Mismatch negativity to pitch change: varied stimulus proportions in controlling effects of neural refractoriness on human auditory event-related brain potentials.
Based on a memory-comparison process, changes in the pitch of repetitive sounds are pre-attentively detected, reflected by the mismatch negativity (MMN) event-related brain potential (ERP). In such oddball sequences, ERP responses are also affected by differential refractory states of frequency-specific afferent cortical neurons. This contamination of MMN can be controlled using an additional blocked sequence of equiprobable tones. The present study investigated effects of varying the in-sequence probabilities of these control tones from 10 to 45%, respectively. Results showed that an equal distribution of all control-sequence tones is not necessary for efficiently removing neural refractoriness effects on the ERPs. The genuine memory-comparison-based frequency-change MMN can be estimated using sequences, within which the number of equiprobable control tones varies between three and nine.
Jacobsen
Thomas
T
Institut für Allgemeine Psychologie, Universität Leipzig, Seeburgstrasse 14-20, 04103 Leipzig, Germany. jacobsen@uni-leipzig.de
Schröger
Erich
E
Horenkamp
Thorsten
T
Winkler
István
I
D000328:Adult; D004569:Electroencephalography; D005072:Evoked Potentials, Auditory; D005260:Female; D006801:Humans; D008297:Male; D008568:Memory; D010897:Pitch Discrimination / Q000502:physiology*; D011930:Reaction Time