Parkinson’s disease impacts feedback production during verbal communication

The current study sought to investigate whether people with Parkinson’s disease (PwPD) produce less feedback than typical people, thus potentially making it more difficult for them to reach mutual comprehension with their conversational partner. In order to do this, a matching task experiment was conducted during which an experimenter described abstract pictures to a participant, who was either a PwPD or a typical participant, so that he or she could organise these pictures in a grid. The participants could produce as much feedback as they liked. The analysis of the utterances produced by the participants revealed that PwPD produced less feedback than typical participants. This effect was mainly driven by two specific types of feedback: acknowledgment tokens and hesitations. From a theoretical perspective, this paper is one of the firsts to specifically document the production of feedback markers in PwPD. Clinical implications are also discussed.