Emotion

Question 1

What are the 6 main emotions?

Answer 1

Anger
Fear
Surprise
Sadness
Joy
Disgust

Question 2

What are emotions?

Answer 2

A composite of subjective feelings, physiological responses, and behaviours that allow humans and other animals to react adaptively to internal and external stimuli

Question 3

Explain the study by Duchenne (1862)

Answer 3

Gave pps electrical stimulation of the facial muscles

Bilateral electrical stimulation of the zygomaticus major muscle mimicked a genuine expression of happiness although shows insufficient contraction of the obicularis oculi compared with spontaneous laughter

Question 4

What did Duchenne (1862) find in their study?

Answer 4

Faradization = electrocuting various muscles in the face

Found there were 2 types of smile
Voluntary smile = pyramidal smile, activates the zygomatic major muscle
Involuntary smile = Obicularis oculi (cannot be voluntary activated) (extra pyramidal)

Question 5

How does voluntary facial paresis provide support for Duchenne?

Answer 5

Patients with unilateral facial paralysis due to damage of descending pathways from the motor cortex have considerable difficulty moving their lower facial muscles on one side either voluntarily or in response to commands - voluntary facial paresis

Many of them produce symmetrical involuntary facial movements when they laugh, frown or cry in response to stimuli

Evidence that there are separate pathways from the forebrain other than the classic motor cortex which activate facial movements

Question 6

How do patients with emotional facial paresis provide support for Duchenne?

Answer 6

Loss of ability to express emotions by using the muscles of the face without loss of volitional control

Such individuals are able to produce symmetrical pyramidal smiles but fail to display spontaneous emotional expressions involving the facial musculature contralateral to the lesion

Question 7

Describe the 2 separate systems for the pyramidal smile and the Duchenne smile

Answer 7

Volitional movement = descending pyramidal and extrapyramidal projections from motor cortex and brainstem
Connects to –> motor neuron pools in facial nucleus –> Activation of facial muscles (Pyramidal smile)
Lesion between these systems causes voluntary facial paresis

Neural systems for emotional expression = descending extrapyramidal projections from medial forebrain and hypothalamus
Connects to –> Motor neuron pools in facial nucleus –> Activation of facial muscles (Duchenne smile)
Lesion between these systems causes emotional facial paresis

Question 8

What did Phillip Bard study?

Answer 8

Bard removed both cerebral cortex in a series of cats
When the anaesthesia wore off the animals behaved as if they were enraged
Cats also exhibited somatic motor components of anger such as arching their back - this behaviour was called sham rage
Found that a transection through the midbrain, disconnecting the hypothalamus and brainstem abolishes sham rage
Suggested that the hypothalamus was a key brain region in expression of emotion

Question 9

What structures are in the Papez circuit?

Answer 9

Hippocampus
Amygdala
Thalamus
Hypothalamus
Parahippocampal regions

Question 10

What is Kluver-Bucy syndrome?

Answer 10

Results from bilateral lesions of the medial temporal lobe including the amygdala

Symptoms
1. Visual agnosia
2. Increased oral tendency
3. Decreased emotional reaction
4. Hyper-sexuality
5. Hyper-metamorphosis

Question 11

What are the subdivisions of the amygdala?

Answer 11

Medial group - connected with olfactory bulb and olfactory cortex
Basal lateral group - cortex, orbital and medial pre-frontal cortex, anterior temporal lobe
Central/anterior group with hypothalamus and brainstem

Question 12

What are the inputs into the amygdala?

Answer 12

Auditory pathways –> Thalamus - Medial geniculate nucleus –> Auditory cortex or amygdala
Auditory cortex –> Amygdala
Somatic sensory pathways –> Amygdala

Question 13

What is the process of fear conditioning in the amygdala - What pairs the stimuli and outputs?

Answer 13

Long term potentiation
Excitation causes frontal cortex connections

Question 14

What are the outputs of the amygdala?

Answer 14

Central nucleus causes an output response e.g., freezing, blood pressure, stress hormones or startle reflex

Question 15

What important structure is needed to unlearn the fear associations of the amygdala?

Answer 15

The medial prefrontal cortex

Question 16

What conditions have a smaller amygdala?

Answer 16

Autism
Psychopathy
Brain injury such as stroke can affect the amygdala

Question 17

What are the theories of emotion?

Answer 17

Common sense
James-Lange
Cannon-Bard
Schachter

Question 18

What is the common sense theory of emotion?

Answer 18

Stimulus causes a conscious feeling i.e., fear which causes autonomic arousal

Question 19

What is the James-Lange theory of emotion?

Answer 19

Stimulus causes autonomic arousal which in turn causes a conscious feeling of fear

Question 20

What is the Cannon-Bard theory of emotion?

Answer 20

Stimulus causes subcortical brain activity which causes autonomic arousal and conscious feeling of fear simultaneously

States that the lower part of the brain, also called the thalamus, controls your experience of emotion. At the same time, the higher part of the brain, also called the cortex, controls the expression of emotion. It is believed that these two parts of the brain react simultaneously

Question 21

What is the Schachter theory of emotion?

Answer 21

Stimulus –> autonomic arousal + appraisal –> conscious feeling

Physiological arousal determines the strength of the emotion, while cognitive appraisal identifies the emotion label

Question 22

Describe the 2 separate systems for the pyramidal smile and the Duchenne smile

Answer 22

Volitional movement = descending pyramidal and extrapyramidal projections from motor cortex and brainstem
Connects to –> motor neuron pools in facial nucleus –> Activation of facial muscles (Pyramidal smile)
Lesion between these systems causes voluntary facial paresis

Neural systems for emotional expression = descending extrapyramidal projections from medial forebrain and hypothalamus
Connects to –> Motor neuron pools in facial nucleus –> Activation of facial muscles (Duchenne smile)
Lesion between these systems causes emotional facial paresis

Question 23

What did LeDoux do in his study?

Answer 23

Trained rats to associate a tone with a mildly aversive foot shock delivered shortly after the onset of a sound
They measured blood pressure and the length of time the animals crouched without moving (freezing)
After training, the onset of the tone caused a marked increase in blood pressure and prolonged period of freezing

Question 24

What did the results of LeDoux tell us about brain areas in emotion?

Answer 24

The medial geniculate complex (dorsal thalamus) is necessary for the development of the conditioned fear response

The responses were still elicited if the connections between the MGC and auditory cortex were severed, leaving only a direct projection between the MGC and the amygdala