Week 9 - Social and Emotional Brain

Question 1

What is emotion?

Answer 1

• Emotion – reaction to an event that includes a combination of strong feelings, behavioural dispositions and physiological responses.

Question 2

What are the two psychological classifications of emotion?

Answer 2

• Categorical vs. dimensional theories of Emotion:

1. Categorical theories - each emotion is distinct (qualitatively different from each other), e.g. fear is qualitatively different from sadness.
2. Dimensional theories - different emotions lie in different points in 2-3 dimensions (the difference is quantitative)

Question 3

What is Ekman’s 1992 theory of six basic emotions?

Answer 3

• Theory of six basic emotions (Ekman, 1992) – thought these emotions were different from each other because they produce different facial expressions:

1. Fear
2. Sadness
3. Anger
4. Surprise
5. Disgust
6. Happiness

• Basic emotions:
  
  • Innate
  • Evolutionary old
  • Shared among animals
  • Facial expressions
  • Universally recognised
• Paul Ekman and Friesen (1976) investigated whether a small set of ‘basic’ emotions is universally recognized:
  
  • ‘Pictures of facial affect’ created by asking models to move facial muscles in specified ways.
  • All facial expressions recognised at above-chance levels in all cultures, using forced-choice responses.
• Ekman (1972) - facial expressions posed by members of the Fore community in New Guinea in response to the stories:
  • “Your friend has come, and you are happy”
  • “Your child has died”
  • “You are angry and about to fight”
  • “You see a dead pig that has been lying there a long time”

Question 4

What is Russell’s 1980 circumplex model of affect?

Answer 4

• Each emotion as a point in 2-D space:

1. Valence (Positive-Negative)
2. Arousal (High-Low)

• Russell (1980) circumplex model of affect - ask participants to rate words such as “Happy,” “Sleepy,” “Afraid,” “Sad” etc. on ordinal scale of valance and arousal

Question 5

Outline James-Lange Feedback Theory of Emotion (late 19th Century)

Answer 5

James-Lange Feedback theory (late 19th century):

• Stimulus directly causes a bodily reaction, which in turn produces an emotional experience, e.g. we feel happy because we smile
• Deterministic relationship between bodily reactions and emotions – one-to-one relationship between bodily reactions and emotions.
• No emotions are felt in absence of bodily reactions
• For example:
  
  • Happy – smile
  • Run away = Fear
• Strack et al. (1988) - participants were asked to rate several cartoons (not at all funny [0] to very funny [9]):
  
  • Funniness ratings were higher for the Teeth condition (hold a pen with teeth) than the Lips condition (hold a pen with lips)
  • Smile –> feeling happy

Question 6

Outline Cannon-Bard’s Theory of Emotion (1920s)

Answer 6

• Cannon-Bard theory (1920s)*:
• Challenge and alternative to James-Lange theory:

1. Bodily responses are too undifferentiated – we cry when we are sad AND when we are happy
2. Bodily responses are too slow to be a source of emotional feeling – when we feel fear we sweat, but this is slow
3. Hormonal injection failed to generate emotions (norepinephrine & fear)

• A stimulus SIMULTANEOUSLY triggers activity in the autonomic nervous system and emotional experience – feeling and body response happen at the same time.
• Cannon-Bard thought Thalamus and hypothalamus play key roles in mediating emotion
• Looked at the Sham Rage expression in a cat:
  
  • Removing a region that involved the thalamus and hypothalamus resulting in no sham rage
  • Removing a region that did not involve the thalamus and hypothalamus resulted in sham rage remaining.

Question 7

Outline the Limbic System Theory of Emotion

Answer 7

• Papez (1937) hypothesised that a neural circuit controls our emotions. Key regions of his circuit included cingulate cortex, hippocampus, and anterior thalamus and hypothalamus.
• In a series of studies from the 1940s to the 1970s, MacLean extended Papez’ ideas to include the amygdala and parts of frontal cortex (orbitofrontal cortex) in an extended ‘limbic system.’
• Not entirely accurate

Question 8

How does Kluver-Blucy syndrome affect a monkey?

