RETRIEVAL PROCESS IN FREE RECALL CREATES ERRORS IN SHORT TERM MEMORY BUT NOT IN LONG TERM MEMORY

An analysis of free recall errors shows that the free recall retrieval process in short term memory is accompanied by a linear rise in errors, without discontinuities, invalidating short term memory models in which stores or states are sequentially emptied. The frequency of errors increases at roughly 1% per second and exponentially if the items to be recalled are strongly related. This leads to a “Heisenberg uncertainty principle” situation: the more items recalled, the less accurate is the recall of those items. The error probability does not reach a plateau, is independent of time passing without a retrieval process being engaged, suggesting that the retrieval process itself introduces errors in short term memory. In contrast, in long term memory the error probability remains constant, indicative of a single store without retrieval induced errors. Error terminated short term memory free recall distributions are the same as distributions terminated by correct items.