Effect of Very Brief Interpolated Activity on Short-Term Retention

Abstract

Short-term retention of 4-, 6-, and 8-digit messages was tested after 1 and 10 sec. Retention intervals were either unfilled or partially filled following a procedure used by Conrad. Retention of 4-digit messages was essentially perfect under all conditions. Retention after 1 sec. was significantly reduced for 6- and 8-digit messages if “0” was interpolated during the interval. Retention of 8-digit messages was significantly reduced, but retention of 6-digit messages was not reduced, by interpolation of “0” in a 10-sec. interval. Results are interpreted as being compatible with both decay and interference interpretations of forgetting and as indicating that interpolation of a brief activity will significantly reduce retention only when messages approach the limit of memory span.