Emotion Flashcards
What are the main theories of emotion?
James-Lange
Schacter and Singer’s two factor theory
Define the James-Lange theory
Emotional experience may derive from bodily experience
James: we feel emotion because of what is happening in the body. ‘We don’t run because we’re afraid, we’re afraid because we run’
Lange: Emotion can be experienced as organic symptoms
Define the Schacter and Singer theory
Cognitive factors are critical for interpreting bodily changes to result in emotional experience
Define emotional behaviour
Behaviour driven by the need to fulfil social and internal goals.
Stems from presence or absence of positive and negative reinforcers.
What are the major responses measured in studies of emotion?
HR BP Galvanic skin resistance (sweating) Muscle tension Arousal (desynchronisation of the EEG)
What are the 5 primary emotions? Why are they called that?
Fear Sadness Anger Happiness Disgust Can detect these in animals
What discredited the James-Lange theory?
Injecting adrenaline to produce tachycardia didn’t produce emotional experiences
What did Hohman find?
Subjective feelings of anger and fear were diminished in patients with spinal cord transections. Effect greater the higher the transection. Patients could ‘act’ emotions, but without emotional coloring and intensity. Shows that cognitions of emotions intact when brain separated from viscera, but emotional experience greatly reduced
Describe the Schacter-Singer experiment
- Injected adrenaline while manipulating cognitive factors to test this
- 3 main groups:
1. Adrenaline ignorant: subjects told while being injected that injection was mild and harmless with no side effects. Patient thus had no externally provided explanation of their bodily state.
2. Adrenaline misinformed: told to expect totally inaccurate side effects – numbness of feet, itching
3. Adrenaline informed: told to expect hand tremor, palpitations, flushing
4. Placebo: given saline, told group 1 - Divide each group into 2 contexts
1. Euphoria: actor behaved euphorically
2. Anger: behaved angrily
What were the results of the Schacter-Singer experiment?
- Ignorant or misinformed subjects showed more emotion than placebo-treated subjects or subjects receiving Adr and informed of its tachycardia inducing effects (no significant difference between these two)
- Quality (euphoria or anger) of emotion determined by subject’s cognitive appraisal of the context in which the bodily changes occurred.
What does the Schacter-Singer experiment tell us?
- Provides support for James-Lange position that peripheral arousal produces a substrate for emotion
- Importance of cognitive factors (attribution or labelling of bodily states) in interpreting this general non-specific arousal as specific emotions
What are the two forms of anxiety?
Somatic anxiety
Psychic anxiety
Define positive reinforcer
something the subject will do more of to get more
Define negative reinforcer
Something the subject will do more of to get less
What are the problems with the Schacter-Singer model?
Tiny numbers of subjects
Hasn’t been replicated
Define somatic anxiety
Anxiety composed of physical experiences e.g. palpitations, hyperventilation
Treatment for somatic anxiety
Beta blockers (e.g. propranolol) Benzodiazepines like Valium , diazepam (enhance effect of GABA at GABA A receptors)
Define psychic anxiety
Anxiety characterised by the contents of consciousness - the feeling of dread or fear. Due to external stressors.
Treatment psychic anxiety
Benzodiazepines
What was Tyrer’s study about?
Treatments of somatic and psychic anxiety: diazepam, propranolol, placebo
What did Tyrer’s study show?
- Results: Diazepam treats both, propranolol only effective for somatic.
- Under propranolol psychic anxiety patients had a greatly reduced pulse rate, but showed no subjective reduction in their anxiety.
Define limbic system
The structures from Papez’ circuit along with the amygdala, septum and prefrontal cortex.
What did Broca discover?
A rim of old cortex on the medial wall of the hemisphere: the Grande lobe limbique. Now known as cingulate gyrus and uncus
What did Papez do?
Combined information from brain damage patients with research on the role of the hypothalamus in the control of emotional reactions in animals to create a theory explaining the flow of information through different structures that underlied emotion: Papez’ circuit
Who was Phineas Gage?
A worker where a metre long iron rod damaged prefrontal cortex and orbitofrontal area. Personality dramatically changed – could no longer regulate emotions effectively. Became quick-tempered, foul mouthed, behaved sexually inappropriately.
What is the Cannon-Bard hypothesis?
Showed removal of the whole cerebral cortex didn’t eliminate rage, but removal of the hypothalamus fragmented the emotional response.
Damage to cingulate gyrus
Apathy, depression, loss of emotional spontaneity
What did Papez include in his circuit which is no longer included, and why?
