Operational efficiency and the growth of short-term memory span

Abstract

Four studies are reported which link developmental increases in memory span with developmental increases in operational speed or efficiency. In the first, a linear relationship is demonstrated between increases in word span and increases in speed of word repetition. In the second, adults and 6-year-olds are equated on speed of word repetition, by manipulating word familiarity. It is shown that their word spans are no longer different under these conditions. Similar findings are then reported for a test of M space called “Counting Span.” First, a linear relationship is demonstrated between increases in Counting Span and increases in speed of counting. Next, adults and 6-year-olds are equated on speed of counting, by forcing adults to count in an unfamiliar language. It is shown that their counting spans are no longer different under these conditions. The conclusion is that developmental increases in memory span do not result from increases in total processing space. Rather, with development, basic operations become faster and more efficient. This means that they require less processing space, and that more space becomes available for storage as a result.