Cognitive Estimation in Non-demented Parkinson's Disease.
OBJECTIVE
The Cognitive Estimation Test (CET) is widely used in clinical and research settings to assess the ability to produce reasonable estimates to items that individuals would not know that the exact answer (e.g., "How fast do race horses run?"). We examined the performance of non-demented Parkinson's disease (PD) patients on the CET, because previous studies reported heterogeneous results about possible cognitive estimation impairments in PD. We also examined whether PD patients improve their performance if given the chance to reconsider their initial CET responses.


METHODS
Thirty non-demented idiopathic PD patients and 30 healthy controls matched in age, gender and years of education performed the two parallel forms of Italian CET. The estimation scores for initial and final responses as well as the number of times individuals changed their answers were examined. Additional neuropsychological tests, evaluating intellectual, frontal executive, speed of processing, naming and arithmetical abilities, were also administered.


RESULTS
The PD group were not significantly poorer than healthy controls at estimating the answers to items on either CET versions. Moreover, PD patients did not significantly differ in their initial and final responses or number of response changes. Performance on the CET was significantly related to performance on a global measure of executive function, processing speed and arithmetic. However, PD patients were impaired compared to controls on the component involving mainly, but not exclusively, length-related estimations.


CONCLUSIONS
Non-demented PD patients have mild impairments in cognitive estimation ability, which may depend on the estimations they are required to provide.
"Rita Levi Montalcini" Department of Neuroscience, University of Turin, Italy.|Psychology Research Laboratory, IRCCS Istituto Auxologico Italiano, Ospedale San Giuseppe, Piancavallo (VCO), Italy.
Federica
F
Scarpina
"Rita Levi Montalcini" Department of Neuroscience, University of Turin, Italy.|Division of Neurology and Neuro-Rehabilitation, IRCCS Istituto Auxologico Italiano, Ospedale San Giuseppe, Piancavallo (VCO), Italy.
Alessandro
A
Mauro
Psychology Research Laboratory, IRCCS Istituto Auxologico Italiano, Ospedale San Giuseppe, Piancavallo (VCO), Italy.
Guido E
GE
D'Aniello
Division of Neurology and Neuro-Rehabilitation, IRCCS Istituto Auxologico Italiano, Ospedale San Giuseppe, Piancavallo (VCO), Italy.
Giovani
G
Albani
Psychology Research Laboratory, IRCCS Istituto Auxologico Italiano, Ospedale San Giuseppe, Piancavallo (VCO), Italy.|Department of Psychology,Università Cattolica del Sacro Cuore, Milan, Italy.
Gianluca
G
Castelnuovo
Psychology Research Laboratory, IRCCS Istituto Auxologico Italiano, Ospedale San Giuseppe, Piancavallo (VCO), Italy.
Erika
E
Ambiel
Centre for Cognitive Ageing and Cognitive Epidemiology, University of Edinburgh, UK.|Department of Psychology, University of Edinburgh, UK.
Sarah E
SE
MacPherson
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D003071:Cognition / Q000502:physiology; D003072:Cognition Disorders / Q000175:diagnosis* / Q000209:etiology*; D056344:Executive Function / Q000502:physiology; D005260:Female; D006801:Humans; D007360:Intelligence / Q000502:physiology; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D010300:Parkinson Disease / Q000150:complications*; D011340:Problem Solving / Q000502:physiology; D018709:Statistics, Nonparametric
Cognitive estimation; Cognitive impairments; Executive function; Neuropsychological test; Parkinson's disease