Causal contributions of the left frontal eye field to conscious perception

Abstract

The quest for the neural correlates of consciousness has led to controversial results. When contrasting consciously seen versus unseen stimuli, some authors have proposed that consciousness is related to activity in visual areas along the ventral cortical visual stream, while others propose the implication of parietal and frontal regions (Dehaene and Changeux 2011). When invisibility is caused by neglect or inattention, high levels of activity recorded in early visual areas (Vuilleumier et al. 2001) suggest that further activity in fronto-parietal regions might be necessary for conscious perception. Recent functional magnetic resonance imaging evidence (Chica, Paz-Alonso, et al. 2012) suggested a key role for the left frontal eye field (FEF) in the attentional modulation of visual consciousness. Here, we used the high temporal resolution and causal power of event-related transcranial magnetic stimulation to explore the causal contributions of the left FEF on conscious perception and to assess whether or not these effects are mediated by the orienting of spatial attention. Our results provide the first causal evidence on the contribution of the left FEF to conscious visual perception and indicate that such effects are likely to be mediated by its known role on attentional orienting.