Week 2 - Emotion and the social brain Flashcards
(21 cards)
Nature of emotions
Basics
- Emotion is a cognitive process that actually contributes to logical thinking.
- Unconscious and conscious signals emanating from the neural machinery underlying emotion significantly influence the mechanisms of reasoning.
- Evolutionary perspective = emotions are remnants of instinctive behaviours driven by survival needs.
Nature of emotions
What are emotions?
Emotion, affective behaviour, neuropsychological perspecive
- Emotion: a cognitive interpretation of subjective feelings, as an inferred behavioural state (affect).
- Affective behaviours: internal, subjective experience that does not rely on where or what a stimulus is.
- Neuropsychological perspective: focuses on dimensions like pleasant/unpleasant and aroused/not aroused.
Nature of emotions
Components of emotions (observable and measurable)
Psychophysiology, distinctive motor behaviour, self-reported cognition and unconscious behaviour
Psychophysiology:
* Includes the central and autonomic nervous system activity and the resulting changes in neurohormonal and visceral (somatic) activity.
* Emotions change heart rate, blood pressure/flow, and the digestive system among other things like hormones.
* Debate = some emotions can likely be differentiated by the associated physiological changes (ex: happiness vs sadness)
Distinctive motor behaviour:
* Facial expressions, tone of voice and posture all express emotional states.
* Important for observing emotions = they convey overt action that can differ from observed verbal behaviour.
Self-reported cognition:
* Cognitive processes are inferred from self-reports.
* Cognition operates in the realm of both subjective emotional feelings (love/hate or being loved/hated) and other cognitive processes (plans, memories, ideas)
Unconscious behaviour:
* Cognitive processes of which we are not aware that influence behaviour (intuition).
* Unconscious interference.
All 4 components must be included in any comprehensive theory of emotion (they often diverge making emotion complex to measure/study).
Historical views
The emotional brain: Jamez-Papez theory
- Introduced the limbic lobe as the anatomical basis of emotion.
- Includes hypothalamus, amygdala and hippocampus.
- Hypothesised that emotions originate from the hypothalamus and that the cortex transforms experiences into subjective feelings.
- Theory combines behavioural phenomena with anatomical structures.
Historical views
Kluver-Bucy Syndrome
Cortical connections of emotions
- Lack of affect.
- Caused by bilateral anterior temporal lobectomy (amygdala + temporal cortex).
- Observed both in monkeys and humans
- Symptoms: loss of fear, indiscriminate eating, increased sexual behaviour, visual agnosia etc.
- Note: amygdala removal alone does not cause syndrome unless temporal cortex is alos removed.
Structures in emotional behaviour
Limbic circuit: papez vs present
Brain circuits for emotion
- Papez = limbic lobe as the emotional brain (hippocampus, hypothalamus and cingulate cortex).
- Modern view = amygdala and prefrontal cortex
Structures in emotional behaviour
Contemporary limbic circuit
Brain circuits for emotion
- The PFC, amygdala and hippocampus all connect to the hypothalamus.
- The hypothalamus projects to thalamus which then connects to the cingulate cortex, hippocampal formation and amygdala.
- These connect with different regions in the hypothalamus = forms a feedback loop critical for emotional regulation.
Structures in emotional behaviour
PFC and emotion
Brain circuits for emotion
- The PFC and specifically the orbitofrontal cortex (OFC) play a crucial role in emotional learning, evaluation of rewards and decision-making based on emotional cues.
- Mid-anterior OFC = tracks sensory pleasure intensity (ex: from food, sex, music).
- Medial OFC = involved in pleasure but more predictive - it monitors and anticipates reward values.
Structures in emotional behaviour
Amygdala and emotion
Brain circuits for emotion
Functions:
* Receives input from all sensory systems (visual, auditory, somatic).
* Produces complex “images” of the emotional significance of sensory stimuli.
* Especially tuned to social and threatening stimuli (ex: faces, predators etc).
Damage causes:
* Lack of fear
* Emotional blunting (ex: Kluver-Bucy syndrome)
* Reduced ability to associate emotions with environmental events (hedonic coding) = involved in evaluating whether stimuli are pleasurable or aversive and it may mediate both positive/negative emotional value assignment.
Neuropsychological theories of emotion
The class of appraisal theories of emotion
Appraisal theories of emotion
- Argues that our emotions are extracted from our appraisal of internal and external events, which causes an affective response.
- Originates from William James = emotions consist of a change in body and brain states in response to the evaluation of a particular event.
Neuropsychological theories of emotion
Damasio’s somatic marker hypothesis
Appraisal theories of emotion
Claim, somatic markers, hypothesis (and evidence) and social functions of emotions (2).
Claim: emotions are not just feelings, but result from changes in the body, triggered by emotionally significant stimuli.
Somatic markers = the body-based signals:
* Changes include motor behaviour, facial expresions, autonomic responses, hormonal changes etc.
* Somatic markers are linked to external events and influence cognitive processing.
* The neural control of emotions includes: brain structures (for body states) + activity of neuromodulatory activating systems (which link them to produce changes in processing).
