Neuropsychology: The Social and Emotional Brain

Question 1

What are different theories about emotions?

Answer 1

-Emotions are multi-faced
-What is first: bodily changes (James-Lange) or emotional itself (Cannon-Bard)
-Many regions word together to produce emotions, including subcortical Papez circuit (including hypothalamus), hippocampus, thalamus (anterior nucleus), cingulate cortex and limbic brain
-Basic emotion categories (Ekman) vs constructive view of emotions being derived from core processes (autonomic reactions) and dimensions such as valence (from negative to positive) and arousal

Question 2

What kind of discussion is there in neuroscience about emotions?

Answer 2

-Whether different emotions have specialized neural hardware
-Tendency to look for particular neural substrate for basic emotions: amygdala in fear, insula in disgust

Question 3

How is the amygdala and/or fear studied with fear conditioning?

Answer 3

-Basic paradigm to study fear
-Fear conditioning in mice with lesion in amygdala
-Fear conditioning in humans
-Amygdala in recognizing fear
-Fear beyond amygdala
-Amygdala beyond fear

Question 4

What is the basic paradigm to study fear?

Answer 4

Auditory tone (neutral stimulus, CS-) + fear evoking stimulus (electric shock: unconditioned stimulus (US) that elicits unconditioned response (UR) = tone will come to elicit fear response by itself (becomes conditioned stimulus, CS+)
(image)

Question 5

What was found with fear conditioning in mice with lesions in the amygdala?

Answer 5

-Lesions of amygdala: disrupt fear conditioning
-Lesions of amygdala after conditioning: disrupt storage of response
-Lesions of amygdala: do not disrupt fear response to shock
-So: amygdala involved in learning association between shock and neutral stimulus
(image)

Question 6

What was found with fear conditioning in humans?

Answer 6

-fMRI: amygdala activity for CS+ stimuli relative to CS- and this correlates with amount of skin conductance response (SCR) (Le Bar et al., 1998)
-Similar pattern when humans watch shock being given to someone else (socially learned fear conditioning) (Olsson & Phelps, 2004)
-Patients with lesions to amygdala fail to show SCR to CS+ but can verbally report association (Bechara et al., 1995)
–>Amnesic patients with hippocampal damage show reverse

Question 7

How is the amygdala related to recognizing fear?

Answer 7

-Fear can be recognized on face of other people: amygdala involved
-Damage to amygdala: impairs recognizing fear expression in faces and sometimes even in voices
-Fear expressions activate amygdala more than other expressions

Question 8

What characteristics does fear have beyond the amygdala?

Answer 8

-Fast and slow routes from sensory cortices to amygdala (Le Doux)
–>Fast route: sensory cortex => visual thalamus => amygdala
–>Slow route: sensory cortex => visual thalamus => visual cortex => amygdala
-Fear may lead to enhanced activity in: visual cortex, hypothalamus, anterior cingulate cortex (preparing bodily responses) and orbitofrontal cortex (evaluating context)
-So: fear circuit with amygdala as “hub”
(image)

Question 9

What characteristics does the amygdala have beyond fear?

Answer 9

-Animal studies: involved in reward-based learning, but mechanics/regions may be different from that in fear conditioning (Baxter & Murray, 2002)
-fMRI: amygdala activity for emotionally intense stimuli relative to neutral ones irrespective of whether they are positive or negative
-Response to happy faces greater for extravert personalities
–>Wondering whether happy faces are more intense for these people
(image)

Question 10

What summery can you give for the relationship between the amygdala and emotions?

Answer 10

-Convincing evidence for role of amygdala in fear, but also clear role in coding for emotional intensity and certain aspects of reward learning
-Several options to reconcile this

Question 11

What options are there to reconcile the different functions of the amygdala?

Answer 11

-Different circuits through amygdala with subregions performing somewhat different functions
-Amygdala may be critical region to fear, but be only one of several important regions for other emotions (involved in emotions generally, but involved in fear critically)
-Apparent fear specificity due to failure to control for all confounding variables (personality types, subjective intensities, other deficits/lesions)

Question 12

How is the insula related to disgust?

