Researchers study impact of head movement on fMRI data

February 19, 2014

Kessler Foundation researchers have shown that discarding data from subjects with multiple sclerosis (MS) who exhibit head movement during functional magnetic resonance imaging (fMRI) may bias sampling away from subjects with lower cognitive ability. The study was published in the January issue of Human Brain Mapping. (Wylie GR, Genova H, DeLuca J, Chiaravalloti N, Sumowski JF. Functional MRI movers and shakers: Does subject-movement cause sampling bias.) Glenn Wylie, DPhil, is associate director of Neuroscience in Neuropsychology & Neuroscience Research at Kessler Foundation. He is also associate director of the Neuroimaging Center at Kessler Foundation, and an associate professor at Rutgers - New Jersey Medical School.

Because during fMRI degrades data quality, data associated with severe movement is frequently discarded as a source of random error. Kessler Foundation scientists tested this assumption in 34 persons with MS by examining whether head movement was related to task difficulty and cognitive status. Cognitive status was assessed by combining performance on a working memory and processing speed task.

"We found an interaction between task difficulty and cognitive status," explained Dr. Wylie. "As task difficulty increased, there was a linear increase in movement that was larger among subjects with lower cognitive ability." Healthy controls showed similar, though far smaller, effects. This finding indicates that discarding data with severe movement artifact may bias MS samples such that only subjects with less-severe cognitive impairment are included in the analyses. However, even if such data are not discarded outright, subjects who move more will contribute less to the group-level results because of the poor quality of their data.

It is important for researchers to be aware of this potential . "Some newer scanners can correct for motion," noted Dr. Wylie. "Another approach is to monitor each subject's motion parameters and ensure that an adequate number of subjects with low cognition are included. Recruiting a large number of subjects may ensure inclusion of a sufficient number of people with low cognition/low movement. It is however, a costly option."

Explore further: Study reports greater brain activation after cognitive rehabilitation for MS

Related Stories

MS researchers study predictors of employment status

January 31, 2014

Researchers at Kessler Foundation have studied the measurement tools used in multiple sclerosis for their effectiveness in predicting employment status. They compared the Expanded Disability Status Scale (EDSS), the Multiple ...

Recommended for you

New insights on how cocaine changes the brain

November 25, 2015

The burst of energy and hyperactivity that comes with a cocaine high is a rather accurate reflection of what's going on in the brain of its users, finds a study published November 25 in Cell Reports. Through experiments conducted ...

Can physical exercise enhance long-term memory?

November 25, 2015

Exercise can enhance the development of new brain cells in the adult brain, a process called adult neurogenesis. These newborn brain cells play an important role in learning and memory. A new study has determined that mice ...

Umbilical cells help eye's neurons connect

November 24, 2015

Cells isolated from human umbilical cord tissue have been shown to produce molecules that help retinal neurons from the eyes of rats grow, connect and survive, according to Duke University researchers working with Janssen ...

Brain connections predict how well you can pay attention

November 24, 2015

During a 1959 television appearance, Jack Kerouac was asked how long it took him to write his novel On The Road. His response – three weeks – amazed the interviewer and ignited an enduring myth that the book was composed ...


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.