Emotion and Motivation

Zara Melikyan, Ph.D. Fall 2015

Lecture Plan

• Emotion and motivation: definition, theories• Emotions and brain– The limbic system– The brainstem– The cerebral cortex– The autonomic nervous system

Definitions

Motivation – is a construct to explain behavior, reasons for actions, desires, needs– Cognitive component– Emotional component

Motivation– Inferred from goal-directed behavior– Goal achievement usually associated with emotion

Definitions

Emotions - +/- reactions to situationsEmotional response:

– Feelings – Physiological changes– Behavior/urge to perform a behavior

Emotion, primary colors:– Happiness, sadness, anger, surprise, disgust, fear

Function of emotion:– Communicate motivational state

Theories of Emotion:The James-Lange Theory

• Emotion = perception of one’s physiological changes in response to a situation

• Physical sensations evoke emotions– We feel afraid

because we tremble

Criticisms of James-Lange Theory

• Incorrect assumption– Each emotion has own set of physiological

changes

• Research– Similar patterns of physiological arousal for

multiple emotions

Theories of Emotion:Cannon-Bard Theory

• Psychological experience and & physiological reactions are simultaneous– Event– Nerve impulses pass through thalamus– Nerve impulses split in half:• To cerebral cortex – Subjective experience of emotion• To hypothalamus – Commands physiological changes

The Cannon-Bard Theory

External Stimulus

Cerebral cortex(Emotional labeling)

Thalamus

Hypothalamus(Physiological

response)

Emotion

8

Criticisms of the Cannon-Bart Theory

• Incorrect physiology– Thalamus is not the center of emotional

experience– Emotion is a function of circuitry, not “centers”

Theories of Emotion:The Papez Circuit

Three proposed circuits:

• Stream of feeling– Limbic system

• Stream of movement– Sensations through thalamus to basal ganglia

• Stream of thought– Sensations through thalamus to cerebral cortex

Emotion – merging of streams

Emotional responses

• Behavioral– Muscular movements: facial expression, entire body

movements

• Autonomic– Quick mobilization, facilitates behaviors.

Sympathetic/parasympathetic NS

• Hormonal– Reinforce autonomic responses: adrenal medulla

secretes EP, NE, steroid hormones

The Limbic System• Thalamus

– Sensory information specific nuclei

• Hypothalamus– Changes in autonomic nervous system (e.g. heart rate)

associated with emotion

The Limbic System

• Amygdala– Fear and aggression– Facial emotion recognition

(esp. negative)– Emotional memory

• Hippocampus– Memory (esp. emotional

memory)

The Brainstem

• Pons– Locus coeruleus– Secretes NE– Experiencing pleasure– Triggers emotional arousal– Too little – depression– Too much over a long period of

time – severe stress

• Midbrain– Substantia nigra– DA– Pleasurable sensations

The Cerebral Cortex

• Temporal lobes– Emotional memory

• Frontal lobe (esp. prefrontal cortex)– Inhibition– Regulating emotions produced by amygdala

The Autonomic Nervous System

• Sympathetic nervous system– “Fight or flight” response

• Parasympathetic nervous system– Energy conservation

In threatening situation ANS responds within seconds– Physical reaction including reflexes– Emotional reaction

Cognition and Emotion: Schacter’s Two-Factor Theory

• Physiological arousal

• Cognitive evaluation based on environmental cues

Fear

Amygdala • Organizes responses to aversive stimuli• Integrates behavioral, autonomic, and hormonal responses• Has reach connections with cortical and subcortical structures

Central nucleus – emotional responses to aversive stimuli– Destruction of SN – no fear, stimulation – fear– Particular stimuli: loud, big; or learned/conditioned S evoke fear response

Basal nucleus Lateral nucleus – physical changes related to response; behavioral, autonomic, hormonal responses

Inhibition of conditioned fear response – Ventromedial prefrontal cortexAmygdala damage impairs memorization, perception of “-” emotional stimuli

Anger, Aggression, Impulse Control

Aggressive behavior– Attacks– Threat behaviors

Threatened demonstrates:– Defensive behavior– Submissive behavior

Sympathetic system is more activated in pray then predatorAggressive behavior

– Muscular movements – brain stem– Brain stem is controlled by hypothalamus and amygdala– Limbic system is controlled by perceptual system, cortex

Anger, Aggression, Impulse Control

SE inhibits aggression, controls risky behaviorLow levels associated with antisocial behaviors, assaultSE agonists (e.g. Prozac) decrease irritability, aggressiveness

Human violence and aggression is serious problem

Hereditary factor in antisocial behavior and aggression

Ventromedial prefrontal cortex – Inhibits reactions, including aggression – Emotional dysregulation, impulsive violence– Phineas Gage destroyed vmPFC bilaterally – Decreased prefrontal activation, increased subcortical (amygdala) activation in

murderers with negative emotions vs. cold-blooded– SE influences on prefrontal cortex

Hormonal Control of Aggressive Behavior

• Males are more aggressive than females

• Male aggressiveness is better tolerated in society

• Androgen stimulates testosterone-sensitive neural circuits that facilitate aggression

Communication of EmotionsHow we feel and what we are likely to do, by:• Postures, movements• Facial expression• Speech and non-verbal sounds

Facial emotional expressions use spices-typical repertoire (cross-cultural studies, blind people) (C. Darwin and others)

Facial emotions recognition:• Fast, automatic, accurate• Visual and auditory systems• Right hemisphere is more involved• Amygdala involved in emotional perception (face and body), especially “-” emotions• Imagining/imitating observed emotions, mirror neurons of parietal lobe

Neural Basis of Emotional Communication

• Volitional facial paresis– Damage to primary motor cortex, motor nucleus of facial nerve– Can not voluntarily move facial muscles, but can express

genuine emotions

• Emotional facial paresis– Damage to the insula of prefrontal cortex, frontal lobe,

thalamus– Can move facial muscles, but can not express emotions on the

affected side of the face

• Understanding jokes and reacting to them – ventromedial prefrontal cortex