Neurons can transmit information about sensory stimuli via their firing rate, spike latency, or by the occurrence of complex spike patterns. Identifying which aspects of the neural responses actually encode sensory information remains a fundamental question in neuroscience. Here we compared various approaches for estimating the information transmitted by neurons in auditory cortex in two very different experimental paradigms, one measuring spatial tuning and the other responses to complex natural stimuli. We demonstrate that, in both cases, spike counts and mean response times jointly carry essentially all the available information about the stimuli. Thus, in auditory cortex, whereas spike counts carry only partial information about stimulus identity or location, the additional availability of relatively coarse temporal information is sufficient in order to extract essentially all the sensory information available in the spike discharge pattern, at least for the relatively short stimuli (< ∼100 ms) commonly used in auditory research.
Bibliographical noteFunding Information:
This work was supported by a Biotechnology and Biological Sciences Research Council grant to J. W. H. Schnupp, a Wellcome Trust studentship to T. D. Mrsic-Flogel, a Wellcome Trust Senior Research Fellowship to A. J. King, by a grant from the Israeli ministry of science to G. Chechik, and by a Volkswagen grant and a GIF grant to I. Nelken.
- Auditory cortex
- Complex sounds
- Mutual information