Stevens' Handbook of Experimental Psychology and Cognitive Neuroscience, Learning and Memory

• Editore: Wiley
• Anno: 2018
• ISBN:
  9781119170020
• Edizione: 4
• Argomento: Psychology
• Categoria: Experimental Psychology

I. Learning & Memory: Elizabeth Phelps & Lila Davachi (Volume Editors) Topics covered include working memory; fear learning; education and memory; memory and future imagining; sleep and memory; emotion and memory; motivation and memory; inhibition in memory; attention and memory; aging and memory; autobiographical memory; eyewitness memory; and category learning.

CHAPTER 1
Emotion and Memory

ELIZABETH A. KENSINGER AND SARAH M. KARK

INTRODUCTION

Although more than a decade has passed since September 11, 2001, most adults will have no problem remembering what happened on that date; by contrast, most of those same adults will have no memory of what happened on the previous day. It is well established that we are less likely to forget emotional events than we are to forget more mundane experiences. Yet, despite this consensus, there continues to be active research and debate about fundamental questions regarding the links between emotion and memory: How does the nature of the emotional reaction affect memory? Which details of an emotional experience are most likely to be retained? What neural processes enable these interactions between emotion and memory, and over what time course do they operate?

In this chapter, we first focus on how two different aspects of an emotional reaction—its valence and arousal—affect the way that the events are remembered. We then turn to a discussion of the time course of those effects, describing how emotion can affect the sequence of processes engaged during encoding and retrieval as well as the processes that unfold over time as memories are consolidated. In each of these sections, we review findings from behavioral, neuroimaging, and psychophysiological studies, because it is from the combination of these methods that many of the key insights regarding emotion and memory have been revealed. We conclude with a brief discussion of three debates that are ongoing in the field: the role of the amygdala in emotional memory, the effects of emotion on memory accuracy, and the effects of emotional appraisals and reappraisals on memory.

HOW VALENCE AND AROUSAL AFFECT MEMORY

Often when we think about an emotional reaction, we think about the physiological reactions elicited, such as our sweaty palms and pounding heart as we are about to make our way onstage in front of an audience. Indeed, much of the research examining the effects of emotion on memory has focused on the influences of this arousal dimension (Mather & Sutherland, 2011; Yonelinas & Ritchey, 2015), building on decades of research using animal models to reveal the neural circuitry implicated in arousal-based modulation of memory (see McGaugh, 2015, for a review). Yet the pleasure or displeasure stemming from an event also can be a powerful predictor of how that event will be remembered. In this section, we describe the influences of these dimensions of arousal (physiological and subjective reactivity) and valence (pleasure or displeasure; see Lang, Greenwald, Bradley, & Hamm, 1993; Russell, 1980, for discussion of these dimensions).

Separable Influences of Valence and Arousal

The emotional events that we experience often elicit shifts in valence and arousal. In other words, as compared to a neutral state, emotional events tend to evoke pleasure or displeasure as well as subjective and physiological arousal. Although shifts in both dimensions often occur when emotion is elicited in real-world contexts, in laboratory settings the influences of these dimensions can be distinguished. Most commonly, this is achieved by selecting stimuli that elicit shifts in one primary dimension or by matching stimuli on one dimension (e.g., valence) and then examining how a change in the other dimension (e.g., arousal) affects memory.

In a series of studies, Kensinger and Corkin (2003, 2004; see Kensinger, 2004, for a review) demonstrated that the presence of either the valence or the arousal dimension (i.e., a change from neutral in either direction) was sufficient to elicit memory enhancements (Kensinger & Corkin, 2003): Words that evoked changes in arousal but not valence (“high-arousal stimuli”) were remembered better than words that elicited neither changes in arousal nor valence, and a similar memory benefit also was revealed for words that evoked changes in valence but not arousal (“valence-only stimuli”). A memory advantage for valenced stimuli, regardless of their arousal, has also been demonstrated using a large corpus of linguistic stimuli (Adelman & Estes, 2013), confirming that shifts in the valence dimension are sufficient to elicit memory benefits. Importantly, however, the mechanisms underlying the valence-only and high-arousal enhancements appear to differ: Kensinger and Corkin (2004) noted that high-arousal stimuli were remembered well even when attention was divided during encoding, whereas memory for the valence-only stimuli was dramatically reduced when attention was divided. In fact, under conditions of divided attention, memory for the valence-only stimuli was no longer greater than memory for neutral words, and the memory enhancement for high-arousal stimuli remained intact (Kensinger & Corkin, 2004).

