1. The Influence of Time on Emotional Differences in Memory
Amelia Erikson, Alanna Kopelman, Laurie Pochette, Ella Kaiser, & Thomas Williams
Faculty Advisor: Brandy Bessette-Symons
Background: It has been established that varying time delay between encoding and memory
assessment (RI; retention interval) influence memory performance differences between
emotional and neutral items (e.g., Denburg, Buchanan, Tranel, & Adolphs, 2003). For example,
Denburg et al. (2003) compared the memory for negative, neutral, and positive images after an
immediate versus eight month RI. They found that recall decreased more for neutral images than
for emotional. Dolcos, LaBar, and Cabeza (2005) found similar results and reported that
preserved memory for emotional materials was dependent on coactivation between the amygdala
and hippocampus during encoding. The majority of emotional memory research manipulating RI
has used free recall (e.g., Mather & Knight, 2005), or has used free recall for the shorter RI and
recall and recognition at the longer RI (e.g., Hamann, Ely, Grafton, & Kilts, 1999). However,
there is a paucity of research that has measured recognition memory across both short and long
RIs. Complicating the understanding of RI’s influence on emotional recognition memory are the
inconsistent findings concerning whether emotion influences memory accuracy, response bias, or
both (for review see Kensinger, 2009). Our study is designed to explore the influence of RI on
recognition memory differences between emotional and neutral items.
Methods: Seventy Ithaca College undergraduate students participated in this study; with half
assigned to the No Delay condition (RI of 10 minutes) and half assigned to the Delay condition
(RI of one week). Participants encoded 135 pictures equally divided by valence (negative,
neutral, positive). During encoding, each picture was rated for arousal and presented on a

2. computer screen for 2.5 seconds. To assess memory, the participants were asked to indicate on a
9-point scale their confidence that a picture was old or new (1 = confident new, 9 = confident
old). At test, a total of 270 pictures were presented consisting of 135 old targets and 135 new
foils.
Results: The results were analyzed through a series of 2x3 mixed ANOVAs, with valence as the
within-subjects variable and RI as the between-subjects variable. The dependent variables
analyzed were hit rates (HR; proportion of old items endorsed as old), false alarm rates (FAR;
proportion of new items endorsed as old), accuracy (one’s ability to distinguish old from new
items) and response bias (one’s willingness to endorse an item as old). Significant main effects
and interactions were explored with repeated measure ANOVAs and t-tests. Results revealed that
there was a main effect of RI for HR, but no main effect of valence or interaction. HR was
greater in No Delay condition than in Delay condition. For FAR there was a main effect of
valence and RI, but there was no significant interaction. FAR was higher for emotional images
than for neutral, and was higher in Delay condition than in No Delay condition. Concerning
accuracy, there was a main effect of valence and of RI and a significant interaction. Exploring
the interaction revealed that accuracy was lower for emotional items than it was for neutral items
in the No Delay condition only. The results for response bias revealed a significant main effect
of valence and RI, and a significant interaction. There was a more liberal response bias for
emotional items than for neutral at both RIs, however all items were associated with a more
liberal response bias in the No Delay condition. The interaction showed that response bias
became more conservative over time for emotional items than for neutral items.

3. Conclusion: Our results provide evidence that the memory for emotional items is less accurate
than for neutral items; however, this is moderated by RI. Our results suggest that with a shorter
RI memory for neutral items is better than for emotional items, but this difference diminishes
with a longer RI. Therefore, our results are in opposition to the findings of several previous
studies indicating better accuracy for emotional items regardless of RI (e.g, Denburg, et al.,
2003). However, our findings are consistent with a growing body of research supporting an
emotional induced (liberal) response bias that does not co-occur with an accuracy enhancement
(e.g, Dougal & Rotello, 2007). The emotional induced bias may serve to facilitate the cognitive
processing of emotional material to enable more rapid subsequent decision making and behavior.
References
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