Neural Mechanisms of Emotion and Emotional Learning.

Neural Mechanisms of Emotion and Emotional Learning. Irene Y. Merzlyak COGS1 Lecture November 18th, 2004

Traditional approach: what we get from philosophy and “common sense” • The people governed by reason are “philosopher kings” • The people governed by emotion are “warriors” • The chariot where the sole rider is Reason, which guides the two horses – “Appetite” and “Spirit”….. (Plato’s “Republic”)

Motivation and Emotion are inherently interconnected with reasoning and decision making. • Theoretical perspective • Experimental Evidence from Psychology • Neural perspective • Examples from research

Theories of emotion and affect: James – Lange Cannon - Bard Cognitive Appraisal Theory: Schachter & Singer

Thalamus sends sensory information to other parts of the brain.

P.J. Lang’s theory of emotion components.

Importance of Physiological Arousal in Emotions and Health

Autonomic Nervous System: Physiological Response of the Body

Neural Structures important in Emotion: Limbic System

Schachter and Singer Experiment • “Study” to examine new drug “Suproxin” • Supposedly enhances vision • Told it would take 20 minutes to take effect • Wait in room with confederate • Really given epinephrine • Causes arousal, rapid heartbeat, etc

Schachter and Singer Experiment • Groups of subjects were given different instructions: • A. Causes arousal – true – informed group • B. Causes itching, headache – misinformed • C. No side effects • D. Placebo (control group) – given no drugs

Schachter and Singer Experiment • Confederate in waiting room acts euphorically – provides context for subject to interpret arousal • After 20 minutes, subjects rate how happy they feel

Results – both arousal and context are necessary!The subjects were asked: How happy are you? • Rated on the scale from 1 to 10

How happy are you? • Control – 4 – no arousal; no explanation

How happy are you? • Control – 4 – no arousal; no explanation • Informed – 3 – arousal is explained by the drug • these subjects rate less euphoric than controls

How happy are you? • Control – 4 – no arousal; no explanation • Informed – 3 – arousal is explained by the drug • these subjects rate less euphoric than controls • Misinformed – 7 – arousal with no explanation • rely on situational cues • Uninformed – 7 – arousal with no explanation • rely on situational cues

Dutton and Aron Bridge Experiment • Male subjects fill out questionnaire for female experimenter • either on high bridge or on low bridge • She leaves phone # with subjects • More call when they were tested on the high bridge • attribute bridge induced arousal to attraction

Sexual Attraction and the Bridge Experiment • Male subjects fill out questionnaire for female experimenter • either on high bridge or on low bridge • She leaves phone # with subjects • More call when they were tested on the high bridge • Attribute bridge induced arousal to attraction

Sexual Attraction and the Bridge Experiment One of the oldest philosophical questions is, "What is love." Isn't this question beyond the scope of science? Most people probably wish it were. However, sociologists, medical researchers, and psychologists have learned a great deal about attraction and love within just the last few decades. From the Kinsey reports (Kinsey, 1948; Kinsey, 1953) which first uncovered the diversity of human sexuality to current neurological research of sexual desire, science has shed light on many mysteries concerning love, relationships, and attraction. One example of modern psychological research on attraction was done by Dutton and Aron (1974) in the 1970's. They placed a female experimenter on two bridges, a high, wobbly bridge and a low, firm one. The experimenter asked men to make up a story about a picture she showed to them, saying the experiment was to study "the effects of scenic attractions on creative expression." She gave her phone number to each man, and told him he could call her if he had any further questions about the study. In fact, the experiment had nothing to do with creative expression. The researcher's hypothesis was that the men would "misattribute" the physical arousal of being on a higher, less safe bridge, to sexual arousal and attraction to the woman. The results were convincing. Most of the men on the higher bridge told stories using sexual or romantic themes, and 39% of the men called the female experimenter, many asking for a date. The men on the lower, safe bridge told few stories with sexual or romantic content, and only 9% called her. The interpretation is that the men on the high bridge did indeed misattribute their arousal on the high bridge as attraction towards the experimenter. Further similar studies, adjusting for possible other factors involved, support the interpretation. Which may beg the question: if you want your date to fall in love with you, what type of movie might you go to see?

