2 Visual memory for features , conjunctions , objects , and locations

In her Multiple-Entry, Modular Memory (MEM) model on human cognition, Marcia Johnson differentiated perceptual subsystems that interact directly with the external environment and reflective subsystems that operate in the absence of external input (Johnson, 1992). Visual memory is an example of processes that are situated at the border between these two. Short-term visual memory directly bridges visual perception with conceptual representation. It is abstracted from visual perception yet operates on perceptual input and retains many properties of visual objects including size, color, orientation, number, and spatial layout. Short-term visual memory can result from active encoding and retention of information in visual working memory (Phillips, 1974), or as a by-product of perceptual analysis of a previous trial event (Maljkovic & Nakayama, 1994, 1996). In either case, content previously stored in short-term memory may remain in long-term visual memory (Hollingworth, 2005), and both short-term and long-term visual memory can be used explicitly or implicitly to guide future visual processing (Brockmole & Henderson, 2006a, 2006b; Chun & Jiang, 1998; Downing, 2000; Vickery, King, & Jiang, 2005). The goal of this chapter is to provide a synthesis of visual memory for different visual attributes.