The development of memory for ignored speech.

Previous studies of the development of children's memory have focused on attended stimuli. Here we examine short-term memory for spoken words that were ignored at the time of their presentation. In Experiment 1, a visual matching task was interrupted occasionally by a set of picture alternatives. The participant was to select the picture matching the most recently heard word, which had been presented 1, 5, or 10 s ago. An age difference in memory was found, but performance levels were quite high. Experiment 2 employed an alternative visual task to tie up phonological processing, bringing performance levels down to a more sensitive range. An age difference in the persistence of memory was obtained under these circumstances. We conclude that relatively attention-free properties of short-term memory may change with development in childhood.