First, as Kornblith et al. (2013) note, texture, unlike viewpoint and depth, may be an important cue for conveying a scene’s identity. As such, it is possible

that the monkeys encoded scenes with different textures as different “places” but encoded scenes from different views and distances as different visual instantiations of the same place. Second, as Kornblith et al. (2013) also note, manipulations of viewpoint and depth are not manipulations of the spatial layout of the scene per se (see Figure 1). Indeed, all of the room stimuli used in this experiment had the same intrinsic geometry (i.e., were the same “shape”). Thus, the question of how LPP and MPP neurons respond to changes in the spatial structure of the scene itself has yet to be explored. Beyond these issues, Kornblith et al. (2013)’s results open the possibility of www.selleckchem.com/products/LBH-589.html addressing a number of important topics using the same techniques. To give one example, recent studies suggest that the PPA responds preferentially not just to scenes but also to nonscene objects that act—or have the potential to act—as landmarks (Troiani et al., 2012). Objects encountered at navigational decision

points (e.g., intersections) elicit greater PPA response than objects encountered at navigationally unimportant locations Ku-0059436 (Janzen and van Turennout, 2004). Likewise, objects that are physically large, immovable, and define the space around them elicit more PPA activity than do objects that are

smaller, movable, and spatially ambiguous (see Mullally and Maguire, 2011, for one example). Thus, the PPA responds to objects that make good landmarks either because of their locations or because of their intrinsic qualities. Future studies might explore response of LPP and MPP neurons to object-like landmarks. It would be especially interesting to know whether the same neurons that encode scenes also encode these landmarks, or whether scenes and object-like L-NAME HCl landmarks are coded by different neuronal populations. The scene areas outside of the LPP and MPP are also ripe targets for future investigation. In humans, the PPA is one of three scene-responsive regions: the other two are the retrosplenial complex (RSC) in the parietaloccipital sulcus and the occipital place area near the transverse occipital sulcus (OPA/TOS). Kornblith et al. (2013) observe scene-preferential response in anterior parietaloccipital sulcus (APOS), which may be the homolog of human RSC, and also in V3A/DP, which may be the homolog of OPA/TOS. Nasr et al. (2011) also found robust scene-selective response in the monkey at approximately the same locations and argued for the same homologies. In contrast to the PPA, which has primarily been implicated in coding of the immediate scene, RSC appears to encode spatial information that allows the local scene to be situated within the broader navigable environment (Epstein, 2008).