Positional and temporal clustering in serial order memory

The well-known finding that errors in serial recall tend to be clustered around the position of the target item has bolstered positional-coding theories of serial order memory. Here we show that this well-known effect is confounded with the tendency for the item recalled prior to an error to come from the correct list position. When the standard analysis of positional clustering is conditioned on the positional-accuracy of the previously recalled item, one can see very strong effects of temporal contiguity, with errors being distributed near the position of the item following the prior recall. We show that a simple associative chaining model with asymmetric neighboring, remote associations, and a primacy gradient can account for both the standard positional clustering effect and the contiguity effect demonstrated here. Using the same parameters, the model produces reasonable serial position curves and captures the change in these curves across study-test trials as well as the gains and losses of item and order information across trials. Keywords: Serial recall, serial order, association, clustering. Associative chaining and positional coding consistute the two classic models of serial order memory. Although as-sociative chaining was the implicit theory in Ebbinghaus