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Decoding the activity of neuronal populations in macaque primary visual cortex

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Visual function depends on the accuracy of signals carried by visual cortical neurons. Combining information across neurons should improve this accuracy because single neuron activity is variable. We examined the reliability of information inferred from populations of simultaneously recorded neurons in macaque primary visual cortex. We considered a decoding framework that computes the likelihood of visual stimuli from a pattern of population activity by linearly combining neuronal responses and tested this framework for orientation estimation and discrimination. We derived a simple parametric decoder assuming neuronal independence and a more sophisticated empirical decoder that learned the structure of the measured neuronal response distributions, including their correlated variability. The empirical decoder used the structure of these response distributions to perform better than its parametric variant, indicating that their structure contains critical information for sensory decoding. These results show how neuronal responses can best be used to inform perceptual decision-making.

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Figure 1
Figure 2: Scheme of the linear log-likelihood decoding framework with parameters of the ELD derived from data set 3.
Figure 3: Orientation estimation accuracy for the ELD, the CB-ELD and the PID.
Figure 4: Orientation discrimination accuracy for the ELD, the CB-ELD and the PID.
Figure 5: Dependency of the discrimination weighting functions with respect to stimulus orientation and neuronal response magnitude for data set 3.
Figure 6: Orientation discrimination thresholds of the ELD corresponding to an accuracy of 0.75 using data set 3.

Change history

  • 16 January 2011

    In the version of this article initially published online, an error was made in the legend for Figure 6. In the legend, 0.75% should read 0.75. This error has been corrected for the print, PDF and HTML versions of this article.


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We are grateful to M. Smith and R. Kelly for their help with recording and to E. Simoncelli and M. Yanike for helpful comments on the manuscript. This research was supported by US National Institutes of Health research grants EY2017 and EY4440, training grant EY7158 and the Swartz Foundation.

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Authors and Affiliations



A.B.A.G., A.K. and J.A.M. designed the experiments, A.B.A.G. and A.K. collected the data, A.B.A.G. created the models and analyzed the data, A.B.A.G. and J.A.M. wrote the manuscript, and A.K. and M.J. contributed to the intellectual development of the project and to the writing of the manuscript.

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Correspondence to Arnulf B A Graf.

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The authors declare no competing financial interests.

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Graf, A., Kohn, A., Jazayeri, M. et al. Decoding the activity of neuronal populations in macaque primary visual cortex. Nat Neurosci 14, 239–245 (2011).

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