Automatic attentional shifts induced by a noradrenergic drug in Alzheimer's disease: evidence from evoked potentials.
Prior research showed that attentional deficits are observed in Alzheimer's disease (AD). These deficits can further impair other cognitive processes. The present experiment was designed to study the shifts in attention induced by a noradrenergic drug (S 12024-2) through their electrophysiological correlates in 12 outpatients with mild AD, using an auditory oddball paradigm. The P3a component, known to be related to automatic attentional processing, was increased by the drug, whereas no changes occurred either in PN or in P3b, which are considered to reflect conscious processing. These results point to an involvement of the noradrenergic system in the modulation of automatic attentional processing, and provide evidence for weakening of the orienting reflex in AD, due to a possible noradrenergic deficit in patients with mild AD.
Missonnier
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Neurosciences Cognitives et Imagerie Cérébrale, LENA--UPR 640--CNRS, Hôpital de la Salpêtrière, Paris, France. lenarr@ext.jussieu.fr
Ragot
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R
Derouesné
C
C
Guez
D
D
Renault
B
B
D018663:Adrenergic Agents; D000368:Aged; D000544:Alzheimer Disease / Q000503:physiopathology*; D001288:Attention / Q000187:drug effects* / Q000502:physiology; D002540:Cerebral Cortex / Q000187:drug effects* / Q000502:physiology; D003072:Cognition Disorders / Q000503:physiopathology*; D018592:Cross-Over Studies; D004192:Discrimination, Psychological / Q000187:drug effects / Q000502:physiology; D004311:Double-Blind Method; D018913:Event-Related Potentials, P300 / Q000187:drug effects / Q000502:physiology; D005071:Evoked Potentials / Q000187:drug effects* / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009025:Morpholines; D015999:Multivariate Analysis; D018697:Nootropic Agents; D009638:Norepinephrine / Q000502:physiology*; D010470:Perceptual Masking / Q000502:physiology; D011804:Quinolines; D014836:Volition / Q000187:drug effects / Q000502:physiology
D018663:Adrenergic Agents; D009025:Morpholines; D018697:Nootropic Agents; D011804:Quinolines; C086272:S 12024; D009638:Norepinephrine