QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

HOME  |   SEARCH  |   ARCHIVE  |   SUBSCRIBE  |   CONTACT  |   HELP

This Article Full Text Full Text (PDF) Submit an eLetter Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Web of Science (19) Citing Articles via Google Scholar Google Scholar Articles by Mechler, F. Articles by Victor, J. D. Search for Related Content PubMed PubMed Citation Articles by Mechler, F. Articles by Victor, J. D.

 Previous Article  |  Next Article 

The Journal of Neuroscience, July 15, 2002, 22(14):6129-6157

Detection and Discrimination of Relative Spatial Phase by V1 Neurons

Ferenc Mechler, Daniel S. Reich, and Jonathan D. Victor

Department of Neurology and Neuroscience, Weill Medical College of Cornell University, New York, New York 10021

Edge-like and line-like features result from spatial phase congruence, the local phase agreement between harmonic components of a spatial waveform. Psychophysical observations and models of early visual processing suggest that human visual feature detectors are specialized for edge-like and line-like phase congruence. To test whether primary visual cortex (V1) neurons account for such specificity, we made tetrode recordings in anesthetized macaque monkeys. Stimuli were drifting equal-energy compound gratings composed of four sinusoidal components. Eight congruence phases (one-dimensional features) were tested, including line-like and edge-like waveforms. Many of the 137 single V1 neurons (recorded at 45 sites) could reliably signal phase congruence by any of several response measures. Across neurons, the preferred spatial feature had only a modest bias for line-like waveforms. Information-theoretic analysis showed that congruence phase was temporally encoded in the frequency band present in the stimuli. The most sensitive neurons had feature discrimination thresholds that approached psychophysical levels, but typical neurons were substantially less sensitive. In single V1 neurons, feature discrimination exhibited various dependences on the congruence phase of the reference waveform. Simple cells were over-represented among the most sensitive neurons and on average carried twice as much feature information as complex cells. However, the distribution of the indices of optimal tuning and discrimination of relative phase was indistinguishable in simple and complex cells. Our results suggest that phase-sensitive pooling of responses is required to account for human psychophysical performance, although variation in feature selectivity among nearby neurons is considerable.

Key words: spatial feature detection; feature discrimination; phase-selective nonlinearity; congruence phase; edge; line; macaque; primary visual cortex; transinformation; simple and complex cells

---

Copyright © 2002 Society for Neuroscience  0270-6474/02/22146129-29$05.00/0

This article has been cited by other articles:

				L. Henriksson, A. Hyvarinen, and S. Vanni Representation of Cross-Frequency Spatial Phase Relationships in Human Visual Cortex J. Neurosci., November 11, 2009; 29(45): 14342 - 14351. [Abstract] [Full Text] [PDF]

				N. A. Crowder, J. van Kleef, B. Dreher, and M. R. Ibbotson Complex Cells Increase Their Phase Sensitivity at Low Contrasts and Following Adaptation J Neurophysiol, September 1, 2007; 98(3): 1155 - 1166. [Abstract] [Full Text] [PDF]

				L. M. Romanski Representation and Integration of Auditory and Visual Stimuli in the Primate Ventral Lateral Prefrontal Cortex Cereb Cortex, September 1, 2007; 17(suppl_1): i61 - i69. [Abstract] [Full Text] [PDF]

				F. Mechler, I. E. Ohiorhenuan, and J. D. Victor Speed Dependence of Tuning to One-Dimensional Features in V1 J Neurophysiol, March 1, 2007; 97(3): 2423 - 2438. [Abstract] [Full Text] [PDF]

				S.-C. Yen, J. Baker, and C. M. Gray Heterogeneity in the Responses of Adjacent Neurons to Natural Stimuli in Cat Striate Cortex J Neurophysiol, February 1, 2007; 97(2): 1326 - 1341. [Abstract] [Full Text] [PDF]

				C. Bardy, J. Y. Huang, C. Wang, T. FitzGibbon, and B. Dreher 'Simplification' of responses of complex cells in cat striate cortex: suppressive surrounds and 'feedback' inactivation J. Physiol., August 1, 2006; 574(3): 731 - 750. [Abstract] [Full Text] [PDF]

				V. Bonin, V. Mante, and M. Carandini The statistical computation underlying contrast gain control. J. Neurosci., June 7, 2006; 26(23): 6346 - 6353. [Abstract] [Full Text] [PDF]

				J. D. Victor, F. Mechler, M. A. Repucci, K. P. Purpura, and T. Sharpee Responses of V1 Neurons to Two-Dimensional Hermite Functions J Neurophysiol, January 1, 2006; 95(1): 379 - 400. [Abstract] [Full Text] [PDF]

				B. B. Averbeck and L. M. Romanski Principal and Independent Components of Macaque Vocalizations: Constructing Stimuli to Probe High-Level Sensory Processing J Neurophysiol, June 1, 2004; 91(6): 2897 - 2909. [Abstract] [Full Text] [PDF]

				D. Aronov, D. S. Reich, F. Mechler, and J. D. Victor Neural Coding of Spatial Phase in V1 of the Macaque Monkey J Neurophysiol, June 1, 2003; 89(6): 3304 - 3327. [Abstract] [Full Text] [PDF]

Home  |   Search  |   Archive  |   Subscribe  |   Contact  |   Help