Answer 12

-Insula damage in humans impairs disgust recognition in faces and (sometimes) voices but not other types of emotion
-Seeing disgust expressions activates insula during fMRI as does feeling disgusted
-Some researchers argue that moral disgust may piggy-back on mechanisms involved in contamination-based disgust

Question 13

What are functions of the insula beyond disgust?

Answer 13

-Involved in bodily perception and bodily feeling in general: interoception
-Important for taste and pain perception
-May monitor for bodily feelings (ex: heart rate, sweating) which are important markers of emotions and may amplify subjective feelings of emotion

Question 14

What is an overview of basic emotions?

Answer 14

-Different neural circuits with relative degrees of specialization for different emotions, but also lots of overlap between emotion categories
-Properties of this overlap in line with constructive view (reconciliation)
-Some widely distributed in brain (happiness), others less so (fear, disgust)

Question 15

How is the orbitofrontal cortex involved in reward values?

Answer 15

-Small et al. (2001): PET study of eating chocolate
–>Initially: wanted and pleasant
–>After excessive consumption: not-wanted and unpleasant
–>Activity in orbitofrontal cortex follows transition: shift from medial to lateral activity
-Blood & Zatorre (2001)
–>Subjective pleasantness of music correlates with orbitofrontal activity

Question 16

How is the orbitofrontal cortex involved in current reward values?

Answer 16

-Computing current reward values gives behavioural flexibility
-Patients with lesions to orbitofrontal cortex lose this flexibility and behave impulsively

Question 17

What evidence is there for patients losing flexibility and behaving impulsively after lesions to the orbitofrontal cortex?

Answer 17

-Rudebeck et al. (2006): lesioned orbitofrontal cortex rats prefer small immediate rewards over larger rewards offered later
-Human patients fail to regulate behaviour using social norms, have inappropriate emotional responses and poor social relationships
-Rolls et al. (2004): patients fail to shift away from previously rewarded stimulus that is no longer rewarded
-Bechara et al. (1994): patients take higher risk gambles

Question 18

How is the ventral striatum involved in reward?

Answer 18

-Part of dopaminergic system, in particular nucleus accumbens
-Increased dopamine release when presented with secondary reinforcers paired with food, or when male rats presented with female
-In humans: implicated in hedonic aspects of drug use (ex: cocaine)
-In human fMRI: activity in ventral striatum correlates with level of potential monetary reward
(image)

Question 19

What do dopamine neurons respond to?

Answer 19

Neurons code difference between predicted and actual reward, rather than reward itself

Question 20

What functions does the anterior cingulate cortex have in emotions?

Answer 20

-Response evaluation, autonomic responses and pain
-Often divided into dorsal (cognitive) and ventral (affective) regions

Question 21

How cognitive is the dorsal anterior cingulate cortex?

Answer 21

-Dorsal anterior cingulate cortex detects errors and response conflict
-Dorsal anterior cingulate cortex computes current value of action
–>Orbital frontal cortex computes value of stimuli
-Dorsal anterior cingulate cortex involved in generating bodily responses that characterize emotions
-Involved in perception of physical pain and in “social pain” triggered by exclusion

Question 22

What are characteristics of reading faces?

Answer 22

-Faces not only visual, but also social object
-Bruce & Young (1986): division between facial identity, expression recognition and gaze processing
-Haxby et al. (2000): division between time-invariant (identity) and time-varying (expression, gaze)
-But expression recognition seems dependent on integrity of “emotional brain” (amygdala, insula, orbitofrontal cortex) and be separated from gaze
-Also role for sensory-motor stimulation, etc.
-Related to resonance theory and embodied cognition

Question 23

What is the role of recognizing facial expressions in sensory-motor stimulation?

Answer 23

-Analyzing muscles used: happiness much more than other emotions
-When using muscles: problems with recognizing emotions on faces
-Motor response: not only role in seeing faces, but also role in recognizing faces

Question 24

What is the role of somatic responses in facial recognition?

