Abstract
In everyday life, we encounter information with various degrees of prior experience. It is not well understood, however, how such familiarity affects the formation of new memories. A previous study demonstrated that repeated exposure of an item decreases its likelihood of associating with new features or locations (Kim et al., 2012). This negative effect of prior experience might be credited either to the reduced probability of retrieval success or to the reduced fidelity of the retrieved representations. The current study compared these two possibilities using a mixture modeling approach (Zhang & Luck, 2008; Sutterer & Awh, 2016). The experiment consisted of three phases. In Phase 1, 30 white silhouettes of objects were presented 10 times. In Phase 2, those 'old' objects and another 30 'new' objects were randomly presented each in a unique color. In Phase 3, white versions of the 60 objects were presented with a color wheel. Participants then recalled and reported each object's color in Phase 2 by clicking on a color wheel. These three phases were repeated six times (total 180 old and 180 new objects). As results (N=28), the RMSE of color memory was greater for the old objects than for the new objects, replicating negative effects of item repetition on source memory (Kim et al., 2012). Next, the aggregated memory errors were fitted to the mixed model using a Bayesian estimation method (Suchow et al., 2013). The resulting posterior distributions of parameter values were compared between two conditions. We found that the probability of guessing (g) was greater for the old objects than for the new objects whereas the fidelity of color memory (SD) was comparable between the old and new objects. Our results suggest that the prior experience of an item may hinder the accessibility, but not the fidelity of new memory representations.
Meeting abstract presented at VSS 2018