Hippocampus
Rabies damages it, results in emotional disturbance
What is Kluver-Bucy syndrome?
Temporal lobe removal in monkeys –> Psychic blindness including tameness, lack of emotional responsiveness, excessive examination of objects often with mouth, eating of previously rejected items, hypersexual behaviour.
What is thought of now as underlying emotion?
Hypothalamus, amygdala, orbitofrontal cortex, ventral striatum (nucleus accumbens), cingulate cortex.
Recently ant hippocampus implicated in emotional processing
What does the amygdala do with respect to emotion?
Learns about the emotional significance of stimuli and subsequent expression of these emotions
Why is the amygdala well placed to regulate emotion?
Connected to brainstem and hypothalamus so well placed to initiate fearful and aggressive responses
What is an unconditioned stimulus?
A stimulus that is intrinsically appealing or aversive
What is a conditioned stimulus?
A stimulus you have to condition the subject to have a response to
What is Pavlovian fear conditioning?
Presenting an animal with a neutral stimulus followed by a mild electric shock
After a while the CS will elicit the same autonomic, endocrine and behavioural responses as the original unconditioned stimulus
Effect of lesions of the amygdala?
Central nucleus: Lose Pavlovian fear conditioning
Impair fear recognition on faces
Evidence that the amygdala is involved in processing faces?
- Lesions impair fear recognition
2. fMRI showed amygdala activated when presented with emotional faces
What does the amygdala stimulate?
Laterla hypothalamus –> symp stim
Dorsal motor nucleus of X, Nucleus ambiguous –> para stim
Parabranchial nucleus –> increased resp
VTA/Locus coerulus/Dorsal lateral tegmental nucleus –> activation DA/NA/ACh
Nucleus Reticularis Pontis Caudais –> increased reflexes
Central grey –> cessation behaviour
Trigeminal/Facial MN –> mouth open, jaw movements
Paraventricular nucleus –>ACTH –> corticosteroids
Define anxiety disorders
Healthy response to, and anticipation of, fear becomes dysfunctional.
What are the categories of anxiety disorders?
- Phobias
- Panic disorder
- PTSD
- Agoraphobia
- GAD
Define phobia
Irrational fear of a specific object or situation
Define panic disorder
Intense and overwhelming attacks of anxiety
Define PTSD
Recurrent flashbacks, intrusive thoughts and anxiety after a traumatic experience
Define agoraphobia
A fear of crowds or public places that often gives rise to panic attacks
Define GAD
Generalised Anxiety Disorder
Pervasive anxiety or worry lasting for months
What are the key characteristics of phobias?
- Persistent fear of a situation or object that most people find tolerable
- Outside the panic situation can acknowledge that the fear is irrational
- Patient changes daily routine to avoid contact with the phobic object or situation. Can become debilitating.
What are the types of phobia?
- Specific: to animals, activities or inanimate objects, illness/injury, blood/needles
- Social phobia: fear of being observed linking to fear of humiliation or embarrassment
- Agoraphobia
What happens physiologically in needle phobia?
HR/BP decreases
Prevalence of phobias in me and women?
8% women, 4% men
What is the evidence that phobias have a genetic component?
First degree relatives of phobic patients 3x more likely to suffer phobias
Twins - 30% heritability
Who was Little Albert?
Conditioned to fear a white rat (CS) by pairing with a loud gong (US) over his head. After 5 exposures, presentation of rat alone elicited crying and hiding behaviour (UR)
Define avoidance.
Phobic patients run away when they see the CS, so CR doesn’t extinguish - they see it as a lucky escape. Negative reinforcement as avoidance relieves anxiety.
Define Mowrer’s 2 factor model
Phobic anxiety is acquired by pavlovian conditioning but maintained by operant conditioning (avoidance)`
Define Seligman’s biological preparedness model. Which studies support it?
There is an evolutionary bias for phobias to develop in response to objects and situations that were harmful to our ancestors (so lack of gun and knife phobias)
- Mineka: rhesus monkeys
- Ohman: extinction trials
Define vicarious conditioning
The development of phobic responses based on observing someone else having a phobic response.
Describe the Mineka study
Lab reared Rhesus monkeys do not exhibit behavioural avoidance or emotional distress to toy snakes, while wild-reared do. Shows early experience can produce phobic reactions. Also showed that lab-reared adolescent monkeys did develop phobic responses if put into a situation where they could observe their parent’s fearful reactions to the same snake stimulus (vicarious conditioning). Vicarious conditioning occurred more easily to the toy snake than to a flower, so suggests snakes have some innate properties that are recognised by the fear system.
