作業難度與智力神經效率假說：資優兒童與一般兒童在語意句法判斷作業之差異

Task Difficulty and Neural Efficiency Hypothesis of Intelligence: Differences of Semantic-Syntactic Error Detection between Gifted and Non-Gifted Children

"從跨文化的證據看來，神經效率假說支持資優兒童在語言能力方面是較早成熟的，在不同的作業表現中發現兒童的神經電訊反應與智力有關連。本研究為探試神經效率假說，設計語意句法判斷實驗來瞭解資優兒童處理語言句子的能力，透過腦磁儀蒐集受試者的大腦神經反應並進行事件相關磁場的分析。實驗過程中受試者必須判斷句尾語氣詞正確與否，亦即語氣詞符合句子（一致情境）或是不符合句子（不一致情境）之語意，及受試者須判斷語詞是否有出現在句子中的回憶作業（填充情境）。 研究對象為國小19位智能資優兒童（資優組）與15位一般兒童（控制組），分析方式採排序t 檢定進行兩兩比較，考驗組間與組內的事件相關磁場差異，疊代次數設定為1000，使用雙尾考驗且顯著水準需小於.05。在組內比較分析發現，資優組在刺激出現後的400毫秒與600毫秒的時間點附近有較強的腦磁振幅，但是控制組僅在600毫秒出現較強的腦磁振幅。在組間比較中，發現不一致情境減去填充情境的事件相關磁場在刺激出現後的650毫秒右枕葉區有組間的顯著差異，腦磁圖顯示資優組兒童在枕顳葉區明顯有強大的磁流；不過，在不一致情境減掉一致情境與一致情境減填充情境的分析過程中，並沒有發現組間有其他顯著差異。 本研究發現在語意句法判斷作業中，資優兒童與一般兒童相比之下，資優兒童的大腦磁流反應較強，尤其是在刺激後較晚的時間點。因此，當提出智力的神經效率假設時，需要考量作業的複雜性或難度，如同此研究結果顯示複雜的任務可能會讓大腦網絡進行更深層次的處理，並且資優兒童表現出比一般兒童更多的大腦活化。"

Gifted children are precocious in verbal abilities. While the neural efficiency hypothesis of intelligence has supporting evidence across cultures, electrophysiological responses associated with intelligence varied in children with different intellectual levels on various tasks. To test the hypothesis by components of the event-related field (ERF) on gifted children, we used a semantic-and-syntactic error detection task to study sentence processing in language comprehension. Three types of determiner-particle final sentences were presented visually to subjects in this magnetoencephalography (MEG) experiment: the congruent (a correct particle with a detection task), incongruent (an incorrect particle with a detection task), and filler (a correct particle followed by a word recall task) conditions. To detect different waveforms within and between the gifted group (GT) (N = 19) and non-gifted group (NG) (N = 15), the permutation t tests (iteration: 1000; p = .05; two tailed) were adopted to compare the ERF of the two groups. For the within group comparison, the NG group showed stronger amplitudes only around 600 ms, while the GT group had early components closed to 400 ms and the late time-window around 600ms. For the incongruent-subtract-filler comparison, a significant ERF difference was found between the two groups at a late time window around 650 ms in the right occipital channel. The topography revealed stronger current in the occipito-temporal region for the GT group during this time-window. In contrast, no statistically significant difference was found by comparing incongruent-subtractcongruent (IC) and congruent-subtract-filler (CF) conditions. Interestingly, this study showed that responses of gifted children had stronger magnetic current at a late time point compared to children with average IQ in the semantic-syntactic judgment task. These results indicate the complex task might engage deeper processing in a brain network and that gifted individuals show greater brain activation than their average peers. Task complexity or difficulty needs to be taken into consideration when the neural efficiency hypothesis of intelligence is proposed.