Habits of Social Interaction and Their Disruption in Parkinson's Disease

Humans' social lives are a series of performances in which they are actors trying to convey a message to their audiences. Over the years they develop habits of social interaction: They learn how to use facial expressions and body language to convey emotions and demeanor. They learn to control the physical expression of their emotions so that they discreetly convey their message. And they strive for consistency in social interactions, avoiding expression of conflicting messages that would confuse their audience. Parkinson's disease symptoms of rigidity, tremors, bradykinesia, and akinesia can hamper coordinated and effortless use of the body. Parkinson's disease highlights the theatrical nature of social interaction because the symptoms can make it difficult to communicate thoughts and feelings spontaneously.