title: Neural dynamics of change detection in crowded acoustic scenes.
abstract: Two key questions concerning change detection in crowded acoustic environments are the extent to which cortical processing is specialized for different forms of acoustic change and when in the time-course of cortical processing neural activity becomes predictive of behavioral outcomes. Here, we address these issues by using magnetoencephalography (MEG) to probe the cortical dynamics of change detection in ongoing acoustic scenes containing as many as ten concurrent sources. Each source was formed of a sequence of tone pips with a unique carrier frequency and temporal modulation pattern, designed to mimic the spectrotemporal structure of natural sounds. Our results show that listeners are more accurate and quicker to detect the appearance (than disappearance) of an auditory source in the ongoing scene. Underpinning this behavioral asymmetry are change-evoked responses differing not only in magnitude and latency, but also in their spatial patterns. We find that even the earliest (~50 ms) cortical response to change is predictive of behavioral outcomes (detection times), consistent with the hypothesized role of local neural transients in supporting change detection.
authors.affiliation: UCL Ear Institute, 332 Gray's Inn Road, London WC1X 8EE, UK. Electronic address: e.sohoglu@gmail.com.
authors.forename: Ediz
authors.initials: E
authors.lastname: Sohoglu
authors.affiliation: UCL Ear Institute, 332 Gray's Inn Road, London WC1X 8EE, UK. Electronic address: m.chait@ucl.ac.uk.
authors.forename: Maria
authors.initials: M
authors.lastname: Chait
mesh_terms: D000328:Adult; D001307:Auditory Perception / Q000502:physiology*; D005072:Evoked Potentials, Auditory / Q000502:physiology*; D005260:Female; D006801:Humans; D015225:Magnetoencephalography / Q000379:methods*; D008297:Male; D011930:Reaction Time / Q000502:physiology; D017603:Signal Detection, Psychological / Q000502:physiology*; D013997:Time Factors; D055815:Young Adult
keywords: Auditory scene analysis; Change deafness; MEG