Emotion Appears To Be Generated in REM Sleep in the Absence of Sensory Input. How Does This Finding Fit with Your Stimulus-Response Model of Emotion?

Chapter
Part of the Vienna Circle Institute Library book series (VCIL, volume 3)

Abstract

Emotions are generally thought of as states of the brain and body elicited by specific stimuli. Fear occurs when we encounter something threatening or dangerous. Rotten food elicits disgust. Sexual arousal occurs in the presence of appropriate partners. Stimuli that elicit emotions are said to have emotional potency or emotional competence. While it is easiest to study emotions elicited by stimuli in the external environment, emotions can also be elicited internally by thoughts and images, and presumably by such internal stimulation during dreams as well.

Emotions are generally thought of as states of the brain and body elicited by specific stimuli. Fear occurs when we encounter something threatening or dangerous. Rotten food elicits disgust. Sexual arousal occurs in the presence of appropriate partners. Stimuli that elicit emotions are said to have emotional potency or emotional competence. While it is easiest to study emotions elicited by stimuli in the external environment, emotions can also be elicited internally by thoughts and images, and presumably by such internal stimulation during dreams as well (LeDoux 1996).

As an example, consider the role of the amygdala in processing fear arousing stimuli. An external sound with innate emotional potency (a very loud sound or a sound associated with predatory species) or learned potency (a meaningless sound that has been associated with pain or other kinds of harm in the past) is processed by auditory regions in the thalamus and cortex that send connections to the lateral nucleus of the amygdala. By way of intra-amygdala circuits, the lateral amygdala then triggers responses of the central amygdala, which controls the expression of behavioral, autonomic, and endocrine responses that help the organism protect itself from the impending danger. Other sensory systems have similar connections with the lateral amygdala. Though over-simplified, this scheme illustrates the basis points of the circuitry. Yet, it only includes the inputs to the amygdala from sensory processing areas. In addition, the amygdala receives massive connections from a variety of cortical association areas in the temporal and frontal lobes, brain areas often associated with higher cognitive functions. Other important connections of the amygdala include the neuromodulatory systems in the brainstem that release monoamines throughout the forebrain and that play key roles in regulating sleep, wakefulness, and dreams (LeDoux 2007).

So there are ample ways in which internal stimuli in the form of images (in sensory processing areas) or thoughts (in higher cortical areas) could interact with generalized arousal in the brain (from monoamine activation) to trigger brain and bodily states typically associated with emotions. These states could then, in the context of a dream, add emotional coloration to the dream.

But another way to think about this is from the point of view of memory. Dreams are essentially explicit or declarative memories (or at least they are assessed as such memories). Amygdala activation has long been known to provide emotional coloration to declarative memories by interacting with the hippocampus directly and by way of amygdala activation of monoamines and hormonal responses (McGaugh 2003). By similar interactions during the dream, memories of dreams can be emotionally colored.

References

  1. LeDoux, J. E. (1996). The emotional brain. New York: Simon and Schuster.Google Scholar
  2. LeDoux, J. E. (2007). Amygdala. Current Biology, 17, R868–R874.PubMedCrossRefGoogle Scholar
  3. McGaugh, J. L. (2003). Emotion and memory. New York: Columbia U. Press.Google Scholar

Copyright information

© Springer International Publishing Switzerland 2014

Authors and Affiliations

  1. 1.Center for Neural ScienceNew York UniversityNew YorkUSA

Personalised recommendations