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 situations Emotional 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 cortex Amygdala 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 predator Aggressive 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 behavior Low levels associated with antisocial behaviors, assault SE 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 Emotions How 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