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Flashcards in Problem 5 Deck (46)
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1
Q

Emotions

A

Refer to cognitive + behavioral responses that are largely

a) automatic
b) unconscious

–> triggered when the brain detects a positively/negatively charged significant stimulus

2
Q

Regulatory mechanisms of emotions are mostly mediated by … ?

A
  1. Amygdala
  2. Striatum
  3. Hypothalamus
  4. Brain stem
3
Q

Feelings

A

Refer to the conscious perceptions of emotional states

4
Q

Emotionally competent stimuli

A

Refer to Stimuli that are naturally significant to trigger emotions

–> other objects/events acquire their significance through association with those

5
Q

In which way can be said that the responses of autonomic NS are specific ?

A

There are different patterns of ANS activity that correspond to different situations + their associated emotional states

6
Q

How is the neural activity relayed ?

A
  1. Forebrain
  2. Hypothalamus
  3. ARAS
7
Q

James peripheral feedback theory

A

Suggests that feelings come about when the bodily expression of that emotional response enters consciousness

–> only involvement of the cortex, but later re-movement of it showed that you can still feel emotions

8
Q

Cannon + bards central theory of emotions

A

Suggests that sensory info is processed in the thalamus

  1. Sent to
    a) hypothalamus
    - -> to produce emotional responses
    b) cerebral cortex
    - -> to produce conscious feelings
9
Q

Bard experiment

A

Involved cutting out cerebral hemispheres out of monkey, where a sham rage (rage with absence of aggressor) only occurred when the caudal hypothalamus was lesioned

  1. Hypothalamus is critical for coordination of somatic + visceral motor components of emotional behavior
  2. Subjective experience of emotion depends on the cortex, whereas the expression of coordinated behaviors doesn’t

=> Hypothalamus is responsible for the brains evaluation of the emotional significance of stimuli + reactions that depend on this appraisal

10
Q

Circuit of papez

A
  1. Hypothalamus
    - -> mammilary bodies
  2. Thalamus
    - -> anterior thalamic nuclei
  3. Cingulate cortex
    - -> here the signals are converged to produce feelings
  4. Hippocampus
    - -> parahippocampal Region
  5. Hypothalamus
11
Q

McLean later fond the “visceral brain” that was later renamed the limbic system

A

Included amygdala to the circuit + the subcortical regions that are connected to it

–> thought the hippocampus was the point of convergence

12
Q

Why did McLean think that emotional responses involved relatively primitive circuits ?

A

Because, he saw emotional responses as essential for survival

–> then realized that emotional states + cognitive processes involve distinct circuits that can functionally be relatively independent

13
Q

Klüver-Bucy syndrome

A

Refers to abnormal/non-emotional behavior seen in monkey after the removal of most of limbic system, then later just amygdala

–> no fear in response to aversive stimuli

14
Q

How was the Klüver-Bucy syndrome explained ?

A

Previously:
Circuit of papez was interrupted

Now:
Removal of amygdala is enough to elicit this

15
Q

LeDoux conducted conditioned fear experiments.

What were his main findings ?

A
  1. MGN in hypothalamus is necessary for the development of conditioned fear response
  2. Response is still there when connectivity to the auditory cortex was cut, so there had to be a direct pathway
  3. Amygdala establishes the association between neutral stimuli + stimuli with reinforcement value
    - -> LTP
16
Q

Neural circuit of fear conditioning

A
  1. Sensory input reaches lateral nucleus indirectly + directly
  2. Amygdala + cortex are activated simultaneously

–> so amygdala can process info before we can consciously feel it

17
Q

How are unconditioned (innate) fear responses processed in the brain ?

A

Are mediated by the olfactory system to the medial amygdala

–> relies on odors

18
Q

Name the input vs output source of the neural circuit of fear conditioning

A
  1. Lateral nucleus (input source)
    - -> receives info about CS from thalamus
  2. Central nucleus (output source)
    - -> project to hypothalamus
19
Q

Does simply telling about a CS or watching someone else, enough to elicit a subsequent fear response ?

A

Yes, as

  1. Amygdala is involved in implicit learning
  2. Hippocampus is involved in explicit learning
20
Q

Role of the orbital + medial frontal lobes

A

Associates info from the sensory modalities + integrates those

–> influence the content that was retrieved from memory to shape a mental response plan parallel to the amygdala

21
Q

The amygdala has additional varieties of connections to cortical areas to be able to modulate

a) attention
b) perception
c) memory
d) decision making

Name these connections.

