title: Acetylcholine affects the spatial scale of attention: evidence from Alzheimer's disease.
abstract: Location precues were used to manipulate the spatial scale of attention in visual search for a target in an array of letters in patients with dementia of the Alzheimer type (DAT) and in age-matched older controls. Cue size varied in the amount of spatial precision conferred. Scopolamine, a muscarinic antagonist, decreased overall arousal and broadened spatial attention after a precise precue (small and valid) to target location for DAT patients but not for controls, suggesting a selective effect for attentional impairment induced by cholinergic blockade. In contrast, physostigmine, a cholinesterase inhibitor, did not alter the distribution of spatial attention relative to no-drug baseline testing for patients. Results support a differential role for cholinergic mechanisms in the modulation of the spatial scale of visual attention.
authors.affiliation: Geriatric Psychiatry Branch, National Institute of Mental Health, USA. jlevy2@dmc.org
authors.forename: J A
authors.initials: JA
authors.lastname: Levy
authors.forename: R
authors.initials: R
authors.lastname: Parasuraman
authors.forename: P M
authors.initials: PM
authors.lastname: Greenwood
authors.forename: R
authors.initials: R
authors.lastname: Dukoff
authors.forename: T
authors.initials: T
authors.lastname: Sunderland
mesh_terms: D000109:Acetylcholine / Q000378:metabolism*; D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000378:metabolism* / Q000523:psychology*; D001143:Arousal / Q000187:drug effects; D001288:Attention / Q000187:drug effects*; D016022:Case-Control Studies; D018678:Cholinergic Agents / Q000494:pharmacology*; D002800:Cholinesterase Inhibitors / Q000494:pharmacology; D003463:Cues; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008959:Models, Neurological; D018727:Muscarinic Antagonists / Q000494:pharmacology; D010364:Pattern Recognition, Visual / Q000187:drug effects*; D010830:Physostigmine / Q000494:pharmacology; D012601:Scopolamine / Q000494:pharmacology; D013028:Space Perception / Q000187:drug effects
chemical_list: D018678:Cholinergic Agents; D002800:Cholinesterase Inhibitors; D018727:Muscarinic Antagonists; D010830:Physostigmine; D012601:Scopolamine; D000109:Acetylcholine