title: Testing the dual-pathway model for auditory processing in human cortex.
abstract: Analogous to the visual system, auditory information has been proposed to be processed in two largely segregated streams: an anteroventral ("what") pathway mainly subserving sound identification and a posterodorsal ("where") stream mainly subserving sound localization. Despite the popularity of this assumption, the degree of separation of spatial and non-spatial auditory information processing in cortex is still under discussion. In the present study, a statistical approach was implemented to investigate potential behavioral dissociations for spatial and non-spatial auditory processing in stroke patients, and voxel-wise lesion analyses were used to uncover their neural correlates. The results generally provided support for anatomically and functionally segregated auditory networks. However, some degree of anatomo-functional overlap between "what" and "where" aspects of processing was found in the superior pars opercularis of right inferior frontal gyrus (Brodmann area 44), suggesting the potential existence of a shared target area of both auditory streams in this region. Moreover, beyond the typically defined posterodorsal stream (i.e., posterior superior temporal gyrus, inferior parietal lobule, and superior frontal sulcus), occipital lesions were found to be associated with sound localization deficits. These results, indicating anatomically and functionally complex cortical networks for spatial and non-spatial auditory processing, are roughly consistent with the dual-pathway model of auditory processing in its original form, but argue for the need to refine and extend this widely accepted hypothesis.
authors.affiliation: Center of Neurology, Division of Neuropsychology, Hertie Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany.
authors.forename: Ida C
authors.initials: IC
authors.lastname: Zündorf
authors.affiliation: Department of Cognitive Psychology, Institute of Cognitive Neuroscience, Faculty of Psychology, Ruhr University Bochum, Bochum, Germany; Leibniz Research Centre for Working Environment and Human Factors, Dortmund, Germany.
authors.forename: Jörg
authors.initials: J
authors.lastname: Lewald
authors.affiliation: Center of Neurology, Division of Neuropsychology, Hertie Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany; Department of Psychology, University of South Carolina, Columbia, SC 29208, USA. Electronic address: Karnath@uni-tuebingen.de.
authors.forename: Hans-Otto
authors.initials: HO
authors.lastname: Karnath
mesh_terms: D000328:Adult; D000368:Aged; D001301:Audiometry, Pure-Tone; D001306:Auditory Pathways / Q000503:physiopathology*; D001307:Auditory Perception; D001921:Brain / Q000473:pathology / Q000503:physiopathology; D002540:Cerebral Cortex / Q000503:physiopathology*; D005108:Extinction, Psychological; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D010468:Perceptual Disorders / Q000503:physiopathology / Q000523:psychology; D010775:Photic Stimulation; D011597:Psychomotor Performance; D013017:Sound Localization; D020521:Stroke / Q000473:pathology / Q000503:physiopathology / Q000523:psychology; D014057:Tomography, X-Ray Computed
keywords: Auditory processing; Dual-pathway hypothesis; Human; Lesion analysis; Sound identification; Sound localization; Stroke