Knowledge Clips Part 1: Psychological Methods of SNS

Subjective Measures:
- Emotional experience assessment
- Personality questionnaires (e.g., STAI/STAS, LSAS, EQ-SQ, BIS-BAS)

How to Use in SNS?
- Control variable
- Correlation with other measures
- Comparison across studies

Observational Measures:
- Frequency of behaviors
- Used in animal and infant studies
- Scoring and counting behaviors
- Camera usage (blinding, inter-rater reliability)
- Eye-tracking

Performance Measures:
- Speed, reaction time, accuracy
- IQ tests
- (Emotion) recognition tests
- Selective attention
  - Implicit association test
  - Stroop task
  - Classical task
  - Emotional task (interference of emotion)
  - Facial fear stroop

Physiological Measures:
- Controlled by the brain and spinal cord
- (Electro)physiological methods
  - Skin conductance
  - Heart rate, respiration
  - Electromyography (EMG)

Skin Conductance Response (SCR):
- Measures sweat gland reactivity
- Related to sympathetic arousal

Heart Rate:
- Declaration and acceleration
- Heart rate variability (HRV)

Electromyography (EMG):
- Measures muscle activity
- Mimicking facial expressions
- Startle potentiation (e.g., eye blink potentiation)

Electrophysiological Brain Imaging:
- Neuron structure: cell body, axon, dendrites
- Single-cell recordings for firing rate measurement

Electroencephalography (EEG):
- Measures neural activity in the cortex
- Frequency bands (e.g., delta waves, beta waves)
- Event-related potentials (ERPs)

Advantages/Disadvantages of ERP:
- Advantage: Excellent temporal resolution
- Disadvantage: Poor spatial resolution

Magnetic Resonance Imaging (MRI):
- Better for spatial resolution compared to ERP
- Relies on alignment of water molecules
- Functional MRI measures blood oxygenation

Advantages/Disadvantages of fMRI:
- Advantage: Good spatial resolution (voxel size as low as 1mm3)
- Disadvantage: Poor temporal resolution

Structural Imaging Methods:
- Diffusion Tensor Imaging (DTI) for mapping white matter microstructure
- Measures communication bundles

Brain Imaging Conclusion:
- MRI measures brain structure, connections, and activation location
- Event-related potentials for timing of activation
- Subcortical brain imaging with high temporal resolution not currently available

Lesion Methods:
- Reversed engineering to infer function by removing a region
- Techniques include chemo/optogenetics
- Human research relies on accidents, stroke, lobectomy, genetic disorders

Transcranial Magnetic Stimulation (TMS):
- Coil with electric current induces a magnetic field
- Focal, reversible, and movable
- Investigates time-course of cognitions

Advantages/Disadvantages of TMS:
- Advantage: Focal stimulation
- Disadvantage: Lack of good placebo condition

Conclusion of Imaging Methods of SNS:
- Different temporal and spatial resolutions and invasiveness

Knowledge Clips Part 2: Amygdala and Emotional Processing

Amygdala Structure:
- Part of the limbic system
- Studied as a single structure in humans
- Evolutionary changes in amygdala size (BLA vs. CeA)

Low and High Routes (LeDoux):
- Visual processing routes in threat perception
- High route: Thalamus to visual cortex to amygdala
- Low route: Thalamus directly to amygdala for rapid fear response

Fearful White Eyes Experiment:
- Amygdala responds to fearful eyes unconsciously
- Urbach Wiethe disease impairs fear recognition
- Patient SM and South African patients show different responses due to specific amygdala damage

Amygdala and Threat Conditioning:
- Reactivity, attention, recognition, learning, memory, and regulation
- Amygdala's role beyond fear: emotionally intense stimuli, positive/negative experiences

Insula:
- Linked to disgust traditionally
- Also involved in taste, pain perception, and general bodily awareness
- Main node of the salience network

Reward System and Motivation:
- Midbrain, striatum, cortex involvement
- Dorsal striatum for motivated behavior and habit formation
- Ventral striatum (nucleus accumbens) for reward experience and anticipation

Orbitofrontal Cortex (OFC):
- Computes/predicts current reward value
- Activity correlates with transitions in reward value
- Importance in behavioral flexibility

Anterior Cingulate Cortex:
- Cognitive and affective parts for conflict monitoring
- Adjusts behavior and updates based on conflicts

Emotions and Decision Making: Traditional View:
- Emotional decision making for intuitive, fast decisions
- Rational decision making for calculated, slower decisions
- Somatic marker theory suggests combining emotional and rational elements for optimal decisions

Somatic Marker Theory (Damasio):
- Emotional and rational parts combined for decision-making
- Importance of ventromedial prefrontal cortex in updating behavior based on somatic signals
- Conflict between ratio and affect in morality dilemmas

Morality and Decision Making:
- Ventromedial prefrontal cortex damage leads to more utilitarian decisions
- Interplay between emotions and rationality in decision-making
- Criticisms of somatic marker theory but general acceptance of vmPFC's role in integrating affective and cognitive information for decision-making.