Emotion Flashcards
(42 cards)
Heritability and emotions
- The trait emotionality is moderately heritable - 40-60%
- Most findings that imply heritability are probably the result of gene-environment interactions
The limbic system
Brain structure underlying emotion
Collection of subcortical structures: Amygdala, hypothalamus, hippocampus, basal ganaglia, Orbitofrontal cortex
The amygdala
Lots of evidence that the amygdala is related to emotions
- Injury of the amygdala is associated with diminshed emotional response - reduced fear
Amygdala and fear
The amygdala plays a key role in fear conditioning;
- It detects the threat on an unconscious level
- regulates behavioural and physiological responses
- sends signals to the cognitive systems which in turn give rise to the conscious feeling of fear
If the amygdala is damaged you lose the ability to fear and learn new fears
LeDoux (1996): High and low roads to fear
Fear conditioning - Rats: Brain lesions (cut connection between the thalamus and sensory cortex - could still fear)
Stimulus → thalamus → sensory cortex → amygdala → response
2 pathways to the amygdala:
1. ‘quick and dirty’ Low road: No cortical processing, unconscious processing of threats, very quick (12ms)
2. ‘Slow but accurate’ high road
The dual process allows us to react and prepare the body before we are consciously aware of the threat
HPA axis
The amygdala stimulates the HPA axis in response to a threat (hypothalamic-pituitary-adrenal)
Hypothalamus (Corticotropin-releasing factor, CRF) → Anterior pituitary (Adrenocortico-trophic hormone, ACTH) → Adrenal cortex (Cortisol)
Cortisol is the primary stress hormone
Survival circuits: LeDoux (2012)
Fear implies subjective experience which is not necessary
- Amygdala is important in triggering the physiological responses to threat but it is less important to subjective feelings
(Inman et al., 2020): Direct electrical stimulation of the amygdala reliably elicits physiological responses, but subjects do not report feelings
(Anderson & Phelps, 2002): patients with amygdala lesions can consciously report emotional experiences, including fear
Amygdala and fear: evaluation
The amygdala is not necessary to generate fear - you can still feel fear with a damaged or lesioned amygdala
The amygdala is not sufficient to generate fear - You can still generate a fear response without subjectively feeling fear
Amygdala and mental disorders
Amygdala is linked to anxiety and depressive disorders
- Patients with theses disorders are associated with amygdala hyper-reactivity or enlarged amygdalas
- Increased amygdala activity leads to HPA-axis activation and increase in stress hormones
Increased amygdala activity requires greater prefrontal cortex activity to suppress the unpleasant emotions
- However, reduced PFC activity is obersved in people with depressive disorders
Components of the reward system
- Liking - affective
- Wanting - motivation
- Learning - classical conditioning
The mesocorticolimbic dopaminergic system is the most important rewrad circuit in the brain
Amygdala and reward processing
Reward detected - signals sent from amygdala to the motivational pathway
Amygdala lesions also impair reward-based behaviour
The orbitofrontal cortex
Important brain area for emotions - is linked to the amygdala
- Integrates information and make judgements in the complicated social world (amygdala processes simple emotions - fear)
- Integrator for the inner and other worlds - gut reactions to people and events
Emotion and brain localisation
- No link between specific brain regions and emotions
- All brain regions are engaged in multiple functions
- Emotions are processed in multiple regions
Brain network perspective of emotion
neuroscientific evidence supports the perspective of a brain network, instead of distinct brain regions
- The whole brain is involved
- Distributed and parallel processes (not sequential and hierarchial)
Pessoa (2014): Brain regions participate in many functions (pluripotency), and many functions are carried out by many regions (degeneracy)
Functional connectivity
Masive connectvity and correlation between all the different brain regions
Features of brain networks
- ## Brain networks contain overlapping brain regions - brain areas belong to several intersecting networks
Three main brain networks
- Salience network: Important for directing attention to conspicuous stimuli (e.g. potential threats)
- Executive control network: Control of executive functions - deliberate attention, working memory, goal-oriented processing
- Default network: Observed during rest states, absecnce of effortful tasks - associated with memory retrieval
emotions and changes in the brain network
- Neuroimaging - neural systems associated with emotions span across cortical and subcortical regions
- Emotional stimuli causes increased functional connectivity between the cortical and subcortical regions
- Functional connectivity increases with reward and decreases with threat (thinking mind less active)
- Stronger signals across the salience network is correlated with stronger negative affect
McMenamin et al. (2014)
Brain network changes over time: Threat
Neuroimaging study: Anticipation of threat (electric shock) or safety (no shock) for 60 seconds
- Initially, threat increased communication in the salience network and decreased in the executive network
- However, with sustained threat, the salience network decreased and the amygdala became engaged in communicating between the networks - Amygdala determines whether we continue to dear or change our response (supress or increase connectivity in slaience network)
Distribution of brain resources - salience network was initial response, but changes over time to other areas and networks
Boiger (2013): Anger expression and cluture
Cross-cultural study: Indicate action tendencies and appraisals for a selection of anger invoking situations
Japan: Dominant characteristic (55% of respondants) responded by nodding and smiling, and rumination
- Hurts relationships least, express emotions in a way that maintains harmony (collectivist ideals)
America: (43%) Blaming and direct expression
- Indivudalistic cultures are more comfortable expressing their emotions
Uchida et al. (2009): Athlete emotion and culture
Analysis of TV interviews of Olympic athletes:
Japanese athletes - More emotion words and more emotions innferred when viewing pictures with teammates
America - less emotion words, more emotion for athletes pictured alone
In Japanese (collectivist) culture, emotion is interpersonal → occurs between people
e.g. someone smiling = something has happened within the social group
America → emotion occurs within people
Culture and neurobiological substrates: Immordino-Yang et al., 2014
fMRI study - Chinese, Asian-American, and European-Americans: Record neurobiological changes during emotional film clips
Dominant Activation:
- Chinese - Ventral anterior insula
- European-american - Dorsal anterior insula
- Asian-american - brain activity equally divided between dorsal and ventral anterior insula
What is emotion?
- Reaction to an event
- bodily responses
- Subjective experience (sometimes)
Charles Darwin
Emotions are a class of mental states that are caused by emotion-specific appraisals of events and cause emotion-specific bodily changes
e.g. Fear has a specific set pf appraisals and bodily states
Facial expressions and recognition of emotions are inherited
