Expertise breaks the magic: Short-term memory is limited by long-term memory representations

Visual short-term memory has a surprising, limited capacity (e.g., Sperling, 1960) and is often described as a being fixed to a magic number (Miller, 1956; Cowen, 2001). Nevertheless, Alvarez and Cavanagh (2004) have suggested that this limitation vary based on stimulus complexity. Also, Jackson and Raymond (2005) made a distinction between physical and perceived complexity. Here we present three studies suggesting that short-term memory capacity is depended on long-term memory representations (Brogaard & Sørensen, in press). In a study by Sørensen and Kyllingsbæk (2012) we demonstrate that memory capacity systematically increases with degree of training and familiarity compared with a baseline condition consisting of linedrawings (Snodgrass & Vanderwart, 1980). These results are later replicated and extended to a different paradigm (Dall, Watanabe, & Sørensen, 2016) demonstrating that training languages modulate the efficiency of representation in short-term memory. Similar results have later been reported for non-language categories link Pokémon cartoons by Xie and Zhang (2017). In the final study presented here we explore the dynamics between physical and perceived complexity in expert observers and demonstrate that both speed of processing and memory capacity is driven by perceived complexity independent of physical complexity (Dall, et al., 2021). Our results align with a view where initial sensory evidence is matched to long-term memory representations as they are selected for encoding in short-term memory (Bundesen, 1990), and as long-term memory templates become stronger with familiarity processing becomes faster and more efficient (Brogaard & Sørensen, in press).