Hearing Loss and Central Auditory Processing

66 Sound Identity vs. Location

Learning Objectives

Know what “what” and “where” pathways represents.

Be able to describe their technical names.

Be able to discuss evidence for how these pathways were discovered.

Beyond the cortical representation of the A1 (labeled AC in the figure below) and the belt area lies the “what” and “where” pathways of the ear. Through modern neuroimaging studies as well as lesion studies, we know sound identity is represented in a more ventral extended network whereas sound location is represented in a more dorsal extended network. The following paragraph is from the OpenStax textbook on visual processing, but the general principles apply to auditory processing, as well!

 

The dorsal auditory pathway carries information through the parietal cortex to the temporal cortex and the ventral stream carries information through the temporal cortex to the parietal cortex.
Fig.6.13.1 Model of dual-stream auditory processing in the primate brain, from Rauschecker (2011). Dorsal (red) and ventral (green) auditory pathways are shown in the human brain. Solid arrows indicate ascending projections from auditory cortex, while dashed arrows indicate reciprocal projections back to the auditory cortex. AC, auditory cortex; AL/CL, anterolateral/caudolateral superior temporal gyrus; CS, central sulcus; DLPFC, dorsolateral prefrontal cortex; IFC, inferior frontal cortex; IPL, inferior parietal lobule; IPS, inferior parietal sulcus; PFC, prefrontal cortex; PMC, premotor cortex; STS, superior temporal sulcus; VLPFC, ventrolateral prefrontal cortex. (Credit: Aniruddh D. Patel, and John R. Iversen. Provided by: Wikipedia. License: CC BY 3.0 Modifications: Modified to only show panel B, the human brain).

The ventral stream identifies visual stimuli and their significance. Because the ventral stream uses temporal lobe structures, it begins to interact with the non-sensory cortex and may be important in visual stimuli becoming part of memories. The dorsal stream locates objects in space and helps in guiding movements of the body in response to visual inputs. The dorsal stream enters the parietal lobe, where it interacts with somatosensory cortical areas that are important for our perception of the body and its movements. The dorsal stream can then influence frontal lobe activity where motor functions originate.

If you would like to learn more about neuroimaging and lesion studies that provided evidence for the “what” and “where” pathways, here is a link to a scholar-edit article that gives an in-depth overview.

License: CC BY 4.0CC LICENSED CONTENT, SHARED PREVIOUSLYOpenStax, Anatomy and Physiology Chapter 14.2 Central Processing
Provided by: Rice University.
Download for free at https://openstax.org/books/anatomy-and-physiology/pages/14-2-central-processing
License: CC Attribution 4.0
References:
Ungerleider, L. G., & Pessoa, L. (2008). What and where pathways. Scholarpedia, 3(11). https://doi.org/10.4249/scholarpedia.5342.

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Introduction to Sensation and Perception Copyright © 2022 by Students of PSY 3031 and Edited by Dr. Cheryl Olman is licensed under a Creative Commons Attribution 4.0 International License, except where otherwise noted.

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