Cross-correlation technique to identify activated pixels in a three-condition fMRI task

Most fMRI studies are conducted with a stimulus `on´ and a stimulus `off´ or control state to delineate pixels activated during a two-condition presentation. The authors have developed a novel cross-correlation technique that is not restricted to two conditions and could be applied to delineate pixels activated in multi-condition tasks. A logic-based analysis to form functional images where each pixel shows highest correlation with a specified reference function has also been developed. Using motor stimulation as an example and using right and left hand movements to represent conditions 1 and 2 respectively, and no movement as condition 3, results of images generated through a three-condition processing technique are in good agreement with images generated through two separate two-condition experiments