Psychophysical and physiological measures of spectro-temporal processing in humans

Abstract

The normal perception of natural acoustic stimuli requires the brain to extract, encode, and interpret multidimensional patterns derived from the acoustic input as relayed by the auditory periphery. Of particular importance in audition are patterns of intensity variations across time and frequency. To better understand the relation between perceptual abilities and underlying physiological mechanisms, one may study the relation between measures of psychophysical performance and physiological coding in humans on a range of auditory tasks. Furthermore, similar physiological measures are easily obtained in a variety of animal species, providing a critical link between human perception and relevant animal models. The first series of experiments to be reviewed involves behavioral and physiological measures of auditory temporal processing including the perception of sinusoidal amplitude modulation and nonsimultaneous masking. The second series involves the perception of spectral envelope features using behavorial and physiological estimates of the spectral modulation transfer function. The ability to combine or compare temporal patterns across different spectral regions will be examined via the comodulation masking release (CMR) paradigm. Finally, the processing of local and global spectral features will be examined and hemispheric dominance for each will be discussed.