Two are not better than one: Combining unitization and relational encoding strategies.

In recognition memory, recollection is defined as retrieval of the context associated with an event, whereas familiarity is defined as retrieval based on item strength alone. Recent studies have shown that conventional recollection-based tasks, in which context details are manipulated for source memory assessment at test, can also rely on familiarity when context information is "unitized" with the relevant item information at encoding. Unlike naturalistic episodic memories that include many context details encoded in different ways simultaneously, previous studies have focused on unitization and its effect on the recognition of a single context detail. To further understand how various encoding strategies operate on item and context representations, we independently assigned unitization and relational association to 2 context details (size and color) of each item and tested the contribution of recollection and familiarity to source recognition of each detail. The influence of familiarity on retrieval of each context detail was compared as a function of the encoding strategy used for each detail. Receiver operating characteristic curves suggested that the unitization effect was not additive and that similar levels of familiarity occurred for 1 or multiple details when unitization was the only strategy applied during encoding. On the other hand, a detrimental effect was found when relational encoding and unitization were simultaneously applied to 1 item such that a salient nonunitized context detail interfered with the effortful processing required to unitize an accompanying context detail. However, this detrimental effect was not reciprocal and possibly dependent on the nature of individual context details. (PsycINFO Database Record (c) 2016 APA, all rights reserved).