1 Chapter Fourteen Emotion

2 What is an Emotion? Emotions  subjective experiences that arise spontaneously and unconsciously in response to the environment around us. Emotions have two components:  physical reaction (rapid heartbeat, etc.).  conscious experience or feeling (sadness, anger, etc.).

3 Lie Detectors Are Unreliable

4 Which comes first, feeling or physiological response?

5 James-Lange Theory of Emotion Emotion arises from physiological arousal Kassin, S. (2001).

6 Cannon-Bard Theory of Emotion “Body” (physiological systems) and “Mind” (emotional experience) are independently activated at the same time

7 Schachter’s Two-Factor Theory of Emotion Physiological arousal  Sweaty palms  Increased heart rate  Rapid breathing Cognitive Label  Attribute source of arousal to a cause.

8 Theories of Emotion and the Capilano Bridge Experiment Men confused fear of the bridge with sexual arousal. James-Lange assumes that emotions produce distinct physical responses, so results here do not support this theory. Cannon-Bard and Schachter would predict these results. © Ted Streshinsky/CORBIS

9 Is Cognition Necessary? Pathway for Fear Without “Thought” Sensation of threat can reach the amygdala via direct path from thalamus  The fast “low road” Sensation of threat also travels from the thalamus to the cortex  The slow “high road” Cortical judgment can override direct path

10 Brain Mechanisms of Emotion: The Limbic System  Amygdala Frontal cortex  lobotomies

Copyright (c) Allyn & Bacon 11 Chapter 16 Schizophrenia

12 Schizophrenia Positive Symptoms  Delusions  Hallucinations  Disorganized speech  Disorganized behavior Negative Symptoms  Social withdrawal  Mood disturbance John Nash © Najlah Feanny/CORBIS

13 Prevalence of Schizophrenia Affects 0.5–1% of the world’s population. Age at diagnosis: Copyright © 2004 Allyn and Bacon

14 Genetics and Schizophrenia Concordance rate in identical twins is 50%. Adoption studies support a strong genetic role. As many as 70 genes may be involved.

15 Medial forebrain bundle (MFB): midbrain (ventral tegmental area – VTA) limbic system (nucleus accumbens) Many neurons in this system use dopamine. This system may function as a “reward circuit.” Mesolimbic System

16 Schizophrenia  How are positive symptoms related to dopamine?  Hypothesis: Mesolimbic system important for reinforcement of behavior We all have irrational thoughts, but usually brush them aside But if mesolimbic system was active when the thought occurred, we might take it more seriously, leading to delusions

17 Schizophrenia  Negative symptoms  Brain damage Many of the negative symptoms are also seen in people with brain damage  Hypofrontality Decreased activity in prefrontal cortex

18 Normal Twin Twin w/ Schizophrenia Negative symptoms: Brain damage

19 Control: Cell bodies arranged neatly. Patient with schizophrenia: Cell bodies relatively disorganized. Courtesy Arnold B. Scheibel, University of California, Los Angeles Negative symptoms: Brain damage

20 Loss of gray matter with age Cause of delay of onset?? Negative symptoms: Brain damage

21 Environmental Contributions to Schizophrenia Rh incompatibility Father’s age Maternal exposure to viruses during pregnancy  Geographical patterns  Seasonality effect Negative symptoms: Brain damage

22 Seasonal Effect Negative symptoms: Brain damage

The Hypofrontality Hypothesis At rest: both groups show similar activation levels in the brain Effortful task: patients with schizophrenia show less frontal lobe activity than participants w/o schizophrenia Courtesy Dr. Karen F. Berman, Clinical Brain Disorders Branch, SchiNIMH, NIH Normal Schizo. Normal Schizo. At rest Effortful cognitive test

24 How are positive & negative symptoms related? VTA Prefrontal Cortex NA Dopamine Hypoactivity (negative symptoms) GABA neurons Dopamine hyperactivity “reward pathway” (positive symptoms)