Speeded near infrared spectroscopy (NIRS) response detection

PLoS One. 2010 Nov 11;5(11):e15474. doi: 10.1371/journal.pone.0015474.

Abstract

The hemodynamic response measured by Near Infrared Spectroscopy (NIRS) is temporally delayed from the onset of the underlying neural activity. As a consequence, NIRS based brain-computer-interfaces (BCIs) and neurofeedback learning systems, may have a latency of several seconds in responding to a change in participants' behavioral or mental states, severely limiting the practical use of such systems. To explore the possibility of reducing this delay, we used a multivariate pattern classification technique (linear support vector machine, SVM) to decode the true behavioral state from the measured neural signal and systematically evaluated the performance of different feature spaces (signal history, history gradient, oxygenated or deoxygenated hemoglobin signal and spatial pattern). We found that the latency to decode a change in behavioral state can be reduced by 50% (from 4.8 s to 2.4 s), which will enhance the feasibility of NIRS for real-time applications.

Publication types

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

MeSH terms

  • Adult
  • Algorithms
  • Brain / physiology*
  • Brain Mapping
  • Female
  • Fingers / innervation
  • Fingers / physiology*
  • Humans
  • Male
  • Motor Cortex / physiology
  • Movement
  • Neurofeedback / physiology
  • Psychomotor Performance / physiology*
  • Spectroscopy, Near-Infrared / methods*
  • Task Performance and Analysis
  • Young Adult