The large-scale organization of shape processing in the ventral and dorsal pathways
- Carnegie Mellon University, United States
- University of Western Ontario, Canada
Abstract
Although shape perception is considered a function of the ventral visual pathway, evidence suggests that the dorsal pathway also derives shape-based representations. In two psychophysics and neuroimaging experiments, we characterized the response properties, topographical organization and perceptual relevance of these representations. In both pathways, shape sensitivity increased from early visual cortex to extrastriate cortex but then decreased in anterior regions. Moreover, the lateral aspect of the ventral pathway and posterior regions of the dorsal pathway were sensitive to the availability of fundamental shape properties, even for unrecognizable images. This apparent representational similarity between the posterior-dorsal and lateral-ventral regions was corroborated by a multivariate analysis. Finally, as with ventral pathway, the activation profile of posterior dorsal regions was correlated with recognition performance, suggesting a possible contribution to perception. These findings challenge a strict functional dichotomy between the pathways and suggest a more distributed model of shape processing.
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Funding
Israel Science Foundation (grant No. 65/15)
- Erez Freud
Yad Hanadiv Postdoctoral Fellowship
- Erez Freud
National Science Foundation (BCS-1354350)
- David C Plaut
- Marlene Behrmann
Pennsylvania Department of Health (Commonwealth Universal Research Enhancement Program)
- David C Plaut
Canadian Institutes of Health Research (MOP 130345)
- Jody C Culham
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Ethics
Human subjects: As detailed in the manuscript, all subjects had normal or corrected-to-normal vision and were financially compensated for their participation. Informed consent and consent to publish was obtained in accordance with ethical standards set out by the Declaration of Helsinki (1964) and with procedures approved by the IRB committee of Carnegie Mellon University.
Copyright
© 2017, Freud 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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The large-scale organization of shape processing in the ventral and dorsal pathways
eLife 6:e27576.
https://doi.org/10.7554/eLife.27576
Further reading
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