Lecture 2: Episodic and Semantic Memory Flashcards
What is episodic memory?
Specific events located at a specific point in time. “Mental time travel”
What is semantic memory?
Memory for facts.
Short delay: information is recalled in episodes
Long delay: the same information is integrated into semantic memory
How are the memory systems different?
Functionally, different types of information and different experiences
Is there neurophysical evidence?
Spiers, Maguire, and Burgess (2001) -> 147 cases of amnesia ; substantial or even dramatic loss of episodic memory ; semantic memory effects more and more variable and generally smaller.
Damage to hippocampus & MTL affects episodic memory
BUT, hippocampal amnesia may affect acquisition of new semantic memories more than retrieval of old ones (Clark & Maguire, 2016)
What are Semantic Dementia patients?
Severe loss of concept knowledge but intact episodic memory (and intact cognitive abilities). Damaged anterior frontal and anterior temporal lobes.
What is Bartlett’s Approach to meaning and schema’s?
- Recall of complex materials (e.g., drawings and folk tales)
- Examined recall errors
- Unlike Ebbinghaus, he stressed participants’ effort after meaning.
What is a schema?
Structured representation of knowledge about the world, events, people or actions. - used to make sense of new material, to store and later recall them. - influenced/determined by social and cultural factors.
What is “The War of the Ghosts”?
> Native American folk tales
People committed many errors and distortions when they asked to recall these
In their recall, made the story more coherent and omitted details
Recalled stories were more “Westernised”
Sulin and Dooling 1974 conducted a study concerning schematic knowledge, what did it do?
Ppts were told a story about dictator, either an unknown one or Hitler.
Test sentence: “He hated the Jews…”
Short delay (5 mins): No difference between the groups
Long delay (1 week): ppts who read about Hitler were more likely to incorrectly agree.
Concluded that schematic knowledge may affect memory especially at longer intervals.
What is the role of meaning?
It is ascribing meaning to stimuli affects encoding and storage.
What did Jenkins and Russell, 1952 conclude?
Related words within lists tend to be recalled as a cluster/together.
When is memory practice guided by meaning?
When ppts are given the opportunity to organise information in a meaningful way.
What is Paivio’s dual-coding hypothesis?
More imageable words are more memorable.
What is Transfer-Appropriate Processing?
Memory retrieval is best when the cues available at testing are similar to those available at encoding.
Why is deeper coding better?
Craik and Tulving, 1975 - richer and more elaborate encoding leads to better memory
What is hierarchical organization?
Proposed by Bower et al., 1969 - recall is better when words are organized than presented when in scrambled order
When are items chunked together?
- When they are linked to a common associate
- When they come from the same semantic category
- When they form a logical hierarchical structure or matrix
What factors aid encoding?
- Creating connections, in the form or imagery and meaning
- Organisation - recall by groups; present in an organised way
- LOP/TAP - deeper processing; similar encoding - retrieval procedures
- Active creation - generate/test
What is the Hierarchical Network Model?
Semantic memory is organized into a series of hierarchical networks.
What is cognitive economy?
Properties are stored higher up to minimise redundancy
Is there support for the hierarchical network model, if so, what is there?
> Sentence verification task - “Decide as quickly as possible whether sentences are true or false”.
Unless the information is directly linked/stored with a concept of semantic memory, we infer the answer from properties of higher nodes
Making more inferences slows verification
Are there any problems with the hierarchical model?
- Familiarity, in the sentence verification example, “a canary has skin” is not a familiar sentence. when controlled, hierarchical distance effect is reduced
- Typicality - verification is faster for more representative member categories, independent of hierarchical/semantic distances
What is the Spreading Activation Model?
Proposed by Collins & Loftus, 1975. Semantic memory is organised by semantic relatedness/distance. The length of links indicates the degree of semantic relatedness. Activity at one node causes activation at other nodes via links.
Is there any support for the Spreading Activation Model?
Yes, the semantic priming task, when presenting one stimulus that is semantically related makes subsequent processing more efficient (e.g., faster).
