title: Sight restoration after congenital blindness does not reinstate alpha oscillatory activity in humans.
abstract: Functional brain development is characterized by sensitive periods during which experience must be available to allow for the full development of neural circuits and associated behavior. Yet, only few neural markers of sensitive period plasticity in humans are known. Here we employed electroencephalographic recordings in a unique sample of twelve humans who had been blind from birth and regained sight through cataract surgery between four months and 16 years of age. Two additional control groups were tested: a group of visually impaired individuals without a history of total congenital blindness and a group of typically sighted individuals. The EEG was recorded while participants performed a visual discrimination task involving intact and scrambled biological motion stimuli. Posterior alpha and theta oscillations were evaluated. The three groups showed indistinguishable behavioral performance and in all groups evoked theta activity varied with biological motion processing. By contrast, alpha oscillatory activity was significantly reduced only in individuals with a history of congenital cataracts. These data document on the one hand brain mechanisms of functional recovery (related to theta oscillations) and on the other hand, for the first time, a sensitive period for the development of alpha oscillatory activity in humans.
authors.affiliation: Biological Psychology and Neuropsychology, University of Hamburg, Von-Melle-Park 11 20146 Hamburg, Germany.
authors.forename: Davide
authors.initials: D
authors.lastname: Bottari
authors.affiliation: Department of Psychology, Queen's University, 62 Arch Street, K7L 3N6 Kingston, Ontario, Canada.|Canadian Institute for Advanced Research, 180 Dundas Street West, Suite 1400, M5G 1Z8 Toronto, Ontario, Canada.
authors.forename: Nikolaus F
authors.initials: NF
authors.lastname: Troje
authors.affiliation: Biological Psychology and Neuropsychology, University of Hamburg, Von-Melle-Park 11 20146 Hamburg, Germany.
authors.forename: Pia
authors.initials: P
authors.lastname: Ley
authors.affiliation: Biological Psychology and Neuropsychology, University of Hamburg, Von-Melle-Park 11 20146 Hamburg, Germany.
authors.forename: Marlene
authors.initials: M
authors.lastname: Hense
authors.affiliation: Jasti V Ramanamma Children's Eye Care Center, LV Prasad Eye Institute, Kallam Anji Reddy Campus, L V Prasad Marg, Banjara Hills, 500 034 Hyderabad, Andhra Pradesh, India.
authors.forename: Ramesh
authors.initials: R
authors.lastname: Kekunnaya
authors.affiliation: Biological Psychology and Neuropsychology, University of Hamburg, Von-Melle-Park 11 20146 Hamburg, Germany.
authors.forename: Brigitte
authors.initials: B
authors.lastname: Röder
mesh_terms: D000293:Adolescent; D000328:Adult; D001766:Blindness / Q000151:congenital* / Q000503:physiopathology / Q000601:surgery; D002648:Child; D004569:Electroencephalography; D005074:Evoked Potentials, Visual; D005260:Female; D006801:Humans; D008297:Male; D010775:Photic Stimulation; D013647:Task Performance and Analysis; D014785:Vision, Ocular; D055815:Young Adult