These behavioral results pointed to dissociable mechanisms supporting the memory benefits for high-arousal and valence-only stimuli and suggested that the memory benefits for the former may occur relatively automatically and the memory benefits for the latter may be linked to more controlled encoding processes. This conclusion is generally consistent with evidence from event-related potentials (ERPs), which suggests arousal is processed faster than valence (Jhean-Larose, Leveau, & Denhière, 2014; Recio, Conrad, Hansen, & Jacobs, 2014; Styliadis, Ioannides, Bamidis, & Papadelis, 2015). In terms of memory encoding, across a range of paradigms, arousing stimuli have been remembered well even when attention is divided (Kern, Libkuman, Otani, & Holmes, 2005; Steinmetz, Waring, & Kensinger, 2014), although the effect may be stronger for negative stimuli than for positive stimuli (Kang, Wang, Surina, & Lü, 2014). Moreover, associations between pairs of high-arousal stimuli can be formed rapidly (Murray & Kensinger, 2013b) and remembered better than neutral stimuli even when attention is divided (Maddox, Naveh-Benjamin, Old, & Kilb, 2012). Debates continue about whether these memory enhancements for high-arousal information occur automatically or whether the processing of that information may be prioritized at the expense of other concurrent processes (Pottage & Schaefer, 2012). But importantly, even if a prioritization explanation is correct, it still appears that the prioritization itself occurs relatively automatically. For instance, high-arousal stimuli typically attract attention and resources (see Bröckelmann et al., 2011; Schmidt, Belopolsky, & Theeuwes, 2015) even when participants are instructed to attend to other concurrent tasks or to ignore those stimuli (see Iordan, Dolcos, & Dolcos, 2013, for a review). Memory enhancements for valence-only stimuli, by contrast, appear to be linked to additional engagement of the same types of controlled, elaborative processes that typically support memory. Thus, when attention is divided, these benefits disappear (Kang et al., 2014; Kensinger & Corkin, 2004), and older adults, who have difficulty engaging elaborative encoding processes show less memory enhancement for valence-only stimuli than for high-arousal stimuli (Kensinger, 2008).

Neuroimaging (functional magnetic resonance imaging; fMRI) studies have provided further evidence of this dissociation. Memory for high-arousal stimuli is linked to engagement of the amygdala at encoding (Kensinger & Corkin, 2004; Mickley & Kensinger, 2008; Steinmetz, Schmidt, Zucker, & Kensinger, 2012) and to correlations between amygdala and hippocampal activity (Fastenrath et al., 2014; Kensinger & Corkin, 2004; Leal, Tighe, Jones, & Yassa, 2014; Richardson, Strange, & Dolan, 2004). By contrast, memory for valence-only stimuli are linked to additional engagement of the same prefrontal cortex (PFC) and hippocampal processes that support memory for neutral information (Kensinger & Corkin, 2004; Steinmetz & Kensinger, 2009).

Combined Influences of Valence and Arousal Dimensions

Although these prior studies demonstrate that the presence of either valence or arousal is sufficient to elicit memory enhancements, in everyday life, these dimensions tend to co-occur. Events that are highly valenced are also arousing, and vice-versa (see Bradley & Lang, 1991; Lang, Bradley, & Cuthbert, 2008, for distribution of stimuli in this two-dimensional space). Extensive research has therefore focused on the combined influences of valence and arousal on memory: How is memory affected when events are highly arousing and also pleasant or unpleasant?

Decades of research has confirmed that these emotional events are more likely to be remembered than neutral ones and can have a shallower forgetting curve than emotional items. Among the first demonstrations of this memory enhancement were demonst...

Indice dei contenuti

• Cover
• Title Page
• Contributors
• Table of Contents
• Preface
• CHAPTER 1: Emotion and Memory
• CHAPTER 2: The Cognitive Neuroscience of Fear Learning
• CHAPTER 3: Episodic Memory
• CHAPTER 4: Sleep and Memory
• CHAPTER 5: Memory and Future Imagining
• CHAPTER 6: Education and Memory: Seven Ways the Science of Memory Can Improve Classroom Learning
• CHAPTER 7: Motivation and Memory
• CHAPTER 8: Inhibition in Memory
• CHAPTER 9: Memory and Attention
• CHAPTER 10: Item and Associative Memory Decline in Healthy Aging
• CHAPTER 11: Assessing Autobiographical Memory: Implications for Understanding the Underlying Neurocognitive Mechanisms
• CHAPTER 12: Working Memory: An Evolving Concept
• CHAPTER 13: Visual Cognition and Working Memory
• CHAPTER 14: Timing and Time Perception: A Critical Review of Neural Timing Signatures Before, During, and After the To-Be-Timed Interval
• CHAPTER 15: Visual Object Recognition
• CHAPTER 16: Eyewitness Science in the 21st Century: What Do We Know and Where Do We Go from Here?
• Author Index
• Subject Index
• End User License Agreement