Recanzone and Sutter Presented by Joseph Schilz Review: The Biological Basis of Audition
Outline • Introduction • Organization of Audition • Auditory Spatial Processing Interactions with visual stimuli Ventriloquism effect Ventriloquism after-effect • Auditory Temporal Processing Temporal integration Forward masking Gap detection
Introduction • Audition and vision major sensory systems • Audition does not have the significant history of research that vision does • Differences between audition and vision • Tasks in decoding audition: Where a sound came from Spectral properties Temporal properties Identifying what sound represents • Review's focus: location and temporal properties
Organization of Audition Fig 1. Recanzone and Sutter
Organization of Audition Fig 2.Recanzone & Sutter
Organization of Audition Tonotopy Fig 2. Kalatsky et al.
Organization of Audition Tonal Tuning Fig 2:Bitterman et al.
Organization of Audition Tonal/Spatial Tuning Fig 2.Bizley & King
Organization of Audition “What” and “Where” Paths? Fig 1: DesignAhveninen et al.
Organization of Audition “What” and “Where” Paths? Fig 2: ResultsAhveninen et al.
Auditory Spatial Processing • Cues • Interactions with visual stimuli Ventriloquism effect Ventriloquism after-effect
Fig 3. Recanzone and Sutter Auditory Spatial Processing Cues
Fig 1. Yu and Young Auditory Spatial Processing Cues
Auditory Spatial Processing Ventriloquism effect • Definition • Cognitive factors “unity assumption” • Non-cognitive factors Timing Compellingness Spatial discrepancy/agreement
Auditory Spatial Processing Ventriloquism effect • Early studies assumed that the more precise modality would “capture” the less precise modality. • Later studies showed a near optimal “mixing” of modality reports, respecting the measure-error variance of each modality.
Auditory Spatial Processing Ventriloquism effect Fig 2: Design and ResultsKording et al.
Auditory Spatial Processing Ventriloquism after-effect • If subject is presented with audio/visual stimuli of a consistent spatial disparity, subjects spatial perception of acoustic space shifted after • Long lasting • Does not transfer across frequencies • Different from other adaption illusions: lasts tens of minutes, does not transfer across frequencies, in the same direction of adapting stimulus.
Auditory Spatial Processing Ventriloquism after-effect Fig 4: Design and ResultsRecanzone
Auditory Spatial Processing Ventriloquism after-effect • Difficulty of single unit recording in illusions. • Direct projection from auditory to visual (observed in primates) • Direct projection from visual to auditory (observed in ferrets) • Several areas in brain with multisensory response • Ghanzafar study
Auditory Temporal Processing • Definition • Temporal integration • Forward masking • Gap detection
Auditory Temporal Processing Definition • Can mean processing of temporal aspects of stimuli or ability of neurons to encode stimulus by temporal aspects of firing • We refer to former • Temporal processing could be interpreted to include spectral processing • We don't consider spectral processing here
Auditory Temporal Processing Temporal integration • Our environments are noisy; audition might wait a bit and let noise average itself out before passing on a percept • On the other hand, some decisions need to be made quickly; audition shouldn't hold onto information for too long • How to assess? At what levels is this occurring?
Auditory Temporal Processing Temporal integration Fig 4. Dallos and Olsen
Auditory Temporal Processing Temporal integration • Varies with loudness, frequency, duration • Bloch's Law (Loudness x Duration = k) • Leaky integrator model • Mean integration times of 30-40msec in humans
Auditory Temporal Processing Temporal integration • Clock et al. found similar constants of integration in chinchilla cochlear nucleus neurons and chinchilla behavior • Exponential leaky integrator fit model well • But, auditory nerve neurons had time constants much larger • Explanation
Auditory Temporal Processing Forward masking • Two sounds presented sequentially, with some gap, sometimes subject will not perceive second sound. • Depends on many factors • Generally measured as afunction of first sound's duration. Fig 4. Recanzone and Sutter
Auditory Temporal Processing Forward masking • Likely a result of adaptation.
Auditory Temporal Processing Gap detection • Temporal resolution vs. temporal integration • One paradigm for temporal resolution: gap detection • Humans able to detect gaps in noise as small as 1-2msec • Auditory nerve firing shows gaping pattern • Likely some role of cortex in detecting gaps, as shown by lesion, deactivation studies
Auditory Temporal Processing Gap detection Fig 2. Zhang et al.
Ahveninen et al. Task-modulated “what” and “where” pathways in human auditory cortex PNAS 2006 103 (39) 14608-14613; published ahead of print September 18, 2006, doi:10.1073/pnas.0510480103 Y. Bitterman, R. Mukamel, R. Malach, I. Fried, & I. Nelken Ultra-fine frequency tuning revealed in single neurons of human auditory cortex Nature 451, 197-201 (10 January 2008) Jennifer K. Bizley, Andrew J. King, Visual-auditory spatial processing in auditory cortical neurons, Brain Research, Volume 1242, Multisensory Integration, 25 November 2008, Pages 24-36, ISSN 0006-8993, DOI: 10.1016/j.brainres.2008.02.087. P. Dallos, W. Olsen, Integration of energy at threshold with gradual rise-fall tone pips. Journal of the Acoustical Soc. of America.Vol. 36, pp. 743-751, April 1964 V Kalatsky, D Polley, M Merzenich, C Schreiner, Mstryker, Fine functional organization of auditory cortex revealed by Fourier optical imaging PNAS 2005 102 (37) 13325-13330; published ahead of print September 1, 2005, doi:10.1073/pnas.0505592102 Additional Works Referenced
Kording KP, Beierholm U, Ma WJ, Quartz S, Tenenbaum JB, et al (2007) Causal Inference in Multisensory Perception. PLoS ONE 2(9): e943. doi:10.1371/journal.pone.0000943 Recanzone G, Rapidly induced auditory plasticity: The ventriloquism aftereffect. Proc. Natl. Acad. Sci. USA Vol. 95, pp. 869–875, February 1998 J Yu, E Young, Linear and nonlinear pathways of spectral information transmission in the cochlear nucleus PNAS 2000 97 (22) 11780-11786 W. Zhang, R.J. Salvi, S.S. Saunders, Neural correlates of gap detection in auditory nerve fibers of the chinchilla, Hearing Research, Volume 46, Issue 3, July 1990, Pages 181-200, ISSN 0378-5955, DOI: 10.1016/0378-5955(90)90001-6. Additional Works Referenced