The effect of perceptual grouping on the mismatch negativity.
The mismatch negativity (MMN) was used as a probe to evaluate changes, with age, of transient auditory memory. Subjects were 16 young (M = 23 years) and 16 old (M = 72 years) people. Standard auditory stimuli were presented in trains of eight tones (1000 Hz) with either a I-s or 8-s intertrain interval (ITI). Occasionally, the first stimulus of a train was replaced with a 1200 Hz tone (deviant). The MMN was recorded while subjects watched a silent movie and ignored the sounds. Both groups of subjects showed an MMN response to deviant stimuli under the 1-s ITI condition, but MMNs were only seen for some subjects under the 8-s ITI condition. After MMN recording, subjects performed a discrimination task to the tones used for recording MMNs. Accuracy for both groups was near 100% at both ITIs. These results suggest that generation of MMN is a function of the perceptual grouping of the acoustical stimuli and that the integrity of perceptual grouping may be maintained with increased age.
Gaeta
H
H
Cognitive Electrophysiology Laboratory, New York State Psychiatric Institute, New York 10032, USA. HG84@.columbia.edu
Friedman
D
D
Ritter
W
W
Cheng
J
J
D000328:Adult; D000368:Aged; D000375:Aging / Q000523:psychology; D001307:Auditory Perception / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008568:Memory / Q000502:physiology*