Desire and Brain Reward Circuits

Neural Structures important in Emotion:

The Case of Phineas Gage An explosion projected a tamping rod through his left cheek. Miraculously, he recovered and had “normal intelligence”. Weeks later, however, Gage began to have startling changes in personality and in mood. He became extravagant and anti-social, a fullmouth and a liar with bad manners, and could no longer hold a job or plan his future. He was quick to anger and often got into fights. "The equilibrium between his intellectual faculties and animal propensities seems to have been destroyed.” - Harlow

The Case of Phineas Gage An explosion projected a tamping rod through his left cheek. Miraculously, he recovered and had “normal intelligence”. Weeks later, however, Gage began to have startling changes in personality and in mood. He became extravagant and anti-social, a foulmouth and a liar with bad manners, and could no longer hold a job or plan his future. He was quick to anger and often got into fights. "The equilibrium between his intellectual faculties and animal propensities seems to have been destroyed.” - Harlow

Rage

A Role for the Prefrontal Cortex in RAGE • One recent study reports that children who received damage to their prefrontal cortex before age seven, developed abnormal social behavior, characterized by an inability to control their frustration, anger and aggression. • A brain imaging study of murderers found evidence that, on average, the prefrontal cortex as well as some deeper brain areas, including the amygdala, functioned abnormally. • Impaired activity in prefrontal cortex and the amygdala also appeared in a preliminary examination of psychopaths with extensive criminal records who, as a group, are generally prone to violence.

Amygdala

Amygdala in Affect: • Enhancement of emotional memories • Recognition of emotional facial expressions (human studies) • Fear Conditioning (rat, monkey, human)

Post-Traumatic Stress Disorder? “In her dreams she hears calls for help from people trapped in the offices of Cantor Fitzgerald, the bond firm that lost more than 600 employees, and in the Windows on the World restaurant, which occupied the top floors of the north tower.”

Emotional Facial Expressions: Urbach-Weithe Patients unable to recognize fear.

Fear Conditioning

Fear conditioning in rat:

Connectivity Patterns of BLA and CeA

Associative Learning • Adaptation to the environment: we naturally adjust behavior appropriately to novel situations (stimuli) over time. • Amygdala has a role in linking novel sensory stimuli with affective (emotional) value: forming stimulus – stimulus associations

“Anatomy of Affect” – Emotion is an important component of Reasoning and Decision Making. • Circuitry underlying valence and arousal components of affect • Connections between Frontal Lobes and the limbic system play a role in Associative Learning and behavioral outcomes • Connections between the Limbic System and the brainstem nuclei play a role in behavioral regulation of autonomic response.

Conclusions: • Emotions involve both physiological and cognitive components. • Emotional learning may guide reasoning and decision making. • Neural structures involved in emotions are also involved in social behavior and reasoning.

Terminology and abbreviations: • “Flashbulb memory” – particularly memorable, highly emotional • OFC (orbitofrontal cortex) – part of PFC (prefrontal cortex) • LA (or L – slide 40) – lateral amygdala • BLA – Basolateral complex of the Amygdala • CeA (or CE) – Central nucleus of the Amygdala • CG – Cingulate Gyrus (slide 39) – these three (CG, LH, PVN) were NOT emphasized in lecture • LH – Lateral Hypothalamus (slide 39) • PVN – Paraventricular nucleus of the Hypothalamus (slide 39) • ANS – Autonomic Nervous System • Urbach-Weithe disease – selective calcification of the amygdala during development • Ekman faces – the 6 basic emotional facial expressions

Neural Mechanisms of Emotion and Emotional Learning.