This article is part of the Research Topic Neurovascular imaging

Original Research ARTICLE

Front. Neuroenergetics, 14 June 2010 | http://dx.doi.org/10.3389/fnene.2010.00012

High-resolution optical functional mapping of the human somatosensory cortex

  • 1 Berlin NeuroImaging Center, Charité Universitätsmedizin Berlin, Berlin, Germany
  • 2 Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany
  • 3 NIRx Medizintechnik GmbH, Berlin, Germany
  • 4 Day Care Clinic for Cognitive Neurology, University Hospital Leipzig, Leipzig, Germany
  • 5 Berlin School of Mind and Brain, Humboldt University Berlin, Germany
  • 6 Center for Stroke Research Berlin, Universitätsmedizin Berlin, Germany

Non-invasive optical imaging of brain function has been promoted in a number of fields in which functional magnetic resonance imaging (fMRI) is limited due to constraints induced by the scanning environment. Beyond physiological and psychological research, bedside monitoring and neurorehabilitation may be relevant clinical applications that are yet little explored. A major obstacle to advocate the tool in clinical research is insufficient spatial resolution. Based on a multi-distance high-density optical imaging setup, we here demonstrate a dramatic increase in sensitivity of the method. We show that optical imaging allows for the differentiation between activations of single finger representations in the primary somatosensory cortex (SI). Methodologically our findings confirm results in a pioneering study by Zeff et al. (2007) and extend them to the homuncular organization of SI. After performing a motor task, eight subjects underwent vibrotactile stimulation of the little finger and the thumb. We used a high-density diffuse-optical sensing array in conjunction with optical tomographic reconstruction. Optical imaging disclosed three discrete activation foci one for motor and two discrete foci for vibrotactile stimulation of the first and fifth finger, respectively. The results were co-registered to the individual anatomical brain anatomy (MRI) which confirmed the localization in the expected cortical gyri in four subjects. This advance in spatial resolution opens new perspectives to apply optical imaging in the research on plasticity notably in patients undergoing neurorehabilitation.

Keywords: near-infrared spectroscopy, optical imaging, optical tomography, somatotopy, somatosensory system, vibrotactile stimulation

Citation: Koch SP, Habermehl C, Mehnert J, Schmitz CH, Holtze S, Villringer A, Steinbrink J and Obrig H (2010) High-resolution optical functional mapping of the human somatosensory cortex. Front. Neuroenerg. 2:12. doi: 10.3389/fnene.2010.00012

Received: 25 February 2010; Paper pending published: 30 March 2010;
Accepted: 26 May 2010; Published online: 14 June 2010

Edited by:

David Boas, Massachusetts General Hospital, USA; Massachusetts Institute of Technology, USA; Harvard Medical School, USA

Reviewed by:

Theodore Huppert, University of Pittsburgh Medical Center, USA
Joseph P. Culver, Harvard Medical School, USA

Copyright: © 2010 Koch, Habermehl, Mehnert, Schmitz, Holtze, Villringer, Steinbrink and Obrig. This is an open-access article subject to an exclusive license agreement between the authors and the Frontiers Research Foundation, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are credited.

*Correspondence: Stefan P. Koch, Berlin NeuroImaging Center, Department of Neurology, Charité University Hospital, Chariteplatz 1, 10117 Berlin, Germany. e-mail: stefan.koch@charite.de