Emotion Flashcards
Darwin
Emotions are seen in all members of a species
Expression of a emotion is an evolved behaviour that’s indicates what an animal will do next
Opposite messages are often signalled by opposite movements
Common sense view of emotion
James and Lange (1884)
An event causes arousal, sensory stimuli received by the cortex triggers changes in the NS and physiological symptoms occur. The brain interprets the symptoms and you feel fear
- Too long, run from an bear?
- Every emotion would have to have specific symptoms
Cannon and bard (1995)
Arousal and emotion occur together, thoughts and behaviour are not considered
Independent of feedback
Modern biopsychological model
Each factor (stimuli, behaviour and emotion) inter relate and influence eachother
Components of a response include the behavioural, autonomic and hormonal responses. The autonomic nervous system coordinates and controls bodily functions - system is antagonistic sympathetic = arousal and parasympathetic = conserves energy
Regulation of emotion in the brain
Bard ( 1920)
Found decorticate cats respond agg to slightest provocation (sham rage) the hypothalamus is essential for expression and the cortex inhibits the response
Papez (1937)
Emotional expression controlled by interconnected nuclei around the thalamus (lymbic system) and their action to the hypothalamus causes emotional expression
McLean (1953) - limbic system theory
Reptiles don’t have a limvic system and differ from mammals - they’re not as maternal, don’t use vocal signalling or play! The limbic system increases sociability
Children only use the limbic system (can’t control emotional behaviour) as we mature the cortex connects and inhibits behaviour
Amygdala gets sensory info 2x as fast as the neocortex - only conscious of things that go to the neocortex so amygdala acts subconsciously
Neocortex needed socially or we’d be emotional and impulsive (alcohol!!)
Facial expressions
Ekman and Friesen (1971)
Universal facial expression means people of cultures can identify emotion
6 primary expressions diff combinations
Limbic system is subconscious so can you fake emotion? 1/10 people can fake a Duchenne smile
Ekman (1985)
1-Micro expressions reveal real emotion
2-subtle differences in muscles used
Videos support Ekman
6 primary expression early found in pure form
Existence of other primary emotions (content)
Body language important
Right side of brain is better at identifying emotions
Facial feedback theory
Facial feedback theory facial emotion tells your brain that you feel that way (empathy)
Mirror neurons involved - accidentally found in monkeys
Fire when an action is watched
This help us to understand and learn what someone is trying to do
Also activated when we see expressions = empathy
Overman (2007)
Pencil in mouth impairs ability to smile and this impaired ability to recognise happiness but not fear or sadness
Neal (2011)
Botox (paralyses) vs fillers
Botox impairs identifying emotion
Dampening facial feedback with restrictive gel means muscles work harder and more activation the brain = best at recognising emotion in eyes not difference in voice. Only activate what you can see via mirror neurones I
Emotional learning - fear conditioning
An animal is shocked, which is associated with a light. Eventually becomes scared of the light!
Removing the amygdala results in the animal being unable to be fear conditioned because they don’t respond to fear. The amygdala responds to loud noise, large animals and heights - these aren’t learnt! Important to learn when something is dangerous (emotional learning)
Fear conditioning results in defensive behaviour (freezing) and sympathetic response (hr and bp). Evolved to avoid danger
LeDoux
Mapped neural mechanisms that Medicare auditory fear conditioning
Destroy auditory cortex (deaf) fear conditioning still occurred. The signal from the thalamus can go to the cortex or the amygdala - so explains why the rat still got scared subconsciously! Once the thalamus was destroyed the signal can’t go anywhere and they don’t get scared
Complex sounds need the cortical route and the amygdala then assesses the emotional significance based on previous experience
To be evolutionary advantageous need to remember context - Hippocampus
Lesions in hippocampus block acquisition of contextual fear but not development of fear response
Bechara (1995) lesions in amygdala impairs acquisition of conditioned emotional response
Hormonal aggression - males
Organisational and activational effect of testosterone
Two surges of testosterone - prenatally and after birth this allows them to respond to it later in life (Ewing, 1980)
Androgens (male hormones) effect the development of nervous system, making neurones more responsive to T
In adulthood androgens activate sex organs and brain areas associated with aggression
Behavioural maculation
Androgens stimulate development of brain areas that respond to T in adulthood producing male sexual behaviour
Behavioural defeminisation
Androgens inhibit brain areas that respond to progesterone so inhibit female behaviour
Prenatal stress of mother = interfere with androgens so they don’t have an organisational effect on males - less agg (Kinsey and svare, 1986)
Testosterone acts in MPA (key area of sexual behaviour)
Hormonal aggression
Females
Testosterone makes women more agg and removing ovaries and injecting T makes them even more agg (T can act on its own and there is no eostrogen)
Androgens are produced naturally by the aderinal gland and if levels change = agg
Vanderburg (2000)
Female rat foetus closer to males are exposed to more androgens and behave more like males and are more agg
Studies for hormonal aggression
Hawke 1951
Prenatal androgenisation increases agg behaviour- chemical castration of male sex offenders reduces sex Drive and sex agg
Zumpe 1991
Steroids decrease sexual activity and male agg to females but increases internal agg
Dabbs and Morris 1990
US war veterans who are most antisocial have highest testosterone levels
Su et al 1993
Testosterone to males increases euphoria and sexual arousal , irritability and hostility
T administration to low level pps increases sexual activity and mood not agg
Perry and Yates (1992)
Athletes who take anabolic steroids are more agg
Cortisol and aggression
Produced by the after all medulla
Role in stress
Inhibits the likelihood of aggressive behaviour
Low levels are associated with higher levels of agg
Studies reported low levels in violent offenders and agg school children
Mixed evidence - some studies have shown no significant differences in cortisol and aggression, some studies find high levels = agg
Neural control of agg
Serotonin
Low levels of serotonin
Serotonin has a inhibitory effect on the brain and so if you don’t have enough of it you can become aggressive
Vergnes 1988
Activity of serotonin synapses inhibit agg and destruction of serotonin neurones facilitate agg
Saudou 1992
Mice lacking serotonin receptors attack intensively
Mann 1990
Weight loss drug to 35 healthy adults known to deplete serotonin
Pps reported an increase in hostility and aggression after the drug treatment - only males
It is possible that aggression is not caused by low levels but by low metabolism which leads to an increased number of receptors
Aurora and meltzer (1889) and Mann (1996) found a relationship between violent suicide and high numbers of receptors in the prefrontal cortex
Serotonin acts in the pre frontal cortex which inhibits certain behaviours so we don’t act with just our limbic system and behave emotionally and aggressively.
Badawy (2006) alcohol stops serotonin being metabolised and people become more aggressive when drinking.
Neural agg
Dopamine
Not as well established
High levels correlate with agg
Dopamine antagonists (drugs) block the action of naturally occurring dopamine
Antipsychotic can be used to block Dona pine receptors - successful in reducing agg
Coupis (2008)
Dopamine plays a role in reinforcing role of agg
Individuals intentionally seek aggressive situations for the rewarding sensation
Ferrari (2003)
Rat allowed to fight for 10 days, on 11th no fight
Measured dopamine and serotonin
Anticipation of fight dopamine increased and serotonin decreased
Experience actually changed the rats brain Chem
Less Dopamine makes it difficult to move so are they less aggressive or just can’t move?!
