Neuroscience of social behavior
and emotional disorders
Lecture 1:
Combination of sociology, social psychology and neuroscience.
Sociology: the study of social behavior or society, including its origings, development, organization,
networks and institutions.
We tend to be favorable to our own group and consequently unfavorable to the out-group. Thus
everyone is prejudiced, it’s part of group behavior.
To understand a prejudice we need to understand the social, economic and historical context.
Social psychology: attempts to understand how the thoughts, feelings and behaviors of individuals
are influenced by the actual, imagined or implied presence of others.
To understand prejudice we need to understand the underlying motivations and emotions.
Neuroscience: attempts to understand behavior by studying the underlying circuitry in the brain.
Oxytocin is a love hormone for the ingroup. (love for child, but aggression to threats)
To understand prejudice we need to understand the neural mechanisms of the underlying motivation
and emotions.
Is there something like ‘the social brain’?
- Is the brain modular?
o Specialized routines and brain structures that perform very specific functions.
- Or non-modular?
o Specific functions are the result of many routines and structures.
The social brain is in general non modular!
- Social and non-social cognition rely on each other and evolved hand in hand.
- In general: bigger brains lead to changes in both social and non-social intelligence.
- Social intelligence hypothesis: pressure to outwit peers may lead to increased intelligence in
non-social domains.
Triune brain model:
- According to this model the human brain is an accumulation of brain regions that can be
roughly divided in three phylogenetic stages:
o The reptilian brain (sub cortex): action-reaction machinery
o The mammalian brain (limbic system): emotionality; behavioral flexibility
o The primate brain (neo-cortex): rationality: behavioral control
- Each newer layer supports more complex functions and exerts some sort of control over the
older layers.
- This also means that a large part of our behavior is still driven by similar brain mechanisms as
our phylogenetic predecessors.
- The primate brain (non-modular): … but, mirror neurons
- The mammalian brain (module like): amygdala/insula – fear/disgust
- The reptilian brain (quite modular): small nuclei with distinct (non)social roles
,Mirror-neurons
- Neurons that respond to both self-behavior and other-behavior
- Thought to serve observational learning
- There may be comparable systems for emotion and sensation as well as action
- Not tightly localizes to one region
A mixed mode: some parts of the social brain might be modular, module like, or non-modular
depending on the specific function. network approach instead of ascribing discreet social
functions to brain regions.
Knowledge clips:
Psychological methods of SNS:
- Subjective measures
o Profiel Of Mood States (POMS)
o Personality questionnaires:
STAI/STAS (anxiety/anger)
LSAS (social anxiety)
EQ-SQ (empathy/systemizing)
BIS/BAS (inhibition/activation)
- Observational measures
- Performance measures
o IQ tests, Recognition tests, Implicit association task, cueing tasks
Selective attention task (STROOP task)
- Classical stroop: interference of a word by colour
- Emotional stroop: interference of emotion (spider phobia and you get spider as word you will
have more interference)
- Facial fear stroop: interference of expression (faces with expression in colours.)
Measuring psychophysiology:
- Controlled by the brain through the spinal cord
- (Para)sympathetic nervous system
o Arousal
Electrophysiological methods:
- Goal: Measure bodily reactions that underlie behavior
- Skin conductance
- Heart rate, respiration
o Deceleration: preparing for danger
o Acceleration: active escape or attack
o Heart rate variability (HRV):
more variability = rest = parasympathetic
less = concentration = enhanced attention = sympathetic
- Electromyography (EMG)
o Measures potential between pairs of close electrodes
Single-cell recordings:
, - Very small electrode implanted into axon (intracellular) or outside axon membrane
(extracellular)
- Records neural activity, number of action potentials per second (but doesn’t stimulate it)
Electroencephalography (EEG):
- Picks up neural activity of a large number of cells
- Possibly due to the column like organization of the cortex
- Directly related to neural activity. Thus, ERP has an excellent temporal resolution.
- Derived from multiple sources in the brain at the same time, therefore ERP has a poor spatial
resolution.
Magnetic resonance imaging: relies on the alignment of water molecules
- Molecules are first aligned in a strong magnet
- Misaligns with a radio pulse
- 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
- Functional MRI measures the blood oxygenation
- A region is ‘active’ if it shows a greater response in one condition relative to another
- Funcional MRI has good spatial resolution but bad temporal resolution
Diffusion tensor imaging (DTI)
- Used to map the white matter microstructure
- Grey matter: unmyelinated neurons
- White matter: myelinated neurons
Brain imaging:
- Using MRI we can measure: brain structure (MRI), brain connections (DTI), activation location
(fMRI)
- Timing of activation EEG-ERP
Lesion methods:
- Acquired sociopathy:
o Phineas Gage: metal through his skull his character strongly changed.
- Reversed engineering: infer the function of a region by removing it and measuring the effect
on the rest of the system
- Animal models
TMS:
- Coil
o Electric current
o Magnetic field
o Evokes action potentials
- this disrupts the cognitive function that they may be
doing at that point in time.
