Week 6 Lecture 6 - the social and emotional brain pt 1 Flashcards
What is emotion?
- a state associated with stimuli that are rewarding (i.e. that one works to obtain) or punishing (i.e. that one works to avoid)
- These stimuli often have inherent survival value, but they can also be learned (= conditioning)
What does emotion play a crucial role in?
- guiding social behaviour
- Emotional brain required in social situations (social decision making)
Name 6 theories of emotion
- Darwin
- Basic emotions theory (Ekman)
- James-Lange theory
- Cannon-Bard theory
- Somatic Marker Hypothesis (Damasio)
- Theory of constructed emotions (Barret)
Which theories of emotion emphasise expression/behaviour?
- Darwin
- Basic emotions theory (Ekman)
Which theories of emotion emphasise the role of bodily changes?
- James-Lange theory
- Cannon-Bard theory
- Somatic Marker Hypothesis (Damasio)
- Theory of constructed emotions (Barret)
Which theories of emotion emphasise subjective nature?
- Theory of constructed emotions (Barret)
What is Darwin’s theory of emotion?
- Many species of animals communicate emotions through changes in posture, facial expression and nonverbal sounds (e.g. sighs, laughs, moans, growls etc.)
Emotional expressions are innate and
biologically determined:
- Observation of his own children
- Corresponding with people in isolated cultures around the world
What is the Basic emotions theory (Ekman)?
Basic emotions are associated with:
- distinctive facial expressions
- voice intonation
- body movement (e.g., gestures)
- distinct neural substrates
- Each emotion has evolved to deal with different survival problems & occurs automatically
- UNIVERSAL -they are mostly culture-independent
What are the 6 basic emotions outlined by Ekman?
- Sadness
- Happiness
- Disgust
- Surprise
- Anger
- Fear
What study provides support for the basic emotions theory?
Question 1: Do members of isolated tribe in New Guinea recognise facial expressions of emotion produced by
Westerners?
- Results: people in the New Guinea tribe could recognise western emotional expressions
Question 2: Can Western people recognize emotion expressions of different cultures?
- Results: Westerners could recognise these expressions
Conclusions: the expression of emotions are unlearned as they are the same in cultures that have not been exposed to each other
What is the James-Lange theory of emotion?
Emotion producing situations elicit:
- physiological responses - Trembling, sweating, heart pounding
- certain behaviours - Run away, feel queasy
- Feedback from the organs and muscles involved in these responses constitutes how we feel emotion
= our own emotional feelings are based on what we find ourselves doing
What is the Cannon-Bard theory of emotion?
Thalamus sends simultaneous signals to:
- the cortex (conscious experience) - I’m afraid
- autonomic nervous system (arousal) - I begin to tremble
What is the Somatic Marker Hypothesis?
- Bodily states are the basis of emotions and decisions as physical reactions can
cause emotional reactions - A threatening stimulus –> the brain will instinctively generate a physiological
response, e.g., accelerated heartbeat - Physiological changes in the body trigger interoceptive signals to be sent to the
brain - This representation of interoceptive signals is termed a somatic marker, which
describes body signals that mark the emotional value of stimuli and events - Somatic markers are experienced as emotions and ‘gut feelings’, a non-conscious biasing signal that facilitates decision-making, particularly in ambiguous situations
What is the theory of constructed emotions?
- Distinct bodily states are not associated
with distinct emotions
Bodily changes influence core affect:
* Pleasant – unpleasant
* High arousal (activation) – low arousal (deactivation)
- There aren’t distinct emotional categories –-> the emotions we feel are
constructed based on the current situation and on our previous experiences - Current emotions we feel depends on:
- Core affect
- Memory of previous similar situations
- Theory of mind
- Language
- Assumed control over the situation and emotions
How does BET and TCE differ in terms of innate facial expressions?
- BET: facial expressions are innate for basic emotion categories
- TCE: all emotions are constructed, thus facial expressions can’t be innate either
How does BET and TCE differ in terms of constructed emotions?
- BET– some emotions might be constructed
E.g. some emotions might be composed of two or more emotions: guilt = joy + fear - TCE – all emotions are constructed
What is the amygdala?
- A small mass of grey matter in the tip of left and right temporal lobes
- Receives a great deal of sensory input
- Fear centre?
- Important for learning and storing the emotional value of stimuli
How did a study involving animals suggest that the amygdala is involved in fear?
Amygdala lesion before learning:
- Animal do not learn the conditioned response
Amygdala lesion after learning:
- Animal forgets the conditioned response = objects lose their learned emotional value
- Role in memory: learning and storing conditioned fear response
- But normal fear evoking stimuli still elicit fear response: role in learned fear response
What did a study involving humans learning to associate visual cue with an electric shock do and find?
- Measures: fMRI + skin conductance response
- Amygdala activation (fMRI) during the learning process
- Amygdala activation correlated with skin conductance response
What evidence is there for a double dissociation between amygdala and hippocampus?
Patients with amygdala damage:
- No conditioned skin conductance response
- Can recall association
Patients with hippocampal damage (amnesia):
- Skin conductance response present
- Cannot recall association
Association is stored in:
- amygdala (conditioned fear response)
- hippocampus (declarative memory)
Give 2 examples of studies that implicate the amygdala in the recognition of fear
- Bilateral amygdala damage impairs fear
expression recognition in faces (Adolphs et al., 1994)
fMRI study (Morris et al., 1996):
- Presented with faces – male-female classification
- Fearful faces – left amygdala activity
- Happy faces – different brain areas activated
What studies suggest that the amygdala can activate without conscious awareness?
