6C - Episodic And Semantic Memory

Question 1

Retrieval

Answer 1

Process of accessing information that has been stored in LTM and bringing it into our conscious awareness in STM
Episodic - hippocampus aids in retrieval
Semantic - frontal and temporal lobes aids in retrieval
both ↓↓↓
Autobiographical Events - personally lived experiences

Question 2

Reconstruction

Answer 2

The combining of stored information with other available information to form a more coherent, complete, accurate memory

Question 3

Possible Imagined Futures

Answer 3

Hypothetical experiences and situation that an individual has the ability to create and conceptualise in their mind

Brain regions that are involved in the retrieval of autobiographical memories are also activated when people construct possible futures

This is because when individuals attempt to mentally construct a possible imagined future, they draw on elements of past experiences from their semantic and episodic memory

Question 4

Possible Imagined Futures - Episodic

Answer 4

allows individuals to construct a possible imagined future that is subjective and includes more richly detailed elements such as the people involved or emotional reactions

Question 5

Possible Imagined Futures - Semantic

Answer 5

allows individuals to envision possible scenarios that are consistent and fit in with what they already know about the world

Question 6

Neurodegenerative Disease

Answer 6

are characterised by progressive loss of neurons in the brain

Question 7

Types Of Neurodegenerative Diseases

Answer 7

• Parkinson’s Disease
• Motor Neuron Disease
• Huntington’s Disease
• Alzheimer’s Disease

Question 8

Alzheimer’s Disease

Answer 8

damages the brain, resulting in impaired memory, thinking and behaviour

• Alzheimer’s occurs mostly in old age
• the biggest risk for having Alzheimer’s disease is increasing age, with three in ten people over 85 having dementia
• Sporadic Alzheimer’s disease can affect anyone of any age
• Familial Alzheimer’s disease is a very rare genetic condition, with an age of onset of less than 65 years

Question 9

Alzheimer’s Disease What Happens

Answer 9

1 - It begins with neuron death in the hippocampus
2 - Neuron death spreads to the cerebral cortex
3 - It affects previously stored LTMs and the processing of new STMs

Neuron death means that the overall mass of the brain reduces in size

Question 10

Other Symptoms Of Alzheimer’s

Answer 10

• cognitive functions impaired
• moods and emotions
• confusion and disorientation
• language difficulties

Question 11

How Does Alzheimer’s Affect The Brain?

Answer 11

A conclusive diagnosis of Alzheimer’s disease can only be made through a post-mortem examination

Lesions - areas of tissue that have been damaged due to disease or injury can be examined through neuroimaging and post-mortem studies

Lesions are predominantly identified in the hippocampus.
↳ Amyloid plaques
↳ Neurofibrillary tangles

Question 12

Amyloid Plaques

Answer 12

• fragments of the protein beta-amyloid accumulate into insoluble
  plaques around the neurons, inhibiting communication between neurons
• these form on the OUTSIDE of neurons, stopping communication

Question 13

Neurofibrillary Tangles

Answer 13

• proteins form into insoluble tangles within neurons, inhibiting the transport of essential substances throughout the neuron and eventually killing it entirely.
• these form on the INSIDE of the neurons

Question 14

How Does Alzheimer’s Disease Affect Episodic And Semantic Memories?

Answer 14

Hippocampus-
- first structure to atrophy
- new explicit memories cannot be encoded or consolidated
Anterograde amnesia

Cerebal Cortex-
- loss of neurons spreads to the cerebral cortex
- loss of stored explicit (including episodic, semantic and autobiographical) LTM
- Retrograde amnesia

When autobiographical memories are lost, the person also loses their capacity for episodic future thinking

Question 15

Aphantasia

Answer 15

A phenomenon in which individuals lack the capacity to generate mental imagery

Question 16

Mental Imagery

Answer 16

refers to the visual representations and experiences of sensory information without the presence of sensory stimuli

Mental imagery can vary in details and vividness, however those with aphantasia describe themselves as not having the power to generate mental imagery altogether

Question 17

How People Retrieve Mental Imagery - Encoding

Answer 17

When creating mental imagery individuals use sensory information that has been organised in STM and then transferred to LTM to recreate perceptual experiences

Question 18

How People Retrieve Mental Imagery - Storage

Answer 18

The sensory information can be stored in both our semantic and episodic memories

Question 19

How People Retrieve Mental Imagery - Retrieval

Answer 19

People without aphantasia = likely to draw on both episodic and semantic memory

Question 20

Autobiographical Events And Aphantasia

Answer 20

Research shows that people with aphantasia struggle to retrieve autobiographical events and construct possible imagined futures

It is difficult to retrieve personally lived experiences as they cannot generate vivid, detailed mental imagery of past autobiographical events from their LTM

This makes it difficult to construct possible imagined futures

Although people with aphantasia are still able to apply non-visual components of autobiographical memories to future events, their lack of mental imagery makes this process more difficult and less vivid than those without the condition

Question 21

Similarities Between Alzheimer’s And Aphantasia

Answer 21

Both impact the individual’s ability to construct possible imagined futures and reconstruct autobiographical memories

Both can occur due to injury. Injury increases the chances of acquiring both

Both seem to have a neurological basis (hippocampus damage and visual regions in the brain are less active based on neuroimaging studies)

Both impair memory of new information

Question 22

Differences Between Alzheimer’s And Aphantasia

Answer 22

Aphantasia is not a neurodegenerative disease, whereas Alzheimer’s is the result of gradual and ongoing atrophy to the brain regions e.g. hippocampus

Aphantasia is congenital (present from birth) or acquired from injury. Visual areas may be underactive. It is a variation of normal experience and does not progress or worsening over time

Alzheimer’s can result in death however aphantasia does not (it is simply a variable of the norm)

Aphantasia does not affect social skills or personality as much as Alzheimer’s.

Alzheimer’s results from hippocampus damage (and then atrophy of the cerebral cortex), whereas Aphantasia results from underactive neo-cortical regions (occipital lobes)