Decay of cortical pre-attentive sound discrimination in middle-age.
Ageing effects on pre-attentive cortical detection of sound change, as indexed by magnetic mismatch negativity (MMNm), were disclosed with whole-head magnetoencephalography (MEG). Seventy healthy subjects (aged 17-82 years) were presented with a sequence of homogeneous standard tones and occasional deviants of shorter duration. The MMNm elicited by the shorter tones was diminished in amplitude (r = -0.42, p < 0.001) and increased in latency in the hemisphere ipsilateral to the ear stimulated (r = 0.38, p < 0.01), these effects being significant even in middle-aged subjects. The results suggest that pre-attentive comparison of incoming stimuli to a short-lived sensory memory trace in the central auditory system is impaired, and delayed in the ipsilateral hemisphere, already by the middle-age.
Jääskeläinen
I P
IP
Department of Psychology, University of Helsinki, Finland.
Varonen
R
R
Näätänen
R
R
Pekkonen
E
E
D000161:Acoustic Stimulation; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000523:psychology*; D001288:Attention / Q000502:physiology*; D001303:Auditory Cortex / Q000502:physiology*; D007839:Functional Laterality / Q000502:physiology; D006801:Humans; D016014:Linear Models; D015225:Magnetoencephalography; D008875:Middle Aged; D010897:Pitch Discrimination; D011930:Reaction Time / Q000502:physiology