Lecture 1 - OFC and constructivism Flashcards
What are emotions?
- positive or negative reactions to a particular situation
- emotions are mechanisms to set goals and establish priorities
- emotions possess an imperative quality ‘control precedence’ meaning that they can interrupt what we are doing and force themselves onto our awareness
- emotions are multicomponent responses to challenges or opportunities that are important to the individuals goals, particularly social ones
- whatever the goal and the source, it is the meaning that gives rise to emotion
- Eckman (1984)
Eckman (1984)
he developed 6 criteria that helps us differentiate emotions from closely related phenomena such as moods, sensations and personality disorders
1) brief - between 1 and 5 secs, anything longer is mood
2) unbidden - they happen to us and seize us in contrast to a lot of cognitive operations that we have control over
3) cross species - emotions are seen across species
4) coherent - facial, behavioural and physiological expression all work together
5) autonomic - emotions involve autonomic, unconscious, very fast appraisal of stimuli
6) quick onset - emotions happen almost instantly as a response to stimuli
Phineas Gage
case study of the inability to regulate emotional life
in an explosion a metal rod penetrated his cheek and came out the top of his head damaging his PFC
before the accident he was described as one with a well balanced mind however after the accident he became fitful, irreverent, grossly profane and unable to settle on any of the plans he had made for future action
Elliot
was a very intelligent man that developed a brain tumour
surgery to remove the brain tumour was successful but left elliot with bilateral damage to his OFC
however psychometric tests showed no signs of brain injury, rather they showed average to superior performance
he could talk intelligently about current issues and even tests used to tax frontal lobe function showed no deficits (Wallis 2007)
it would therefore appear that elliot was unaffected by the damage however months later he proceeded to make some terrible life decisions - he lost money to a scam artist, divorced his wife and married a prostitute
THIS ILLUSTRATES THAT THE OFC PLAYS AN IMPORTANT ROLE IN DECISION MAKING
The role of the OFC in decision making
Elliot lost a large sum of money to scam artists
One of the earliest deficits with associated with OFC lesions in monkeys is the failure to perform on stimulus-reward reversals (Wallis 2007)
A monkey learns that chasing one of the two objects will lead to a reward but when the contingencies change and the previously unrewarded object leads to a reward, the monkey with OFC damage were unable to inhibit responding to the previously rewarded object - a behaviour called preservation (Jang et al 2015)
Sul et al (2010)
found that the OFC conveyed signals related to the animals past choices and their outcomes over multiple trials, but neural signals for chosen value and reward prediction based decision making and that the OFC plays a prominent role in updating the values of outcomes expected from the chosen action
Stimulus reward learning and flexible behaviour
the same deficit that underlies the patient’s inability to reverse stimulus reward associations might also underlie the patients poor decisions
one possibility is that the patient is unable to modify his/her behaviour in response to negative feedback
for example scam artists may initially work to gain our trust but we realise their intentions before we allow them to take advantage of us
in contrast elliot may have been unable to modify his initial trust and thus was taken advantage of
only patients with OFC damage have problems with reverse learning (Wallis 2007)
Somatic marker hypothesis
Domasio (1994)
- the main point of the hypothesis is that decision making is a process guided by emotions
- thus there is a link between the abnormalities in emotion and the patients with OFC damage’s severe impairment in judgement (Bechara, Damasio et al 2002)
- the somatic marker hypothesis can be tested using the lowa gambling paradigm for measuring decision making (Bechara, Tranel & Damasio 2000)
lowa gambling task
4 decks of cards and the participant has to pick one card at a time, unbeknownst to the participant two of the decks incur large wins in addition to large and frequent loses - thus choosing from these decks is a losing strategy
- control subjects initially favour the decks that incur large gains but when they realise that they are associated with large loses they alter their strategy
- patients with OFC damage likewise initially favour these decks until they lose all their money (Mares, 2002)
SRCs
OFC patients have unusual autonomic responses during performance on the task
During learning, control subjects showed a marked increase in their Skin Conductance Responses (SRCs) immediately before a selection of one of the risky decks
This anticipatory SRC was missing in the OFC patients
From these results Domasio (1994) developed the SM hypothesis
* He argued that bodily states correspond to the emotions produced while evaluating different courses of action (so called somatic markers) to help facilitate decision making
* The role of the OFC is to store associations between patterns of environmental inputs and the somatic states that those inputs produce
*when making a decision, the OFC activates the somatic states that can then bias decision making
Gut feeling
Damage to the OFC destroys the patients ability to activate the somatic states thus all choice outcomes become emotionally equivalent. In this state the person must rely on their cognitive appraisal of the situation. Consequently, the large number of variables needed to assess a choice can easily overwhelm the decision making process. In the process the patient loses the ability to make a decision by gut feeling (Schuman et al 2014)
What happened to Elliot?
he lost the connections between the OFC and the primitive brain areas that generate emotions
the OFC integrates visceral emotions into decision making
the OFC connects feelings generated by the primate brain areas (e.g. amygdala and brain stem) to the stream of conscious thought
when we are drawn to an entry on the menu or have to choose between a 7am or 10am lecture this is much easier to decide than having to pick between Dr Smith or Dr Jones - this is because we go with our gut feeling
*a brain that can’t feel can’t make up its mind therefore
value of a reward (Wallis 2007)
- OFC neurons integratie multiple sensory features of a reward to determine its value
- in the study monkeys made choices between different volumes of different types of liquid
to make its choice effectively the monkey needs to consider both variables
*for example, a thirsty monkey might prefer the taste of the juice to water thus is the volumes were equal the choice would be juice
*however increasing the volume of the water can compensate for its less desirable taste - the firing OFC neutrons vary systematically with the value of the drinks rather than with the physical properties such as their taste or volume
the value of a reward
- the value of a reward depends on other potential rewards
- rewards must satisfy a need
- reward is relative e.g. you may be happy getting a raise of £1000 until you find out your coworker got £5000
- patients with OFC damage react positively or negatively to winning or losing money but do not experience regret by making the wrong choice (Camille et al 2004)
- they do not seem to be able to stimulate what would happen if they chose the alternative
Constructivism
1) biology has no role in emotion - differences between emotions do not reside in low level physiological functions according to the constructivist view
Danner, Snowdon & Freisen (2001) - happy nuns do not suffer from alzeimers as they have created a culture that overwhelms the physiological process
2) emotions are an open system - as opposed to the evolutionary approach that believes emotions are closed systems that fire in a coherent way and are not subject to environmental or cultural variation; facial expression, vocalisations and touch patterns can be arranged by culture into any configuration
3) culture and emotions shape each other in a bidirectional fashion - emotions shape culture and culture shapes what we think
emotions are social roles i.e. air hostesses are constantly smiling however they’re not constantly happy - this is their culture as their job requires them to stay smiling throughout the flight.