Describe the Ohman experiment
Presented human subjects either 1 or 5 pairings of a picture CS and shock US. Picture was of a potentially phobic stimulus (snake) for half the subjects, and a neutral stimulus (flower) for the remainder. CR measured in extinction (just CS, not US). Control groups, to check any change in SCR (sweating) was due to the positive temporal correlation of CS and US, received simple exposure either to shock alone or to the picture alone.
What did the Ohman experiment show?
- Showed that conditioned group showed larger SCR than controls
- More conditioning to phobic CS (snake) than to neutral (flowers) – indicating that certain stimuli are more easily established than others as CSs for an aversive US.
What did the Ohman experiment modified by instruction that the US would no longer occur show?
Instructions reduced SCR responding to the CS when a neutral stimulus was employed, but there was no effect when a phobic CS was used, i.e. the conditioned fear response persisted.
Treatments of phobias?
- Flooding - patient exposed to CS until their anxiety subsides in absence of the US
- Modelling therapy: patient observe another person experience the CS in a non-fearful manner. Assumes that conditioning processes can occur vicariously. By watching another person behave according to the stimulus, our own fear reactions are modified
- Systematic desensitisation
What did Doogan and Thomas observe?
Dog phobia can be transmitted to children from parents
What are the stages of systematic desensitisation?
- Train patient in a relaxation technique
- Patient and doctor develop a hierarchal list of fear situations, from slightly scary to full exposure
- Expose to first situation and implement relaxation to counter-condition their anxiety
- Once can handle with no fear reaction, progress to second scenario,
Define predisposing factors
Biological or psychological factors that increase the risk of developing a phobia e.g. being bitten by a dog in childhood
Define precipitating factors
Factors that bring the issue to the surface, e.g. moving to a new house where the phobic stimulus is encountered more often
Define maintaining factors
Factors that interact with the triggering factors to perpetuate the problem, e.g. avoidance, hypervigilance, thought suppression
What is the effect of hypervigilance?
Constantly checking for the phobic stimulus means the patient detects more of them
What is the effect of thought suppression?
Patient actually thinks about it more
What is the Spider-Stroop task?
Spider phobics slower to read the colour of spider-associated words
What did Thorpe and Salkovskis show?
That phobic patients don’t appreciate their irrationality in the phobic situation
Define cognitive behavioural therapy
a type of psychotherapy in which negative patterns of thought about the self and the world are challenged in order to alter unwanted behaviour patterns or treat mood disorders such as depression.
How is the brain altered in anxiety disorders?
Overactive amygdala
Underactive prefrontal cortex - suggests normally prefrontal cortex acts to downreg amygdala responsivity to aversive stimuli
What do benzodiazepines do?
E.g. valium Treat anxiety Anti-convulsant Hypnotic Sleep-inducers
What are the advantages and disadvantages of benzodiazepines?
Advantage: hard to lethally overdose
Disadvantage: associated with dependence-withdrawal that includes insomnia, loss of appetite, anxiety
What is the Geller-Seifter conflict procedure?
A mildly thirsty or hungry rat trained to press a lever for water or food, but occasionally a neutral light or tone stimulus is presented terminated with a mild electric footshock. Provides conflict, when the now CS is presented alone, resulting in suppression of behaviour until the anxiety-eliciting CS is switched off.
What is the effect of benzodiazepines on the Geller-Seifter conflict?
Increases number of responses made during periods signalled by fear CS - ‘anxiolytic’
What do benzodiazepines bind to and where?
GABA-A in amygala
What do SSRIs do?
Selective serotonin reuptake inhibitors e.g. Prozac
Only work after a few weeks, probably regionally up or down regulate specific 5-HT receptors
What is the genetic basis of the amygdala hypersensitivity to aversive stimuli?
Subjects with less effective (short) allele of 5-HT transporter show increased amygdala responses to fearful facial expressions and are at increased risk of anxiety compared to subjects with the more effective long allele.
Serotonin also involved in developing brain circuits, so short allele probably has effects on development, and so may have changes beyond those specific to serotonin.
What are the treatments of anxiety?
- Benzodiazepines e.g. Valium
- SSRIs like Prozac
- Rarer 5-HT receptor blockers
- Propanolol for somatic anxiety
