title: Aging and enumeration: a selective deficit for the subitization of targets among distractors.
abstract: The term subitization has been used to refer to the fast and accurate enumeration of up to about 4 items. Beyond 4 items, enumeration becomes more serial and less accurate, with each additional item adding to the total enumeration time. The effects of aging on visual enumeration of targets (Os) were assessed with and without the presence of distractors (Xs). Young participants (n = 30; 18-27 years) showed the usual subitization-counting enumeration function, both with and without the presence of distractors. In contrast, for older participants (n = 35; 65-79 years), evidence for subitization was found only when distractors were absent. This occurred even though they could detect an individual target among distractors in parallel across the field. The results are discussed in relation to recent theories of visual selection and enumeration.
authors.affiliation: Department of Psychology, University of Warwick, Coventry, England. d.g.watson@warwick.ac.uk
authors.forename: Derrick G
authors.initials: DG
authors.lastname: Watson
authors.forename: Elizabeth A
authors.initials: EA
authors.lastname: Maylor
authors.forename: Nicola J
authors.initials: NJ
authors.lastname: Manson
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000375:Aging / Q000502:physiology*; D001288:Attention; D003072:Cognition Disorders / Q000175:diagnosis* / Q000453:epidemiology; D005260:Female; D006801:Humans; D008297:Male; D008433:Mathematics; D011340:Problem Solving; D011930:Reaction Time; D012720:Severity of Illness Index; D014796:Visual Perception