Executive Response Monitoring and Inhibitory Control in Children With Phenylketonuria: Effects of Expectancy

Abstract

Response monitoring (post-error slowing) and inhibitory control (commission errors) were examined in children with phenylketonuria (PKU) and controls (6–18 years) using Go/No-Go tasks with higher (PKU n = 37; control n = 55) versus lower (PKU n = 24; control n = 25) non-target expectancy. On both tasks children with PKU exhibited impaired monitoring and inhibitory control, but the post-error slowing pattern was different. With higher expectancy children with PKU slowed more (less efficient monitoring) and with lower expectancy slowed less (less monitoring) than controls. No effects of age or phenylalanine level were noted. These results indicate that expectancy differentially effects monitoring and inhibitory control in PKU.

ACKNOWLEDGMENTS

The authors thank Laurie Sprietsma and Kathleen Huntington for their contributions to the study. The authors also express their appreciation of the work of Evonne Timmermann, who passed away, for her dedication to the betterment of the lives of children with neurodevelopmental disorders.

This research was supported by the National Institute of Child Health and Human Development grant R01HD044901 and by the National Institute of General Medical Sciences grant T32GM081739.