The principle of encoding specificity states that memory retrieval will be most successful when the memory cues available at retrieval match those present at study. Here, we investigate the ability of the memory system to alter the set of available cues on the fly during the search process, by retrieving and maintaining contextual details associated with the studied items. Thus, by retrieving context, the human memory system returns to the state it had during encoding, facilitating further recalls. We investigated this dynamic in a series of free-recall experiments in which encoding task context varied within a list. The encoding tasks included pleasantness, size, and animacy judgements. Analyses of recall transitions and serial-position effects suggest that the context of the encoding task exerted a strong influence on the organization of memory. Specifically, subjects showed a strong tendency to cluster items according to encoding task, and this task clustering shows an interaction with temporal clustering (the tendency to successively recall items studied nearby in time). Here, we explore the dynamics of a model of memory search that incorporates features of Howard and Kahana's Temporal Context Model (TCM), as well as a model of task context developed by Cohen and colleagues. This model explains the interaction between task and temporal clustering by the simultaneous use of the two context representations to probe memory. |