Answer 8

• The Klüver-Bucy syndrome (1939) - removing temporal lobes (including hippocampus, amygdala) in the rhesus monkey. Monkey symptoms:
  
  • Loss of fear
  • Hypersexuality
  • hyperorality (tendency or compulsion to examine objects by mouth)
  • altered food preferences

Question 9

How is the amygdala important for fear learning?

Answer 9

• Amygdala is important for Fear Learning:

1. Pavlov’s dog experiment (classical conditioning)
2. Fear learning (or fear conditioning) = classical conditioning using an aversive stimulus. Instead of reward they use an aversive stimulus.

• Results from Mice Studies (Late 1970s and early 80s):
  
  • Lesions of amygdala disrupt fear conditioning
  • Lesions of amygdala after conditioning also disrupt storage of response
  • Amygdala is important for both forming stimulus associations (learning) and for subsequently expressing learned behavioural responses.

Question 10

Outline the case of SM who had Urbach-Wiethe disease

Answer 10

Adolphs et al. (1994) - Case SM who had Urbach-Wiethe disease:

• Bilateral amygdala damage.
• Rare recessive genetic disorder
• About 50–75% of the diagnosed cases of Urbach– Wiethe disease show bilateral symmetrical calcifications on the medial temporal lobes.
• SM was asked to rate intensity of each emotion in facial expressions.
  
  • Abnormal ratings of fear.
  • Note that some other emotions (especially anger) were not entirely normal, but fear was the worst affected.
• Feinstein et al. (2011) – patient SM:
  
  • Bilateral amygdala damage.
  • Multiple examples of lack of fear in laboratory tests and in everyday life.
  • held up at knife point and at gun point
  • physically accosted by a woman twice her size
  • nearly killed in an act of domestic violence
  • explicitly threatened with death many times
  • Not fearful of anything – makes mistakes categorising fear again and again

Question 12

How does functional brain imaging studies show fear?

Answer 12

Functional brain imaging studies (Calder, Lawrence & Young, 2001) – fear. For facial expressions, the techniques involve:

• Comparing blood flow between fear and neutral expressions
• OR measuring how blood flow changes as the fear expression becomes more intense.
• Differences shown in amygdala activation.

Question 13

How is disgust related to the insula?

Answer 13

• For facial expressions, the techniques mostly involve comparing blood flow between disgust and neutral expressions.
• The participant is not usually asked about the expression.

Calder, Lawrence & Young (2001):

• Insula and putamen activated for disgust.

Calder et al. (2000) - disgust recognition and experience - patient NK:

• Left-sided lesion involving the insula and putamen.
• Impaired recognition of disgust from face, voice or posture.
• Reduced experience of disgust in responses to disgust-provoking scenarios (e.g., maggots on rotten meat)

Question 14

What are the two accounts for the brain basis of emotion?

Answer 14

1. Locationist account:

• Each emotional state is biologically basic and inherited, and cannot be broken down into more basic psychological components
• Discrete emotion categories (e.g., fear, anger) are consistently and specifically localised to discrete brain locales or anatomical networks (i.e., one-to-one mapping between brain region and emotion)

1. Psychological constructionist account:

• Emotions are psychological events that emerge out of more basic psychological operations that are not specific to emotion
• Some brain regions are commonly activated by different emotions

Question 15

What account does the evidence support?

