Emotion

Question 1

What is Emotion?

Answer 1

neuropsychologists identify emotion as affect, a conscious, subjective feeling about a stimulus

Four principal behavioural components to emotion:
- Physiology e.g., changes in heart rate
- Distinctive motor behaviour e.g., running away.
- Self-reported cognition e.g., I am scared.
- Unconscious behaviour e.g., adapting without awareness.

Question 2

Anatomy of emotion

Answer 2

The Limbic System- part of the brain that is responsible for emotional responses.

Amygdala- quick, early processing of emotional stimuli

Question 3

James Papez (1937)

Answer 3

Argued that the limbic system was responsible for emotion and the cortex was where it was represented or experienced.

Papez proposed that the circuit connecting the hypothalamus to the limbic system was the basis for emotional experiences.

Question 4

Kluver-Bucy Syndrome (1937)

Answer 4

-Bilateral damage to the amygdala – lack of affect
-Bilateral anterior temporal lobectomy in monkeys (including bilateral amygdala and inferior temporal cortex)
-No fear response even to innately dangerous objects e.g., snakes

Klüver-Bucy syndrome also demonstrated the role emotion played in many behaviours.
-Animals became indiscriminate in their diet.
- Increased and inappropriate sexual behaviour
-A tendency to attend and react to all visual stimuli.
-Oral fixation.
-Visual agnosia

Question 5

Cortical role in emotion

Answer 5

-Animal studies suggest the frontal lobes are also critical for emotions and emotional behaviour.

Frontal lobe lesions in monkeys result in:

1. Reduced social interaction.
2. Loss of social dominance
3. Inappropriate social interaction
4. Altered social preference.
5. Reduced affect.
6. Reduced vocalisation.

Question 6

Theories of emotion: Damasio

Answer 6

Damasio., A The Somatic Marker Hypothesis, 1994
Internal signals from the body (somatic markers) become associated with emotions and situations.
E.g., Increased heart rate associated with excitement/fear.

vmPFC lesion patients tend to choose the higher risk piles (Damasio and colleagues e.g., Bechara et al., 1994, 1997)
Damasio argues that risky decisions are due to vmPFC patients that risky decisions are due to vmPFC patients being unable to utilise the physical cues associated with risk/reward to guide their behaviours.

Question 7

LeDoux: Model of Fear

Answer 7

Argues that emotion evolved to support survival, and that as the brain evolved, cognitive and emotional systems became more interrelated.
-The theory focuses on a single emotion- fear.
- Feared stimuli can be broader (e.g., fear of a social situation)

Studies have shown that there are two pathways through which the amygdala’s fear responses can be triggered: a ‘fast’ low road from the thalamus to the amygdala, and slower ‘high road’ that passes from the thalamus to the neocortex and only then to the amygdala.

Fast route
-Quick processing of threat stimulus
-Fast, automatic fear response
-Important for survival

Slow route
-More detailed and accurate processing of stimulus
-If stimulus really is threatening, leads to consciously perceived fear.
-If stimulus is not actually threatening, can terminate fear response.

The Amygdala and Fear
According to LeDoux, there are two possibilities for the amygdala recognising something as frightening:

-There may be genetically based neural networks- the brain is hard wired to respond to dangers.
-Evidence – some fears seem to be innate e.g., spiders, snakes, and heights.

or

-Experience can associate stimuli with fear (classical conditioning)
-We also learn to fear many things that are not innately dangerous (guns, bombs, etc)
-The hippocampus, when damaged, interferes with the development of fear responses.

Question 8

Gainotti (1972) Hemispheric Theory

Answer 8

Cognitive appraisals of emotion depend on hemispheric specialisation.
LH lesions that lead to aphasia are often accompanied by depressive symptoms – ‘catastrophic’ reactions.
-RH lesions led to ‘indifference’ reactions e.g., anosognosia (lack of insight into one’s illness)

-Argues that the catastrophic reactions were appropriate, and indifferent reactions inappropriate for the patient’s situation.
Gainotti, 1972 suggested RH is dominant for emotion (like LH is dominant for language)
LeDoux, 1978 in split brain patients, emotional stimuli presented to the left visual field (so RH) led to emotional responses.

Hemispheric specialisation in the healthy brain.
-The right hemisphere seems specialised for emotional processing of faces.
-Visual scenes presented to the LVF (RH) are viewed as more unpleasant and frightening than those showed to the RVF (LH)
-The left ear (RH) shows an advantage for identifying the emotional tone of the voice, the right ear (LH) is better at recognising content.
Example, hemispheric specialisation of the insula

Damage to the insula can lead to apathy (lack of enthusiasm/interest)
- The insula has a role in consciously experiencing emotions and internal bodily signals (intereoception- Craig, 2009)

Question 9

Recognising others’ emotions: Empathy

Answer 9

• The ability to understand and share feelings of another.
• Neural substrates for empathy appear like those for experiencing one’s own emotion. (e.g., amygdala, insula, OFC and vmPFC)