Topic 1: The Brain Mechanisms of Emotion Flashcards
Compare and contrast the two major theories of the physiology of emotion.
The James-Lange theory (1884) posits that emotion is expressed in response to physiological changes in the body. (Sensory input –> ANS response –> emotion) while the Cannon-Bard theory (1927-) postulates that emotional experience can occur independently of emotional expression, and that there’s no correlation between emotion and physiological state.
Describe what is meant by the term “limbic lobe”.
Broca’s limbic lobe:
cingulate cortex, and medial temporal cortex, including hippocampus
The term “limbic” and structures in limbic lobe later became associated with emotion
Describe what is meant by the term “Papez circuit”.
Limbic structures, including cortex, involved in emotion, links cortex with hypothalamus. Includes:
Neocortex (emotional colouring)
Cingulate cortex –>
Hippocampus –>
Hypothalamus –>
Anterior nuclei of thalamus –> (back to cingulate)
In Papez circuit the cingulate gyrus affects the hypothalamus via hippocampus and fornix thus linking expression of emotion with experience of emotion
Describe what is meant by the term “limbic system”.
An “emotion system” exists in medial wall of brain; however, there’s no single emotion system
Briefly describe the anatomy of the amygdala.
Positioned just below the cortex in the temporal lobe. (Located in pole of temporal lobe)
Nuclei divided into three groups:
Corticomedial nuclei
Central nucleus
Basolateral nuclei
Describe the major inputs
and outputs of the amygdala.
Inputs: neocortex of all lobes
Hippocampal and cingulate gyri.
All sensory systems feed into the amygdala (basolateral nuclei)
– each sensory system has different projection pattern to
amygdala
- interconnections within amygdala allow integration of
inputs from different sensory systems
Outputs include hypothalamus, periaqueductal grey matter in brainstem, cerebral cortex
Describe the experimental evidence for a role of the amygdala in “learned fear”.
Rabbits trained to associate tone with mild electric shock
• Rabbit hears two tones, one accompanied by a shock to the feet, the other innocuous
• after training heart rate developed a fear response to tone associated with pain, but not to benign tone
• before training neurons in central nucleus of amygdala did not respond to tone used in experiment
• after training neurons responded to tone that caused fear, but not to innocuous tone
• after training lesions of amygdala abolished learned response
rats respond to aversive electric shocks by increased heart rate and “freezing” behaviour
• rats do not normally respond in this way to tones
• rats then given aversive electric shocks coupled with tones
• after training these “fear” responses were produced by sounding tone alone
• responses were abolished by amygdala lesions
• learning blocked by NMDA receptor antagonists in amygdala
Describe the evidence for a role of the hypothalamus in aggression.
Electrical stimulation of regions of the hypothalamus evokes signs of fear or rage e.g.
stimulating medial hypothalamus = affective aggression; stimulating
lateral hypothalamus = Predatory aggression
sham rage does not occur if posterior hypothalamus is also removed (along with cerebral hemispheres)
Describe the evidence for a role of serotonin in aggressive behaviour.
Mice isolated in small cage become aggressive towards other
mice
– have decreased turnover of serotonin in brain
– decrease only occurs in mice that become unusually
aggressive (females do not become aggressive and show
no change in serotonin turnover)
• Drugs that block synthesis/release of serotonin increase
aggressive behaviour
Describe the James-Lange theory.
The James–Lange theory: emotion experienced in response to physiological changes in body
What are the two major recent theories of emotion.
– Basic emotion theories
– Dimension emotion theories
Phineas Gage (1848) had damage to his Prefrontal Cortex (PFC) when an iron rod went through his skull. Which of the following personality changes did he exhibit? (Select all that apply)
A. became fitful
B. became irreverent, profane and obstinate
C. became consistently happy and excited
D. made many plans then abandoning them for others
A. became fitful
B. became irreverent, profane and obstinate
D. made many plans then abandoning them for others
Outline the basic emotion theories.
Certain emotions unique, indivisible, universal experiences
Basic emotions have distinct
representations or circuits in brain
Patterns of activity (fMRI or PET), not single areas, may represent emotions, or most highly active area = emotion
What is the empirical evidence for the experience of unconscious emotions? Choose the correct option.
Select one:
A. James Papez proposed a link between cingulate cortex (emotional experience) and the hypothalamus (emotional expression) in what is called the Papez circuit.
B. Experiments by Heinrich Klüver and Paul Bucy using temporal lobectomy in rhesus monkeys demonstrated the Klüver–Bucy syndrome.
C. Experiments by Arne Öhman, Ray Dolan, and their colleagues showed autonomic responses to angry faces that had not been consciously perceived.
D. Experiments by Joseph LeDoux showed the effects of fear conditioning and learned visceral responses.
C. Experiments by Arne Öhman, Ray Dolan, and their colleagues showed autonomic responses to angry faces that had not been consciously perceived.
List the six universal/innate emotions, according to basic emotion theories.
Anger, disgust, fear, happiness, sadness, surprise
