Visual attention and autistic behavior in infants with fragile X syndrome

Area of Science:

• Neurodevelopmental disorders
• Pediatric psychology
• Autism spectrum disorder research

Background:

• Aberrant attention is a hallmark of fragile X syndrome (FXS), yet its developmental course and physiological underpinnings remain unclear.
• Atypical visual attention patterns are recognized early indicators of autism in idiopathic autism spectrum disorder.
• Understanding attention development in FXS is crucial for early identification and intervention strategies.

Purpose of the Study:

• To investigate the developmental trajectory of visual attention in infants with FXS.
• To explore the physiological correlates of attention deficits using heart activity and gaze direction.
• To compare visual attention in infants with FXS to typically developing infants.

Main Methods:

• A biobehavioral approach was employed, analyzing gaze direction and heart activity.
• Infants with FXS were studied at 9, 12, and 18 months of age.
• A cross-sectional comparison was made with typically developing 12-month-old infants.

Main Results:

• Infants with FXS at 12 months exhibited lower heart rate (HR) variability and shallower HR decelerations compared to controls.
• Prolonged visual look durations were observed in 12-month-old infants with FXS.
• Longer look durations and increased latency to disengage attention were associated with greater autistic behavior severity, independent of mental age.

Conclusions:

• Infants with fragile X syndrome display distinct visual attention patterns and physiological responses from early infancy.
• These attention differences, particularly prolonged engagement and difficulty disengaging, are linked to the severity of autistic behaviors.
• The findings highlight the importance of biobehavioral markers for understanding attention deficits in FXS and their relation to autism.