Tactile discrimination of grating orientation: fMRI activation patterns.

Grating orientation discrimination is employed widely to test tactile spatial acuity. We used functional magnetic resonance imaging (fMRI) to investigate the neural circuitry underlying performance of this task. Two studies were carried out.

Neural networks active during tactile form perception: common and differential activity during macrospatial and microspatial tasks.

Prior studies have shown that tactile perception recruits activity not only in somatosensory but also in visual cortical areas. The present study used functional magnetic resonance imaging to investigate the distribution of neural activity during tactile perception of 2D form. In a macrospatial form task, raised letters (uppercase T and V) were presented upside-down.