The magical mystery four: how is working memory capacity limited, and why? Curr Dir Psychol Sci

Working memory storage capacity is important because cognitive tasks can be completed only with sufficient ability to hold information as it is processed. The ability to repeat information depends on task demands but can be distinguished from a more constant, underlying mechanism: a central memory store limited to 3 to 5 meaningful items for young adults. I discuss why this central limit is important, how it can be observed, how it differs among individuals, and why it may exist. Keywords working memory capacity limits, central storage capacity limits, chunking, grouping, core capacity It may not really be magical, but it is a mystery.1 There are severe limits in how much can be kept in mind at once (about 3–5 items). When, how, and why does the limit occur? In a famous paper humorously describing ‘‘the magical number seven plus or minus two,’ ’ Miller (1956) claimed to be persecuted by an integer. He demonstrated that one can repeat back a list of no more than about seven randomly ordered, meaningful items or chunks (which could be letters