Week 10: Semantic Memory

Question 1

What is episodic memory?

Answer 1

Memory for experienced events, defined in terms of spatio-temporal relations

Question 2

What is semantic memory?

Answer 2

Memory for general knowledge, defined in terms of conceptual relations

Question 3

Who distinguished between episodic and semantic memory?

Answer 3

Endel Tulving

Question 4

How is retrieval different for episodic and semantic memory?

Answer 4

Episodic memory retrieval is experienced as remembering an event whereas semantic memory is experienced as knowing

Question 5

Name two paradigms used to study episodic memory

Answer 5

List learning paradigms (recall and recognition) and autobiographical memory paradigms

Question 6

What are three tasks used to study semantic memory?

Answer 6

Lexical decision task, naming task and sentence verification

Question 7

What do the earliest spreading activation models describe?

Answer 7

Words are nodes in a network, with connections representing their relations; activation spreads through the network when a word is presented

Question 8

What is a key limitation of spreading activation models?

Answer 8

They provide a network structure but lack a sense of the dynamics of the network, such as how long activation lasts or decays

Question 9

How can priming effects be observed in both episodic and semantic memory?

Answer 9

By studying pairs of words (e.g. CUP-KING) and observing priming during recognition memory experiments or lexical decision tasks

Question 10

What is the main revision in the compound cue model compared to the SAM model?

Answer 10

Multiple cues can be held in short term memory and used for recognition memory, such as using both the present word and the word from the previous trial

Question 11

How is retrieval in recognition memory explained in the context of SAM?

Answer 11

It involves a global similarity computation where context and item associations are multiplied together to determine overall similarity

Question 12

According to distributional models, how is the meaning of a word learned?

Answer 12

Based on patterns of word usage and co-occurence, typically defined within documents

Question 13

What is a major problem with learning word meaning through co-occurence?

Answer 13

Synonyms rarely co-occur in natural language, leading to high similarity between associates but not between synonyms

Question 14

What technique does Latent Semantic Analysis (LSA) use to extract relationships between words?

Answer 14

Singular Value Decomposition (SVD) and dimension reduction

Question 15

What is a key success of LSA when applied to the Test of English as a Foreign Language (TOEFL)?

Answer 15

LSA scored about 64% on exam, comparable to second language English speakers

Question 16

What are the two types of representations learned by the BEAGLE model?

Answer 16

Item vectors and order vectors

Question 17

How does BEAGLE handle word order to understand grammatical class?

Answer 17

It learns that verbs tend to be flanked by nouns, and adjectives tend to be followed by nouns

Question 18

How does word2vec differ from LSA in its training process?

Answer 18

Word2vec uses prediction in learning and prevents overlearning through negative sampling (adjusts weight only if prediction error)

Question 19

How can semantic memory representations augment episodic memory models?

Answer 19

By helping understand false memory or effects of categorised word lists

Question 20

What is an example of how episodic memory models can produce semantic representations?

Answer 20

The instance theory of semantics shows that episodic memory models can be scaled up to natural language to construct semantic representations based on context

Question 21

What is a key difference between retrieval-based and non-retrieval-based models of semantics?

Answer 21

Retrieval based models construct semantic representations as needed, whereas non-retrieval based models like LSA,BEAGLE and Word2vec learn static representations

Question 22

What might semantic memory be according to recent research?

Answer 22

A collection of episodes rather than a separate system from episodic memory

Question 23

What is the semantic contiguity effect?

Answer 23

The finding that in free recall, participants tend to follow a just recalled item with and item that is semantically similar (eg dog would often be followed by cat)

Question 24

What are some criticisms of LSA?

Answer 24

LSA lacks word order, lacks iterative learning, and confounds associative and semantic similarity