Identifying cortical columns for slow/rapid vibrotactile stimulation in human S1 using 7T fMRI.

COEX 

Cortical columns are functionally distinct units of the cerebral cortex that are organized perpendicular to cortical layers and typically process similar types of information (e.g., orientation preference). The extensive identification of cortical columns across the cortex has led some to propose that columnar organization might be a fundamental principle of the entire neocortex. However, evidence for such columnar organization in the human primary somatosensory cortex (S1) remains limited (see [1, 2]).

Columnar organization presumed to relate to slowly adapting (SA) and rapidly adapting (RA) receptors, has been identified in primate SI [3,4]. Recent studies, however, suggest that S1 neurons are organized by feature selectivity (e.g., shape, movement, vibration) rather than strictly by receptor type [5]. Despite this, there may still be columnar organization in human S1 related to processing specific frequencies, such as 3Hz (SA, intermittent pressure) and 30Hz (RA, vibration), which merits further research [6].

Here, we seek to adapt approaches proven effective in identifying visual columns (e.g., ocular dominance) using UHF fMRI to probe for SI columnarity.