In our paradigm, the human-like characters were also unexpected, unrepeated, and distinctive visual events. But, notably, our experimental settings did not involve any primary task; rather, any attentional set arose only as a consequence of the coherent unfolding of the visual environment over time. This demonstrates that, in complex and dynamic settings, task-irrelevant stimuli can activate the rTPJ even when they do not interfere with any

prespecified task rules or task sets (see click here also Iaria et al., 2008). In our study, despite being fully task-irrelevant, the human-like characters were very distinctive visual events. The orienting efficacy of these stimuli may relate to the fact that they can be recognized on the basis of previous knowledge and/or Navitoclax chemical structure category-specific representations (see also Navalpakkam and Itti, 2005 and Einhäuser et al., 2008). Also, human-like characters may have attracted attention because they

were the only moving objects in the scene. Motion was not included in our computation of salience because currently available computational models do not separate the contribution of global flow due to self motion from the local flow due to character motion, which are known to be processed in distinct brain regions (Bartels et al., 2008). Instead, to we examined the possible relationship between the human-like characters and points of maximum saliency, computed using intensity, color, and orientation. This revealed that 14 out of the 25 characters did not show any coincidence with the location of maximum saliency. Five characters coincided with the location of maximum saliency for at least 25% of the character’s duration. Three of these were scored as attention grabbing and two as non-grabbing, indicating that there was no systematic relationship between maximum saliency and the appearance of the

human-like characters in the scene. This further supports our main conclusion that the efficacy of low-level salience and the efficacy of distinctive visual events are processed separately in the dorsal and ventral attention systems, respectively. Nonetheless, future developments of saliency models will hopefully disentangle global and local motion components, which would permit further discrimination of the contribution of low-level saliency compared with that of higher-order category effects during the processing of moving objects/characters in dynamic environments. The results discussed above are derived from hypothesis-based analyses involving computations of only a few indexes of attentional orienting (e.g., shifts, timings, and distances).