Implementing conditional inference in the auditory system: What matters?

Authors

  • Juanita Todd,

    1. School of Psychology, University of Newcastle, Callaghan, Australia
    2. Priority Research Centre for Brain and Mental Health Research, University of Newcastle, Callaghan, Australia
    3. Schizophrenia Research Institute, Darlinghurst, Australia
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  • Daniel Mullens

    1. School of Psychology, University of Newcastle, Callaghan, Australia
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  • This research was supported by a Project Enhancement Grant from the Faculty of Science and Information Technology and by the School of Psychology at the University of Newcastle. We wish to gratefully acknowledge the contributions of Gavin Cooper for programming support. We thank the many participants for their time and co-operation. We thank also the reviewers of our prior studies in this area for their excellent feedback indirectly shaping this study.

Address correspondence to: Juanita Todd, School of Psychology, University of Newcastle, University Drive, Callaghan, NSW, Australia, 2308. E-mail: Juanita.Todd@newcastle.edu.au

Abstract

In prior studies, we have used a conditional linkage between rare deviations in a regular sound pattern to determine if the auditory system can use the first deviation to anticipate the probable features of the second deviation (i.e., make a conditional inference). This study was designed to test two hypotheses about why the mismatch negativity (MMN) to a duration deviant sound seems more susceptible to conditional inference effects. The MMNs to duration and frequency glide deviant sounds were significantly smaller when their occurrence was conditionally linked to the identity of a prior deviant as opposed to when they occurred randomly in a sequence. Results provide support for the learned conditional inference interpretation of reduced MMN size to linked deviants. We discuss alternate explanations and conclude that conditional inference studies could provide insight into the dynamics of probability-based prediction in the auditory system.

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