Journal of Neuroscience Methods 213 (2013) 32–38 Contents lists available at SciVerse ScienceDirect Journal of Neuroscience Methods journa l h omepa g e: www.elsevier.com/locate/jneumeth Basic Neuroscience Design and evaluation of an innovative MRI-compatible Braille stimulator with high spatial and temporal resolution Weronika Debowska a,∗ , Tomasz Wolak b , Pawel Soluch c , Mateusz Orzechowski d , Malgorzata Kossut a,e a Department of Molecular and Cellular Neurobiology, Nencki Institute of Experimental Biology, 3 Pasteur St., 02093 Warsaw, Poland b Bioimaging Research Center, World Hearing Center, 17 Mokra St., 05830 Kajetany/Nadarzyn, Poland c Institute of Sensory Analysis, 1 Plowiecka St., 04501 Warsaw, Poland d Neuro Device Group LLC, 1 Plowiecka St., 04501 Warsaw, Poland e University of Social Sciences and Humanities, 19/31 Chodakowska St., 03815 Warsaw, Poland h i g h l i g h t s ◮ Experimental evaluation of the MRI- compatible tactile stimulator. ◮ Same-different discrimination task on Braille characters. ◮ Validity of using spatially and tem- porally precise tactile stimuli. g r a p h i c a l a b s t r a c t a r t i c l e i n f o Article history: Received 17 September 2012 Received in revised form 4 December 2012 Accepted 6 December 2012 Keywords: Braille Tactile stimulation Blind Visually impaired Event-related fMRI a b s t r a c t Neural correlates of Braille reading have been widely studied with different neuroimaging techniques. Nevertheless, the exact brain processes underlying this unique activity are still unknown, due to subopti- mal accuracy of imaging and/or stimuli delivery methods. To study somatosensory perception effectively, the stimulation must reflect parameters of the natural stimulus and must be applied with precise timing. In functional magnetic resonance imaging (fMRI) providing these characteristics requires technologically advanced solutions and there have been several successful direct tactile stimulation devices designed that allow investigation of somatotopic organization of brain sensory areas. They may, however, be of limited applicability in studying brain mechanisms related to such distinctive tactile activity as Braille reading. In this paper we describe the design and experimental evaluation of an innovative MRI-compatible Braille Character Stimulator (BCS) enabling precise and stable delivery of standardized Braille characters with high temporal resolution. Our device is fully programmable, flexible in stimuli delivery and can be easily implemented in any research unit. The Braille Character Stimulator was tested with a same- different discrimination task on Braille characters during an event-related fMRI experiment in eleven right-handed sighted adult subjects. The results show significant activations in several cortical areas, including bilateral primary (SI) and secondary somatosensory (SII) cortices, bilateral premotor and sup- plementary motor areas, inferior frontal gyri, inferior temporal gyri and precuneus, as well as contralateral (to the stimulated hand) thalamus. The results validate the use of the BCS as a method of effective stimuli application in fMRI studies, in both sighted and visually impaired subjects. © 2012 Elsevier B.V. All rights reserved. ∗ Corresponding author at: Laboratory of Neuroplasticity, Department of Molec- ular and Cellular Neurobiology, Nencki Institute of Experimental Biology, 3 Pasteur Street, 02093 Warsaw, Poland. Tel.: +48 225892248. E-mail address: w.debowska@nencki.gov.pl (W. Debowska). 1. Introduction Functional magnetic resonance imaging (fMRI) is now a widely used non-invasive method to study the functional organiza- tion of the human brain. Besides its great scientific value, the 0165-0270/$ – see front matter © 2012 Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.jneumeth.2012.12.002