Neural tuning matches frequency-dependent time differences between the ears
Victor Benichoux,
Bertrand Fontaine,
Tom P Franken,
Shotaro Karino,
Philip X Joris,
Romain Brette
Affiliations
Victor Benichoux
Institut d'Etudes de la Cognition, Ecole Normale Supérieure, Paris, France; Université Pierre-et-Marie-Curie, UMR_S 968, Institut de la Vision, Sorbonne Universités, Paris, France; U968, Institut de la Vision, Institut National de la Santé et de la Recherche Médicale, Paris, France; UMR_7210, École des Neurosciences de Paris Île-de-France, Centre National de la Recherche Scientifique, Paris, France
Bertrand Fontaine
Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, New York, United States; Laboratory of Auditory Neurophysiology, University of Leuven, Leuven, Belgium
Tom P Franken
Laboratory of Auditory Neurophysiology, University of Leuven, Leuven, Belgium
Shotaro Karino
Laboratory of Auditory Neurophysiology, University of Leuven, Leuven, Belgium; Department of Otolaryngology, Faculty of Medicine, University of Tokyo, Tokyo, Japan
Laboratory of Auditory Neurophysiology, University of Leuven, Leuven, Belgium
Romain Brette
Institut d'Etudes de la Cognition, Ecole Normale Supérieure, Paris, France; Université Pierre-et-Marie-Curie, UMR_S 968, Institut de la Vision, Sorbonne Universités, Paris, France; U968, Institut de la Vision, Institut National de la Santé et de la Recherche Médicale, Paris, France; UMR_7210, École des Neurosciences de Paris Île-de-France, Centre National de la Recherche Scientifique, Paris, France
The time it takes a sound to travel from source to ear differs between the ears and creates an interaural delay. It varies systematically with spatial direction and is generally modeled as a pure time delay, independent of frequency. In acoustical recordings, we found that interaural delay varies with frequency at a fine scale. In physiological recordings of midbrain neurons sensitive to interaural delay, we found that preferred delay also varies with sound frequency. Similar observations reported earlier were not incorporated in a functional framework. We find that the frequency dependence of acoustical and physiological interaural delays are matched in key respects. This suggests that binaural neurons are tuned to acoustical features of ecological environments, rather than to fixed interaural delays. Using recordings from the nerve and brainstem we show that this tuning may emerge from neurons detecting coincidences between input fibers that are mistuned in frequency.
