Understanding Emotions: Components, Theories, and Brain Areas

Posted on Feb 14, 2025 in Psychology

Emotions Components

  • Feelings
  • Cognitions
  • Actions

James-Lange Theory

2 Hypotheses:

  • Weaker action/physiology = less emotion
  • Stronger action/physiology = stronger emotion

Is physiological arousal sufficient for emotions?

Möbius Syndrome (M.S.)

Condition where subjects are unable to move facial muscles for smiling.

  • M.S. subjects are able to experience happiness & joy.
  • Autonomic rather than muscular activity triggers affective components of emotions.

Brain Areas Associated with Emotion

  • Limbic system: areas of the forebrain around the thalamus.

Ways to Study Brain Activity

By telling stories, showing pictures or videos with varied emotional content and measuring evoked responses in:

  • Electroencephalography (EEG)
  • Functional magnetic resonance imaging (fMRI)
  • Positron emission tomography (PET)
  • Different emotions, varied in brain localization; disgust was the only emotion that has shown some consistent localization: insular cortex
  • A patient with damage in the insular cortex did show deficits in: Experience of disgust and Recognizing disgust in other people.
  • Insula also reacts to frightening pictures.
  • Other areas of the brain also can react to disgusting stimuli.

BAS: Behavioral Activation System

  • ↑ activity in Frontal and temporal lobes of the L hemisphere
  • Linked to “approach” tendency like in anger and happiness
  • Low to moderate autonomic arousal.
  • Outgoing, extroversion, happiness.

BIS: Behavioral Inhibition System

  • ↑ activity in Frontal and temporal lobes of the Right hemisphere linked to “inhibition” tendency like in fear and disgust. Rises in arousal, attention, decrease of actions.
  • Introversion, insatisfaction, prone to unpleasant emotions.

Damage to Prefrontal Cortex

  • Blunt emotions.
  • Disrupt decision making.
  • Decisions fast/impulsive.

Best predictor of strongest violent/criminal behavior: Low levels of MAO combined with strong traumatic events in infancy.

MAOa: Monoamine Oxidase A

Enzyme that breaks down: dopamine, norepinephrine and serotonin, lowering their levels.

Hormones and Emotions

  • Testosterone increases activity of areas related to emotion (e.g., amygdala) but decreases cerebral cortex ability to recognize emotion at conscious level.
  • Besides testosterone, serotonin, a neurotransmitter has also been linked to aggression.
  • Tryptophan is a precursor of serotonin that can cross the blood brain barrier (BBB) by a specific transporter (located between blood vessels and brain). The same transporter can also be used by other large amino acids, that do sort of competition.
  • The other five large amino acids (LNAA) are: Valine, leucine, isoleucine, tyrosine and phenylalanine.
  • Food rich in LNAA, tryptophan decrease, and subsequently serotonin will decrease.
  • Decrease in serotonin level in brain is related to increase in aggressiveness.

Klüver-Bucy Syndrome and Human Studies in Amygdala

  • Activated during signaling of fear conditioning (learning of fear).
  • Human amygdala activates when people are looking at: Other people expressing fear or anger. Pictures, videos of frightening stimuli. Heightened if evaluating famous people (Heitler, M. Teresa ) as good or bad.
  • People with amygdala damage, tend to decrease attention to emotional details and detecting emotions in other persons.

Anxiety Reducing Drugs

  • Target the synapses in the amygdala.
  • Increasing gamma aminobutyric acid (GABA) activity, reduces anxiety.
  • Increasing CCK activity, increases anxiety.