Hiroki Asari

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We explore the use of sparse representations for separation of a monaural mixture signal, where by a sparse representation we mean one where the number of non-zero elements is smaller than might be expected. This is a surprisingly powerful idea, as the ability to express a signal sparsely in some known, and potentially overcomplete, basis constitutes a(More)
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)
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)
Objective: To report the distinctive clinical features of cryptogenic new-onset refractory status epilepticus (C-NORSE) and the C-NORSE score based on initial clinical assessments. Methods: A retrospective studywas conducted for 136 patients with clinically suspected autoimmune encephalitis who underwent testing for autoantibodies to neuronal surface(More)
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