بازداری در گروه لکنتی (13٫09±10٫47) و (15٫11±30٫21) درمقایسه با گروه غیرلکنتی (6٫17±8٫02) و (13٫73±24٫66) بیشتر به دست آمد؛ اما از نظر آماری تفاوت های معناداری نداشت. همچنین میانگین زمان واکنش بیشتری، در گروه لکنتی (73٫9±627٫06) درمقایسه با گروه غیرلکنتی (53٫37±615٫4) مشاهده شد؛ ولی این تفاوت میانگین در کودکان لکنتی و غیرلکنتی از نظر آماری معنادار نبود. نتیجه گیری: نتایج این پژوهش براساس تکلیف بروبایست شنیداری، مشخص کرد کودکان لکنتی و غیرلکنتی در کنترل بازداری تفاوت معناداری ندارند. بین دو گروه کودکان دارای لکنت و غیرلکنتی در متغیرهای ارتکاب و بازداری و زمان واکنش تفاوت معناداری مشاهده نشد.

Comparison of the Inhibitory Control Ability in Children with Stuttering and Normal Peers

Background & Objective: Inhibition refers to the ability to actively suppress, interrupt or delay an action. Several authors have shown a possible role for self–regulatory processes, attentional control processes, and more specifically inhibitory control in the development of stuttering. Inhibition control (IC) is essential for doing daily tasks and implicate in cognitive development, executive functioning and the conscious use of attention or attentional control. Inhibition control relates to the coordination and integration of mental processes in successful task doing and plays an important role in the self–regulation of emotional states. Children who stutter (CWS) have low adaptability, lower in biological rhythmicity and less efficient in emotional regulation. Based on role of IC in speech motor planning and production, study in this field is important. The aim of this study was to investigate differences in inhibitory control performance between CWS and children who not stutter (CWNS).Methods: This cross sectional study investigated inhibitory control ability of 30 children diagnosed with developmental stuttering and 30 typically developing nonstuttering children aged 7–13 in Tehran (capital city of Iran), matched by age and gender to the children who stutter. All children were monolingual speaking (Persian). All participants had normal or corrected to normal vision and normal speech and language development (except for stuttering in the experimental group), based on the criteria described below. Participants had no known or reported neurological, psychological, developmental or hearing problems. Auditory Go/No Go task was used that assess to inhibitory control in CWS and CWNS. One of two easily discriminated auditory stimuli –the low frequency tone (1000 Hz) and high frequency tone (1300 Hz) – is randomly presented for 100 milliseconds. Pairs corresponding to trials present stimuli. Inter–stimulus interval in a pair was equal to 1000 millisecond. Two different pairs of stimuli are presented only: Low–Low pair (“Go” trial) and Low–High pair (“Nogo” trial). Trials presented at random order with 50% probability. Subject has to press a button (right arrow key) as soon as possible in case of presentation of Low–Low pair and ignore Low–High pairs of stimuli. The total number of trials was equal to 480. The parameters of performance were calculated for Go and No Go condition. Data analysis in this cross sectional study was done using descriptive–analysis statistics such as independent sample T–test, Mann–Whitney test and Pearson correlation coefficient test using SPSS program 24 series.Results: Mean percentages of Commission errors and Omission errors were higher in the stuttering group (M=10.47, SD=13.09), (M=30.21, SD=15.11) than in the nonstuttering group (M=8.02, SD=6.17), (M=24.66, SD=13.73). Nevertheless, there was not any significant differences in Commission errors and Omission errors statically. The mean reaction time was higher in the stuttering group than in the nonstuttering group (M=627.06, SD=73.9) (M=615.4, SD=53.37). However, the mean reaction time for CWS and CWNS was not significantly different.Conclusion: According to results obtained in this study, based on auditory Go/No Go task, showed that CWS and CWNS not differ in inhibitory control. CWS had lower mean in inhibitory control, which suggests a lowered ability to inhibit prepotent response tendencies. The findings were showed that inhibitory control ability had important role in persistent developmental stuttering. CWS, who exhibit a lowered IC, would most likely exhibit difficulties in suppressing prepotent responses across a variety of settings (school setting, playing with a friend). Therefore it might be important to council parents that these children may have more difficulties dealing with everyday situations requiring response inhibition (following instructions, waiting for something, ending an activity), resulting in increased emotional arousal.