fMRI based BCI control using spatial visual attention at 7T

Abstract

In this study we have investigated the potential of using visual attention as a control-method for Brain-Computer-Interfaces (BCI). We show using high-field (7T) fMRI that subjects can control their visuospatial attention and that the BOLD effect is strong enough to base a reliable control-signal on. The strength and location of activation was determined for six subjects. In an additional experiment two of the subjects got real-time feedback based on the activation in the activated regions.

Real-time decoding of covert attention in higher-order visual areas

“…Andersson et al. used primary retinotopic cortex for a rt-fMRI BCI, decoding spatial attention at 7 T. Participants covertly directed attention to a high contrast grating or a high luminescence arrow ( Andersson et al., 2013b , Andersson et al., 2012 , Andersson et al., 2011 , Andersson et al., 2010 , Andersson et al., 2009 ). Accuracy for four-quadrant decoding reached 79% on average.…”

“…These regions may therefore act as sites of top-down modulation, or serve as ‘binding’ points for multiple sources of information, including object and spatial information. As a result, the neural activity produced in these regions may offer a high signal-to-noise ratio ( Gattass et al., 2005 , Sclar et al., 1990 , Serences and Yantis, 2007 ) for the successful implementation of a BCI decoding command signals modulating higher order visual information linked to the allocation of visual attention ( Andersson et al., 2011 , Andersson et al., 2009 , Astrand et al., 2014 , Bahramisharif et al., 2010 ).…”