Auditory event-related potentials during target detection are abnormal in mild cognitive impairment

• Published in: Clinical neurophysiology Vol. 113; no. 1; pp. 151 - 161
• Main Authors: Golob, Edward J, Johnson, J.K, Starr, A
• Format: Journal Article
• Language: English
• Published: Shannon Elsevier B.V 01.01.2002; Elsevier Science
• Subjects: Acoustic Stimulation; Age associated memory impairment; Aged; Alzheimer Disease - physiopathology; Alzheimer's disease; Biological and medical sciences; Cognition Disorders - physiopathology; Disease Progression; Electrodiagnosis. Electric activity recording; Event-Related Potentials, P300 - physiology; Evoked Potentials, Auditory - physiology; Female; Humans; Investigative techniques, diagnostic techniques (general aspects); Male; Medical sciences; Nervous system; Neuropsychological Tests; P300; P50; Reaction Time - physiology; Space Perception - physiology; P1; P50; Alzheimer's disease; P300; Age associated memory impairment; Human; Memory disorder; Cognitive disorder; Alzheimer disease; Central nervous system; P300 potential; Auditory cortex; Electrodiagnosis; Bereitschaftspotential; Auditory evoked potential; Risk factor; Reaction time; Auditory pathway; Elderly; Event evoked potential; Brain (vertebrata)
• ISSN: 1388-2457
• DOI: 10.1016/S1388-2457(01)00713-1

Objective: To define brain activity and behavioral changes in mild cognitive impairment (MCI), an isolated memory deficit in the elderly that is a major risk factor for Alzheimer's disease. Methods: Brain potentials and reaction time were examined in elderly controls (n=12) and MCI (n=15) using a target detection paradigm. Subjects listened to a sequence of tones and responded to high-pitched target tones (P=0.20) that were randomly mixed with low-pitched tones (P=0.80). Measures were a pre-stimulus readiness potential (RP), post-stimulus potentials (P50, N100, P200, N200, P300), and reaction time. Results: Accuracy was equivalent between groups, but there was a trend for longer reaction times in MCI (P=0.08). Two potentials differed between groups: (1) P50 amplitude and latency were significantly increased in MCI, and (2) P300 latency was significantly longer in MCI. Results from two MCI subjects that converted to Alzheimer's disease are also discussed. Conclusions: Brain potentials in MCI subjects during target detection have certain features similar to healthy aging (RP, N100, P200, N200), and other features similar to Alzheimer's disease (delayed P300 latency, slower reaction time). P50 differences in MCI may reflect pathophysiological changes in the modulation of auditory cortex by association cortical regions having neuropathological changes in early Alzheimer's disease.