title: Cross-modal activation of auditory regions during visuo-spatial working memory in early deafness.
abstract: Early deafness can reshape deprived auditory regions to enable the processing of signals from the remaining intact sensory modalities. Cross-modal activation has been observed in auditory regions during non-auditory tasks in early deaf subjects. In hearing subjects, visual working memory can evoke activation of the visual cortex, which further contributes to behavioural performance. In early deaf subjects, however, whether and how auditory regions participate in visual working memory remains unclear. We hypothesized that auditory regions may be involved in visual working memory processing and activation of auditory regions may contribute to the superior behavioural performance of early deaf subjects. In this study, 41 early deaf subjects (22 females and 19 males, age range: 20-26 years, age of onset of deafness < 2 years) and 40 age- and gender-matched hearing controls underwent functional magnetic resonance imaging during a visuo-spatial delayed recognition task that consisted of encoding, maintenance and recognition stages. The early deaf subjects exhibited faster reaction times on the spatial working memory task than did the hearing controls. Compared with hearing controls, deaf subjects exhibited increased activation in the superior temporal gyrus bilaterally during the recognition stage. This increased activation amplitude predicted faster and more accurate working memory performance in deaf subjects. Deaf subjects also had increased activation in the superior temporal gyrus bilaterally during the maintenance stage and in the right superior temporal gyrus during the encoding stage. These increased activation amplitude also predicted faster reaction times on the spatial working memory task in deaf subjects. These findings suggest that cross-modal plasticity occurs in auditory association areas in early deaf subjects. These areas are involved in visuo-spatial working memory. Furthermore, amplitudes of cross-modal activation during the maintenance stage were positively correlated with the age of onset of hearing aid use and were negatively correlated with the percentage of lifetime hearing aid use in deaf subjects. These findings suggest that earlier and longer hearing aid use may inhibit cross-modal reorganization in early deaf subjects. Granger causality analysis revealed that, compared to the hearing controls, the deaf subjects had an enhanced net causal flow from the frontal eye field to the superior temporal gyrus. These findings indicate that a top-down mechanism may better account for the cross-modal activation of auditory regions in early deaf subjects.See MacSweeney and Cardin (doi:10/1093/awv197) for a scientific commentary on this article.
authors.affiliation: 1 Department of Biomedical Engineering, Tianjin University, Tianjin 300072, People's Republic of China chunshuiyu@tijmu.edu.cn.
authors.forename: Hao
authors.initials: H
authors.lastname: Ding
authors.affiliation: 2 Department of Radiology and Tianjin Key Laboratory of Functional Imaging, Tianjin Medical University General Hospital, Tianjin 300052, People's Republic of China.
authors.forename: Wen
authors.initials: W
authors.lastname: Qin
authors.affiliation: 3 School of Medical Imaging, Tianjin Medical University, Tianjin 300070, People's Republic of China.
authors.forename: Meng
authors.initials: M
authors.lastname: Liang
authors.affiliation: 1 Department of Biomedical Engineering, Tianjin University, Tianjin 300072, People's Republic of China.
authors.forename: Dong
authors.initials: D
authors.lastname: Ming
authors.affiliation: 1 Department of Biomedical Engineering, Tianjin University, Tianjin 300072, People's Republic of China.
authors.forename: Baikun
authors.initials: B
authors.lastname: Wan
authors.affiliation: 4 Technical College for the Deaf, Tianjin University of Technology, Tianjin 300384, People's Republic of China.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Li
authors.affiliation: 2 Department of Radiology and Tianjin Key Laboratory of Functional Imaging, Tianjin Medical University General Hospital, Tianjin 300052, People's Republic of China chunshuiyu@tijmu.edu.cn.
authors.forename: Chunshui
authors.initials: C
authors.lastname: Yu
mesh_terms: D000161:Acoustic Stimulation; D000328:Adult; D001306:Auditory Pathways / Q000098:blood supply / Q000473:pathology*; D001307:Auditory Perception / Q000502:physiology; D001921:Brain / Q000098:blood supply / Q000473:pathology*; D003638:Deafness / Q000473:pathology* / Q000503:physiopathology*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008570:Memory, Short-Term / Q000502:physiology*; D010100:Oxygen / Q000097:blood; D010775:Photic Stimulation; D065853:Spatial Learning / Q000502:physiology*; D018709:Statistics, Nonparametric; D014796:Visual Perception / Q000502:physiology; D055815:Young Adult
chemical_list: D010100:Oxygen
keywords: early deafness; functional magnetic resonance imaging; superior temporal gyrus; visuo-spatial recognition; working memory