Lecture 8 - Emotion in Psychological Disorders Flashcards
How Emotions involve the body: What is the Fight or Flight Response?
Fight or Flight Response
Parasympathetic Response:
o Stimulates release of bile
o Contracts Bladder
o Slows Heartbeat
o Stimulates saliva flow
Sympathetic Response
o Dilates pupil
o Accelerates heartbeat
o Breakdown of glycogen
o Secretion of adrenaline and noradrenaline
What is James-Lange Theory (1995) of emotions
Evidence: Critchley HD et al.
Emotions = sets of bodily responses that occur in response to emotive stimuli
–> Different patterns of bodily change code different emotions
(eg. We feel afraid because we tremble)
How is this measured?
–> Heart rate
–> Skin conductance (increases when we sweat)
Facial expressions can be differentiated on the basis of evoked heart rate response
Critchley HD et al. (2005)
–> Heart rate for correctly identified sad and angry faces > happy or disgusted faces
–> Expressions of disgust mid-identified as sadness/anger evoked heart rate changes more typical of anger/sadness than disgust (as predicted by James-Lange)
What is Cannon-Bard Theory (1920s)
Argued AGAINST James-Lange theory because…
1. Emotions occurred even if brain disconnected from internal organs
2. Bodily changes are not emotion-specific (heart rate increases in lots of emotions)
3. Bodily changes are too slow
4. Stimulation of bodily change doesn’t always induce an emotional response
BUT contradictions to this said…
1. You CAN but they are much less intense
2. There are partial emotion-specific patterns
3. Some changes are quite rapid
4. Example: CCK –> can induce nausea and panic
Integration of both theories: Emotions depend on BRAIN mechanisms (bodily responses can be encoded in our memory, and when we see this again can reactivate these brain areas but not always reproduce the bodily response)
How can bodily state be represented in the brain?
Once you’ve encountered a stimulus in the environment, you will get activation in a range of different brain systems (eg. sight, sound and feeling)
–> when you later think about that event, you might reactivate (for example the visual) representation –> which can then trigger activity in the other brain areas
–> the ‘embodied experience’ is an important aspect of memory
What is Schachter and Singer’s Two-Factor Theory of Emotion?
Emotion is a function of both cognitive factors (appraisal) AND physiological arousal
–> People search the immediate environment for emotionally relevant cues to label and interpret unexplained physiological arousal
Gave misinformed subjects adrenaline injections; resulting arousal/emotions were interpreted on basis of contextual cues - provided by stooges
–> People that were NOT informed about the side effects of adrenaline acted in A MORE EMOTIONAL WAY - the adrenaline was causing their heart rate increase and making them have these physiological arousal responses, which is what they then interpreted as their reaction to the stooge’s emotional state
WHEREAS
–> people that were informed ahead of time about the symptoms they’d feel didn’t show this strong emotional response to the stooge (put it down to the drug effects)
Appraisal and Emotions: Lazarus (1991)
Relational Meaning
–> Emotions are NOT caused by events in the environment or by intra-psychic factors (within the individual)
–> They are caused by PERSON-ENVIRONMENT relationships that can change over time and circumstances
–> What does this event mean to me?
–> Emotion is rooted in APPRAISAL: the relationship you have with one event - therefore can change over time
Placed a much bigger role on conscious interpretation rather than physiological response
The Emotional Brain: Outline Papez’s Neural Circuit of Emotion
Historically: the limbic system seen as very important in emotion
–> Amygdala: KEY ROLE that is particularly activated by negative experiences
Neural Circuit of Emotions see onenote doc for full picture to learn
Emotions: Role of the Amygdala:
- Including the ‘low’ road and the ‘high’ road
The Amygdala (temporal lobe)
–> Plays an important role in emotion processing
Evidence:
–> Lesions in monkeys: changes in social behaviour, and absence of emotional motor and vocal (eg. fear) reactions
–> Lesions in humans result in emotional blunting and reduced fear conditioning
Amygdala Pathways
Joseph LeDoux - 2 Amygdala Pathways (1986):
THE HIGH ROAD
Stimuli –> Sensory Thalamus –> Sensory Cortex –> Amygdala –> Emotional Response
o Usual Processing - stimulus goes into the thalamus
THE LOW ROAD
Stimuli –> Sensory Thalamus –> Amygdala –> Emotional Response
o Signal is rapidly sent to the amygdala - triggers a quick motor response so can react to potential threats to the environment (without really knowing what they are)
fMRI studies show the amygdala is particularly activated with FEAR
Influence of Genes of Amygdala Response (Hariri et al.)
