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ERIC Number: EJ858855
Record Type: Journal
Publication Date: 2009-Nov
Pages: 10
Abstractor: As Provided
Reference Count: 0
ISSN: ISSN-1363-755X
Asymmetrical Cortical Processing of Radial Expansioncontraction in Infants and Adults
Shirai, Nobu; Birtles, Deirdre; Wattam-Bell, John; Yamaguchi, Masami K.; Kanazawa, So; Atkinson, Janette; Braddick, Oliver
Developmental Science, v12 n6 p946-955 Nov 2009
We report asymmetrical cortical responses (steady-state visual evoked potentials) to radial expansion and contraction in human infants and adults. Forty-four infants (22 3-month-olds and 22 4-month-olds) and nine adults viewed dynamic dot patterns which cyclically (2.1 Hz) alternate between radial expansion (or contraction) and random directional motion. The first harmonic (F1) response in the steady-state VEP response must arise from mechanisms sensitive to the global radial motion structure. We compared F1 amplitudes between expansion-random and contraction-random motion alternations. F1 amplitudes for contraction were significantly larger than those for expansion for the older infants and adults but not for the younger infants. These results suggest that the human cortical motion mechanisms have asymmetrical sensitivity for radial expansion vs. contraction, which develops at around 4 months of age. The relation between development of sensitivity to radial motion and cortical motion mechanisms is discussed.
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Publication Type: Journal Articles; Reports - Research
Education Level: N/A
Audience: N/A
Language: English
Sponsor: N/A
Authoring Institution: N/A