, 2003), further suggesting a major role for the hippocampus in initial feature binding. Although most research on the MTL has focused on its role in long-term memory, it is increasingly evident that the hippocampus plays a much broader role in perception and reflection. With respect to short-term memory, MTL damage impairs working memory for visual objects across delays as short

as 4 s (Olson et al., 2006). Furthermore, object-location conjunction information can be impaired across delays as short as 8 s with MTL damage (Hannula et al., 2006 and Olson PS-341 molecular weight et al., 2006). During perception, contextual representations mediated by the hippocampus/MTL can facilitate object recognition (Bar, 2004), guide the focus of attention

(Chun and Phelps, 1999 and Summerfield et al., 2006), and generate perceptual anticipation (Turk-Browne et al., 2010). Differences in eye movement patterns when viewing a previously seen versus a novel stimulus provide an implicit measure of memory, and hippocampal activity and its connectivity with lateral PFC predicts eye movement measures of memory for relational information (Hannula and Ranganath, 2009). Furthermore, MTL damage can also impair perceptual tasks requiring difficult object discriminations (Baxter, 2009; but see Suzuki, 2009) or visual associations (Degonda selleck chemicals et al., 2005 and Chun and Phelps, 1999). These findings of hippocampal involvement in long-term memory, working memory, and perception make clear that the hippocampus is engaged in an ongoing fashion during cognition. Is there a general function being served in these various situations? One possibility is that PLEKHM2 the hippocampus helps bridge temporal and spatial gaps between features of experience so that information that is not strictly contiguous can be bound together (Johnson and Chalfonte, 1994 and Staresina and Davachi, 2009). Of course, the hippocampus may bind whatever features are contiguous (perceptually or reflectively) and other regions (e.g., frontal and parietal)

may actually do the bridging, for example, via refreshing (Park et al., 2010 and Park and Chun, 2009). From the PRAM perspective, a critical issue is how perceptual and reflective attention affect MTL function. Assuming that attention modulates MTL regions, are different frontal, parietal, and/or MTL regions engaged during perceptual and reflective attention? Do attentional networks that include MTL depend on the type of perception (e.g., focal, peripheral), the type of reflection (e.g., refreshing, reactivating), or the type of target (scenes versus objects versus faces)? Intriguing recent work demonstrates that hippocampal-cortical interactions occur not only during encoding, but also during retention intervals during which participants have no explicit task (“rest”).