Our amygdala responses to pictures signalling threat - is influenced by our genes
–> Amygdala rich in serotonin
–> We have a serotonin transporter gene, that ‘mops’ up serotonin in the synaptic clefts - less serotonin around to transmit
–> Short-Form of the serotonin transporter: less efficient transporter - more serotonin
Hariri (2005)
–> Task required participants to identify which (in a question) matched the top/bottom face (emotional condition) or shape (control condition)
o Subtracting the results of B and A leaves areas controlled by emotion
FINDINGS: Emotional task - strong activation in the amygdala
–> Short form of gene: more serotonin - showed a stronger amygdala response in the task (more reactive to scary faces)
Clinical Examples: Risk of Depression
People with the SHORT-FORM of the serotonin-transporter gene AND adverse life events = more likely to have depression as an adult
–> Effect of life events on depression was STRONGER among people carrying an s allele
AGAIN for childhood maltreatment: association between childhood maltreatment and adult depression
–> short-short allele for the serotonin-transporter gene + severe maltreatment = higher probability for major depression
Orchid Hypothesis: Short form of the gene makes more people more emotionally sensitive/reactive
Clinical Examples: Major Depression
Asking people with major depression to identify the emotion in faces…
–> Compared with healthy controls people with depression are LESS likely to say a mildly happy face is happy
–> They are less sensitive to happiness/positive stimuli
–> More sensitive negative expressions (have a negative emotional bias)
Meta-analysis shows small effect sizes that people with depression show reduced recognition for emotion in general - but not for sadness
People with depression show INCREASED amygdala responses to negative facial expressions
–> This higher response was NORMALISED (similar to the control) when participants were given an SSRI treatment
Clinical Examples - Antidepressants and Depression
Antidepressants decrease amygdala response to fear faces in healthy people
–> Antidepressants REGARDLESS all seem to have a similar profile of changing a patient’s ability to identify emotional expressions
–> Harmer et al. (2004): healthy people given 7 days of antidepressants showed decreased recognition of negative emotional expressions
Harmers (2021) Model
–> Proposes that it takes a WHILE for the changes in how the brain identify emotional stimuli to trickle down and change a person’s mood
–> CRUCIALLY: it may be that we need SOCIAL INTERACTIONS for effect to show
Clinical Examples: Obsessive-Compulsive Disorder (Disgust - Insula)
Insula Cortex - Human Lesions
–> Stimulation: perception o unpleasant tastes, nausea, salivation and swallowing
–> Lesions: decreased subjective experience and recognition of disgust (impairs disgust processing)
OCD: Elevated Disgust in washing symptoms?
–> Some people will have hoarding, checking, washing symptoms (contamination obsession)
–> Contamination concern: disgust seems to be highly involved
–> Mataix-Cols et al. (2004): Activation in the insula positively correlated with washing OCD “Imagine you’ve got to touch these objects and not wash your hands*
Discrete v Dimensional Emotions: Evidence from Brain Imaging
Evidence shows for BOTH theoretical accounts…
–> Evidence suggests some brain areas get activated in response to lots of emotions, but many emotions show a discrete preference to certain areas of the brain
Arousal emotions: dimension to AMYGDALA
Eg. Disgust - discretely preferences to anterior insula
Eg. Fear - preferences to amygdala
