TY - JOUR
T1 - Gain modulation as a mechanism for coding depth from motion parallax in macaque area MT
AU - Kim, Hyung Goo R.
AU - Angelaki, Dora E.
AU - DeAngelis, Gregory C.
N1 - Funding Information:
This work was supported by NIH Grant EY013644 and by a CORE Grant (EY001319) from the National Eye Institute, and D.E.A. was supported by EY022538. We thank Dina-Jo Knoedl and Swati Shimpi for assistance with animal surgery and training, and Akiyuki Anzai for helpful comments on the paper.
Funding Information:
Received Feb. 9, 2017; revised June 30, 2017; accepted July 20, 2017. Author contributions: H.R.K., D.E.A., and G.C.D. designed research; H.R.K. performed research; H.R.K. analyzed data; H.R.K., D.E.A., and G.C.D. wrote the paper. ThisworkwassupportedbyNIHGrantEY013644andbyaCOREGrant(EY001319)fromtheNationalEyeInstitute, and D.E.A. was supported by EY022538. We thank Dina-Jo Knoedl and Swati Shimpi for assistance with animal surgery and training, and Akiyuki Anzai for helpful comments on the paper. The authors declare no competing financial interests. Correspondence should be addressed to Dr. Gregory C. DeAngelis, Deptartment of Brain and Cognitive Sciences, Center for Visual Science, 310 Meliora Hall, University of Rochester, Rochester, NY 14627-0268. E-mail: [email protected]. H. Kim’s present address: Molecular and Cell Biology, Harvard University, Cambridge, MA 02138. DOI:10.1523/JNEUROSCI.0393-17.2017 Copyright © 2017 the authors 0270-6474/17/378180-18$15.00/0
Publisher Copyright:
Copyright © 2017 the Authors.
PY - 2017/8/23
Y1 - 2017/8/23
N2 - Observer translation produces differential image motion between objects that are located at different distances from the observer’s point of fixation [motion parallax (MP)]. However, MP can be ambiguous with respect to depth sign (near vs far), and this ambiguity can be resolved by combining retinal image motion with signals regarding eye movement relative to the scene. We have previously demonstrated that both extra-retinal and visual signals related to smooth eye movements can modulate the responses of neurons in area MT of macaque monkeys, and that these modulations generate neural selectivity for depth sign. However, the neural mechanisms that govern this selectivity have remained unclear. In this study, we analyze responses of MT neurons as a function of both retinal velocity and direction of eye movement, and we show that smooth eye movements modulate MT responses in a systematic, temporally precise, and directionally specific manner to generate depth-sign selectivity. We demonstrate that depth-sign selectivity is primarily generated by multiplicative modulations of the response gain of MT neurons. Through simulations, we further demonstrate that depth can be estimated reasonably well by a linear decoding of a population of MT neurons with response gains that depend on eye velocity. Together, our findings provide the first mechanistic description of how visual cortical neurons signal depth from MP.
AB - Observer translation produces differential image motion between objects that are located at different distances from the observer’s point of fixation [motion parallax (MP)]. However, MP can be ambiguous with respect to depth sign (near vs far), and this ambiguity can be resolved by combining retinal image motion with signals regarding eye movement relative to the scene. We have previously demonstrated that both extra-retinal and visual signals related to smooth eye movements can modulate the responses of neurons in area MT of macaque monkeys, and that these modulations generate neural selectivity for depth sign. However, the neural mechanisms that govern this selectivity have remained unclear. In this study, we analyze responses of MT neurons as a function of both retinal velocity and direction of eye movement, and we show that smooth eye movements modulate MT responses in a systematic, temporally precise, and directionally specific manner to generate depth-sign selectivity. We demonstrate that depth-sign selectivity is primarily generated by multiplicative modulations of the response gain of MT neurons. Through simulations, we further demonstrate that depth can be estimated reasonably well by a linear decoding of a population of MT neurons with response gains that depend on eye velocity. Together, our findings provide the first mechanistic description of how visual cortical neurons signal depth from MP.
KW - Depth
KW - Extrastriate cortex
KW - Motion parallax
KW - Neural coding
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U2 - 10.1523/jneurosci.0393-17.2017
DO - 10.1523/jneurosci.0393-17.2017
M3 - Article
C2 - 28739582
AN - SCOPUS:85030617568
SN - 0270-6474
VL - 37
SP - 8180
EP - 8197
JO - Journal of Neuroscience
JF - Journal of Neuroscience
IS - 34
ER -