, - Advantage: no deep brain regions; reversible and moveable; investigate the time course of
cognition
- Disadvantage: there is not a good placebo conditions
Literature: CHapter 1: introduction to social neuroscience
Cognition in an individual brain is characterized by a network of flowing signals between different
regions of the brain. However, social interactions between different individuals can be characterized
by the same principle: a kind of ‘mega-brain’ in which different regions in different brains can have
mutual influence over each other. This is not caused by a physicial flow of activity between brains,
but by our ability to perceive, interpret and act on the social behaviors of others.
Social psychology: an attempt to understand and explain, using neural mechanisms, how the
thoughts, feelings, and behaviors of individuals are influenced by the actual, imagined, or implied
presence of others.
Cognitive psychology has an important role to play in social neuroscience because it aims to
decompose complex social behaviors into simpler mechanisms that are amenable for exploration
using neuroscientific methodologies.
Stanley and Adolphs provide a compelling summary of the current state of the field and point to its
future evolution: although we have moved from regions to networks, the next key step is to identify
the flow of information through these networks to follow social information processing from
stimulus through to response. This requires an understanding of the detailed computations
implemented by the different nodes in the networks as well the dynamic interplay between them.
One could make the analogy of moving from words to sentences to propositions to conversations.
We are still solidly in the age of sentences and are only beginning to enter the age of propositions
and conversations.
Ecological validity: an approach or measure that is meaningful outside the laboratory context.
Is the social brain special in any way?
One possibility is that there are particular neural substrates in the brain that are involved in social
cognition but not in other types of cognitive processing. This relates to the notions of modularity and
domain specificity.
- Modularity: the notion that certain cognitive processes are restricted in the type of
information they process and the type of processing carried out.
- Domain specificity: the idea that a cognitive process is specialized for processing only one
particular kind of information.
The alternative approach is to argue that the social brain is also involved in non-social aspects of
cognition. The evolution of general neural and cognitive mechanisms that increase intellect, such as
having bigger brains, may make us socially smarter too.
Another possibility is that it is not particular regions of the social brain that are special but rather that
there are particular kinds of neural mechanisms especially suited to social processes. The key insight
is that there may be a simple mechanisms that enables a correspondence between self and other.
This relates to mirror neurons.
In figure 1.5 barret and Satpute offer a useful overview of this general debate concerning the nature
of the social and emotional brain They consider three broad ways:
, 1. The first scenario is a simple domain-specific view consisting of brain regions that are
specialized for processing particular kinds of social information and non-social information.
2. The second scenario postulates networks of regions in which each region in the network has
a high degree of specialization, whereas in the third scenario neither brain regions nor
individual brain networks are functionally specialized or segregated into social and non-social
functions.
3. The second and third scenarios involve the idea of brain networks and are more compatible
with contemporary ideas in the literature.
Reductionism: one type of explanation will become replaced with another, more basic, type of
explanation over time. However most researchers in social neuroscience are attempting to create
bridges between different levels of explanation rather than replace one kind of explanation with
another. Another common way in which neuroscience data are used to bridge levels of explanation
has been termed the reverse inference approach. Reverse inference: an attempt to infer the nature
of cognitive processes from neuroscience data.
There is no scenario in which brain-based data could have no significant impact on our understanding
of social processes – and that is the blank slate scenario: the idea that the brain learns environmental
contingencies without imposing any biases, constraints, or preexisting knowledge on that learning.
According to the blank slate, the structure of our social environment is created entirely within the
environment itself, reflecting arbitrary but perpetuated historical precedents. Social processes are all
in the brain, but some of them are created by environmental constraint and historical accidents
whereas others may be caused by the inherent organization, biases, and limitations of the brain
itself.
One good illustrative attempt at linking multiple levels of explanation in social neuroscience comes
from a newly coined sub-discipline termed cultural neuroscience. Cultural neuroscience is an
interdisciplinary field bridging cultural psychology, neurosciences and neurogenetics. It explicitly
assumes that not only will cultural differences influence the brain, but also that the brain will impact
on culture itself.
Gene-culture co-evolution: culture can influence gene frequencies in a population, and genes have
an impact on cultural evolution via psychological predispositions. The outcome of this iterative
process is that there is a good fit between a particular genotype and a particular cultural practice.
In a collecitivst culture the goals of the social group are emphasized over individual goals. In an
individualist culture the goals of the individual are emphasized over the social group.
Chapter 2: The methods of social neuroscience
The main methods of cognitive neuroscience can be placed on a number of dimensions:
- The temporal resolution refers to the accuracy with which one can measure when an event is
occurring.
- The spatial resolution refers to the accuracy with which one can measure where an event is
occurring.
- The invasiveness of a method refers to whether or not the equipment is located internally or
externally.
Three different ways of measuring behavior and cognition: performance-based, observation-based
and first-person-based.
