Spike-timing codes enhance the representation of multiple simultaneous sound-localization cues in the inferior colliculus. 2006

Steven M Chase, and Eric D Young
Center for Hearing Sciences, Department of Biomedical Engineering, Johns Hopkins University, Baltimore, Maryland 21205, USA.

To preserve multiple streams of independent information that converge onto a neuron, the information must be re-represented more efficiently in the neural response. Here we analyze the increase in the representational capacity of spike timing over rate codes using sound localization cues as an example. The inferior colliculus receives convergent input from multiple auditory brainstem nuclei, including sound localization information such as interaural level differences (ILDs), interaural timing differences (ITDs), and spectral cues. Virtual space techniques were used to create stimulus sets varying in two sound-localization parameters each. Information about the cues was quantified using a spike distance metric that allows one to separate contributions to the information arising from spike rate and spike timing. Spike timing enhances the representation of spectral and ILD cues at timescales averaging 12 ms. ITD information, however, is carried by a rate code. Comparing responses to frozen and random noise shows that the temporal information is mainly attributable to phase locking to temporal stimulus features, with an additional first-spike latency component. With rate-based codes, there is significant confounding of information about two cues presented simultaneously, meaning that the cues cannot be decoded independently. Spike-timing-based codes reduce this confounded information. Furthermore, the relative representation of the cues often changes as a function of the time resolution of the code, implying that information about multiple cues can be multiplexed onto individual spike trains.

UI MeSH Term Description Entries
D007245 Inferior Colliculi The posterior pair of the quadrigeminal bodies which contain centers for auditory function. Colliculus, Inferior,Brachial Nucleus of the Inferior Colliculus,Caudal Colliculus,Colliculus Inferior,Inferior Colliculus,Posterior Colliculus,Colliculi, Inferior,Colliculus Inferiors,Colliculus, Caudal,Colliculus, Posterior,Inferior, Colliculus,Inferiors, Colliculus
D009622 Noise Any sound which is unwanted or interferes with HEARING other sounds. Noise Pollution,Noises,Pollution, Noise
D009778 Occipital Lobe Posterior portion of the CEREBRAL HEMISPHERES responsible for processing visual sensory information. It is located posterior to the parieto-occipital sulcus and extends to the preoccipital notch. Annectant Gyrus,Calcarine Fissure,Calcarine Sulcus,Cuneate Lobule,Cuneus,Cuneus Cortex,Cuneus Gyrus,Gyrus Lingualis,Lingual Gyrus,Lunate Sulcus,Medial Occipitotemporal Gyrus,Occipital Cortex,Occipital Gyrus,Occipital Region,Occipital Sulcus,Sulcus Calcarinus,Calcarine Fissures,Calcarinus, Sulcus,Cortex, Cuneus,Cortex, Occipital,Cortices, Cuneus,Cortices, Occipital,Cuneate Lobules,Cuneus Cortices,Fissure, Calcarine,Fissures, Calcarine,Gyrus Linguali,Gyrus, Annectant,Gyrus, Cuneus,Gyrus, Lingual,Gyrus, Medial Occipitotemporal,Gyrus, Occipital,Linguali, Gyrus,Lingualis, Gyrus,Lobe, Occipital,Lobes, Occipital,Lobule, Cuneate,Lobules, Cuneate,Occipital Cortices,Occipital Lobes,Occipital Regions,Occipitotemporal Gyrus, Medial,Region, Occipital,Regions, Occipital,Sulcus, Calcarine,Sulcus, Lunate,Sulcus, Occipital
D011930 Reaction Time The time from the onset of a stimulus until a response is observed. Response Latency,Response Speed,Response Time,Latency, Response,Reaction Times,Response Latencies,Response Times,Speed, Response,Speeds, Response
D002415 Cats The domestic cat, Felis catus, of the carnivore family FELIDAE, comprising over 30 different breeds. The domestic cat is descended primarily from the wild cat of Africa and extreme southwestern Asia. Though probably present in towns in Palestine as long ago as 7000 years, actual domestication occurred in Egypt about 4000 years ago. (From Walker's Mammals of the World, 6th ed, p801) Felis catus,Felis domesticus,Domestic Cats,Felis domestica,Felis sylvestris catus,Cat,Cat, Domestic,Cats, Domestic,Domestic Cat
D003463 Cues Signals for an action; that specific portion of a perceptual field or pattern of stimuli to which a subject has learned to respond. Cue
D000161 Acoustic Stimulation Use of sound to elicit a response in the nervous system. Auditory Stimulation,Stimulation, Acoustic,Stimulation, Auditory
D000818 Animals Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA. Animal,Metazoa,Animalia
D013017 Sound Localization Ability to determine the specific location of a sound source. Auditory Localization,Auditory Localizations,Localization, Auditory,Localization, Sound,Localizations, Auditory,Localizations, Sound,Sound Localizations
D013997 Time Factors Elements of limited time intervals, contributing to particular results or situations. Time Series,Factor, Time,Time Factor

Related Publications

Steven M Chase, and Eric D Young
January 2012, Frontiers in neural circuits,
Steven M Chase, and Eric D Young
June 2003, Journal of the Association for Research in Otolaryngology : JARO,
Steven M Chase, and Eric D Young
June 2014, Journal of neurophysiology,
Steven M Chase, and Eric D Young
November 2010, PLoS computational biology,
Steven M Chase, and Eric D Young
April 1986, The Journal of neuroscience : the official journal of the Society for Neuroscience,
Steven M Chase, and Eric D Young
August 2000, Acta oto-laryngologica,
Copied contents to your clipboard!