Emotion- Lectures 8&9 Flashcards
Defining Emotion
Elkman & Friesen (1971)
6 Universal types of expressions:
- Sad
- Happy
- Angry
- Fearful
- Disgusted
- Surprised
Robert Plitchik (1927-2006)
- There is a gradient of emotion
- Each can vary in intensity
Plutchik’s Psycho-evolutionary theory of basic emotions
- Ten assumptions
1-Applies to all animals including humans
2-Have an evolutionary history and have evolved various forms of expression in different species
3-Adaptive role in helping organisms deal with survival issues in environment
4-Are common elements, or prototype patterns across species
5-Small number of basic, primary, or prototype emotions.
6- Other emotions (not primary) are mixed or derivative states occurring in combinations of the primary emotion
7-Primary emotions are hypothetical constructs or idealised states
8-Primary emotions can be conceptualised in terms of pairs of polar opposites (happy-sad)
9-All emotions vary in their degree of similarity to one another.
10-can exist in varying degrees of intensity
Rolls (1990)- Classification of emotion based on reinforcement learning
-Learn to associate neg./pos. outcomes with specific stimuli >Primary reinforcers- directly influence behaviour >Secondary reinforcers- something that you can achieve a specific outcome
-Includes expectation in the model
expect a negative response to a stimuli but experience the opposite, we experience relief
Emotion is what motivates our behaviour- but it is the expectation of emotion
Rolls (1995 continued…)
Dimensions of Emotion
> Emotions are graded
Can be externally or internally controlled (stimuli
or expectation)
Emotion modifies behaviour
Investigating emotion:
Methods of Eliciting emotion
Mood induction-ask to achieve target emotion
Reward & punishment- give primary or secondary reinforcers for negative or positive emotion
Emotionally Evocative stimuli- International affective picture system
Investigating emotion:
Measuring emotion
Direct assessment- self report (introspection..)
Indirect assessment-
- Study choice behaviour
- Measure reaction times
Psychophysiological variables-
Emotion directly affects autonomic nervous system
e.g. look at startle reflex, skin conductance, heart rate
Lesion studies
Papez (1937)- Hypothalamus, anterior thalamus, cingulate gyrus and hippocampus
MacLean (1952)- adds amygdala and orbitofrontal cortex & part of basal ganglia
fMRI studies
Measures task specific haemodynamic response in different regions of the brain
The Amygdala
In medial temporal lobe adjacent to hippocampus
Damage to Amygdala
Can cause:
- Loss of fear response (In monkeys)
- Impaired implicit learning and explicit memory
- Social responses
- Vigilance
Phelps and LeDoux (2005)
Animal & human Models
-Impact on understanding of Amygdala and emotional processing
Implicates amygdala in fear and other emotional processes:
- implicit emotional learning and memory
- emotional modulation of memory
- emotional influences on attention and perception
- emotion and social behaviour
- emotion inhibition and regulation
Amygdala:
Implicit learning
Neutral stimuli can take on aversive properties when paired with aversive events
>Fear conditioning
Individual can become fearful of a neutral non-threatening stimuli if it has previously been paired with a naturally threatening unconditioned stimulus (shock).
Implicit learning and Amygdala damage
Impairs conditioned fear response -‘fear learning’ not stimulus perception
I.e. get a fright every time but cannot learn the association
Blocks ability to acquire and express a response to the neutral conditioned response when paired with aversive unconditioned stimulus
LeDoux
2 main functional components of Amygdala
- Lateral nucleus of Amygdala (convergence area):
- Formation of associations underlying aversive conditioning - Central Nucleus of Amygdala (initiating area):
- Receiving projections from lateral nucleus to initiate emotional response to aversive stimulus
LeDoux- 2 main functional components of Amygdala:
Function in implicit learning
Convergent input through 2 routes :
>low and high road
- Low road: Direct from sensory thalamus (quick but unspecific)
- High road: Projections via primary sensory and association cortices (slow but specific)
Phelps et al. (1998)
Lesions in Amygdala lead to no physiological response to aversive stimuli (electric shock)
-patients skin conductivity does not increase in line with controls
BUT.. they do have good cognitive understanding and interpretation of experience
Amygdala- evolutionary function
Used to respond to early signs of threatening stimuli- involved in very early on stages of responding
Amygdala:
Emotion modulation
Emotional responses modulate memory formation
-traumatic/ stressful events are recalled much better than everyday events
LaBar & Phelps (1998).
Patients with amygdala damage forget arousing and non-arousing stimuli at the same rate
-Compared to control, this is unusual as arousing stimuli is usually retained for longer
Amygdala:
Social Responses
Human amygdala majorly not involved in explicit evaluation of events
1 exception:
-Evaluating fearful facial expressions Adolphs (1994;1999)
Breiter et al. (1996)
Largest amygdala activation to fearful expressions
> Behavioural data supported by imaging data
Amygdala:
Social Responses
Vigilance
Vigilance in ability to detect fear in others
Fearful expressions in isolation do not trigger emotional responses but activate the amygdala
-activity in amygdala neurones causes increased excitability in other cortical areas (acetylcholine)
Amygdala:
Emotional Influence on attention and perception
Emotionally aversive stimuli is often more easily recognised than neutral stimuli
The Attentional Blink
Raymond et al. (1992)
After attention is diverted to a target subject, there is a gap in attention afterwards, that means a second target cannot be detected milliseconds after,
Amygdala:
Influence on attention and perception
Anderson & Phelps (2001)
Emotional Attentional blink
The attentional blink shows that:
-after identifying a single target stimulus, there is a transient impairment in awareness for a subsequently presented second target
-Consistent with the notion of a differential sensitivity toward significant events, this deficit in perceptual awareness is greatly attenuated for aversive verbal stimuli
»>Control observers identified negative words with greater accuracy than neutral words across all temporal lags
Lesions in both left and right amygdala
LHS lesion shows no attentional blink-impair attentional (fast) evaluation of written words.
RHS lesion shows a big attentional blink