A
  1. a) amygdala
    b) thalamus
    c) orbital + medial frontal lobes
  2. a) amygdala
    b) Basal ganglia
    - -> which receives info from the PFC

=> amygdala influences the selection + initiation of behaviors and obtains rewards vs avoids punishment

22
Q

Volitional movement

A

Involve the classical motor areas of the voluntary somatic motor control

–> cortex –> brainstem

23
Q

Emotional expression

A

Involves the descending projections from medial + ventral forebrain

  1. Termine on visceral motor centres in

a) reticular formation
b) somatic motor neuron pools
- -> also receive info from volitional centre

24
Q

Reticular formation

A

Receives info from + projects to

a) somatic
b) autonomic

effector systems in brainstem + spinal cord

25
Q

Forced smile

A

Involves the voluntary contraction of the facial muscles

–> pyramidal smile, driven by motor cortex which communicates with brain stem + spinal cord via pyramidal tract

26
Q

Spontaneous emotional smile/

Duchenne smile

A

Is motivated by the motor areas in the anterior cingulate gyrus

–> facial muscles are accessed via multi synaptic extrapyramidal pathways through the reticular formation

27
Q

What does the activation of the hypothalamus generate ?

A

Motivational states + their associated affects

–> eating, drinking

28
Q

Central patterns controllers

A

Are cell groups that generate motivational states

–> connect to the midbrain + spinal cord to control the generation of actual movement (primitive actions)

29
Q

Non-limbic system arousal

A

Is evoked by stimulating the ARAS in the brainstem

–> leads to arousal when we encounter novel/unexpected stimuli

BUT: Habituation with repeated exposure

30
Q

Limbic system arousal

A

Is evoked by increased motivation + strong negative/positive affect, by receiving input by visceral sensory structures

a) negative affect
- -> central grey area

b) positive affect
- -> VTA

BUT: resistant to habituation

31
Q

Name the structures of the limbic system.

A
  1. Cortex
  2. Limbic cortex
  3. Olfactory system
  4. Intermediate level
    - -> amygdala + hippocampus
  5. Hypothalamus
32
Q

The more an animal depends on learning to develop its full potential of meaningful behaviors, the more it is affected by a removal of the hypothalamic + forebrain regions.

Why is that ?

A

Forebrain is important in linking species typical action patterns

–> learning instinctive movements

33
Q

Memory subsystems

A
  1. EM division
    - -> circuit of papez
  2. Spatial memory/orientation division
    - -> parahippocampal circuit
34
Q

Emotional subsystem

A
  1. a) amygdala
    b) stia terminalis
    c) septal nuclei + pre-opic nucleus of hypothalamus
  2. Main output channel
  3. Nuclei are responsible for emotional expression
35
Q

Olfactory system

A

Includes the

  1. Primary olfactory cortex
  2. Amygdala
  3. Hippocampus

–> which are closely connected within the uncut

BUT: input of odors occurs via amygdala to categories objects/events

36
Q

Limbic cortex

A

Is the high end side, involved with the cortex + voluntary behavior

37
Q

Cortex

A

Includes the default mode network
–> affect related, has 2 subcortical networks

a) hippocampal-diencephalic circuit
b) Temporo-amygdala-orbitofrontal network

=> PCC + ACC are connected via the dorsal cingulum, are active during “resting state”

38
Q

Hippocampal-diencephalic circuit

A

Connects the memory subsystem via the cingulum with the PCC

–> PCC is first major medial hub of default mode network

39
Q

Temporo-amygdala-orbitofrontal network

A

Connects the amygdala via the orbitoinsular cortex with ACC

–> ACC is the second major hub of default mode network

AND: Integrates the visceral + emotional states with cognition + behavior

40
Q

Anxiety disorder

A

Stress response occurs when the central nucleus of amygdala is active

–> inappropriate response –> HPA-axis hyperactive –> degeneration of hippocampus

VICIOUS CYCLE

41
Q

Monoamine hypothesis

Affective disorder

A

Mood is tied to levels of released monoamines in the brain

–> depression results from a deficit on one of the diffuse modulatory systems

42
Q

Diathesis-stress hypothesis

A

Suggest that the HPA-axis is the main site of where genetic + environmental influences converge to cause mood disorders

43
Q

Diathesis

A

Having a predisposition for a certain disease

44
Q

What does the limbic lobe consist of ?

A

Parahippocampal region + cingulate gyrus

–> cingulum connects it (white matter)

45
Q

Where does hebbian learning take place ?

A

Lateral nucleus

–> US and CS converge on here

46
Q

What do lesions of the amygdala lead to ?

A

No implicit learning of US + CS, so no emotional learning and physiological learning

–> BUT: declarative memory of it