Investigating the Roles of the Dorsal and Ventral Striatum in Humor Comprehension and Appreciation Throughout Health, Aging, and Parkinson’s Disease
Abstract
Humor processing is thought to involve two distinct components. The first, humor comprehension, involves detecting and resolving incongruities that are present within a humorous stimulus. This is related to cognitive processes such as ambiguity resolution, response inhibition, working memory, and cognitive flexibility, functions that are mediated in part by the dorsal portion of the striatum (DS). Humor appreciation, on the other hand, refers to the subjective amusement and mirth that one experiences in response to a joke. This is related to reward processing, which implicates the ventral portion of the striatum (VS). Across three separate studies, we investigated the involvement of the DS and the VS in humor comprehension and appreciation (Chapter 2), the effects of aging on humor comprehension and appreciation and associated neural activation (Chapter 3), and finally, whether Parkinson’s disease (PD), the medication used to treat it, or the interaction between the two, influences humor comprehension and/or appreciation (Chapter 4). We found that in healthy young adults, the DS and the VS are implicated in humor comprehension, and the VS, but not the DS, is implicated in humor appreciation. We also found that humor comprehension ability is negatively affected by age, and that decreases in humor comprehension were related to reductions in DS activation in healthy older adults. Finally, we found that there is a humor comprehension deficit associated with PD that was not improved by dopaminergic medication.