Assessment of executive functions for children with developmental disorders : Using behavioral and physiological measures

本研究旨在探讨健康成人、典型发育儿童和发育障碍儿童在言语流畅性任务中执行功能的性质。言语流畅性任务是临床和实验认知功能检测中应用最广泛的神经心理学测验之一。通常，参与者被要求口头生成尽可能多的以给定字母开头的单词（例如，F）或给定类别（例如，动物在有限的时间内。采用对执行功能和额叶功能敏感的语音流畅性任务。在针对健康成年人的研究I中，我们通过使用“易”和“难”字母以及作为时间函数的提取效能来检验词汇量效应。在言语流畅性测试中获得了两个行为指标（回忆项目总数和提取率随时间的变化），并获得了两个生理指标（事件相关电位听觉oddball范式的P3波幅和潜伏期）。提取率的时间变化与额叶P3波幅呈显著负相关，这支持了言语流畅性任务中提取率的时间变化能充分反映执行功能和额叶功能的假设。在研究II中，发育障碍儿童的提取率随时间的变化与一般智力水平有关。研究三以典型发展的小学低年级儿童为被试，发现不同年级儿童的时间提取率的变化规律不同。

The aim of this study was to investigate the nature of executive functions on verbal fluency task in healthy adults, typically developing children, and children with developmental disorders. Verbal fluency task is one of the most widely employed neuropsychological tests in clinical and experimental examinations of cognitive function. Typically, participants are asked to generate orally as many words as possible beginning with a given letter (e.g., F) or of a given category (e.g., animals) within a limited time period. We adopted phonological verbal fluency task known to be sensitive to executive functions and frontal lobe functions. In Study I for healthy adults, we examined the vocabulary-size effect by using "easy" and "hard" letters and retrieval efficacy as a function of time. We obtained two behavioral measures in verbal fluency test (total number of recalled items and change of retrieval rate in time), and obtained two physiological indices (P3 amplitude and latency from auditory oddball paradigm in event-related potentials). Significant negative correlation between change of retrieval rate in time and frontal P3 amplitude was found. It supports the assumption that change of retrieval rate in time during verbal fluency task adequately reflects executive functions and frontal lobe functions. In Study II for children with developmental disorders, change of retrieval rate in time was related with level of general intelligence. In Study III for typically developing children in the lower grades of elementary school, it can be prove that the shift patterns of retrieval rate in time were different as their grade level.