The neural correlates of orienting: An integration of fMRI and skin conductance orienting

In fMRI studies, the averaging of neural activity across multiple trials mi ght obscure important psychophysiological subprocesses. The orienting respo nse (OR) is a distinctive subprocess signalling the active orientation of a ttention towards potentially significant events. We sought to elucidate fMR I activity associated with visual stimuli that did or did not evoke simulta neously recorded electrodermal ORs (using customised skin conductance recor ding). 'With-OR' stimuli were associated with significant activity in the h ippocampus, anterior cingulate and ventromedial prefrontal cortex. Averaged analysis revealed activity only in the expected visual circuits. Our resul ts suggest that potentially significant stimuli (with-OR) activate differen t functional networks to familiar (without-OR) stimuli, and that orienting may therefore be an informative subprocess to consider in cognitive fMRI st udies. NeuroReport 11:3011-3015 (C) 2000 Lippincott Williams & Wilkins.