Selective Attention in Auditory Processing as Reflected by Event-Related Brain Potentials

Authors

  • Kimmo Alho

    Corresponding author
    1. Cognitive Psychophysiology Research Unit, Department of Psychology, University of Helsinki, Helsinki, Finland
      Address requests for reprints to: Kimmo Alho, Department of Psychology, University of Helsinki, Ritarikatu 5, 00170 Helsinki, Finland.
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  • Address given upon receipt of the Distinguished Early Career Contribution to Psychophysiology Award, Society for Psychophysiological Research, Boston, October 1990.

  • The author is grateful to Risto Näätänen, David L. Woods, Juha Lavikainen, Patrick May, Kalevi Reinikainen, Wolfgang Teder, and Hannu Tiitinen, as well as to Michael Coles. Walter Ritter, and an anonymous reviewer, for their constructive comments and criticism, and to Teija Niittyvuopio and Hannu Tiitinen for their help in preparing the figures. This work was supported by the Academy of Finland and by a Fogarty International Research Fellowship (FO5 TWO4283) from the U.S. Public Health Service during the author's visit in David L. Woods's laboratory (Neurology Department, University of California at Davis) supported by grants from the VA Research Service and the NIDCD.

Address requests for reprints to: Kimmo Alho, Department of Psychology, University of Helsinki, Ritarikatu 5, 00170 Helsinki, Finland.

ABSTRACT

Measures of event-related brain potentials (ERPs) have revealed two kinds of selective-attention mechanisms that operate on attended and unattended auditory stimuli. The processing negativity of the ERP reveals a mechanism of intramodal selective attention in the auditory cortex controlled by frontal cortex. This mechanism selects attended auditory stimuli for further processing when they differ from unattended stimuli in location or tonal frequency. Studies of intermodal selective attention have compared auditory ERPs during auditory and visual attention. At least in part different brain mechanisms may be involved in the selection of auditory stimuli among other auditory stimuli (intramodal selective attention)and in the selection of auditory stimuli among visual stimuli (intermodal selective attention). This is suggested by the results showing that the earlier component of the processing negativity, which is generated in the auditory cortex during intramodal selective attention, differs in scalp distribution from the early attention-related negativity elicited during intermodal selective attention. With respect to the unattended auditory stimuli, ERP studies of selective attention suggest that physical features of these stimuli are extensively processed. This is shown by the mismatch negativity component of the ERP, which is usually elicited by infrequent physical deviations in an auditory stimulus sequence both when this sequence is attended and when it is ignored. This would be impossible if the physical stimulus features were not extensively processed, even in the absence of attention.

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