Ch.11: Emotion, Reward, Aggression, and Stress

emotions

• positive or negative experience associated with a certain pattern of physiological activity

• two components: physical/physiological reaction & conscious experience or feeling

James-Lange Theory of Emotion

• bottom-up: emotion happens b/c of physiological response

• external stimulus → perception → physiological response → emotional reaction

Cannon-Bard Theory of Emotion

• top-down: emotion and physiological response happens at the same time

• external stimulus → perception → physiological response & emotional reaction

Schachter-Singer Theory of Emotion

• two factor theory: cognitive processing of physiological response (categorize to emotion: happy, sad based on response)

  • physiological arousal contributes to emotion's intensity, while identity of emotion is based on cognitive appraisal

Voluntary Facial Expression

• Cranial Nerve VII originates in facial nuclei in pons

• motor cortex

• contralateral: right up control left bottom

• bilateral: left up control left down

involuntary/spontaneous facial expression

• subcortical regions (cortex NOT involved)

• basil ganglia → red nucleus → facial nucleus VII → facial nerve VII → contraction of face

Brain regions involving emotional regulation

• cingulate cortex: amygdala → cingulate cortex → motor cortex → behavioral response

• hypothalamus: physiological response

• amygdala: emotion and fear

• prefrontal lobe: top-down control over amygdala

  • judging a situation and respond accordingly

regions associated with reward

• MFB

• lateral hypothalamus (orexin)

• mesolimbic pathway (dopamine)

medial forebrain bundle (MFB)

connects VTA to lateral hypothalamus (orexin) and nucleus accumbens

mesolimbic pathway

dopamine in VTA → nucleus accumbens → activate receptor → feel pleasure

lateral hypothalamus

orexin (increase motivation) → VTA and nucleus accumbens

genetic of aggression

MAO-A protein = destroys monoamine

• low MAO-A = not efficient in destroying → more monoamine = more aggressive

• high MAO-A = destroys more → less monoamine = more anxiety and affiliative behavior

brain regions associated with aggression

• hypothalamus & amygdala: motivational + emotional signals/initiations of impulsive aggressive acts (physiological response)

• prefrontal, anterior cingulate cortex: control CAC activity and aggressive actions (cognitive control)

• PAG: initiation of anger (motor) response

Sympathetic Nervous System (SNS)

• SNS stimulates adrenal medulla for norepinephrine/epinephrine/adrenaline = increase output from heart and gives energy for fight/flight response

• very fast - first response to stressful stimulus

Hypothalamic Pituitary Adrenal (HPA) Axis

• cortisol = gives even more energy when stress lasts long (a few mins)

• slow response and long-lasting (activated after adrenal gland activated)

negative and positive effects of stress

• positive: can make you more motivated to respond; increase immune system

• negative: too much stress = compromise immune system