Recognition of emotions conveyed by facial expression and body postures in myotonic dystrophy (DM)

Neuromuscular diseases may be of neuropsychological interest insofar as they may affect representations based on embodied cognition theories. Previous studies have shown impaired ability to recognize facial emotions and an association between facial emotion recognition and visuospatial abilities in myotonic dystrophy type 1 (DM1) patients. Here we examined the ability of both DM1 and DM2 patients to recognize emotions expressed by body postures and its relation, and their association with cognitive performance.

Participants included 34 DM1 patients, 8 DM2 patients, and 24 healthy control subjects. Emotional recognition ability was assessed through two computerized matching tasks (face and bodies). A neuropsychological battery was used to measure cognition in three domains and global cognition. We used univariate and adjusted linear regression models to investigate the association between cognition and emotion recognition performance.

DM patients (combined DM1 and DM2) performed worse on emotional facial expression (p = .006) and body posture (p = .004) accuracy measures than healthy controls. In linear regression models, DM patients' facial expression accuracy was associated with executive function (p = .013) and visuospatial (p < .001) z-scores. Body posture accuracy was associated with visuospatial (p = .001) and memory (p = .012) z-scores. There were no associations among controls or between cognition and reaction time.

These findings suggest that impaired emotional recognition among DM patients is also extended to emotions conveyed by body postures. Consistent with embodied cognition theories, people affected in their body and its movement may have impaired sensorimotor representation in ways that have yet to be fully understood.