Head Motion and Inattention/Hyperactivity Share Common Genetic Influences: Implications for fMRI Studies of XXXX .

@entity135 @entity71 @entity28927
@entity135 ( @entity135 ) is a well known confound in analyses of functional MRI (fMRI) data. Neuroimaging researchers therefore typically treat @entity135 as a nuisance covariate in their analyses. Even so, it is possible that @entity135 shares a common genetic influence with the trait of interest. Here we investigate the extent to which this relationship is due to shared genetic factors, using @entity135 extracted from resting-state fMRI and maternal and self report measures of Inattention and Hyperactivity-Impulsivity from the Strengths and Weaknesses of @entity71 Symptoms and Normal Behaviour ( @entity28927 ) scales. Our sample consisted of healthy young adult twins (N = 627 (63% females) including 95 MZ and 144 DZ twin pairs, mean age 22, who had mother-reported @entity28927 ; N = 725 (58% females) including 101 MZ and 156 DZ pairs, mean age 25, with self reported @entity28927 ). This design enabled us to distinguish genetic from environmental factors in the association between head movement and @entity71 scales. @entity135 was moderately correlated with maternal reports of Inattention (r = 0.17, p-value = 7.4E-5) and Hyperactivity-Impulsivity (r = 0.16, p-value = 2.9E-4), and these associations were mainly due to pleiotropic genetic factors with genetic correlations [95% CIs] of rg = 0.24 [0.02, 0.43] and rg = 0.23 [0.07, 0.39]. Correlations between self-reports and @entity135 were not significant, due largely to increased measurement error. These results indicate that treating @entity135 as a nuisance covariate in neuroimaging studies of @entity71 will likely reduce power to detect between-group effects, as the implicit assumption of independence between @entity135 and Inattention or Hyperactivity-Impulsivity is not warranted. The implications of this finding are problematic for fMRI studies of @entity71 , as failing to apply @entity135 correction is known to increase the likelihood of false positives. We discuss two ways to circumvent this problem: censoring the motion contaminated frames of the RS-fMRI scan or explicitly modeling the relationship between @entity135 and Inattention or Hyperactivity-Impulsivity.
