Acoustic processing requires integration over time. We have used in vivo intracellular recording to measure neuronal integration times in anesthetized rats. Using natural sounds and other stimuli, we found that synaptic inputs to auditory cortical neurons showed a rather long context dependence, up to > or =4 s (tau approximately 1 s), even though… (More)
A striking feature of many sensory processing problems is that there appear to be many more neurons engaged in the internal representations of the signal than in its transduction. For example, humans have approximately 30,000 cochlear neurons, but at least 1000 times as many neurons in the auditory cortex. Such apparently redundant internal representations… (More)
The role of sparse overcomplete models of sensory representations has recently attracted attention on theoretical (e. grounds. Here we show that a natural consequence of a sparse overcomplete model is that represenations are noiseless at the population level even though single neuron responses can be highly variable.
Multielectrode arrays (MEAs) allow for acquisition of multisite electrophysiological activity with submillisecond temporal resolution from neural preparations. The signal to noise ratio from such arrays has recently been improved by substrate perforations that allow negative pressure to be applied to the tissue; however, such arrays are not optically… (More)
Auditory system detects sound signals and uses the temporal-frequency information of the sound signals to conduct sound identification, sound localization, and sound source separation. Thanks to the past studies, we know that the hair cells at cochlea show frequency-dependent responses against input sound signals. But, little is known about how the sound… (More)
A striking feature of many sensory processing problems is that there appear to be many more neurons engaged in the internal representations of the signal than in its transduction. For example, humans have about 30,000 cochlear neurons, but at least a thousand times as many neurons in the auditory cortex. Such apparently redundant internal representations… (More)