Many spouses and partners complain that their loved one is sometimes clueless that a conversation is getting strained. The person with PD seems to miss some of the clues that the partner is not happy. There is probably no greater problem among couples with PD than relationship strain arising out of conversations that seem to go nowhere. Often, I hear this frustration described as lack of concern or attention on the part of the person with the PD.
The person with the PD may actually be getting the blame for a little-discussed problem arising from the disease rather than the person.
Although we are used to calling Parkinson’s disease a movement disorder, it can also described as a “communication altering illness” because of its impact on interactions with significant other people in one’s life. A growing body of research has documented many deficits in communication that impair social functioning.
The research suggests many people with PD have some difficulty recognizing emotional cues others express through voice and facial expressions. Missing indicators of how another person is feeling raises the possibility for blocked communication. The person with PD risks responding inappropriately, or even worse, not at all.
The brain is the locus of our interactions with the world. We understand this intuitively but often overlook the possibility that PD-related changes in the brain might change those interactions. However, the bulk of research on cognitive changes with Parkinsons has focused on memory, attention, language, spatial perception, and some of the higher level thought processes we identify with the somewhat enigmatic term “executive function.” Changes in these areas have been documented but they do not fully explain why some people with PD struggle with empathetic communication.
Only recently has research focused on how the disease might affect social cognition. This is the term for the array of brain activities that allow us to engage in meaningful social interactions. Perhaps not surprisingly, deficits in how individuals with PD perceive and process social cues have been documented. What’s more these changes are relatively independent of motor changes suggesting that are not simply a product of a movement disorder. For example, individuals with PD tend to have word-finding difficulties, difficulty generating words to a specific cue, and use a relatively simplified sentence structure when compared with neuorologically-intact individuals. People with PD may have mild deficits in comprehending sentences, may be less effective with their appreciation for verbal context, and demonstrate deficits in interpretation of figurative language. These changes may be somewhat mild in absolute terms but in the face of the subtleties that are so common in human communication, could be quite disruptive.
In addition to difficulties parsing the language of others, some people who have PD have difficulty reading expressed emotions, particularly negative ones such as anger, fear,sadness and disgust. That is, they are less able to identify the signals in the faces and voices of the people they interact with. A 2010 meta-analysis by Heather Gray and Linda Tickle-Degen combined the findings of many smaller studies to confirm these deficits were real. A later study by Sharon Buxton and colleagues (2013) found that identification of prototypical emotional cues was intact among individuals with PD; problems tended to arise when more subtle expressions of emotion were presented. Interestingly, the problems with emotion recognition appeared to exist independently of the depression so commonly seen among men and women with PD. Difficulties with emotion recognition, particularly when subtle, may make it more challenging to accurately appraise interactional data resulting in increased interpersonal stress. PD-related deficits in emotion identification correlate with social frustration and feelings of lost connectedness suggesting that this may be one reason for decline in quality of life above and beyond the impact of motor problems.
The mechanism for the problems with accurate assessment of emotions from the rhythm, intonation, and stressed components of speech of others may be partly a function of higher order brain changes in the area of the frontal lobes of the brain. For example, vocal inflections can alter the meaning of a simple statement such as “You really understand me” depending on whether the speaker is being sarcastic or expressing honest appreciation. PD-related deficits in interpreting the prosodic elements of speech can cause misinterpretation of the speaker’s intent.
The accurate assessment of emotion from facial expressions in others may also have frontal lobe inputs but the area of the brain associated with movement difficulties, the basal ganglia also share connections with portions of the brain known to be involved in emotion interpretation. A 2014 study by Michelle Marneweck’s team found that the level of voluntary control in facial musculature was correlated with accuracy in emotional identification even when age and overall disease severity werecontrolled for. Recent theories about how humans perceive emotions have suggested that a covert process of emotional simulation may be in play. Thus, impaired covert mimicry of observed expressions may play a role in the deficits observed among individuals with PD. Their facial muscles are less able to translate the mimicry into an accurate assessment of another person’s emotional status.
It appears possible that facial masking may obscure more than the internal state of the person with PD.
There is evidence that interpersonal difficulties are common with PD and tend to have a greater impact on quality of life. Many spouses and partners complain that the person with PD doesn’t seem to understand them and can seem oblivious to how upset their loved one really is. I frequently hear of emotions of a significant other boiling over, much to the surprise of the person with PD. “I don’t understand what happened,” is a common description by the person with PD.
In my work with couples, I have begun to make communication patterns a central part of what I do. When I can help a person with PD more accurately assess what is going emotionally with their partner, I find the work on other aspects of PD proceeds more smoothly.