title: Size and reversal learning in the beagle dog as a measure of executive function and inhibitory control in aging.
abstract: Several studies converge on the idea that executive processes age earlier than other cognitive processes. As part of a larger effort to investigate age-related changes in executive processes in the dog, inhibitory control was measured in young, middle-aged, old, and senior dogs using size discrimination learning and reversal procedures. Compared to young and middle-aged dogs, old and senior dogs were impaired on both the initial learning of the size task and the reversal of original reward contingencies. Impaired performance in the two aged groups was characterized as a delay in learning the correct stimulus-reward contingencies and, among the senior dogs in particular, an increase in perseverative responding. These separate patterns of reversal impairments in the old and senior dogs may reflect different rates of aging in subregions of the frontal cortex.
authors.affiliation: Department of Psychology, University of Toronto, Scarborough, Ontario, Canada M1C 1A4.
authors.forename: P Dwight
authors.initials: PD
authors.lastname: Tapp
authors.forename: Christina T
authors.initials: CT
authors.lastname: Siwak
authors.forename: Jimena
authors.initials: J
authors.lastname: Estrada
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Head
authors.forename: Bruce A
authors.initials: BA
authors.lastname: Muggenburg
authors.forename: Carl W
authors.initials: CW
authors.lastname: Cotman
authors.forename: Norton W
authors.initials: NW
authors.lastname: Milgram
mesh_terms: D000375:Aging / Q000502:physiology*; D000818:Animals; D003071:Cognition / Q000502:physiology*; D004193:Discrimination Learning / Q000502:physiology*; D004285:Dogs; D005625:Frontal Lobe / Q000502:physiology; D007266:Inhibition, Psychological; D012193:Reversal Learning / Q000502:physiology*