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PSY2304 Biological Basis of Behaviour > Emotion > Flashcards

Flashcards in Emotion Deck (21)
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1

emotions as response patterns

Emotion has 3 categories:
(1) Behavioural
(2) Autonomic
(3) Hormonal

2

behavioural emotions

Central and peripheral nervous system

see slides

3

somatic NS

that translates sensory to voluntary muscular movement

see notes

4

autonomic NS

portion of the nervous system that translates sensory into physiological process.

see notes

Symapthetic = excitatory

Parasympathetic = inhibitory

5

somatic emotion

Voluntary skeletal muscles are organised in opposing pairs.

Neurons connected to muscle groups

see slides

6

autonomic emotion

The somatic and autonomic nervous systems can be distinguished by their anatomical organisation.

Whereas the somatic nervous system connects external sensory organs through the brain to muscles (red), the autonomic nervous system connects the brain to the organs and glands (blue).

see slides

Organs that secrete hormones regulating brain and physiology.

Hormones are like neurotransmitters but spread diffusely throughout the body and brain to modulate activity levels across of a variety of organs and neurons by coupling to receptors on those targets.

They are involuntary and regulated by the autonomic nervous system.
- Can gain conscious control

Hypothalamus and pituitary = master glands

see slides

Sympathetic and Parasympathetic ANS can be distinguished by their anatomical arrangements.

Sympathetic nerves - thoracic and lumber spinal cord – excitation

Parasympathetic nerves - cranial nerves (project directly out of the brainstem) and sacral spinal cord.

Structural division

Spinal injury – damage to one side – may be more excitatory/inhibitory

see slides

Cranial nerves emerge directly from the brainstem (collectively the pons, medulla and midbrain).

The 12 cranial nerves (labelled I-XII) may be sensory or motor or mixed.

Those labelled A play a role in the autonomic NS controlling organs and glands.

The rest are part of the somatic NS.

Sensory – come from the sense

Motor – involved in generation of voluntary motor action within face and neck

A – change physiological state

see notes

7

organs

mechanical things – heart, liver, lungs

8

glands

produce hormones and imp for communication systems

9

hormonal emotion

Hypothalamus is the master endocrine gland.

Controls the pituitary gland to release hormones into the blood stream via the circle of Willis, to act on receptors on endocrine gland and major organs to change physiological state.

Hormonal outflow from pituitary complex and lots of permutations can take

see slides

Hypothalamus uses ‘hypothalamic releasing factors’ to control pituitary.

Pituitary releases 9 know hormones which act on different endocrine glands, to change their function and hormonal output.

Each Endocrine gland has a range of hormones.

Illustrates the complexity of physiological parameters underpinning emotion.

Cascade of hormonal events can be many and varied and controlled by hypothalamus

see notes

10

hypothalamus ANS master

Hypothalamus receives diverse input from the rest of the brain, and has nerve projections broadly into the somatic and autonomic nervous system, as well as controlling circulating hormones from the pituitary.

Hypothalamus is a cluster of diff nuclei

Channel that connects higher parts of the brain

see slides

11

amygdala

The amygdala receives sensory information from the cortex, thalamus and hippocampus.

Detection of emotionally salient stimuli translated into somatic emotion via the striatum, increases sensory and motor signal flow via thalamus, increased arousal via brainstem, autonomic activity via hypothalamus

Important for fear and neg emotions

Equally imp for pos emotions, appetite, sexual interest, joy

Thalamus = projection site into cortex

Receives sensory info from all over cortex, thalamus, hippocampal formation

Outflow – filter and decide which sensory info need to have emotional reaction to

Ties emotionally relevant stim with emotionally relevant response – via ventral striatum – somatic component

Can also change processing of info up and down spine

Can have effects on ANS via projections to hypothalamus

see notes

Amygdala projects widely to a range of nuclei which produce specific aspects of emotional response

Amygdala lesions abolish emotional responses – somatic, autonomic and hormonal aspects.
Stimulation produces emotional reactions encompassing somatic, autonomic and hormonal aspects.

see slides

12

amygdala - Campese et al. (2015)

Conditioning of a tone to predict shock enables the tone to elicit a conditioned freezing (fear) response – emotional reaction

Lesions of the amygdala abolish conditioned fear indicating that it is the region mediating fear learning to previously neutral stimuli.

