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

HOME  |   SEARCH  |   ARCHIVE  |   SUBSCRIBE  |   CONTACT  |   HELP

The Journal of Neuroscience, October 13, 2004, 24(41):9185-9194; doi:10.1523/JNEUROSCI.1884-04.2004

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 ISI 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 ISI Web of Science (6) Citing Articles via Google Scholar Google Scholar Articles by Grunewald, A. Articles by Skoumbourdis, E. K. Search for Related Content PubMed PubMed Citation Articles by Grunewald, A. Articles by Skoumbourdis, E. K.

 Previous Article  |  Next Article 

Behavioral/Systems/Cognitive
The Integration of Multiple Stimulus Features by V1 Neurons

Alexander Grunewald and Evelyn K. Skoumbourdis

Harlow Center for Biological Psychology, Departments of Psychology and Physiology, University of Wisconsin-Madison, Madison, Wisconsin 53706

We investigated how V1 neurons integrate two stimulus features by presenting stimuli from a stimulus set made up of all combinations of eight different directions of motion and nine binocular disparities. We investigated the occurrence and shape of the resulting joint tuning function. Among V1 neurons, 80% were jointly tuned for disparity with orientation or direction. The joint tuning function of all jointly tuned neurons was separable into distinct tuning for disparity on the one hand, and orientation or direction tuning on the other. The degree of separability and the mutual information between the stimulus and the firing rates were strongly correlated. The mutual information of jointly tuned neurons when both features were decoded together was highly correlated with the mutual information when the two features were decoded separately, and the information was then summed. Jointly tuned neurons were just as good at representing information about single features as neurons tuned for only a single feature. The tuning properties of most jointly tuned neurons did not dynamically evolve over time, nor did jointly tuned neurons respond earlier than neurons tuned for only a single feature. The response selectivity of V1 neurons is low and decreases the information that a neuron represents about a stimulus. Together these results suggest that distinct stimulus features are integrated very early in visual processing. Furthermore, V1 generates a distributed representation through low response selectivity that avoids the curse of dimensionality by using separable joint tuning functions.

Key words: striate cortex; orientation; direction; disparity; joint tuning; separability; information; binocular; motion; depth

---

Received May 14, 2004; revised August 20, 2004; accepted September 9, 2004.

This article has been cited by other articles:

				Y. E. Cohen, F. Theunissen, B. E. Russ, and P. Gill Acoustic Features of Rhesus Vocalizations and Their Representation in the Ventrolateral Prefrontal Cortex J Neurophysiol, February 1, 2007; 97(2): 1470 - 1484. [Abstract] [Full Text] [PDF]

				P. Neri and D. M. Levi Spatial Resolution for Feature Binding Is Impaired in Peripheral and Amblyopic Vision J Neurophysiol, July 1, 2006; 96(1): 142 - 153. [Abstract] [Full Text] [PDF]

				C. C. Pack, B. R. Conway, R. T. Born, and M. S. Livingstone Spatiotemporal Structure of Nonlinear Subunits in Macaque Visual Cortex J. Neurosci., January 18, 2006; 26(3): 893 - 907. [Abstract] [Full Text] [PDF]

Home  |   Search  |   Archive  |   Subscribe  |   Contact  |   Help