Mismatching Expressions: Spatiotemporal and Kinematic Differences in Autistic and Non-Autistic Facial Expressions

Area of Science:

• Neuroscience
• Psychology
• Human-Computer Interaction

Background:

• Preliminary research indicates differences in facial expressions between autistic and non-autistic individuals.
• It remains unclear if these differences persist after accounting for facial morphology and alexithymia, or if production differences correlate with perception differences.

Purpose of the Study:

• To comprehensively compare the spatiotemporal and kinematic properties of autistic and non-autistic facial expressions, controlling for facial morphology and alexithymia.
• To investigate the relationship between facial expression production and emotion perception in autistic and non-autistic adults.

Main Methods:

• Utilized facial motion capture to record cued and spoken expressions of anger, happiness, and sadness from autistic and matched non-autistic adults.
• Extracted spatiotemporal and kinematic data (activation, jerkiness) from facial landmarks across time.
• Administered an emotion recognition task to all participants.

Main Results:

• Autistic participants used the mouth more and eyebrows less for anger; produced less exaggerated smiles for happiness; and used the upper lip more for sadness.
• Alexithymia was associated with less differentiated expressions of anger and happiness.
• For non-autistic individuals, precise spoken expressions correlated with higher emotion recognition accuracy, but no production factors influenced autistic emotion recognition.

Conclusions:

• Significant differences exist in the facial expression production of autistic and non-autistic individuals, even after controlling for confounding factors.
• The observed production-perception mismatch may contribute to mutual difficulties in emotion recognition between autistic and non-autistic individuals, suggesting distinct communication patterns.
• Facial expressions in autism may represent a different 'language' of emotional communication compared to neurotypical individuals.