Sensory info into amygdala from shock detector – hard wired connections with freezing response – don’t need to learn

Have to learn tone is predictor of shock – also into amygdala

Synapse can be adapted through Hebbian learning

Contingency between CS and US = synapse strengthened

see notes

13

Amygdala-VMPFC - Phelps et al. (2004)

In humans, the magnitude of a fear CR (GSR) to a shock paired CS+ is correlated with amygdala activation to the CS+.

Extinction of the CS+ (presentation without shock) results in a decline in the CR.

Extinction learning was correlated with activation of the VMPFC in response to the CS+.

Shock Ps in scanner

GSR – tone = think shock will happen – fingers sweat

Magnitude of conditioned response in GSR to CS predicted by level to which amygdala activated by tone

Present tone but no shock – activation of VMPFC correlates with success which show extinction – ability to unlearn conditioned emotional response – how much VMPFC activated by CS

see notes

14

amygdala-VMPFC (OFC) - Schoenbaum et al. (2007)

VMPFC and orbitofrontal cortex (OFC) can be used interchangeably.

The role of the frontal cortex in extinction learning could be due to it exerting inhibitory control over the amygdala, it may be quicker at adapting to changes in contingency and override the amygdala (faster at learning), or it may encode the expected outcome to-be-compared with the actual outcome to generate a prediction error signal, i.e. when expectations are defied, which drives teaching signals (DA and 5HT) to modify associative learning in the amygdala.

Evidence supports the latter position.

Inhibit amygdala – old model of how brain works

see notes

15

anger and aggression - Manuck et al. (1998)

Human aggression and impulsivity are associated with reduced 5-HT (serotonin).

This association has been found in assault, arson, murder, child beating, personality disordered patients, alcoholics, adolescents with disruptive behavior disorders and a history of fire setting and unpremeditated homicide among incarcerated adult offenders.

Aggressive acts are species specific

see notes

16

anger and aggression

In primates, low levels of serotonin are prospective risk factor for being dead at time 2 (presumably due to aggressive/risky behaviour)

see notes

17

anger and aggression - Hornak et al. (2004)

How to connect VMPFC (OFC) and 5-HT in a theory of aggression.

Humans with bilateral lesions to the OFC cannot switch choice when it ceases to payoff, showing perseveration in a reversal task.

Fits with the view that the OFC encodes the expected outcome, to be compared to the actual outcome, to generate a prediction error signal which modifies learning.

Touch screen

Diff images – one more like to get paid money and other more likely to lose money

Learn to press correct images

Then reverse contingency

Should see dip and realise losses and switch strategy

Bilateral damage to OFC – learn initial correct start – but don’t change strat – perseveration

Losing more than should – drives teaching strat

see notes

18

anger and aggression - Schoenbaum et al. (2007)

In Schoenbaum’s model, the discrepancy between the expected and actual outcome is calculated by the dopamine and 5-HT neurotransmitter systems, to modify learning.

Low 5-HT would weaken this learning.

Low 5-HT may produce aggression and impulsivity because such individuals fail to learn to modify their aggressive behaviour when it produces no payoff.

Haven’t got outflow from prediction error – stuck with aggressive pattern of behav

19

laterality of emotions

The right hemisphere appears to play a more important role than left hemisphere in recognition of emotion.

Borod et al. (1998) found that patients with right hemisphere damage were less able to identify emotional faces or words than patients with left hemisphere damage. Left damage was the same as controls.

Not switched off from doing task as can still discriminate

see notes

Adolphs et al. (2000) tested the ability of 108 patient with focal brain damage to recognize emotional faces.

The heat map shows that poorer recognition of emotional facial expressions was correlated with damage to somatosensory cortex of the right but not left hemisphere.

20

mirror neuron hyp

neurons in the somatosensory cortex which respond to the person producing particular facial expressions also respond to someone else producing those same facial expressions.

Shows that the right somatosensory strip is activated by the concept of an emotional expression, irrespective of its source

see slides

Neurons controlling emotional recognition and expression are linked.

Supported by automatic mimicry of facial expressions by infants.

Babies cannot see their own face in a mirror, so how do they know that their expression corresponds with their mother’s? – only has sensory feedback from face to tell them what they’re doing

Neurons for recognition must be connected to neurons controlling expression.

Hardwired link between somatosensory and motor cortex?

21

Mirror neuron hyp - Sackeim et al. (1978)

If the right controls emotion recognition, and is linked to expression in the motor strip, then the left face should be more expressive.

Chimerical faces – faces stitched together from left side (controlled by the right) are judged as more expressive.

Suggests the concept of emotions in the right cortex is the primary driver of facial emotional expressions