Functional magnetic resonance imaging (fMRI) experiments on tactile perception are difficult to perform because the special characteristics of an MRI environment restrict the experimental setup. Although recently developed actuators have made it possible to apply vibrotactile stimuli to the skin during an fMRI experiment, the projection of spatially extended patterns is still precluded. In order to examine the processing of tactile perception, a new pneumatically-driven tactile device (PTD) has been built. This device is capable of stimulating the skin, using arbitrary time sequences that consist of 2D tactile images up to 64 pixels. It is shown how the device is implemented in a 2 T fMRI environment, and show that it operates without generating artifacts. Dedicated software allows the generation of complex paradigms and provides a user-friendly interface to other brain mapping systems, as well as automated operation. This paper describes the PTD elucidates its features, and demonstrate its reliability by reporting results from an fMRI study based on an event-related protocol involving six subjects.Magn Reson Med 51:828 -834, 2004.

We have built and operated an interactive tactile graphics display based on 48 piezoelectric actuators assembled in a movable tactile output unit. The unit can be positioned at any location on a two dimensional surface to explore the structure of a virtual image. The virtual tactile display (VTD) can receive data either from a camera system or from a data base on a computer. Both static and dynamic patterns can be displayed. The maximun refresh rate of the tactile image is 20 Hz. This paper covers the technical description of an improved version of the virtual tactile display which takes into account all experience gained with an initial prototype. A short overview of the results obtained in tests done with 6 blind and 4 sighted subjects using the initial prototype shows the capacity of the underlying concept.

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