Answer 24

-Emotional response (ex: skin conductance) often used to decide whether person is familiar or not
-Capgras delusion: believe that familiar people are imposters (but can recognize familiar faces)
–>Abnormal SCR (skin conductance response)
–>Response stronger when seeing face of very familiar person

Question 25

What is reading minds?

Answer 25

-Thoughts, feelings and intentions are private and subjective
-But humans may have evolved skills that enable to infer what others are thinking, feeling, etc. from behaviour
-Ex: expression on face, where looking, projecting how we might feel in situation

Question 26

What is the empathy and simulation theory?

Answer 26

-Simulation theory: assumes sharing of cognitive resources between action/emotion perception and action/emotion production
-Extension of mirror neuron idea, and of results with face expression
-May enable us to empathize with others
-When we see someone hurt/happy, we (literally) feel own experiences of hurt/happiness that enables us to empathize

Question 27

What is empathy?

Answer 27

-Feeling for someone, possibility to understand others’ feelings
-When seeing someone upset or happy: literally feel own feelings of pain or happiness
–>Activates insula and anterior cingulate cortex
–>System modulated if other person is perceived to deserve pain

Question 28

How does false belief and theory of mind explain if simulation is enough?

Answer 28

-Simulation may be important, but not clear it can account for all mind-reading (such as false belief)
-False belief: understand that another person holds belief different from own and, indeed, is different from present state of reality
–>Content of own minds differs from that of other people
-May require form of meta-representation: theory of mind

Question 29

What is the Theory of Mind?

Answer 29

-Meta-representation
-Understanding that other people have mental states that may differ from own, and from true state of world

Question 30

What is the neural basis of theory of mind?

Answer 30

-Temporoparietal junction
-Temporal poles
-Medial frontal lobe

Question 31

How is the temporoparietal junction related to theory of mind?

Answer 31

-Also important for detecting other agents (ex: biological motion)
-Acquired lesion in area disrupts performance in false-belief tasks, and also activated in such tasks in fMRI

Question 32

How are the temporal poles related to theory of mind?

Answer 32

-Semantic schemas that specify current social and emotional context
-Castelli et al. (2000): fMRI of animated triangles (ex: chasing, encouraging)

Question 33

How is the medial frontal lobe related to theory of mind?

Answer 33

-Attending to internal states (ex: intentions of self and others)
-Active in all fMRI studies of mentalizing (ex: playing game requiring cooperation or competition with another player)

Question 34

What are characteristics of autism spectrum disorder (ASD)?

Answer 34

-Often not good in false belief tasks
-Defined as:
–>Markedly abnormal development/impairment in social interaction and communication
–>Markedly restricted repertoire of interests and activities
-Developmental condition noted before 3 years and persisting throughout life

Question 35

What accounts of autism are there?

Answer 35

-Problems with specialized theory of mind mechanism
-Broken-mirror theory (problem with simulation)
-Deficit in theory of mind just 1 symptom of wider change in processing style
–>Weak central coherence (global vs local processing)
–>Systemizing vs empathizing (male brain hypothesis)
–>Executive function failure
–>Predictive coding

Question 36

What seems to be the neural basis of autism?

Answer 36

Representations elicited by observation of social touch, analyzed in 3 sets of brain regions
-Perceptual areas (processing style)
-Temporoparietal junction as theory of mind region
-Somatosensory regions (broken mirror: simulation)

Question 37

What did the fMRI study by Masson et al. show us about perceptual areas/processing style in autism?

Answer 37

-75 touch actions, differing in
–>Social nature (action involving person or object)
–>Arousal and valence
-Results: no group differences in
–>Representation of visual dimensions (ex: motion processing)
–>Representations of social nature (action to person or object)
-Representation of emotional content: measured by correlation between emotional similarity and similarity in brain response
–>Differences in somatosensory regions BA1 and BA2 (but not in temporoparietal junction or sensory regions)