Lecture 8 Flashcards
1
Q
Structure of LTM
A
- Non declarative (implicit):
- -> Unconscious
- -> Procedural knowledge
- -> Priming and conditioning
- -> Processed in bottom-up
- Declarative (explicit):
- -> Semantic
- -> Episodic
- -> Processed in top-down
2
Q
Evidence for structure of LTM
A
- Amnesia patients
- Lesions of rats
- Memory disturbance related to size of injury rather than location
- HM
- Motorbike accident
- Epileptic seizures after accident
- Got rid of his bilateral medial temporal lobe
- After surgery had no declarative memory but non-declarative memory in tact
- Memory for new personal events impaired
- Memory for new skills and STM in tact
3
Q
Skills considered normal in amnesic patients
A
Tower of Hanoi:
- Tower on stick –> start with larger stick and place smaller ones on top
- Only set number of moves
- HM = forgot he had done it before but got better at the task the more times he did it = non-declarative intact
Mirror reading:
- Read text back to front in mirror
- HM didn’t know he had done task before but got better at it over time
4
Q
Neural circuit for explicit memory
A
Prime structures for explicit memory:
- Medial temporal region
- -> Hippocampus
- -> Amygdala
- -> Entorhinal cortex
- -> Parahippocampal cortex
- -> Perirhinal cortex
- Frontal cortex (dorsolateral and ventrolateral)
5
Q
Disconnecting implicit memory
A
- Double dissociation –> implicit and explicit memories independent
- Patient JK:
- -> Impaired implicit but intact explicit
- -> Developed Parkinsons –> damage to basal ganglia
- Couldn’t perform tasks he had done all his life but could recall events
6
Q
Implicit memory neural circuits
A
- Basal ganglia
- Ventral thalamus
- Substantia nigra
- Premotor cortex
7
Q
Semantic dementia
A
- Impaired semantic memory
- Degeneration of anterior temporal lobe
Study:
- Ppts had to produce factual info from 3 life stages
- Number of semantic memories was poor
- Episodic intact
8
Q
Impaired episodic memory
A
- KC
- Lesion from motorcycle accident
- Couldn’t produce episodic events but semantic intact
9
Q
Conditioning
A
- Type of implicit
- Skinner trained pigeons peck at moving dot under glass
10
Q
Priming
A
- Processing a stimulus is influenced by prior experience
- Initial response to a stimulus
- Priming effect in brain called repetition suppression effect
11
Q
Theories of forgetting
A
- Decay = fading of memory trace
- Interferences = memory trace disrupted or changed by other material
12
Q
Study for interference
A
- Put cockroaches in cage with electrical field
- Learnt they would be shocked in a corner, so learnt to avoid it
- Then split into 2 groups
- 1 group put into cone so couldn’t move
- Group 2 left free in cage
- Found when group 1 put back in cage, they avoided the corner but the group that were left free ran into it as forgot
13
Q
Consolidation of memories
A
2 stages:
- Temporary storage in hippocampus = not sufficient to consolidate memories but can make memory trace
- Then transfers to cortex
14
Q
Anterograde and retrograde amnesia
A
- EP –> no new memories after viral infection (AA) and for short period before infection (RA)
- Retrograde period due to problem with consolidation
- Memories can’t be established in the cortex
15
Q
Consolidation and sleep
A
- Healthy people studied
- Had to recall nonsense syllables
- 1 group slept after encoding and the other didn’t
- On recall sleep group outperformed non-sleeping pmts
- For declarative and non declarative memories
