|
|
||||||||
University of Toronto
The effects of attention on the neural processes underlying auditory scene analysis were investigated through the manipulation of auditory task load. Participants were asked to focus their attention on tuned and mistuned stimuli presented to one ear and to ignore similar stimuli presented to the other ear. For both tuned and mistuned sounds, long (standard) and shorter (deviant) duration stimuli were presented in both ears. Auditory task load was manipulated by varying task instructions. In the easier condition, participants were asked to press a button for deviant sounds (target) at the attended location, irrespective of tuning. In the harder condition, participants were further asked to identify whether the targets were tuned or mistuned. Participants were faster in detecting targets defined by duration only than by both duration and tuning. At the unattended location, deviant stimuli generated a mismatch negativity wave at frontocentral sites whose amplitude decreased with increasing task demand. In comparison, standard mistuned stimuli generated an object-related negativity at central sites whose amplitude was not affected by task difficulty. These results show that the processing of sound sequences is differentially affected by attentional load than is the processing of sounds that occur simultaneously (i.e., sequential vs. simultaneous grouping processes), and that they each recruit distinct neural networks.
This article has been cited by other articles:
![]() |
J. S. Snyder and C. Alain Sequential Auditory Scene Analysis Is Preserved in Normal Aging Adults Cereb Cortex, March 1, 2007; 17(3): 501 - 512. [Abstract] [Full Text] [PDF] |
||||
![]() |
C. Alain and K. L. McDonald Age-Related Differences in Neuromagnetic Brain Activity Underlying Concurrent Sound Perception J. Neurosci., February 7, 2007; 27(6): 1308 - 1314. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. S. Snyder, C. Alain, and T. W. Picton Effects of Attention on Neuroelectric Correlates of Auditory Stream Segregation J. Cogn. Neurosci., January 1, 2006; 18(1): 1 - 13. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. Gutschalk, C. Micheyl, J. R. Melcher, A. Rupp, M. Scherg, and A. J. Oxenham Neuromagnetic Correlates of Streaming in Human Auditory Cortex J. Neurosci., June 1, 2005; 25(22): 5382 - 5388. [Abstract] [Full Text] [PDF] |
||||
![]() |
C. Alain, K. Reinke, Y. He, C. Wang, and N. Lobaugh Hearing Two Things at Once: Neurophysiological Indices of Speech Segregation and Identification J. Cogn. Neurosci., May 1, 2005; 17(5): 811 - 818. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| NEURAL COMPUTATION | J COGNITIVE NEUROSCIENCE | MIT PRESS JOURNALS |