11 – Memory 6 – semantic vs episodic memory

Question 1

What are the three types of implicit memory?

Answer 1

1. Classical conditioning effects (e.g. conditioned emotional reactions)
2. Procedural memory (motor skills, habits, tacit rules)
3. Priming (implicit activation of concepts in long-term memory)

Question 2

What are the two types of explicit memory?

Answer 2

1. Episodic memory (one’s own experiences)

2. Semantic memory (facts, general knowledge)

Question 3

Tulving (2002) claims episodic memory is a ______ of semantic memory. It is
• Recently-________, late-________ and _____-deteriorating
• Probably unique to _______
• Requires “______ retrieval mode” -> conscious _________

Answer 3

Episodic memory a subsystem of semantic memory BUT
• Recently-evolved, late-developing and early-deteriorating
• Probably unique to humans
• Requires “episodic retrieval mode” -> conscious recollection

Question 4

What are three defining and distinguishing features of episodic memory?

Answer 4

– “mental time travel”
– “Autonoetic awareness” – knowledge of ourself in the event
– Linked to self; autobiographical

Question 5

What are two differing views of episodic memory?

Answer 5

1. Tulving (2002): episodic memory a “subsystem” of semantic memory.

Question 6

What do double dissociations show?

Answer 6

That two systems are completely dependent. You can remove the first without affecting the second; and remove the second without affecting the first.

Question 7

What are two pieces of neuropsychological evidence for dissociations between episodic and semantic memory?

Answer 7

1. Semantic dementia
   – Gradual deterioration in semantic memory while episodic memory remains intact.
2. Developmental amnesia
   – Early damage to hippocampus associated with selective impairment in episodic memory. People born with or suffer early damage.

Question 8

How does loss of information progress in semantic (fronto-temporal) dementia?

Answer 8

General properties and prototypical items preserved much better as disease progresses. Attributes typically shared by category members are attributed to items that are exceptions e.g. Say every bird is duck or chicken. A year later, all called bird. 6 months later, some called cats. 6 months later, all animals.

Episodic/autobiographical knowledge relatively preserved despite loss of semantic information

Question 9

What does way information is lost in semantic (fronto-temporal) dementia tell us about the PDP model?

Answer 9

It supports PDP. Suggests semantic system deteriorates from the more precise to the more general, consistent with predictions of PDP models.

Question 10

Abnormal brain function in Semantic Dementia is localised to ______ _____ ____. And more severe on ____ side.

Answer 10

Abnormal brain function in Semantic Dementia is localised to anterior temporal lobe. And more severe on left side.

Question 11

How do Alzheimer’s and semantic dementia provide a dissociation between episodic and semantic memory?

Answer 11

Performance in semantic tasks is more impaired in semantic dementia than Alzheimer’s disease. By contrast, Alzheimers disease associated with impairments in episodic memory.

Question 12

What are the two theories of how semantic knowledge is distributed in the brain?

Answer 12

1. Distributed-only view
   We don’t have a single place that captures all information about a concept. No single ‘dog’ node. Semantic knowledge is embodied in perceptual experience and stored within brain areas that code that particular knowledge. This implies that different tasks might preferentially make use of different types of information.
2. Distributed-plus-hub view
   Although there may be distributed information, there is a region that binds attributes of an object. All cues will first of all access task-independent conceptual representation which will then retrieve more specific attributes stored in specific areas that code that information.

Question 13

What kind of deficits are experienced by those with developmental amnesia (bilateral damage to hippocampus)?

Answer 13

• Impairments in episodic memory for everyday life, but can acquire semantic knowledge with repeated exposure in way that does not require hippocampus.
• Impairments on tests of recall, but not of recognition.

Question 14

In what way might semantic and episodic memory lie on a continuum?

Answer 14

Pure episodic memories are those that happened recently, while pure semantic memories could beevents that have been consolidated within distributed memory system. Autobiographical memories, like the first time you rode a bike, may have become very generic and semantic.

Question 15

What brain areas are involved in recovery and experience of an autobiographical memory?

Answer 15

Hippocampus is involved in recovery.

Visual cortex and other areas of the perceptual system are involved in experiencing the memory.

Question 16

What does the fact that episodic memory is preserved in semantic dementia suggest about the binding together of concepts needed for episodic memory?

Answer 16

That this binding process is independent of the network of semantic information distributed throughout the brain.

Question 17

What distinguishes true from false memories, neurologically?

Answer 17

True and false memories are distinguished by extent of perceptual detail: real memories show increased activation in early visual areas

Question 18

What aspects of memory does the computer metaphor fail to capture?

Answer 18

We do not preserve exact details of episodes: memory is reconstructive not reproductive.

Question 19

Constructive nature of episodic memory is adaptive for……

Answer 19

Constructive nature of episodic memory is adaptive for imagining and simulating the future.

Question 20

How does susceptibility to false memories vary over types of memory loss?

Answer 20

Alzheimer’s and amnesics are LESS susceptible to false memory than normals.

Question 21

Is there a special neural system that stores memories?

Answer 21

No. Memories are distributed throughout the brain.