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In this paper we provide a focused review of the literature examining neural mechanisms involved in cognitive control over memory processes that can influence, and in turn are influenced, by emotional processes. The review is divided into two parts, the first focusing on working memory and the second on long-term memory. With regard to working memory, we discuss the neural bases of 1) control mechanisms that can select against distracting emotional information, 2) mechanisms that can regulate emotional reactions or responses, 3) how mood state influences cognitive control, and 4) individual differences in control mechanisms. For long-term memory, we briefly review 1) the neural substrates of emotional memory, 2) the cognitive and neural mechanisms that are involved in controlling emotional memories and 3) how these systems are altered in post-traumatic stress disorder. Finally, we consider tentative generalizations that can be drawn from this relatively unexplored conjunction of research endeavors. KeywordsEmotion; Cognitive Control; Working Memory; Long-term Memory; Prefrontal Cortex; Anterior Cingulate; Amygdala; Hippocampus; Post-traumatic Stress Disorder; Rumination; Depression; Genetics; Human IntroductionThe prefrontal cortex has been implicated as playing an important role in cognitive control. Although a variety of models have been proposed to suggest how prefrontal cortex exerts such © 2008 Elsevier Ltd. All rights reserved. *Corresponding Author: e-mail: Marie.Banich@colorado.edu, . Publisher's Disclaimer: This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final citable form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. NIH Public Access Author ManuscriptNeurosci Biobehav Rev. Author manuscript; available in PMC 2010 May 6. NIH-PA Author ManuscriptNIH-PA Author Manuscript NIH-PA Author Manuscript control, some points of general agreement are relevant for the issues we examine in this paper. First many models emphasize the idea that frontal regions are involved in the selection of processes related to goal-oriented aspects of behavior. For example, Miller and Cohen (2001) have argued that cognitive control acts like a series of switches selecting the processes that will be invoked to reach a goal, much as switches select the route of a train from the departure station to its destination. Although some researchers suggest that the prefrontal cortex does not have a specific organization for such executive processes (e.g., Duncan and Owen, 2000), other researchers view subprocesses as each occurring in distinct regions of prefrontal cortex. This latter viewpoint, for example, has been supported by data from meta-analyses of neuroimaging work (e.g....

Uncertainty about potential negative future outcomes can cause stress and is a central feature of anxiety disorders. The stress and anxiety associated with uncertain situations may lead individuals to overestimate the frequency with which uncertain cues are followed by negative outcomes, an example of covariation bias. Using functional magnetic resonance imaging, we found that uncertainty-related expectations modulated neural responses to aversion. Insula and amygdala responses to aversive pictures were larger after an uncertain cue (that preceded aversive or neutral pictures) than a certain cue (that always preceded aversive pictures). Anticipatory anterior cingulate cortex (ACC) activity elicited by the cues was inversely associated with the insula and amygdala responses to aversive pictures following the cues. Nearly 75% of subjects overestimated the frequency of aversive pictures following uncertain cues, and ACC and insula activity predicted this uncertainty-related covariation bias. Findings provide the first evidence of the brain mechanisms of covariation bias and highlight the temporal dynamics of ACC, insula, and amygdala recruitment for processing aversion in the context of uncertainty.

Prior research has shown memory is enhanced for emotional events. Key brain areas involved in emotional memory are the amygdala and hippocampus, which are also recruited during aversion and its anticipation. This study investigated whether anticipatory processes signaling an upcoming aversive event contribute to emotional memory. In an event-related functional MRI paradigm, 40 healthy participants viewed aversive and neutral pictures preceded by predictive warning cues. Participants completed a surprise recognition task directly after functional MRI scanning or 2 weeks later. In anticipation of aversive pictures, bilateral dorsal amygdala and anterior hippocampus activations were associated with better immediate recognition memory. Similar associations with memory were observed for activation of those areas in response to aversive pictures. Anticipatory activation predicted immediate memory over and above these associations for picture viewing. Bilateral ventral amygdala activations in response to aversive pictures predicted delayed memory only. We found that previously reported sex differences of memory associations with left amygdala for women and with right amygdala for men were confined to the ventral amygdala during picture viewing and delayed memory. Results support an established animal model elucidating the functional neuroanatomy of the amygdala and hippocampus in emotional memory, highlight the importance of anticipatory processes in such memory for aversive events, and extend neuroanatomical evidence of sex differences for emotional memory.aversion ͉ expectancy ͉ functional MRI ͉ neuroimaging ͉ recognition memory M emories for emotional events are more persistent and vivid than other memories (1-3). Previous research has shown that the amygdala and hippocampus are necessary for the enhanced memory observed for emotional material and contexts (4-12). Recent neuroimaging studies have shown that amygdala and hippocampus activation during encoding of emotional stimuli is related to better recollection of those stimuli (13-23). Other studies have shown that these areas already are recruited in anticipation of aversive emotional stimuli (24-29). Moreover, emotional arousal and emotional influences on attention and perception, which are emphasized in the literature on emotional memory (2-7, 30, 31), are key features of anticipating aversion. Specifically, the anticipation of aversive events is associated with heightened arousal, as indexed by startle (25,(32)(33)(34)(35) and the modulation of perception and attention (36-39) that, in turn, is important for memory encoding (40-42).The present functional MRI (fMRI) study tested whether activation of the amygdala and hippocampus during the anticipation of aversive events is related to subsequent memory of these events. Based on previous findings in our laboratory (24), we expected the dorsal amygdala and anterior hippocampus to be activated both in anticipation of and response to aversive pictures, consistent with the idea that there is one system that governs ...

The present study was undertaken to determine whether aversiveness contributes to startle potentiation in anticipation of affective pictures above and beyond the effects of emotional arousal. Further, participants high in trait anxious apprehension, which is characterized by worry about the future, were expected to show especially pronounced anticipatory startle responses. Startle blink reflex was measured during warning stimuli that predicted the valence of ensuing aversive/unpleasant, pleasant, or neutral pictures. Startle magnitude was larger in anticipation of aversive than of pleasant pictures and smallest in anticipation of neutral pictures. Enhanced startle potentiation was not found in anxious apprehension subjects. These data suggest that the aversive nature of stimuli contribute to the potentiation of startle above and beyond the effects of emotional arousal, which may be a universal phenomenon not modulated by individual differences.