| Abstract: | Adults and 8-, 10-, 12-, and 14-year olds completed a serial reaction-time task with two stimuli mapped to each of two responses and 100-, 500-, and 1000-msec response-stimulus intervals (RSIs). Trials were classified as (1) identical (same stimulus and same response on two consecutive trials), (2) response equivalent (different stimulus but same response on two consecutive trials), or (3) different (different stimulus and different response on two consecutive trials). Identical and different trials were compared as a general indication of repetition effects. Response-equivalent minus identical reaction time identified stimulus contributions, and different minus response-equivalent reaction time identified response contributions. Adults received a repetition advantage at all RSIs and children received a repetition advantage at 500- and 1000- but not 100-msec RSIs. Stimulus contributions accounted for the repetition effect for both adults and children. At the 500- and 1000-msec RSIs, both the overall repetition effect and stimulus contribution were positive and decreased in magnitude as age increased. The response contribution was independent of RSI and was negative for 8- and 10-year-olds and near zero or positive for older performers. At the longer RSIs, positive stimulus contributions were sufficient to overcome the negative response contributions present for younger children. |
