Another element of novelty in our study is that, unlike most previous fMRI studies, we found a relationship between activity in the dorsal system and orienting of attention toward task-irrelevant locations. Here, subjects did not perform any task and salient locations were computed only on the basis of low-level features (local disparities in color, intensity, and line orientations). Our fMRI results

extend electrophysiological data reporting that parietal and premotor neurons are modulated both by intrinsically catching and by behaviorally relevant stimuli (see Gottlieb et al., 1998, Constantinidis and Steinmetz, 2001 and Thompson et al., 2005), here showing activation of these areas when salient locations become behaviorally relevant (i.e., when they trigger a shift of gaze/attention). This indicates selleck chemicals llc that the dorsal fronto-parietal network combines

bottom-up and endogenous signals to guide spatial attention, consistent with the hypothesis that the dorsal attention network represents current selleck screening library attentional priorities (Gottlieb, 2007). For the Entity video we considered transient brain activations associated with the appearance of human-like characters. We found that these unexpected events activated the rTPJ extending in the pMTG, as well as bilateral motion-sensitive MT-complex (V5+/MT+), precuneus, ventral occipital cortex, and right premotor cortex (see Figure 3A). Attention grabbing characters

activated rTPJ more than non-attention grabbing characters, linking the activation of these regions to attention rather than mere sensory processing. This was further confirmed by the modulation of the characters’ responses by specific attention-related parameters in the rTPJ and right pMTG (see Figure 3B). A more targeted ROI analysis revealed that also the rIFG showed to a pattern of activation similar to rTPJ and right pMTG (cf. Supplemental Experimental Procedures). The finding of transient activation in rTPJ and rIFG (and of specific attentional effects in these regions) is in agreement with the view that these two regions are core components of the ventral fronto-parietal attentional network (Corbetta et al., 2008). The ventral system has been associated with stimulus-driven reorienting toward task/set-relevant stimuli, while irrelevant stimuli typically do not activate this network (e.g., Kincade et al., 2005; but see Asplund et al., 2010). In the present study, the unexpected human-like characters activated rTPJ/rIFG despite the fact that they were fully task-irrelevant. Recently, Asplund and colleagues reported activation of the TPJ for task-irrelevant stimuli, but these were presented during performance of a primary ongoing task (i.e., task-irrelevant faces presented within a stream of task-relevant letters; Asplund et al., 2010).