Hypothesis: we could predict that a reduction in the bodily reaction to a stimulus should reduce the intensity of emotions.
* Evidence: spinal cord injury showed that reduced emotionality is correlated with the severity of the lesion.
Social function of emotions:
* Emotion is fundamental to the individual’s survival within an environment (social and physical)
* Emotion is not only a fundamental experience but also necessary to make rational decisions.
Neuropsychological theories of emotion
The class of cognitive-emotional interaction theories
Cognitive-emotional interaction theories
Argues that emotions evolved to enahnce animals’ survival, and as it evolved, cognitive and emotional processes grew more and more interrelated.
Neuropsychological theories of emotion
LeDoux’s theory on fear
Cognitive-emotional interaction theories
Fear system, classical condition, role of amygdala, fear and context, frontal lobes and fear regulation
Fear system = dual processing:
* Unconscious fear - automatic, survival focused.
* Conscious fear - evaluative, cognitive.
Studying fear via classical conditioning:
* Neutral stimulus + aversive stimulus.= conditioned fear.
* Pathway = auditory -> thalamus -> cortex and amygdala.
Role of amygdala:
* Key structure in developing a conditioned fear because its involved in = hormone release, ANS, suppressing pain and evoling fear behaviours.
* Damage = impaired fear conditioning.
* two neural pathways = genetically evolved networks + learned associations.
* Sensitive to facial expressions, emotional context and danger cues.
* Interacts with the cortex to direct attention and influence affective behaviour.
Fear and context:
* Stimulus may be threatening in one context but not in another.
* The hippocampus is critical for forming contextual fear associations.
Frontal lobes and fear regulation:
* OFC and PFC have reciprocal connections with amygdala to help regulate thoughts about fear, learned vs instinctual fear, and pathological anxiety.
Neuropsychological theories of emotion
Cognitive asymmetry and emotion
Emotional control is lateralised:
* Right hemisphere = more emotional, automatic responses - generates emotional feelings.
* Left hemisphere = more cognitive, language-based interpretations - interpretes feelings through language abilities and produces a conceptual (cognitive) level of emotional processing (affective behaviour)
Assymmetry in emotional processing
Left vs right hemisphere lesions
Producing emotional behaviour
Left hemisphere lesions:
* Flattened affect and depression-like symptoms.
* Increased spontaneous talking.
* Content deficits.
Right hemisphere lesions:
* Decreased spontaneous talking
* Aprosodia = absence of tone in speech
* Motor aprosodia = inability to produce affective components of language (results from Broca’s area).
* Sensory aprosodia = deficits in interpreting the emotioanl components of language (results from Wernicke’s area).
Both = facial expressions reduced in intensity and frequency.
Assymmetry in emotional processing
Emotional behaviour might appear atypical through:
Interpreting emotional behaviour
- Inability to produce the appropriae behaviour (an expression)
- Misinterpreting the social or emotioanl signals coming from others.
Assymmetry in emotional processing
Temporal-lobe personality
Definition, high score on traits and what it reflects
Temporal lobe patients often exhibit distinctive personality profile.
Patients score high on traits like:
* Viscosity (mental inflexibility, repettitive thoughts).
* Hypergraphia (excessive writing)
* Anger
* Humourless
Traits reflect deepened emotionality, rigid thought patterns and over-engagement with internal experiences.
The social brain and social cognition
Cerebral lesions in humans
What it affects and key findings of specific lesions (insula, amygdala, vmPFC, right vs left vmPFC
Frontal and temporal lesions affect:
* Facial expressions
* Social speech
* Recognition of emotions
* Personality and empathy
Key findings:
* Insula lesions = impair empathy
* Amygdala lesions = impair fear recognition
* Ventromedial PFC lesions = poor social conduct, judgement and decision-making.
* Right side of vmPFC lesions = greater social dysfunction than left side and can result in acquired sociopathy.
The social brain and social cognition
The 4 social neural networks
Amygdala network, mentalising network, empathy network and mirror/action-perception network = brain areas + functions
Amygdala network:
* Includes OFC and temporal cortex
* Detects and responds to socially relevant stimuli
Mentalising network:
* Includes STS and anterior temporal cortex
* Understands others’ thoughts and intentions
Empathy network:
* Includes insula and cingulate cortex.
* Activated during empathy and attribution of intention
Mirror/stimulation/action-perception network:
* Includes parietal and premotor cortex
* Observes and imitates actions; tied to self-concept
The social brain and social cognition
The self and social cognition
Self awareness + support from networks
Self-awareness: understanding one’s own mental states and actions.
Supported by:
* Right frontoparietal mirror neuron network: activated during self-recognition (right hemisphere domination).
* Cortical midline network: associated with internal self-representations
* Medial frontal cortex: involved in understanding psychological traits.
The social brain and social cognition
Cognitive control of emotion
Regulating emotions and cognitive strategies (re-appraisal)
Humans can regulate emotions using cognitive strategies:
* Re-appraisal invovles the PFC and cingulate cortex