Answer 15

Past emotion studies appear to support the locationist account view. However, a more recent meta-analysis supports the psychological constructionist account:

• Lindquist et al. (2012) – meta analysis of emotion:
  
  • First they tested the popular locationist view (Panksepp, 1998):
  • Meta-analysis included a total of 234 neuroimaging studies (fMRI and PET) on emotion:
  • A wide range of emotions caused activation in areas like the amygdala – not specific to fear.
  • Disgust didn’t cause a huge activation in the insula compared to other emotions.
• Is any single region specific to a single category of emotion? No (i.e., evidence against the locationist account)
• Locationist account is too simplistic (no simple one-to-one relationship)
• Lindquist et al. (2012) found:
  
  • Regions that were consistently activated across all emotion neuroimaging studies
  • These are brain regions related to emotions in general
  • Supports constructionist approach

Question 16

What about other emotions?

Answer 16

Social emotions (e.g., pride, guilt, embarrassment, shame, envy, etc.):

• Require higher cognitive ability (e.g., “theory of mind” or ability to understand other’s mental state)
• Example: Embarrassment
  
  • Specific to humans = No animal model
• Social and affective neuroscientists have started investigating the neural bases of complex social emotions

Question 17

What is the role of dACC in social and emotional processes?

Answer 17

• dACC important for processing pain and empathy (empathy for pain), social pain (social rejection)
  
  • Empathy - the capacity to comprehend and resonate with another’s emotional experience, which leads to a sharing of that person’s feelings.

Question 18

What have the neuroimaging studies on empathy for empathy and pain shown?

Answer 18

• Majority of past studies focused on empathy for pain:
  • Easy to manipulate (electric shock, cold water, heat pain, etc.)
  • Neural mechanisms of pain is well-known so that we can directly compare neural bases of direct pain and empathy for pain
  • Effect is stronger (easy to induce)
• Singer et al. (2004), fMRI for empathy of pain:
  • 16 couples participated in the study
  • Female partners were scanned by fMRI while – they themselves received painful electric stimulation; they observed that their partners get the stimulation
  • dACC and insula activation by their own pain and by witnessing their partner’s pain.

Question 19

What did Singer’s extra study show about the affective link between empathy and pain?

Answer 19

Singer at al. (2006) did another study on empathy and pain but with Affective link manipulation:

• Before entering an fMRI scanner, each participant met two confederates and played an economic game (sequential Prisoner’s dilemma game) with each of them
• One of them played the game fairly, while the other played unfairly
• Results showed that brain empathic responses are modulated by the affective link between individuals
• Men show less empathic response to unfair players compared to women
• Nucleus accumbens (ventral striatum), a part of reward network, was activated only in men when unfair person gets electric stimulation.

Question 20

What is empathy for pleasure?

Answer 20

• Mobbs et al. (2009):
  
  • Ventral striatum (a part of the reward network) was activated when;

1. Participants themselves won a game
2. Similar/likable other won a game

Question 21

What is social rejection?

Answer 21

• Social pain - the experience of pain as a result of interpersonal rejection or loss, such as rejection from a social group, bullying, or the loss of a loved one.
• Eisenberger, Lieberman & Williams (2003) – cyberball paradigm in fMRI:
  • Participant taking part in a computer game where ball is thrown to them and a computer person. After several throws, the participant is excluded from being passed the ball.
  • Results showed activation in dACC when comparing exclusion > inclusion
  • In addition, the more distress the participants felt, the more activation in the dACC.

Question 22

What is the Neural basis of “theory of mind”?

Answer 22

• Theory of Mind - the ability to attribute mental states to oneself and others and to understand that others have beliefs, desires, intentions, and perspectives that are different from one’s own.
• Theory of Mind starts developing at 3-5 years old
• Ability to understand false belief (recognise that others can have beliefs about the world that are not consistent with reality) – false belief task used for testing such as the Sally-Anne task.
• A variety of different tasks that require reading other people’s minds:
  
  • False belief task
  • Competitive game (e.g., rock paper and scissors; human vs. computer)
• When we compare computer vs. human, or false belief vs. non-false belief tasks, we see activation in these brain regions:

1. Medial prefrontal cortex (mPFC)
2. Temporal pole
3. Temporo-parietal junction (TPJ)