Thus, this data-driven FK228 manufacturer approach confirmed the participation of both dorsal (aIPS/FEF)

and ventral (rTPJ) attentional networks during viewing of the complex dynamic environments, and further supported the specificity of the rTPJ and right pMTG for the processing of the Entity video containing human-like characters. We completed the investigation of spatial covert orienting in complex dynamic environments by considering the functional coupling of the rTPJ with the rest of the brain. We found that, irrespective of the video (Entity/No_Entity) and viewing condition (covert/overt), there was a significant covariation between activity in rTPJ and activity in the IFG, bilaterally, and activity in the left TPJ (see Table 4, plus Figure 4C). A 2 × 2 AVOVA comparing rTPJ couplings in the four conditions

did not reveal any significant main effect or interaction, indicating that the functional coupling between posterior (rTPJ) and anterior (IFG) nodes of the ventral attentional network was similar for the two types of video and the two forms of spatial orienting. The present study aimed at investigating stimulus-driven visuo-spatial attention in a complex and dynamic environment, combining computational modeling, behavioral measures, and BOLD activation. Our results demonstrate that task-irrelevant bottom-up input is processed both in the dorsal and the ventral attention systems. ABT-737 in vivo others Activity in the two systems was associated with the efficacy of bottom-up signals for covert orienting of spatial attention. The results also revealed a distinction between the two systems: dorsal areas were found to continually represent the efficacy of background salience, while ventral

regions responded transiently to attention-grabbing distinctive events. By using ecologically valid settings, these findings challenge traditional models of visuo-spatial attention, demonstrating that the efficacy of bottom-up input determines activation of the attention control systems, rather than the input signal or the orienting process as such. We used saliency maps to characterize our visual environment (Itti et al., 1998). The fMRI analyses showed that mean saliency covaried on a scan-by-scan basis with activity in the occipital visual cortex and the left aIPS (see Figure 1C). More targeted ROI analyses indicated that also the other nodes of the dorsal fronto-parietal network (right aIPS, and FEF bilaterally) showed an effect of mean saliency. The effect of salience in occipital cortex is not surprising, as movie segments with high saliency values typically comprise a larger and/or a greater number of disparities in basic visual features that are represented in occipital cortex. These findings are consistent with those of Thielscher et al.