Principles of Neuroscience Lecture 26 Fear Flashcards
Describe how there is development and change of emotion (and fear) over the course of one’s life
4-6 robbers, kidnappers
6-10: bodily harm
10-11: social fears
Describe how the cat lobotomy study helped to determine which areas were important for fear
When the hypothalamus was removed, there was no evidence of fear
When the hypothalamus was partly removed, and the cerebral cortex completely removed, there was sham rage.
The cerebral cortex is required for ‘directing’ rage at something
What are some common disorders associated with dysfunction of emotional systems
Panic disorder Panic attacks Obsessive compulsive PTSD Phobias
What are the symptoms of panic attacks
Shivering
Accelerating heart rate
Sweating
Nausea
Thus motor, cognitive, autonomic, thermoregulatory affected
Differentiate between volitional and emotional displays of emotion
Eg. Facial expressions
There are social smiles and also the smile that is the result of facial muscles moving when we hear a joke for example
The two are distinguishable, and an individual may be able to produce one and not the other
Which area of the brain has a main role in emotional expression ?
The hypothalamus
Differentiate between the medial and lateral inputs of emotional and volitional emotional behaviour
Medial: visceral representation of emotion, gain setting
Eg. Increased heart rate, butterflies in stomach
Lateral: somatic representation of specific emotional behaviours eg. Facial expression, waving arms about etc.
What is the function of the limbic system, and what areas comprise it?
Amygdala
Hippocampus
Hypothalamus
This area is related to descending control of emotion via the hypothalamus and memory of the fear
Connections from the limbic lobe to the Orbital and Medial PFC: planning of behaviour according to one’s emotional response to a stimulus;
- avoiding a punisher or
- seeking the reward
When is the amygdala activated?
When we receive a primary enforcer fear stimulus, such as a foot shock or something that we are evolved to be afraid of
Eg. When we see a face that we consider untrustworthy
What goes on in the orbital and medial prefrontal cortex?
Generation of outcomes of complex situations especially evil, dark ideas
Planning of behaviour according to our emotional response to a stimulus
Implicit motor actions in response to stimuli that evoke emotions
Which areas of the brain does the amygdala interact with?
- Olfactory bulb
- Hypothalamus and brain stem
Autonomic response to a stimulus that elicits a certain emotion
Eg. Increased heart rate, butterflies in stomach, gut feelings - Orbital and medial prefrontal cortex
Structuring of behaviour according to the emotional response to a stimulus
Describe the process of fear conditioning with reference to a particular study.
What is the mechanism of fear learning?
The rat in a cage receiving foot shocks
The mechanism is long term potentiation
When the rat received a shock at the same time as a musical tone was heard, the connection between the neuron in the amygdala and the input from the auditory tract would be strengthened
Describe the effect of damage to the amygdala
No longer reacts to a face that normally generates fear in other individuals
Unable to draw a face depicting the emotion of fear
All other emotions are intact
What is required for awareness of emotion?
What do problems in this area lead to?
Amygdala and hippocampus
Panic disorders due to dysfunction of this interaction
How does fear affect pain perception?
In extremely scary situations, pain is not felt
Fear over rides the perception of pain
