title: Microcontroller based fibre-optic visual presentation system for multisensory neuroimaging.
abstract: Presenting visual stimuli in physical 3D space during fMRI experiments carries significant technical challenges. Certain types of multisensory visuotactile experiments and visuomotor tasks require presentation of visual stimuli in peripersonal space, which cannot be accommodated by ordinary projection screens or binocular goggles. However, light points produced by a group of LEDs can be transmitted through fibre-optic cables and positioned anywhere inside the MRI scanner. Here we describe the design and implementation of a microcontroller-based programmable digital device for controlling fibre-optically transmitted LED lights from a PC. The main feature of this device is the ability to independently control the colour, brightness, and timing of each LED. Moreover, the device was designed in a modular and extensible way, which enables easy adaptation for various experimental paradigms. The device was tested and validated in three fMRI experiments involving basic visual perception, a simple colour discrimination task, and a blocked multisensory visuo-tactile task. The results revealed significant lateralized activation in occipital cortex of all participants, a reliable response in ventral occipital areas to colour stimuli elicited by the device, and strong activations in multisensory brain regions in the multisensory task. Overall, these findings confirm the suitability of this device for presenting complex fibre-optic visual and cross-modal stimuli inside the scanner.
authors: School of Psychology and Cardiff University Brain Research Imaging Centre (CUBRIC), Cardiff University, CF10 3AT, United Kingdom. veldri@gmail.com
authors: Veldri
authors: V
authors: Kurniawan
authors: Jane
authors: J
authors: Klemen
authors: Christopher D
authors: CD
authors: Chambers
mesh_terms: D001921:Brain / Q000502:physiology; D001931:Brain Mapping / Q000295:instrumentation* / Q000379:methods; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging / Q000295:instrumentation / Q000379:methods; D010775:Photic Stimulation / Q000295:instrumentation* / Q000379:methods; D012984:Software; D014796:Visual Perception / Q000502:physiology