Parallel processing, hierarchical transformations, and sensorimotor associations along the 'where' pathway
Abstract
Visually guided behaviors require the brain to transform ambiguous retinal images into object-level spatial representations and implement sensorimotor transformations. These processes are supported by the dorsal 'where' pathway. However, the specific functional contributions of areas along this pathway remain elusive due in part to methodological differences across studies. We previously showed that macaque caudal intraparietal (CIP) area neurons possess robust three-dimensional (3D) visual representations, carry choice- and saccade-related activity, and exhibit experience-dependent sensorimotor associations (Chang et al., 2020b). Here, we used a common experimental design to reveal parallel processing, hierarchical transformations, and the formation of sensorimotor associations along the 'where' pathway by extending the investigation to V3A, a major feedforward input to CIP. Higher-level 3D representations and choice-related activity were more prevalent in CIP than V3A. Both areas contained saccade-related activity that predicted the direction/timing of eye movements. Intriguingly, the time-course of saccade-related activity in CIP aligned with the temporally integrated V3A output. Sensorimotor associations between 3D orientation and saccade direction preferences were stronger in CIP than V3A, and moderated by choice signals in both areas. Together, the results explicate parallel representations, hierarchical transformations, and functional associations of visual and saccade-related signals at a key juncture in the 'where' pathway.
Data availability
All data generated or analyzed during this study are available through the Open Science Framework. https://osf.io/8wxk7/
Article and author information
Author details
Funding
National Institutes of Health (T32EY027721)
- Raymond Doudlah
National Science Foundation (DGE-1545481)
- Raymond Doudlah
- Lowell W Thompson
National Institutes of Health (T32NS105602)
- Lowell W Thompson
McPherson Eye Research Institute (Graduate Student Support Initiative)
- Lowell W Thompson
Alfred P. Sloan Foundation (FG-2016-6468)
- Ari Rosenberg
Whitehall Foundation (2016-08-18)
- Ari Rosenberg
Greater Milwaukee Foundation (Shaw Scientist Award)
- Ari Rosenberg
National Institutes of Health (EY029438)
- Ari Rosenberg
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Ethics
Animal experimentation: This study was performed in strict accordance with the recommendations of the National Institutes of Health's Guide for the Care and Use of Laboratory Animals. All experimental procedures and surgeries were approved by the Institutional Animal Care and Use Committee (IACUC) at the University of Wisconsin-Madison (Protocol #: G005229).
Copyright
© 2022, Doudlah et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
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