Week B1 Memory & Sleep I Flashcards

1
Q

Types of Memory (list)

A
Working
STM
Semantic
Episodic
Motor Sequencing
Emotional Learning
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2
Q

Primary Brain Areas for Each Type of Memory

A

Working = Prefrontal cortex - controlling other cortical regions

STM = Hippocampus - Forming associations across cortical activity

Episodic = Temporal Lobe - associating other regions

Semantic = Connectional structure of the Whole Cortex

Motor Sequencing = Striatum, Cerebellum & Pre-motor cortex

Emotional Learning = Amygdala, Cingulate, Hippocampus, Reward Systems

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3
Q

Description: Working Memory

A

To do with attention -> sustained mental representations, associated with focus on a task - “holding it in working memory”

A type of ‘controlled’ mental attention - attention is paid to a certain or certain stimuli, whilst disregarding other stimuli

This can only be maintained will we need to process other inputs

(Prefrontal cortex)

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4
Q

Description: STM

A

Orientation, sequence of the day and sequence of activity

Forms temporary linkages between different areas of the cortex, indexing the days events

STM become lasting (LTM) if relevant enough. EMotional responses from the anygdala can attribute salience to STM in this way*

(Hippocampus)

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5
Q

Description: Semantic

A

Facts - ‘general’ knowledge about the world, not related to a time-frame

(Connectional structure of Whole cortex)

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6
Q

Description: Episodic

A

Long-term recollection of specific times and event sequences

LTM of this type requires that the associations/linkages between areas of the cortex endure - requiring alterations to the cortex

*

(Temporal)

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7
Q

Description: Motor Sequencing

A

Learned patterns of movement, enabling smooth movements and sequencing

(Striatum, Cerebellum and Pre-motor cortex)

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8
Q

Description: Emotional Learning

A

Emotional responses associated with people, places, things, etc.

(Amygdala, Cingulate, Hippocampus and Reward Systems)

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9
Q

How do the different areas of the brain, and sleep, interact to form memories (long term, and semantic ‘knowledge’)

A

Working memory (prefrontal cortex) sends flow of information to the Hippocampus, which organises indexing of the days events. The Amygdala feeds emotional associations into the hippocampus as these events are being indeed. During REM (slow-wave) sleep, information is send to the Tempotal Lobe for longder-term ndexing and formation of associations. With ongoing time and familiarity, ‘knowledge’ separates somewhat from ‘time-based memory’, and becomes associated with the ‘whole cortex’ -> this ‘knowledge’ can be accessed without need for temporal indexing.

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10
Q

How are LTMs formed?

A

Temporal Lobe

Formation of enduring associational links between different cortical regions -> because long term, requires alterations to the cortex

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11
Q

Describe the act of remembering, in basics?

A

The act of remembering involves reconstructing the activity in parts of the cortex that originally processed the experience

*Note: memories can be altered by subsequent experiences

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12
Q

What is sleep?

A

Daily loss of consciousness.
Reversible state of reduced/loss of responses to the environment and percentual disengagement.
A complex mixture of physiological and behavioural processes.

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13
Q

How is the activity level of the cortex modulated?

A

Kept active by arousal from thalamus

And from modulatory neurotransmitter systems in the brainstem - ascending arousal systems

Multiple nuclei in the brainstem and midbrain modulate cortex activity during the day

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14
Q

How do we observe sleep?

A

EEG: electro-encephalogram

EOG: electro-oculargram

EMY: electro-myogram

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15
Q

What does EEG measure?

Categorizations?

A

Electric impulses along the scalp
-> arising from voltage flactuations resulting from ionic current flows through neurons

Categorized into ‘desynchronized’ (associated with wakefulness and REM sleep) and ‘synchronised’ (associated with non-REM sleep)

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16
Q

What does EOG measure?

A

Eye movements (not in response to visual stimuli)

17
Q

What does EMG measure?

A

Electrical activity produced by skeletal muscles

18
Q

What are the types of EEG rhythms, and what stages of sleep/waking are each associated with?

A

Awake:
Alert = Beta
Drowsy = Alpha

Sleeping:
Non-REM stage 1 = Theta
Non-REM stage 2 = Theta with sleep spindles and K-complexes

Non-REM stage 3-4 = Delta waves (increasing)

REM sleep = Beta with sawtooth pattern

19
Q

Describe Alpha Waves:

A

Frequency= 8-13 Hz
Amplitude shifts up and down, repsresenting transient relaxations during waking

(Awake but drowsy)

20
Q

Describe Theta Waves:

A

The most common wave form described during sleep

Lower frequency= 3-7 Hz

Most prominent in Vertex (upper surface of the head) region

No particular amplitude requirements

NREM stage 1-2

21
Q

Describe Delta Waves:

A

“Slow waves” at very low frequency: 0.5-2 Hz

High amplitude: at least ~75um

Occur independently in local regions.

Propagate from the Cortex to Hippocampus

NREM stage 3-4

22
Q

What is ‘sensory gating’?

A

Bursts of activity between the Cortex and Thalamus

Visualized on EEG as ‘Spindles’ usually seen amongst Theta Waves during NREM stage 2

23
Q

Describe Spindles

A

Short oscillations 12-14 Hz

Ranging from 0.5-3 seconds, 6-7 cycles

Represent bursts of activity between the Cortex and Thalamus

Localized in small regions - thus represent Desynchrony

Occur amongst Theta Waves of NREM stage 2

24
Q

Describe K Complexes:

A

Slow, sharp waves

Steep negative then positive wave form

Indicitive of NREM stage 2

No amplitude criteria

Predominantly central-vertex in origin

Occur with or without stimulation

Also thought to be associated with sensory gating

25
Q

Effect of opening/closing eyes whilst awake on EEG?

A

Shifts from Alpha Waves to Beta Waves

26
Q

Features of ‘Awake But Drowsy’ on EEG, EOG and EMG:

A

EEG: >50% of each Epoch is Alpha Waves

EOG: Slow rolling eye movements, slow blinking

EMG: Relatively high submental muscular tone

27
Q

Features of NREM Stage 1 on EEG, EOG and EMG:

A

EOG: Slow, rolling eye movements

EEG: Theta waves = 50% or more of the epoch, Alpha waves accounting for <50%

EMG: Relatively high submental muscular tone

28
Q

Features of NREM Stage 2 on EEG, EOG and EMG:

A

EOG: Eyes are still, so EOG picks up EEG

EEG: Mostly Theta Waves. Spindles and K-Complexes occur episodically.

EMG: Relatively high sibmental muscular tone

29
Q

Features of NREM Stage 3 on EEG, EOG and EMG:

A

EOG: Eyes still, so EOG picks up EEG

EEG: 20-50% of each epoch is Delta

EMG: Slightly reduced submental muscular tone

30
Q

Features of NREM Stage 4 on EEG, EOG and EMG:

A

Not distinct from N3:

EOG: Eyes still, EOG reflects EEG

EEG: 20-50% Delta

EMG: Slightly reduced submental muscular tone

31
Q

Features of REM sleep on EOG, EEG and EMG:

A

EOG: Rapid eye movements, as if watching a scene

EEG: Mixed frequencies, including Beta (like waking state)

EMG: Submental tone nearly absent