Centre for Theoretical and Computational Neuroscience, University of Plymouth, UK
Wednesday 14 June 2006
Seminar Room B10 (Basement)
Alexandra House, 17 Queen Square, London, WC1N 3AR
Auditory perceptual organisation: change detection and predictive modeling
Sounds provide us with useful information about our environment which complements that provided by other senses, but also pose specific processing problems. How does the auditory system disentangle sounds from different sound sources? And what is it that allows intermittent sound events from the same source to be associated with each other? I will present a computational model of auditory processing which replicates some of the temporal response properties observed in auditory cortex (Denham 2001), and show that this model can also replicate responses in primary auditory cortex to auditory streaming tone sequences (Fishman, Reser et al. 2001; Fishman, Arezzo et al. 2004). I will then discuss the results of a perceptual experiment which confirm the bi-stable nature of auditory streaming, and the proposal that the apparent gradual build-up of streaming may be an artefact of averaging across many subjects (Pressnitzer and Hupe in press). These findings suggest that computational models of auditory stream segregation require four basic processing elements; clustering, predictive modelling, competition and adaptation, and that it is the formation of effective predictive models which allows the auditory system to keep track of different sound sources in a complex auditory environment.
Denham, S. (2001). Cortical synaptic depression and auditory perception. Computational Models of Auditory Function. S. Greenberg and M. Slaney. Amsterdam, IOS Press.
Fishman, Y. I., J. C. Arezzo, et al. (2004). "Auditory stream segregation in monkey auditory cortex: effects of frequency separation, presentation rate, and tone duration." J Acoust Soc Am 116(3): 1656-70.
Fishman, Y. I., D. H. Reser, et al. (2001). "Neural correlates of auditory stream segregation in primary auditory cortex of the awake monkey." Hear Res 151(1-2): 167-187.
Pressnitzer, D. and J. M. Hupe (in press). "Temporal dynamics of auditory and visual bistability reveal common principles of perceptual organization." Current Biology.