AFFECTIVE NEUROSCIENCE NOTES
LECTURE 1–What is emotion?............................................................................................................2
LECTURE 2-The emotional brain.........................................................................................................8
LECTURE 3-Frontal lobes and emotion.............................................................................................14
LECTURE 4-Left brain/ Right brain and emotions..............................................................................19
LECTURE 5-The social brain..............................................................................................................24
,LECTURE 1–What is emotion?
1-What is emotion?
“Emotions are episodes of co-ordinated changes in several components (including physiological activation, motor expression
& subjective feeling) in response to external or internal events of major significance to the organism.” Scherer in
Neuropsychology of Emotion (ed. Borod, 2000, p138)
“Episodes” - emotions have limited duration, they start, last for a certain amount of time and then they stop (i.e.,
short lasting). Moods are longer lasting affective states.
“Significance to the organism” - for survival, reproduction, & (in humans) self-esteem, social status, etc. The term
‘organism’ suggests that emotions occur in non-humans animals.
This implies that organisms must make an evaluation or appraisal that the event is important to them there’s a
cognitive aspect to emotions since evaluation is a cognitive process.
Emotions consist of “changes in several components” (i.e., components that make up an emotion):
motivation: drive to respond to the situation the situation that has triggered that emotion
feelings: they’re just one component of emotion, not the only one. They are distinct subjective
experiences, different from other mental states like being tired, hungry or thirsty
physiological changes (e.g. heart rate, sweating) that prepare the organism for action (i.e., dealing with
this important event)
behaviour: anything visible (e.g. approach, avoidance, freezing)
1.1 - Components of emotion
There’s an event, that event must be appraised/evaluated
(i.e., cognitive information processing component of
emotion) and then, on the base of that evaluation, emotional
responses take place.
These emotional responses have different aspects:
Subjective experience
Peripheral/autonomic nervous system changes
Central nervous system changes
Behaviour changes
1.2 - Detecting & measuring emotional responses
All these aspects of emotional response are all sources of data: if you want to detect emotions, all of them are usable sources
of data. None take priority over the others.
Subjective experience: measure detected using verbal reports of ‘feelings’ (e.g., using rating scales)
Peripheral/autonomic nervous system changes: measured as changes in heart rate, blood pressure, skin
conductance, etc.
Central nervous system changes: measuring changes in brain activity (EEG, fMRI, etc.)
Behaviour changes: measured as facial expressions, laughing, crying, approach/avoidance behaviour, etc.
2-Basic emotions, facial expressions & ANS psychophysiology
2.1 - Basic emotions theory
We can organise emotions in different categories Categorical organization: different ‘basic’ emotions are distinct
categories or types, each with a specific motivational function. There are various versions of the basic emotion’s theory, but
the most used emotions are:
Fear: function is to beware of dangerous situation
Disgust: function is to avoid toxins, contamination, disease
Anger: function is to remove obstructions to goals
Sadness: function is to disengage from a goal that cannot be achieved
Happiness (or joy): function is to maintain current situation we are in
This idea is how non-psychologists think about emotions. It seems to fit well with subjective experience (i.e., fear, disgust,
anger, sadness and happiness all feel different), they all feel different. It’s supported by evidence of distinct facial expressions
for different basic emotions. But not much support from studies using physiological measures: the fact that we don’t see
, much evidence for there being distinct patterns of physiological activity for these different basic emotions causes some
problems when it comes to studying emotion.
2.2 - Facial expression of basic emotions
These are some examples of basic facial expressions that people would recognise
easily and match with these ‘basic’ emotions. However, are there more than 5 ‘basic’
emotion expressions? There are studies that establish that there are other basic
emotions that have their own facial expressions:
Surprise: often claimed to have a ‘distinct facial expression’ – but studies of
emotion perception show it is often confused with fear or joy and it could
be considered a ‘precursor’ or ‘trigger’ for emotion rather than an emotion
in itself, i.e., something happens that surprises you and then you feel an
emotion such as happiness or fear surprise is a cognitive state which
appears when something happens.
Contempt (desprecio) has also been suggested (e.g. Ekman & Friesen,
1986) – others argue it is not ‘basic’ but is a combination of other emotions
(disgust + anger).
Measuring facial expressions
Facial Action Coding System (FACS, Ekman & Friesen, 1978). It identifies 44 distinct muscle movements involved in
producing facial expressions.
But its usage requires extensive training (i.e., trained to recognise what muscles form which expression) and very time
consuming to use. A trained FACS coder can take up to 100 minutes to code 1 minute of video recording.
Facial-EMG: electronic sensors (on skin) can detect and record electrical activity in facial muscles. Stick sensorial
electrodes in the skin. EMG = electromyography. You can measure how
big the activity is and how long it lasts for. There are two groups of
muscles used:
o Corrugator muscle activity (near eyebrow) produces frowning
o Zygomatic muscle activity (cheek) produces smiling
Not possible to measure activity in all facial muscles at same time, but corrugator and zygomatic muscle activity both
show strong relationships with subjective reports of emotion (e.g., when people report to feel happy, activity in the
zygomatic muscle can be observed).
Facial-EMG has been validated as measure of ‘pleasure’ (or ‘valence’) in studies using photographic images & film
clips. In other words, the amount of activity in these muscles correlates with people’s subjective report of how pleasant
or unpleasant something is. Other advantage is that it can detect muscle activity that is not visible to an observer (i.e.,
sometimes facial expressions are not visible, but the person would report to feel happy when looking at a photograph
and that would match with the activity shown in the facial EMG). But placing sensors on face might lead to inhibition or
exaggeration of facial expressions (i.e., unnatural). There's a little bit of concern about how putting these electrodes on
someone's face might actually change how they behave.
3-Autonomic nervous system (ANS)
Physiological activity in the ANS is important when studying emotion. The ANS is part of the peripheral nervous system.
It controls glands (hormones) & muscles of internal organs, which regulates heart rate, blood pressure, breathing, digestion,
etc. It has two branches:
Sympathetic ANS = ‘fight or flight’ responses, increased arousing
Parasympathetic ANS = ‘rest & digest’ responses, calming effect
They work in exact opposition to each other; their physiological answers are opponents.
3.1 - Measuring ANS activity
The study of the effects of psychological factors (e.g. emotional content of stimuli) on physiological activity is called
psychophysiology. Changes in ANS activity can be monitored and recorded using a variety of electronic sensors.
A polygraph can be used to measure activity in a number of different physiological systems at the same time – e.g. heart rate,
breathing rate (how deeply and quickly), skin conductance (sweating), skin temperature & peripheral blood flow. Polygraph
detects emotion changes in the ANS, known as a lie detector.
