The Short-Term Storage as a Buffer Memory Between Long-Term Storage and the Motor System? Not Exactly

This study reports a replication and extension of Ulrich and Dietz (1985) on the possible role of the short-term storage (STS) as a buffer memory between long-term storage (LTS) and the motor system in free recall tasks. This STS buffer would allow for the parallel unfolding of the search of LTS and the motor output of responses by temporarily storing retrieved items until their final production. In the study, this view was examined against the alternative hypothesis whereby the fast initial production of items in free recall relies on a controlled or “strategic” search of LTS rather than on the accrual of retrieved items in STS. In two independent replications, 54 native German language speakers and 39 native Bosnian language speakers performed letter verbal fluency task under the manipulation of STS preload (no preload vs. preload) and delay interval (1 sec vs. 10 sec between the presentation of the target letter and the signal for the start of recall). Contrary to the assumption of STS as a buffer memory, the results revealed that STS preload did not cancel out the effect of the delay. Accordingly, the results were interpreted in the context of controlled LTS search models.