Columnar Segregation of Magnocellular and Parvocellular Streams in Human Extrastriate Cortex

DSpace/Manakin Repository

Columnar Segregation of Magnocellular and Parvocellular Streams in Human Extrastriate Cortex

Citable link to this page

 

 
Title: Columnar Segregation of Magnocellular and Parvocellular Streams in Human Extrastriate Cortex
Author: Tootell, Roger B.H.; Nasr, Shahin

Note: Order does not necessarily reflect citation order of authors.

Citation: Tootell, Roger B.H., and Shahin Nasr. 2017. “Columnar Segregation of Magnocellular and Parvocellular Streams in Human Extrastriate Cortex.” The Journal of Neuroscience 37 (33): 8014-8032. doi:10.1523/JNEUROSCI.0690-17.2017. http://dx.doi.org/10.1523/JNEUROSCI.0690-17.2017.
Full Text & Related Files:
Abstract: Magnocellular versus parvocellular (M-P) streams are fundamental to the organization of macaque visual cortex. Segregated, paired M-P streams extend from retina through LGN into V1. The M stream extends further into area V5/MT, and parts of V2. However, elsewhere in visual cortex, it remains unclear whether M-P-derived information (1) becomes intermixed or (2) remains segregated in M-P-dominated columns and neurons. Here we tested whether M-P streams exist in extrastriate cortical columns, in 8 human subjects (4 female). We acquired high-resolution fMRI at high field (7T), testing for M- and P-influenced columns within each of four cortical areas (V2, V3, V3A, and V4), based on known functional distinctions in M-P streams in macaque: (1) color versus luminance, (2) binocular disparity, (3) luminance contrast sensitivity, (4) peak spatial frequency, and (5) color/spatial interactions. Additional measurements of resting state activity (eyes closed) tested for segregated functional connections between these columns. We found M- and P-like functions and connections within and between segregated cortical columns in V2, V3, and (in most experiments) area V4. Area V3A was dominated by the M stream, without significant influence from the P stream. These results suggest that M-P streams exist, and extend through, specific columns in early/middle stages of human extrastriate cortex. SIGNIFICANCE STATEMENT The magnocellular and parvocellular (M-P) streams are fundamental components of primate visual cortical organization. These streams segregate both anatomical and functional properties in parallel, from retina through primary visual cortex. However, in most higher-order cortical sites, it is unknown whether such M-P streams exist and/or what form those streams would take. Moreover, it is unknown whether M-P streams exist in human cortex. Here, fMRI evidence measured at high field (7T) and high resolution revealed segregated M-P streams in four areas of human extrastriate cortex. These results suggest that M-P information is processed in segregated parallel channels throughout much of human visual cortex; the M-P streams are more than a convenient sorting property in earlier stages of the visual system.
Published Version: doi:10.1523/JNEUROSCI.0690-17.2017
Other Sources: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5559769/pdf/
Terms of Use: This article is made available under the terms and conditions applicable to Other Posted Material, as set forth at http://nrs.harvard.edu/urn-3:HUL.InstRepos:dash.current.terms-of-use#LAA
Citable link to this page: http://nrs.harvard.edu/urn-3:HUL.InstRepos:34375158
Downloads of this work:

Show full Dublin Core record

This item appears in the following Collection(s)

 
 

Search DASH


Advanced Search
 
 

Submitters