Beyond Surface Performance: Analyzing Grammatical Production and Judgment Abilities in Boys With Fragile X Syndrome

Area of Science:

• Linguistics
• Developmental Psychology
• Neurodevelopmental Disorders

Background:

• Fragile X syndrome (FXS) is associated with morphosyntactic weaknesses, especially in finiteness markers.
• Existing research primarily focuses on grammatical production, with less attention to receptive grammatical judgment.
• Understanding both production and judgment is crucial for effective intervention in FXS.

Purpose of the Study:

• To investigate grammatical production and judgment in boys with FXS.
• To analyze patterns and individual differences in grammatical skills.
• To compare receptive grammatical judgment with grammatical production.

Main Methods:

• Thirty-three boys with FXS (aged 9-18) completed grammatical probes (third-person singular, BE/DO) and judgment tasks.
• Data analysis involved pattern analysis and categorization using a median split for production vs. judgment comparison.
• Unscorable responses were coded to ensure accurate assessment.

Main Results:

• Participants exhibited significant variability in both grammatical production and judgment, with mean scores below ceiling.
• Over half of the participants showed discrepant performance between production and judgment domains.
• Linguistic profiles were not correlated with chronological age or nonverbal cognitive ability.

Conclusions:

• Boys with FXS experience persistent difficulties in producing and judging finiteness markers, especially 'BE' forms.
• Significant heterogeneity exists in the linguistic profiles of individuals with FXS.
• Comprehensive assessment of both grammatical production and judgment is essential for tailored intervention in FXS.