Neural mechanisms underlying the effects of emotional arousal on memory

Emotional events (e.g., seeing a snake while hiking) typically stay in the memory longer and in more detail than neutral ones (e.g., seeing a bird while hik-ing). This emotion-induced memory enhancement has been attributed to the amyg-dala’s modulation on other brain regions, such as the medial temporal lobe and visual cortices. In line with this amygdala modulation hypothesis, previous brain imaging research revealed enhanced amygdala activity when encoding and retriev-ing emotional stimuli compared with non-emotional stimuli. However, emotion does not always enhance memory. Indeed, researchers have long been aware that emotion sometimes enhances and sometimes impairs memory. Yet, the underlying mechanisms of the opposing effects of emotion are relatively unknown. For example, if the amygdala’s modulation on other brain regions is critical in the emotion- memory interaction, how does it result in the enhancement effects for some aspects, while impairing other aspects of memory? In this chapter, we argue an alternative possibility: that norepinephrine released by the locus coeruleus under arousal plays a critical role in the complex effects of emotion on memory

Concepts and Dysfunctions of Emotion in Neuropsychiatric Research

This chapter aims to provide a perspective of the complex formation of emotion and its operational usage in neuroscience. In the first section, the essence and function of emotion will be introduced from different perspectives. After an overview of historical and ongoing debates in the second section, the neuroscientific findings regarding emotional instances in healthy subjects and psychiatric patients will be outlined throughout the third and fourth sections. In the last section, a comprehensive approach of the newly developing field of computational psychiatry to emotion will be introduced

Affective Cognition and its Disruption in Mood Disorders

In this review, we consider affective cognition, responses to emotional stimuli occurring in the context of cognitive evaluation. In particular, we discuss emotion categorization, biasing of memory and attention, as well as social/moral emotion. We discuss limited neuropsychological evidence suggesting that affective cognition depends critically on the amygdala, ventromedial frontal cortex, and the connections between them. We then consider neuroimaging studies of affective cognition in healthy volunteers, which have led to the development of more sophisticated neural models of these processes. Disturbances of affective cognition are a core and specific feature of mood disorders, and we discuss the evidence supporting this claim, both from behavioral and neuroimaging perspectives. Serotonin is considered to be a key neurotransmitter involved in depression, and there is a considerable body of research exploring whether serotonin may mediate disturbances of affective cognition. The final section presents an overview of this literature and considers implications for understanding the pathophysiology of mood disorder as well as developing and evaluating new treatment strategies