The effects of a distracting N-back task on recognition memory are reduced by negative emotional intensity.

Luciano G Buratto,Catriona M Morrison,Claire L Pottage,Charity Brown,Alexandre Schaefer

doi:10.1371/journal.pone.0110211

Luciano G Buratto, Catriona M Morrison + Show 3 more

Open Access

https://doi.org/10.1371/journal.pone.0110211

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Abstract

Memory performance is usually impaired when participants have to encode information while performing a concurrent task. Recent studies using recall tasks have found that emotional items are more resistant to such cognitive depletion effects than non-emotional items. However, when recognition tasks are used, the same effect is more elusive as recent recognition studies have obtained contradictory results. In two experiments, we provide evidence that negative emotional content can reliably reduce the effects of cognitive depletion on recognition memory only if stimuli with high levels of emotional intensity are used. In particular, we found that recognition performance for realistic pictures was impaired by a secondary 3-back working memory task during encoding if stimuli were emotionally neutral or had moderate levels of negative emotionality. In contrast, when negative pictures with high levels of emotional intensity were used, the detrimental effects of the secondary task were significantly attenuated.

Highlights

A wealth of research has demonstrated that encoding information in memory while depleting cognitive resources by a concurrent task leads to a decrease in subsequent memory [1,2]
In the analyses reported in this study, we used corrected K responses (Kcor), which take into account the number of R responses produced by the participant and is given by Kcor = K/(1–R), where K is the proportion of K responses (K-Hit rate (HR) if the response is given to an Old picture, K-False-alarm rate (FAR) if given to a New picture) and R is the proportion of R responses (R-HR if the response is given to an Old picture, R-FAR if given to a New picture)
We found that negative emotional content can reduce and even cancel the impact of cognitive depletion on recognition memory

Summary

Introduction

A wealth of research has demonstrated that encoding information in memory while depleting cognitive resources by a concurrent task leads to a decrease in subsequent memory [1,2]. Studies using recall tasks to measure memory performance have found that memory costs due to divided attention are smaller for emotional stimuli than for neutral stimuli [3,4] These results suggest that emotional content can moderate the effects of cognitive depletion on recall. Clark-Foos and Marsh [5] showed that recognition accuracy was higher for negative words than for neutral words under both full and divided attention conditions These results showed that the emotional enhancement of memory survived the restriction of cognitive resources at encoding. These authors have not found a significant interaction between encoding task and stimulus emotionality, suggesting that emotional content did not moderate cognitive depletion effects in their study. Other studies combining a divided attention paradigm with recognition tests for emotional stimuli reported no interaction between emotional content and encoding task (full vs. divided attention), using both word and face stimuli [6,7]

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