分类： 心理学 >> 发展心理学 提交时间： 2021-02-25
摘要： The neural mechanism of orthographic-phonological integration was influenced by the temporal relationship of cross-modal stimuli. However, previous studies mainly investigated the neural mechanism of letter-speech sound integration in precise temporal synchrony or small temporal asynchrony conditions. In this study, character-speech sound integration was investigated in a relatively wide temporal window. Chinese characters were presented synchronously to the onset of speech sounds or before speech sound by 300 or 600 ms (referred as AV0, AV300 and AV600). ERP responses evoked by congruent condition (speech sounds were paired with congruent visual characters) and baseline condition (speech sounds were paired with Korean characters) were compared. Different electrophysiological markers were found in the temporal synchrony and temporal asynchrony conditions. In the AV0 condition, developing dyslexia (DD) and typically developing (TD) children showed similar congruency effect on P1, N170 and N300 components, demonstrating the influence of speech sound on visual character processing. In the AV300 condition, DD group showed left-lateralized congruency effect on N200, whereas TD children showed bilateral congruency effect on N200. Both groups showed bilateral congruency effect on N200 in the AV600 condition. We speculate that the insufficient character-speech sound integration exhibited by dyslexic children in the AV300 condition was probably caused by their slow visual processing speed. The results provide unique insight into the neural mechanism of print-speech integration in a wide temporal window and point out the necessity to investigate neural mechanism of print-speech integration in a relatively wide temporal window.
分类： 心理学 >> 发展心理学 提交时间： 2020-10-10
摘要： Building robust letter-to-sound correspondences is a prerequisite for reading, and such audiovisual integration becomes progressively automatic with development. However, the neural mechanisms underlying the development of audiovisual integration for reading are largely unknown. This study used functional magnetic resonance imaging (fMRI) in a lexical decision task to investigate the changes of brain functional networks that support audiovisual integration for reading between normally developing children (9-12 years old) and adults (20-28 years old). The identified networks were further examined in children with developmental dyslexia (9-12 years old). Results revealed that adults enhanced connectivity in a prefrontal-superior temporal network relative to children, reflecting the attentional modulation to the development of audiovisual integration. Moreover, this network was disrupted in dyslexics, confirming its essential role in audiovisual integration for reading. This study, for the first time, elucidates the neural basis underlying the development of audiovisual integration for reading.
分类： 心理学 >> 认知心理学 提交时间： 2020-06-30
摘要： Metacognition refers to the ability to introspect our cognitive ability, which plays an essential role in guiding and optimizing our activities. However, little is known about metacognitive capacity for highly practiced motor behaviors and its neural correlates. Using structural and functional magnetic resonance imaging (MRI), the present study examined the brain substrates underlying individual differences in self-awareness of handwriting in adults, a highly practiced visuomotor skill. Results showed that adult writers generally overestimate their handwriting skill, which is more pronounced in males relative to females. The extent of overestimation of handwriting quality was positively correlated with grey matter volume in the left fusiform gyrus, right middle frontal gyrus and right precuneus. Moreover, the activation of these regions in a handwriting task was not correlation with self-awareness of handwriting, confirming that the identified connection between brain structures and handwriting self-awareness is independent of task performances. The left fusiform gyrus and right middle frontal gyrus are thought to represent domain-specific brain mechanisms for handwriting self-awareness, while the right precuneus is likely to be a domain-general brain mechanism, suggesting that the ability of introspect practiced visuomotor skills relies on both domain-general and domain-specific brain systems. Together, this study is the first to reveal the neuroanatomical correlates of a highly practiced motor behavior, extending our understanding about the neural basis of human metacognition.
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