Parkinson’s disease(PD)isassociatedwithmotorandnon-motorrigiditysymptoms(e.g.,cognitiveand
personality). ThequestionisraisedastowhetherrigidityinPDalsoextendstoperception,andifso,
whether perceptual,cognitive,andpersonalityrigiditiesarecorrelated.Bistablestimuliwerepresented
to 28non-dementedindividualswithPDand26normalcontroladults(NC).Neckercubeperceptionand
binocular rivalrywereexaminedduringpassiveviewing,andtheNeckercubewasadditionallyusedfor
two volitional-controlconditions: Hold one perceptinfront,and Switch between thetwopercepts.Re-
lativetopassiveviewing,PDweresignificantly lessablethanNCtoreducedominancedurationsinthe
Switch condition, indicatingperceptualrigidity.Testsofcognitive flexibilityandapersonalityques-
tionnaire wereadministeredtoexploretheassociationwithperceptualrigidity.Cognitive flexibilitywas
not correlatedwithperceptualrigidityforeithergroup.Personality(noveltyseeking)correlatedwith
dominance durationsonNeckerpassiveviewingforPDbutnotNC.Theresultsindicatethepresencein
mild-moderatePDofperceptualrigidityandsuggestsharedneuralsubstrateswithnoveltyseeking,but
functional divergencefromthosesupportingcognitive flexibility.Thepossibilityisraisedthatperceptual
rigidity maybeaharbingerofcognitiveinflexibilitylaterinthediseasecourse.