TY - JOUR
T1 - Neural mechanisms of rhythmic masking release in monkey primary auditory cortex
T2 - Implications for models of auditory scene analysis
AU - Fishman, Yonatan I.
AU - Micheyl, Christophe
AU - Steinschneider, Mitchell
PY - 2012/5/1
Y1 - 2012/5/1
N2 - The ability to detect and track relevant acoustic signals embedded in a background of other sounds is crucial for hearing in complex acoustic environments. This ability is exemplified by a perceptual phenomenon known as "rhythmic masking release" (RMR). To demonstrate RMR, a sequence of tones forming a target rhythm is intermingled with physically identical "Distracter" sounds that perceptually mask the rhythm. The rhythm can be "released from masking" by adding "Flanker" tones in adjacent frequency channels that are synchronous with the Distracters. RMR represents a special case of auditory stream segregation, whereby the target rhythm is perceptually segregated from the background of Distracters when they are accompanied by the synchronous Flankers. The neural basis of RMR is unknown. Previous studies suggest the involvement of primary auditory cortex (A1) in the perceptual organization of sound patterns. Here, we recorded neural responses to RMR sequences in A1 of a wake monkeys in order to identify neural correlates and potential mechanisms of RMR. We also tested whether two current models of stream segregation, when applied to these responses, could account for the perceptual organization of RMR sequences. Results suggest a key role for suppression of Distracter-evoked responses by the simultaneous Flankers in the perceptual restoration of the target rhythm in RMR. Furthermore, predictions of stream segregation models paralleled the psychoacoustics of RMR in humans. These findings reinforce the view that preattentive or "primitive" aspects of auditory scene analysis may be explained by relatively basic neural mechanisms at the cortical level.
AB - The ability to detect and track relevant acoustic signals embedded in a background of other sounds is crucial for hearing in complex acoustic environments. This ability is exemplified by a perceptual phenomenon known as "rhythmic masking release" (RMR). To demonstrate RMR, a sequence of tones forming a target rhythm is intermingled with physically identical "Distracter" sounds that perceptually mask the rhythm. The rhythm can be "released from masking" by adding "Flanker" tones in adjacent frequency channels that are synchronous with the Distracters. RMR represents a special case of auditory stream segregation, whereby the target rhythm is perceptually segregated from the background of Distracters when they are accompanied by the synchronous Flankers. The neural basis of RMR is unknown. Previous studies suggest the involvement of primary auditory cortex (A1) in the perceptual organization of sound patterns. Here, we recorded neural responses to RMR sequences in A1 of a wake monkeys in order to identify neural correlates and potential mechanisms of RMR. We also tested whether two current models of stream segregation, when applied to these responses, could account for the perceptual organization of RMR sequences. Results suggest a key role for suppression of Distracter-evoked responses by the simultaneous Flankers in the perceptual restoration of the target rhythm in RMR. Furthermore, predictions of stream segregation models paralleled the psychoacoustics of RMR in humans. These findings reinforce the view that preattentive or "primitive" aspects of auditory scene analysis may be explained by relatively basic neural mechanisms at the cortical level.
KW - Auditory stream segregation
KW - Multiunit activity
KW - Simultaneous suppression
KW - Spectral integration
UR - http://www.scopus.com/inward/record.url?scp=84860503079&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84860503079&partnerID=8YFLogxK
U2 - 10.1152/jn.01010.2011
DO - 10.1152/jn.01010.2011
M3 - Article
C2 - 22323627
AN - SCOPUS:84860503079
SN - 0022-3077
VL - 107
SP - 2366
EP - 2382
JO - Journal of neurophysiology
JF - Journal of neurophysiology
IS - 9
ER -