Emotions Flashcards
Emotions
Rolls (2000)
States elicited by rewarding or aversive stimuli (S+ or S-)
and their omission ( – ) or termination (!).
Name an example of a rewarding stimuli (S+)
Ecstasy
Name an example of Termination of an aversive stimulus (S-!)
Relief
What are the similarities between mammal brains?
All have some sort of cortical structure
Subcortical structure
to Brainstem outputs
to effect/ explain/ cause behaviour
How can anxiety and fear be characterised without reference to subjective feelings?
A state caused by the presence of an aversive stimulus (S-)
What emotion/ feeling would be a state caused by the omission or termination of an aversive stimulus?
(S-!)
Relief
What emotion/ feeling would be a state caused by the omission or termination of a rewarding stimulus?
(S+!)
Anger, rage, sadness
An object or event that elicits approach and is worked for is known as…
A reward
Reward stimulus an animal works for
Name the 4 techniques to identify brain substrates of reward:
Instrumental conditioning (appetitive)
Intracranial electrical self-administration
Intracranial drug self-administration
Intracerebral microdialysis (measures NTM Rewarding S)
Which technique involves a motor response to a lever pressed in response for food to identify brain substrates of reward?
Instrumental conditioning (appetitive)
Which technique involves electrodes being implanted to different brain areas and see if the animal works for stimulation to that area?
Intracranial electrical self-administration
Animal should signal a reward when the brain area is triggered Areas that are not important in rewarding stimuli should suggest animal is not bothered (links to addiction)
Which technique involves the animal pressing levels to self-administrate drug doses?
Intracranial drug self-administration
Which technique involves implanting microdialysis to measure neurotransmitters associated with rewarding stimuli?
(measures NTM Rewarding S)
Intracerebral microdialysis
Depending on how much NTM you find is a reflection of how much NTM is in the brain area of interest
What does the yellow line represent?
Meso-corticolimbic dopamine system
Specifies rewards increasing Nucleus Accumbens dopamine (NAC DA)?
What does the green line represent?
Cholinergic projection from PPTg to VTA:
Electrical self-stimulation of PPTg which activates the DA system (Yellow line)
leads to DA release in NA
Cholinergic drugs: are self-administered into VTA
Nicotine
Acetycholine mimics nicotine
Which system in the brain is systematic and intra-NAC DA antagonists block responses normally maintained by reward?
Meso-corticolimbic dopamine system
Why is nicotine addictive?
Because it stimulates VTA DA neurons
What does the blue line represent?
Glutamate projections from Pre-Frontal Cortex to VTA:
Electrical self-stimulation of PFC stimulates the increase of DA in NAC
When testing an animal, we cannot conclude that the lever pressing it is due to pleasure (like) or due to desire (wanting). so for now research concludes that it could be both
So, animals may want self-administration of drug because they want (desire) it but don’t find pleasure in having it (like)
What are opioid receptors in the Nucleus Accumbens important for?
For us to experience pleasure (liking)
Which mechanism makes us want (desire) things?
Dopamine
What are brain substrates of emotional states associated with?
Aversive stimuli and appetitive stimuli (rewards)
They overlap
Dopamine and nucleus accumbens play important roles in which type of processes?
Fear-related processes
in addition to role in reward-related states and responses
The forebrain dopamine has been associated with classical conditioning with which three areas of the brain?
NAC
mPFC
Amygdala
Apart from playing key role in fear-related responses, the Amygdala has also been implicated in responses to?
Amygdala has also been implicated in responses to appetitive stimuli(rewards)
DNQX injection into nucleus accumbens elicits appetitive or defensive behaviours?
DNQX injection into nucleus accumbens elicits BOTH appetitive and defensive behaviours
Functional implications:
A ‘common currency’ of emotion may enable the brain to generate adaptive responses based on integrated assessment of positive and negative stimuli.
They rely on overlapping mechanisms
Expand on this.
Brain substrates
eg. DA, NAC, Amy may not play a specific role in emotion
But may contribute to fundamental cognitive processes
are associated with both aversive and appetitive stimuli
eg. all mechanisms may signal salience and attention or associative learning
Can emotional responses can be measured objectively?
Yes, enabling the scientific study of emotions in animals and humans.
In animal experiments, the measurement of emotional responses can be combined with a variety of techniques to do what?
to manipulate and monitor brain function
This reveals brain substrates of emotion and their dysfunctions
(eg. fear/anxiety and related disorders)
How can the detailed information from animal experiments be confirmed?
By appropriate research on human emotions in healthy subjects and clinical populations.
Name an example of an Aversive stimulus (S-)
Fear
Name an example of the Termination of a rewarding stimulus (S+!)
Anger/ rage
