Auditory processes on different temporal scales revealed by cortical oscillation Xiangbin Teng Poeppel Lab Psychology Department New York University Auditory Splash
Transcript
Auditory processes on different temporal scales revealed by
cortical oscillation Xiangbin Teng Poeppel Lab Psychology
Department New York University
Vision :How does the auditory system extract features from
sounds? Audition Water frequency frequency Multiple filters Two
filters Cortical responses entrained by sounds TimeTime 3 kinds of
sound; 90 trials Procedure 2 s Time One trial Continuous MEG
recoding Baseline 1 1.5 s Which Sound? Three stimuli Three
timescales Theta band 4 7 Hz Alpha band 8 12 Hz Gamma band 30 45 Hz
27100190Duration(ms) 2000 500 1000 1500 2000 500 1000 1500 2000 500
1000 1500 0 .5 1 1.5 2 Time (s) frequency(Hz) b)a) ~27 ms ~100 ms
~190 ms sound sound sound 2 10 19
Inter-trial phase coherence sound sound sound Z Score of ITC **
* ** * * theta alpha beta gamma 10 20 30 40 50 Frequency (Hz) 4-7
Hz 8-12 Hz 13-30 Hz 31-45 Hz Zscore -.5 .5 1.5 2.5 3.5 2 Zscore -.5
.5 1.5 2.5 3.5 theta alpha beta gamma .17 .25 .17 .22 .17 .20 .17
.20 sound sound sound Topography of Inter-trial phase coherence
Decoded Label StimulusLabel Phase Decoding Power Decoding Decoded
Label .42 .30 Confusion Matrix Percentage Decoding performance
using phase and power Detailed decoding procedure can be seen in
Ng, Logothetis, and Kayser, 2013 sound sound sound Phase decoding
Power decoding .3 .2 .1 0 d *** *** *** *** ** .25 .20 .15 .10 d
.05 N N N NY Y Y Y theta alpha beta gamma Effects of Frequency Band
on Phase Decoding
Summary Phase of cortical oscillations, not power, encodes
acoustic dynamics. Cortical oscillations at theta and gamma bands
track acoustic dynamics, and contribute to decoding of all stimuli.
Cortical oscillation at alpha band can not be entrained by stimulus
with corresponding modulation rate. Beta frequency band did not
provide information for decoding different stimuli. The auditory
system mainly uses theta and gamma bands to sample and represent
sound, which supports a two-timescale processing strategy.
Thank you
Single-trial Classification Trial 1 e.g. sound (25 trials)
Trial 2 Trial 24 Trial 25 Phase Template Power Template
Phase Template of Circular distance Phase Template of Phase
Template of The smallest distance Label: l2 distance Label:
Without theta band With theta band Contribution of each band to
decoding different sounds