PWS Patients Struggle with Certain Aspects of Social Cognition, Study Finds

People with Prader-Willi syndrome (PWS) have difficulty recognizing negative emotions throughout their lives, often confusing sadness with anger, a study reports.

In addition, they have trouble understanding the sincere intentions of others, the findings also showed.

The study, “Profiles and Trajectories of Impaired Social Cognition in People with Prader-Willi syndrome,” was published in the journal PLOS ONE.

PWS is associated with rigid thinking, resistance to change, inattention, and impulsivity, which result in significant social problems, such as problems forming relationships with peers, sustaining friendships, and getting along with others.

Social cognition refers to the ability of people to recognize and understand emotions, intentions, and behaviors in themselves and others.

In healthy people, these skills, including being able to recognize complicated emotions, normally evolves over time, leading to a more nuanced understanding of emotional expressions and social exchanges. As a result, adults are able to do these more complex tasks better than children or adolescents.

Only two domains of social cognition have been previously studied in PWS — theory of mind and emotion recognition — both finding deficits in these patients. Theory of mind refers to understanding others in a social world, i.e., the ability to correctly interpret desires, intentions, and beliefs of others. This skill normally develops between 3 and 5 years of age.

Researchers at Vanderbilt University Medical Center addressed two gaps in PWS knowledge: social perceptions, or how patients use cues to understand social situations, and whether emotion recognition and social perception skills develop with age.

The study included 94 participants with PWS, ages 5 to 62 (54.3% females), who were divided into three age groups at different developmental stages: 44 children, 5 to 10 years old; 34 adolescents, 11 to 19 years old; and 16 adults, 20 to 52 years old.

Standardized IQ tests, parent-reported measures of inattention and inflexibility, and standard emotion recognition photos (fear, sadness, anger, happiness) were used to measure emotion recognition and social perception at two time points, with an interval ranging between 1.5 to four years (average 2.3 years).

Social perception was also measured by showing the participants six brief videotaped vignettes using youth actors in a school setting to depict a problematic situation or negative event placing one of the characters at a disadvantage. Three videos depicted sincere/benign intentions and the other three insincere/hostile intentions. Participants were then asked to recall what happened and to judge whether the protagonist had been “mean.”

Results showed that PWS patients had trouble with recognizing negative emotions across different ages. In particular, they confused sadness with anger, which is typically resolved in early childhood, the researchers said.

People with a higher IQ were better at recognizing sadness. Although their ability to detect the social cues in the videos improved with time, no such improvements were seen in judging the intentions of others, particularly when drawing conclusions about sincere or benign intentions (followed by apologies).

In contrast, the participants were significantly better at detecting negative social cues, and judging trickery, deceit, and lying.

“Many people with PWS have deficits in recognizing sad, anger and fear, and accurately perceiving the sincere intentions of other people,” the researchers wrote.

Although the impact of these deficits on social behavior and relationships needs to be better understood, the findings “have novel implications for interventions to help people with PWS strengthen or acquire specific social cognition skills,” they added.