Custom-molded headcases have limited efficacy in reducing head motion during naturalistic fMRI experiments

Abstract

Effectively minimizing head motion continues to be a challenge for the collection of functional magnetic resonance imaging (fMRI) data. The development of individual-specific custom molded headcases have been offered as a promising solution to minimizing motion during data collection, but to date, only a single published investigation into their efficacy exists in the literature. That study found headcases to be effective in reducing motion during short resting state fMRI scans (Power et al, 2019). In the present work, we examine the efficacy of these same headcases in reducing motion for a larger group of participants engaged in naturalistic scanning paradigms that consist of long movie-watching scans (~20-45min), as well as speaking aloud inside the MRI. Unlike previous work, we find no reliable reduction in head motion during movie viewing when comparing participants with headcases to those who were simply situated with foam pillows or foam pillows with medical tape. Surprisingly, we also find that for those wearing headcases, head motion is worse while talking relative to those situated with just foam pillows. These differences appear to be driven by large brief rotations of the head as well as translations in the z-plane as participants speak. Smaller, constant head movements appear equivalent with or without headcases. The largest reductions in head motion are observable when participants were situated with both foam pillows and medical tape, consistent with recent work by Kraus and colleagues (2019). Altogether, this work suggests that in a non-clinical, non-developmental population, custom-molded headcases may provide limited efficacy in reducing head motion beyond existing tools available to researchers. We hope this work can help improve the quality of custom headcases, motivate the investigation of additional solutions, as well as help researchers make more informed decisions about their data acquisition procedures.

HALO: A software tool for real‐time head alignment in the MR scanner

“…Physical constraint measures such as head molds/stabilizers are supposedly helpful in ensuring consistent positioning but are also known to introduce discomforts. Moreover, recent analysis pooling multiple fMRI datasets failed to confirm the effectiveness of these head molds 15 . HALO provides an alternative to these options that enables head position to be aligned across sessions to maintain consistent relationships between brain tissue and the B0 field and does not require access to 3D printers or introduce extra discomfort during the scan.…”

Predicting multiscan MRI outcomes in children with neurodevelopmental conditions following MRI simulator training

“…Scans including prospective motion correction have been shown promising for structural scans (e.g., T1-weighted) ( Ai et al, 2020 ). CaseForge has been shown to be effective at reducing head motion in small samples of children and two adults completing R-fMRI ( Power et al, 2019 , Lynch et al, 2021 ), but not in another sample of adults completing task-fMRI ( Jolly et al, 2020 , 2021 ). The role of CaseForge in limiting motion for longer multimodal scan sessions including different structural scans is also unknown.…”

The promises and pitfalls of functional magnetic resonance imaging hyperscanning for social interaction research

“…For instance, in fMRI, motion can negatively affect data quality: motion artifacts produce systematic decreases in and variable disruptions of fMRI signal (Power et al., 2012). People need to move their mouths when speaking, and state‐of‐the‐art methods of reducing speaking‐related motion (via personalized 3D printed head cases) do not appear to be effective (Jolly et al., 2020). To what extent might movement disrupt the quality of different neural measures (e.g., response magnitude in brain regions across the brain, spatial patterns, neural coupling)?…”