- Fast and slow routes to the amygdala (Le Doux, 1996)
Ohman & Soares, 1994:
- Images of spiders and snakes are presented to participants with spider or
snake phobias subliminally
- Participants did not report seeing the
images
- But SCR was measured – emotional response to images
Tamietto et al., 2012:
- fMRI – amygdala activated by fearful facial expression in patients with visual
cortex damage
What evidence suggests that the amygdala is a part of a wider fear network?
Amygdala activity leads to enhanced activity (Morris et al., 1998) in other brain areas:
- In the visual cortex activity
- in regions such as hypothalamus and anterior cingulate and orbitofrontal cortex
- Affects autonomic system to generate fight or flight response
= Fear circuit with amygdala as a hub, not as a fear centre
Apart from fear, what is the amygdala’s wider role in emotion?
- Amygdala is involved in learning
positive associations (e.g. certain food
is hidden under a certain shape) - Amygdala activation to pleasant and
unpleasant, but not to neutral smells
What is the insula?
- An island of cortex lying bilaterally underneath the temporal lobes
It is implicated in the creation of bodily feelings associated with emotions:
- Disgust
- Interoception
How is the insula related to disgust?
- Insula lesions affects disgust perception (Calder et al., 2000)
Insula activation if (Wicker et al. 2003):
- Feeling disgusted
- Seeing someone else disgusted
- Moral disgust also activates insula (Moll et al., 2005)
How is the insula related to interoception?
Interoception:
- monitoring the internal state of the body - interoceptive signals from receptors in skin, muscles, organs are sent to the brain (insula) along the spinal cord
- This bodily monitoring process can be
conscious (e.g. pain) and unconscious
Bodily changes play an important role in
emotions according to several theories:
- James-Lange theory, Somatic Marker Hypothesis, Theory of Constructed Emotion
What is the orbitofrontal cortex?
Computing the current value of a stimulus:
- How rewarding the stimulus is within the current context
- Important for social interactions, new learning and regulation of emotions
What evidence suggests that the orbitofrontal cortex is linked to reward and punishment?
PET study (Small et al, 2001):
- Initially chocolate was rewarding, and participants wanted to have it –> activity in the medial regions of the OFC = pleasant, reward
- Then chocolate became less pleasant, and participants were less motivated to
eat it –> activity in the lateral regions of the OFC = unpleasant, punishment
Social stimuli:
- Lateral orbitofrontal cortex activity when instead of an expected smile participants are presented with an angry face (Kringelbach & Rolls, 2003)
What is the Anterior Cingulate Cortex (ACC)?
- The anterior cingulate cortex lies above the corpus callosum on the medial surface of each hemisphere
- Dorsal region implicated in executive functions
- Ventral region implicated in emotional processing
How is the ACC related to response evaluation?
- motivation
- determining the cost and benefit of actions
- Value of a response – whether an action will result in reward and punishment
How is the ACC related to bodily response?
Processing bodily signals that characterize emotions:
- Output of bodily responses (insula-input)
- Lesion interrupts skin conductance response, changes in blood pressure and
hearth rate
Regulating feelings of pain:
- fMRI activity in ACC for physically painful stimuli
- Activity in ACC for watching somebody else in pain = responds to perception of
pain in others
How is the ACC related to pain?
Regulating feelings of pain (Singer et al., 2004):
- Physical pain –> Experiencing a mild electric shock
- Social pain –> Seeing a loved one in pain also activates ACC (and )
= ACC responds to perception of pain in
others
- ACC responds to perception of pain in
others - But the response can be affected by
cognitive processes - Pain sensitive activity is modulated if
the other person is perceived to
“deserve” the pain
How is the ACC related to social pain?
Social pain – being excluded socially
(Eisenberger et al., 2003)
- fMRI study: Virtual tossing ball game
- 3 conditions: inclusion, exclusion and
justified exclusion - ACC activity correlates with subjective
distress
What is the ventral striatum?
Part of the basal ganglia:
- Dorsal striatum - sensorimotor properties –> involved in habit formation
- Ventral striatum - specialised in emotions
Reward-based learning loop: ‘the limbic
circuit’:
- Dopaminergic system
- Linked to compulsive behaviours, such as
substance abuse
What evidence suggests that the ventral striatum is linked to reward?
Monetary reward:
- fMRI –> Task with great monetary reward = greater activity in VS (Knutson et al., 2001)
Social reward:
- Activity is greater when monetary reward is obtained via cooperation with another human compared to non-cooperation or computer (Rilling et al., 2002)
Predicted vs actual reward:
- It is not simple reward coding
- Activity is greater when reward is better than expected
What is the social motivation hypothesis?
- deficits in representing the reward value of social stimuli
- children with ASD do not actively attend to the social environment because they do not find it intrinsically rewarding, leading to reduced cortical specialization
Deficits in social reward processing –>
Reduced seeking and liking of social interactions –>
ultimately manifesting as global deficits in social functioning
BUT: mixed evidence (meta-analysis: Bottini, 2018)
