Interference Effects from Observed Movement in Parkinson's Disease

Previous research has demonstrated that Parkinson’s disease patients have an increased susceptibility to response conflict. Here, we investigate whether Parkinson patients have a similar sensitivity to interference from observed movements. Ten patients and ten controls performed horizontal and vertical arm movements, while watching a video of a person performing similar movements or a moving dot. Movements were performed in the same plane (congruent) and orthogonal to the observed movement (incongruent). The off-axis variance of movements was our index of interference. While patients tended to exhibit more off-axis variability than controls, both groups demonstrated similar congruence effects, with greater variance in incongruent conditions. These results indicate that increased susceptibility to interference in Parkinson’s disease does not extend to interference from observed movements