Neural competition as a developmental process: Early hemispheric specialization for word processing delays specialization for face processing

• Published in: Neuropsychologia Vol. 51; no. 5; pp. 950 - 959
• Main Authors: Li, Su, Lee, Kang, Zhao, Jing, Yang, Zhi, He, Sheng, Weng, Xuchu
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.04.2013; Elsevier
• Subjects: Age Factors; Analysis of Variance; Behavioral psychophysiology; Biological and medical sciences; Brain - growth & development; Brain Mapping; Child; Child development; Child, Preschool; Developmental psychology; Dominance, Cerebral - physiology; Electroencephalography; Electrophysiology; ERP; Evoked Potentials, Visual - physiology; Face; Face processing; Female; Fundamental and applied biological sciences. Psychology; Humans; Male; Neural development; Pattern Recognition, Visual - physiology; Photic Stimulation; Psychology. Psychoanalysis. Psychiatry; Psychology. Psychophysiology; Reaction Time; Reading; Spectrum Analysis; Visual word processing; Vocabulary; ERP; Face processing; Visual word processing; Neural development; Competition; Word; Central nervous system; Electrophysiology; Cognition; Encephalon; Language; Development; Face; Child; Preschool age; Human; Hemispheric specialization; Experimental study; Time lag; School age; Vision; Information processing; Perception; Early; Event evoked potential
• ISSN: 0028-3932; 1873-3514
• DOI: 10.1016/j.neuropsychologia.2013.02.006

Little is known about the impact of learning to read on early neural development for word processing and its collateral effects on neural development in non-word domains. Here, we examined the effect of early exposure to reading on neural responses to both word and face processing in preschool children with the use of the Event Related Potential (ERP) methodology. We specifically linked children's reading experience (indexed by their sight vocabulary) to two major neural markers: the amplitude differences between the left and right N170 on the bilateral posterior scalp sites and the hemispheric spectrum power differences in the γ band on the same scalp sites. The results showed that the left-lateralization of both the word N170 and the spectrum power in the γ band were significantly positively related to vocabulary. In contrast, vocabulary and the word left-lateralization both had a strong negative direct effect on the face right-lateralization. Also, vocabulary negatively correlated with the right-lateralized face spectrum power in the γ band even after the effects of age and the word spectrum power were partialled out. The present study provides direct evidence regarding the role of reading experience in the neural specialization of word and face processing above and beyond the effect of maturation. The present findings taken together suggest that the neural development of visual word processing competes with that of face processing before the process of neural specialization has been consolidated. ► The effect of early reading on neural responses to word and face stimuli was examined. ► The greater the amount of word knowledge, the greater the left-lateralization of word N170 and γ band power. ► The word N170 left-lateralization had a negative effect on the face N170 right-lateralization. ► Children's sight vocabulary had a negative effect on the face N170 right-lateralization. ► The neural development of word processing competes with that of face processing in preschool years.