Summary NSBED
Clips and lectures
Clip 1.1 Psychological methods
Psychological methods of social neuroscience can be separated in three measures:
- Subjective measures
o Emotional experience
Interview/questionnaires to determine how an individual experienced an
experiment
POMS (profile of mood states)
o Personality questionnaires
STAI/STAS (state-trait-anxiety/anger)
LSAS (Liebowitz social anxiety scale)
EQ-SQ (empathy/systemizing)
BIS/BAS (behavioral inhibition/exhibition)
o These data can be used as a control variable or for correlation with other measure
- Observational measures
o Frequency of behaviors
Observations. What will the participant do? Often used in animal studies and
infant studies. You can observe them “live” or film them and look at it later.
Eye tracking.
- Performance measures
o Reaction time
o Accuracy
Speed-accuracy trade-off.
For instance IQ tests, emotion recognition tests.
Selective attention: participant has to do a certain test but gets distracted.
For example implicit association task, stroop task.
There’s also an emotional stroop task and a facial fear stroop.
Clip 1.2 Physiological methods
You measure bodily reactions to emotion. The body is controlled by the brain through the spinal cord.
This control can be divided in the sympathetic (stress/active) and the parasympathetic (relaxed)
nervous system
There are three often used physiological methods to measure bodily reactions that underlie/precede
(social) behavior.
- Skin conductance
o Sweat gland activity
Related to sympathetic arousal
Activity makes the body temperature rise and therefore you’ll start sweating
Signal will peak between 1-5 s after the emotional event
Can also occur in absence of conscious perception of that event, so also
measures unconscious emotional response
, - Heart rate, respiration
o Preparation for fight/flight
Deceleration: heart rate will first go down in preparing for danger
Acceleration: active escape or attack, heart rate will rapidly go up when the
danger happens.
Heart rate variability (HRV): more variability = rest = parasympathetic. Less =
concentration, enhanced attention = sympathetic.
- Electromyography (EMG)
o (Involuntary/automatic) muscle activity
Measures potential between pairs of close electrodes.
(Facial) muscle activity
Mimicking facial expressions (affective empathy).
Eye blink startle potentiation. Eye blinks aren’t controllable, in research it is
found that people blink more in threatened situations.
Clip 1.3 Brain imaging – Electrophysiology
All imaging is about neuronal activity or structure. All neurons have the same basic structure: cell
body, axon (action potentials), dendrites.
- Single-cell recordings
o To measure the firing rate of an electrode.
o Very small electrode implanted into axon (intracellular) or outside axon membrane
(extracellular).
o Records neural activity, number of action potentials per second. It doesn’t stimulate
it, only measures the frequency.
o Only done in animals, unethical.
o Evidence for mirroring. Monkey eating peanuts or looking at someone eating
peanuts.
- Electroencephalography (EEG)
o Picks up neural activity of a large number of cells.
o Possible due to column-like organization of the cortex, therefore also limited to the
cortex.
o Works by placing electrodes on the outside of the head.
o Two ways:
Frequency bands – looking at the amount of waves and the amplitude.
Delta waves (1-4Hz) – motivational system: bottom-up drive.
Beta waves (12-30Hz) – cortex: top-down modulation.
Event-related potentials – signal is averaged over many trials. The resulting
ERP is a series of positive and negative peaks. Location, amplitude and timing
reflect brain activity in response to the event.
The N170 is relatively specialized for faces. When a face is presented,
after 170 ms there’s a negative peak. This tells you that this specific
brain area reacts to faces.
It’s a direct measure, very precise. However, the signal is always
derived from multiple sources in the brain so you never know the
exact location. High temporal resolution, low spatial resolution.
,Clip 1.4 Brain imaging – Magnetic Resonance Imaging MRI
MRI relies on the alignment of water molecules. Spatial resolution is way better than whit EEG.
- Molecules are first aligned in a strong magnet by placing you in the MRI machine.
- When the magnetic field is off, the direction of the water molecules is quit random, but when
the magnetic field is turned on, they all align.
- A radio transmitter makes the molecules turn into another position.
- Realignment to the magnetic field emits a recordable radio pulse.
- Realignment depends on tissue properties.
Functional MRI
- Hemodynamic method: neural activity consumes oxygen, thus needs blood flow.
- Functional MRI measures the blood oxygenation.
o Oxygen slows re-alignment of water molecules.
- A region is “active” if it shows a greater response in one condition relative to another.
- If inappropriate conditions the activity will be meaningless (junk in, junk out) – functional
imaging isn’t foolproof.
- Good spatial resolution but bad temporal resolution compared to EEG.
o Voxel-size can be as low as 1mm3.
o BOLD response: Blood Oxygen Level Dependent contrast. Hemodynamic response
function, change in BOLD over time. Thus, temporal resolution in the order of a
couple of seconds.
Structural imaging
- Diffusion tensor imaging (DTI)
o Used to map the white matter microstructure
Grey matter in unmyelinated and white structure is myelinated.
o Diffusion of water molecules
o It’s also an MRI, but from multiple angles and time-point to get a 3D image.
So to sum up:
- Brain structure MRI
- Brain connections DTI
- Activation location fMRI
- If we also want timing of activation we can use EEG-ERP, but only in cortex
- Subcortical brain imaging with high temporal resolution is currently not available.
o Deep brain electrodes are highly invasive, only applicable in combination with
specialized treatment of disease, for example in Parkinson’s disease.
Clip 1.5 brain imaging – Lesion and disruption of function
Lesion methods
- Reversed engineering
o Infer the function of a reguion (or cognitive mechanism) by removing it and
measuring the effect on the rest of the system.
o Animal models
, For instance chemo/optogenetics, but there are many more techniques.
o Human models
Accidents like Phineas Gage
Stroke
Lobectomy studies, often used in patients with very severe epilepsy.
Rare genetic disorders like Urbach-Wiethe disease – UWD: see next lecture.
o Transcranial Magnetic Stimulation TMS
Coil
Electric current, magnetic field, evokes action potentials.
This disrupts the cognitive function of that they may be doing at that point in
time.
Virtual lesion.
Coil overloads the brain era which leads to overstimulation and thus it not
working anymore.
Disadvantage of TMS: there is no good placebo possible
Lecture 1 Introduction
Social neuroscience is a combination of multiple fields, it attempts to link these different levels of
explanation
- Sociology (groups)
o The study of social behavior or society, including its origins, development,
organization, networks, and institutions.
o We tend to be favorable to our own group and consequently unfavorable to the out-
group. Thus everyone is prejudices, it’s part of group-behavior.
o To understand a prejudice, we need to understand the social, economic and historical
context.
- (Social) psychology (individuals)
o Attempts to understand how the thoughts, feelings, and behaviors of individuals are
influenced by the actual, imagined, or implied presence of others.
For instance, ‘dehumanization’.
Slavery, violent jihad, flaming.
Takes away all motivation to empathize with the outgroup.
o To understand prejudice we need to understand the underlying motivations and
emotions.
- Neuroscience (biology)
o Attempts to understand behavior by studying the underlying circuitry in the brain
See neuroscience clips 1.1 tm 1.5.
For instance oxytocin – the love hormone, but only for the ingroup.
o To understand prejudice we need to understand the neural mechanisms of the
underlying (automatic) motivations and emotions.
Is there something like ‘the social brain’?
- Is the social brain modular?
o Specialized routines and brain structures that perform very specific functions.
- Or is the social brain non-modular?
o Specific functions are the result of many routines and structures.