Karteikarten
Semantic Memory
Karten in diesem Stapel (48)
- 1semantic memory (meaning of things)* Declarative memory
* general knowledge
*conceptual knowledge
*knowledge of objects, word meanings, facts and people
*not linked to place and time
*knowing what toast is - 2Episodic memory (episode, first second, here, there)*recollection of events in time and space
*memory of events in specific temporal and spatial context
*Knowing what you had for breakfast - 3* semantic or episodic? dogs have fur and four legssemantic
- 4semantic or episodic? I got a bath robe for my birthdayepisodic
- 5Long term memory division*declarative memory
*procedural memory - 6Declarative memory (declare.. state)* Factual information
*verbal - 7Procedural memory*actions
*proceedures
*how to ride a bike - 8Division of Declarative memory*semantic
* episodic - 9semantic memory impairment*can't comprehend pictures, meaning of words
*can't express ideas - 10Sentence verification Task (what is?)*early experiment for developing theories of semantic memory organisation
- 11Sentence verification Task (How is it?)* subjects are asked if a sentence is true or false
8Reaction time measured - 12Sentence verification Task (types of sentences)* subject - predicate
the canary is a bird
*subject - bird
* predicate _ rest of sentence_ is a bird - 13Sentence verification Task set inclusionCanary
* is a ........ bird (true)
*is a........whale (false) - 14Sentence verification Task Property attributioncanary
* has a .... wing (true)
*has a....fin (fasle)
* features of the subject - 15Network Models* old modles to explain semantic memory
*use nodes for concepts___ canary___ bird____ sing
*relationships between nodes (concepts) linked by isa or has links
*canary to bird isa link (set inclusion)
canary to sing has link (property atribution) - 16Heirarchial Network Model*Collins & Quillian 1969
* concepts organised in heirarchy
*animal> bird > canary - 17Heirarchial Network Model Cognitive economy* thought that property attribution concepts (has) stored only at top level
*can move, breathe stored at animal node level not bird node or canary node level
*has wings stored at bird node level not canary node level - 18Heirarchial Network Model predictions* that if the subject and predicate nodes are closer in hierarchy than verification (saying if true or false is quicker)
* canary is a bird is quicker to verify that canary can breathe
* experiments showed this - 19Heirarchial Network Model Problems*Conrad (1972) challenged cognitive economy
* said that verification speed can be explained by the frequency of co occurrence of concepts not how far up the hierarchy you have to go
* peacock has feathers verified much faster than canary has feathers
*because we associate feathers with peacocks more frequently than with canaries - 20Heirarchial Network Model Problems* RT reaction time not always mirroring hierarachy
* dog is an animal (2 levels) verified faster that dog is a mammal (1 level)
* RT on same level has different times
* canary is a bird faster than ostrich is a bird - 21Heirarchial Network Model Problems with negative concepts* RTs not faster for false sentences where concepts close
* actually slower
* canary is an ostrich is slower that canary is a salmon - 22Spreading Activation Model* Collins & Loftus (1975)
* concepts organised non hierarchical
* links vary in associative strength
* this explained problems with the hierarchical model
*did not explain the RTs for negative sentences - 23Spreading Activation Model predictsSemantic priming effect
- 24Semantic priming effect* response to a word is faster if a semantically related word is before it
* so if asked if truck is a word and this has come after car response is faster than if it came after flower
* because the car would have already stimulated the truck node - 25Semantic Priming Efeect used to study* organisation of semantic memory
* automaticity ----Unconscious processing - 26Feature comparison Model* explains how knowledge can be retrieve even if some of it is in accurate
* e.g. actor from pirates of carribean who smuggled cats into australia
* even though it was dogs we can still retrieve jonny depp - 27Feature comparison Model assumes* Knowledge not represented by a node with links
* represented by distributed features in a semantic space
* so bird with all features related to the bird is stored together - 28Feature comparison Model decision making*Two stage decision
*Similarity of features of subject and predicate compared
*Canary (subject) is a bird (predicate)
*explained the sentence verification experiment - 29Feature comparison Model Feature types*defining features
*Characteristic features - 30Feature comparison Model Defining features* essential features
* bird has beak, wings, feathers - 31Feature Comparison Model Characteristic features* less important features
*bird can fly, build nests - 32Feature comparison Model two stage decision process First*Compare all features of subject and predicate for over all similarity
*canary is bird high similarity quick response
*canary is a fruit low similarity quick response - 33Feature comparison Model two stage decision process second* compare defining features when not strong or low similarity
* ostrich is a bat
*Ostrich is a bird - 34Feature comparison Model problems*not clear what was a defining feature and what was a characteristic
* if sparrow lost its wings is it still a sparrow? - 35Historical models of semantic memory organisation 3*Hierarchal network model
*Spreading activation Model
*Feature comparison model - 36Sentence verification experiment problems*data explained by more than one model
*is data showing structure of memory or process of memory
*Stimulus is recognition of words/ is that same as recognition of objects? - 37Neuropsychological studies of impairment in semantic memory*Show selective impairment of categories
*selective impairment of living things with intact knowledge of non living things especially tools like kitchen utensils
* and Category specific impairment
*knowledge of body parts with impairment of living things
*knowledge of non living things with impairment of knowledge of musical instruments - 38JBR case study*1984 warrington and shall ice
*impaired knowledge of living things
*specifc category impairment of musical instruments - 39JBR case study theories to explain*Perceptual functional theory (1984 warrington and shall ice)
leading to
*Distributed plus hub (hub and Spokes) Theory Patterson et al 2007 - 40Perceptual Functional Theory*impairments reflect different types of property
*Living things distinguished by perceptual (mostly visual) properties. lion tiger leopard----plain , striped , spotted
* non living distinguished by functional properties hammer, wrench, screwdriver----different actions - 41Perceptual Functional Theory explains*common impairments with living things as visual properties more frequent
*category specific impairments e.g. musical instruments as these distinguished by visual properties - 42Perceptual Functional Theory problems*Patients don't show just perceptual or functional knowledge
*some knowledge are neither perceptual or functional
* can't decide if a kangaroo is australain native through perceptual or functional knowledge. you need conceptual knowledge - 43Distributed- plus - hub- theory*Hub for each concept e.g. a camel, a pumpkin
and
*disributed modality specific information (that is functional info, visual info, sound how it feels)that is shared between the hubs like colour - 44Distributed- plus - hub- theory predicts*item specific deficit
and
*modality specific deficit - 45Distributed- plus - hub- theory Patterns*preserved knowledge of category as whole e.g. vegetables
*impaired in item specific information
* shown a green pumpkin vs a orange pumpkin, green lettuce and orange lettuce
Impaired patients choose the green pumpkin and green celery because green is the typical colour feature of vegetables
* lost the concept of pumpkin but not vegetable - 46Distributed- plus - hub- theory shown pictures to draw from memory* generalise the duck and draw general animal features
Camle looses the hump
* so remember distributed features but loose specific features - 47Why do we have Hubs?* efficient way of integrating information
*Makes it easier to detect semantic similarity in concepts that differ greatly in modality specific concepts
scallops and prawns look very different but are similar for seafood eating humans like cow and sheep - 48Where are hubs stored*ATL
Anterior Temporal lobes
Degeneration in this part of brain seen in semantic dementia patients
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- Karteikarten am Semantic Memory, erstellt von Vicki Hanna am 05/05/2016.
- Erstellt von
- Vicki Hanna
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