Pattern classification of volitional functional magnetic resonance imaging responses in patients with severe brain injury

Arch Neurol. 2012 Feb;69(2):176-81. doi: 10.1001/archneurol.2011.892.


Background: Recent neuroimaging investigations have explored the use of mental imagery tasks as proxies for an overt motor response, in which patients are asked to imagine performing a task, such as "Imagine yourself swimming."

Objectives: To detect covert volitional brain activity in patients with severe brain injury using pattern classification of the blood oxygenation level-dependent (BOLD) response during mental imagery and to compare these results with those of a univariate functional magnetic resonance imaging analysis.

Design: Case-control study.

Setting: Academic research.

Participants: Experiments were performed in 8 healthy control subjects and in 5 patients with severe brain injury. The patients with severe brain injury constituted a convenience sample.

Main outcome measures: Functional magnetic resonance imaging data were acquired as the patients were asked to follow commands or to answer questions using motor imagery as a proxy response.

Results: In the controls, the responses were accurately classified. In the patient group, the responses of 3 of 5 patients were correctly classified. The remaining 2 patients showed no significant BOLD response in a standard univariate analysis, suggesting that they did not perform the task. In addition, we showed that a classifier trained on command-following data can be used to evaluate a later communication run. This technique was used to successfully disambiguate 2 potential BOLD responses to a single question.

Conclusions: Pattern classification in functional magnetic resonance imaging is a promising technique for advancing the understanding of volitional brain responses in patients with severe brain injury and may serve as a powerful complement to traditional general linear model-based univariate analysis methods.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Behavior
  • Brain Injuries / pathology*
  • Brain Injuries / psychology
  • Case-Control Studies
  • Data Interpretation, Statistical
  • Female
  • Humans
  • Image Processing, Computer-Assisted / methods*
  • Imagination / physiology
  • Magnetic Resonance Imaging / classification*
  • Magnetic Resonance Imaging / methods*
  • Male
  • Middle Aged
  • Motor Cortex / pathology
  • Oxygen / blood
  • Persistent Vegetative State / etiology
  • Persistent Vegetative State / pathology
  • Quadriplegia / etiology
  • Quadriplegia / pathology
  • Young Adult


  • Oxygen