Symbolic sequence learning is associated with cognitive–affective profiles in female FMR1 premutation carriers

This study examines implicit sequence learning impairments that may indicate at‐risk cerebellar profiles proposed to underlie some aspects of subtle cognitive and affective dysfunctions found among female fragile X mental retardation 1 (FMR1) premutation (PM)‐carriers. A total of 34 female PM‐carriers and 33 age‐ and intelligence‐matched controls completed an implicit symbolically primed serial reaction time task (SRTT) previously shown to be sensitive to cerebellar involvement. Implicit learning scores indicated a preservation of learning in both groups; however, PM‐carriers demonstrated poorer learning through significantly elevated response latencies overall and at each specific block within the symbolic SRTT. Group comparisons also revealed a core deficit in response inhibition, alongside elevated inattentive symptoms in female PM‐carriers. Finally, strong and significant associations were observed between poor symbolic SRTT performance and executive, visuospatial and affective deficits in the PM‐carrier group. These associations remained strong even after controlling motor speed, and were not observed in age‐ and intelligence quotient‐matched participants. The findings implicate cerebellar non‐motor networks subserving the implicit sequencing of responses in cognitive–affective phenotypes previously observed in female PM‐carriers. We contend that symbolic SRTT performance may offer clinical utility in future pharmaceutical interventions in female PM‐carriers .