The influence of head motion on intrinsic functional connectivity MRI

“…However, such effects would tend to increase connectivity globally; this is at odds with prior reports (including our own) that motion tends to increase connectivity for short-range connections, and decrease connectivity for long-range connections (VanDijk et al, 2011; Power et al, 2011; Satterthwaite et al, 2012). We suspected that the inclusion of the global signal in confound regression might influence the impact of motion artifact on functional connectivity measures and produce this pattern of results.…”

“…Within the human functional connectome, densely interconnected brain regions are organized into well-defined functional networks, subserving sensory, motor, and cognitive functions. Our findings indicate that this network organization is stable between 10 and 26 y of age, countering earlier findings that suggested developmental changes in network organization reflect a shift from localized to distributed organization, which may have been confounded by head motion artifact [ 17 , 21 , 22 , 45 , 46 ]. The current study applied a wide array of advanced preprocessing steps to limit head motion artifact, including wavelet despiking [ 47 ], simultaneous bandpass filtering the time series data and nuisance regressors [ 23 ], as well as scrubbing [ 21 ].…”

“…For BpReg, consistent with previous reports (Van Dijk et al, 2012; Satterthwaite et al, 2012), head motion was associated with larger functional connectivity estimates for short-range connections (see Figure 7, top panel), although the motion–connectivity association was significantly positive regardless of distance ( adj. ps < .0001).…”