Investigating Humor Processing in Parkinson's Disease
Abstract
Dopamine has a demonstrated role in humor processing. Humor comprehension (i.e., “getting the joke”) relies on dorsal striatum (DS) mediated problem-solving mechanisms, whereas humor appreciation (i.e., “funniness”) relies on ventral striatum (VS) mediated reward processing. Despite this, relatively little research has been conducted on potential deficits in humor processing in Parkinson’s disease (PD). The present study investigated the comprehension (i.e., categorization as jokes or non-jokes) and appreciation (i.e., funniness ratings) of verbal jokes and non-jokes in PD patients and healthy age-matched controls while ON and OFF levodopa medication. Relative to controls, PD patients demonstrated reduced humor comprehension in the form of decreased accuracy identifying non-humorous stimuli. Furthermore, controls found jokes to be less funny while ON medication. This suggests that dopamine hypoactivity in the DS of PD patients could contribute to problems understanding humor, whereas levodopa can reduce the rewarding nature of humor via overdose of the VS.