title: Correlation index: a new metric to quantify temporal coding.
abstract: The standard procedure to study temporal encoding of sound waveforms in the auditory system has been Fourier analysis of responses to periodic stimuli. We introduce a new metric--correlation index (CI)--which is based on a simple counting of spike coincidences. It can be used for responses to aperiodic stimuli and does not require knowledge of the stimulus. Moreover, the basic procedure of comparing spiketimes in spiketrains is more physiological than currently used methods for temporal analysis. The CI is the peak value of the normalized shuffled autocorrelogram (SAC), which provides a quantitative summary of temporal structure in the neural response to arbitrary stimuli. We illustrate the CI and SACs by comparing temporal coding in the auditory nerve and output fibers of the cochlear nucleus.
authors.affiliation: Laboratory of Auditory Neurophysiology, K.U. Leuven, Medical School, Campus Gasthuisberg O&N2 bus 1021, Herestraat 49, B-3000 Leuven, Belgium. philip.joris@med.kuleuven.be
authors.forename: Philip X
authors.initials: PX
authors.lastname: Joris
authors.forename: Dries H
authors.initials: DH
authors.lastname: Louage
authors.forename: Liesbeth
authors.initials: L
authors.lastname: Cardoen
authors.forename: Marcel
authors.initials: M
authors.lastname: van der Heijden
mesh_terms: D000161:Acoustic Stimulation; D000818:Animals; D001306:Auditory Pathways / Q000502:physiology*; D001307:Auditory Perception / Q000502:physiology*; D002415:Cats; D004594:Electrophysiology; D005583:Fourier Analysis; D009475:Neurons, Afferent / Q000502:physiology; D046709:Pattern Recognition, Physiological / Q000502:physiology*; D013997:Time Factors