Assessment of tonotopically organised subdivisions in human auditory cortex using volumetric and surface-based cortical alignments

Langers, Dave R.M. (2014) Assessment of tonotopically organised subdivisions in human auditory cortex using volumetric and surface-based cortical alignments. Human Brain Mapping, 35 (4). pp. 1544-1561. ISSN 1065-9471

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Abstract

Although orderly representations of sound frequency in the brain play a guiding role in the investigation of auditory processing, a rigorous statistical evaluation of cortical tonotopic maps has so far hardly been attempted. In this report, the group-level significance of local tonotopic gradients was assessed using mass-multivariate statistics. The existence of multiple fields on the superior surface of the temporal lobe in both hemispheres was shown. These fields were distinguishable on the basis of tonotopic gradient direction and may likely be identified with the human homologues of the core areas AI and R in primates. Moreover, an objective comparison was made between the usage of volumetric and surface-based registration methods. Although the surface-based method resulted in a better registration across subjects of the grey matter segment as a whole, the alignment of functional subdivisions within the cortical sheet did not appear to improve over volumetric methods. This suggests that the variable relationship between the structural and the functional characteristics of auditory cortex is a limiting factor that cannot be overcome by morphology-based registration techniques alone. Finally, to illustrate how the proposed approach may be used in clinical practice, the method was used to test for focal differences regarding the tonotopic arrangements in healthy controls and tinnitus patients. No significant differences were observed, suggesting that tinnitus does not necessarily require tonotopic reorganisation to occur

Item Type: Article
Keywords: topographic maps; tonotopy;cochleotopy; auditory cortex; functional magnetic resonance imaging (fMRI); registration; tinnitus; plasticity
Schools/Departments: University of Nottingham UK Campus > Faculty of Medicine and Health Sciences > School of Medicine > Division of Clinical Neuroscience
Identification Number: https://doi.org/10.1002/hbm.22272
Depositing User: Liu, Mr Zhenxing
Date Deposited: 07 Apr 2014 09:49
Last Modified: 16 Sep 2016 16:33
URI: http://eprints.nottingham.ac.uk/id/eprint/2569

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