Magnetoencephalographic recordings demonstrate attentional modulation of mismatch-related neural activity in human auditory cortex

• Published in: Psychophysiology 1998-05, Vol.35 (3), p.283-292
• Main Authors: WOLDORFF, MARTY G., HILLYARD, STEVEN A., GALLEN, CHRIS C., HAMPSON, SCOTT R., BLOOM, FLOYD E.
• Format: Article
• Language: English
• Subjects: Acoustic Stimulation; Adult; Attention; Attention - physiology; Auditory Cortex - physiology; Behavioral psychophysiology; Biological and medical sciences; Dichotic Listening Tests; Electrophysiology; ERP; Evoked Potentials, Auditory - physiology; Fundamental and applied biological sciences. Psychology; Humans; Magnetoencephalography; MEG; Mismatch negativity; MMF; MMN; Psychology. Psychoanalysis. Psychiatry; Psychology. Psychophysiology
• ISSN: 0048-5772; 1540-5958; 1469-8986
• DOI: 10.1017/S0048577298961601

It is widely agreed that the negative brain potential elicited at 150–200 ms by a deviant, less intense sound in a repetitive series can be modulated by attention. To investigate whether this modulation represents a genuine attention effect on the mismatch negativity (MMN) arising from auditory cortex or attention-related activity from another brain region, we recorded both the MMN and the mismatch magnetic field (MMF) elicited by such deviants in a dichotic listening task. Deviant tones in the attended ear elicited a sizable MMF that was well modeled as a dipolar source in auditory cortex. Both the MMN and MMF to unattended-ear deviants were highly attenuated. These findings support the view that the MMN/MMF elicited in auditory cortex by intensity deviants, and thus the underlying feature-analysis and mismatch-detection processes, are not strongly automatic but rather can be gated or suppressed if attention is strongly focused elsewhere.