Semantic Memory Flashcards
What does semantic memory refer to?
Sometimes our memories do not refer to specific events but are more encyclopedic. This general knowledge is semantic memory.
How does the effect of priming demonstrate a salient characteristic of the semantic memory?
A salient characteristic of semantic memory is its organized and regular structure. Remembering one concept brings related memories closer to awareness. This facilitation of related ideas is priming
How is semantic memory structured? i.e what is it based on
Semantic memory is structured based on shared aspects of meaning metaphorically stored closer together. Because they are more activated, if there is then a need to use them they are now closer to conscious awareness and can be used more readily.
What task are people typically given in a priming study?
A lexical decision task. That is, they are given strings of letters and asked to indicate whether they are words. In these studies, there are pairs of words: a critical item, called a prime, is followed by a target. What is of interest is how fast people respond to the target (such as by pressing a button).
How quickly is priming observed in ERP recordings? Why?
Priming is even observed in ERP recordings as early as 250 ms after the target word is presented. This is because it is easier for the brain to activate that information, so it doesn’t need to work as hard.
Functionally, why does semantic priming occur? (2)
Semantic priming occurs because concepts are not understood in isolation but in terms of how they relate to each other. By activating related concepts, people bring to bear a larger set of knowledge to help them understand and think.
Priming also helps people detect inconsistencies. When people encounter semantically anomalous information, such as hearing the sentence “the doctor listened with his carrot,” ERP recordings show an increased electrical negativity around 400 ms after first seeing it.
What is meant by mediated priming?
When retrieving the concept “lion” it is likely that the concept “tiger” is activated because these are both large, predatory cats. If “tiger” is primed, are concepts related to it also activated, such as “stripes”? This would be mediated priming because the connection between “lion” and “stripes” is mediated by “tiger.”
Does mediated priming actually occur when studied?
In general, mediated priming does occur, as shown by using both response times and ERP recordings. However, mediated priming is more fragile than direct priming. Its priming is smaller in magnitude and it is sometimes not observed
What is the fan effect and how does it relate to the semantic memory?
In episodic memory, increased numbers of associations with a concept can slow down retrieval time, as in the fan effect. Semantic memory is made up of very large numbers of associations among concepts. This interconnectivity can be thought of as a complex network of concepts and associations.
And so, based on the fan effect, one would expect that it should be difficult to retrieve semantic information. However, the opposite is true. Specifically, concepts in semantic memory that have more interconnections are retrieved faster
Why is this different pattern of results regarding the fan effect associated observed?
In semantic memory these associations provide both direct and indirect connections among concepts. Two concepts might be directly associated but also share a number of intermediate concepts, which functionally increases the number of retrieval pathways between them. As a result, there are many ways that concepts can prime one another.
How is inhibition related to semantic memory?
Like episodic memory, inhibition can be used to help narrow a memory search to the appropriate part of semantic memory.
During retrieval, related concepts may be inhibited. For example, people retrieve the concept “salmon” for the category FISH more slowly if they had recently retrieved several other examples of fish.
How long does the conversion of episodic to semantic memory take and how may it be accelerated?
Information requires a great deal of time to move from episodic to semantic memory. For example, in a study by Dagenbach, Horst, and Carr (1990), students at Millersville University did not show
significant priming of newly learned words until after five weeks of practice. Thus, the conversion of knowledge from episodic to semantic memory can be a long process. That said, this process can be accelerated if new learning is done in many different contexts or settings rather than just one
When people process concepts through the semantic memory, do they tend to rely on more associative (what words tend to occur together) or similarity information?
For semantic memory, when people process abstract concepts (e.g., barrier) they tend to rely more on associative information (what words tend to occur together), but when they are concrete concepts (e.g., mushroom) people rely more on similarity information
That said, it may be the case that even abstract concepts have an embodied element. Concepts such as horror and beauty have an associated emotional element, and the bodily experience of the emotion may be tied, in some way, to some abstract concepts
Describe a study which demonstrates that semantic knowledge is influenced by how we physically interact with the world
Pecher, Zeelenberg, and Barsalou (2003) gave students a property identification task in which they were shown pairs of words, such as “BLENDER–loud.” The task was to indicate whether the second word was a property of the first. Students were faster when the property was from the same sensory modality as the previous trial. For example, people were faster to respond to “BLENDER– loud” if it immediately followed “LEAVES–rustling” (which also involves sound) than if it followed “CRANBERRIES–tart” (which involves the sense of taste).
What is the purpose of categorisation?
The process of categorization allows us to draw on prior experience in a regular and reliable fashion in new situations. We can assume that some of the elements of the new situation will be like those that were observed previously. (e.g dog)
What are the three levels of categorisation?
basic- The one at which we operate at most often. It is at this level that categories are defined by features that provide enough detail to allow us to treat different members as similar but without providing more detail than is often necessary (saw, dog, chair, drum).
subordinate- Provides detailed information about more specific portions of a basic category. (camping saw, miniature poodle, leather recliner, and kettle drum)
Superordinate- very general information that captures a wide range of basic-level categories ( tool, pet, furniture, and musical instrument)
How does retrieval speed differ between these categories? (3)
In general, basic-level category information is retrieved better than the other two. People can retrieve more attributes for basic level categories and are able to retrieve the names of basic- level categories faster than the others. This suggests that the basic level has some primacy in semantic memory.
Categories have many members. Describe three ways in which their combined influence may manifest themself
First, categories exhibit a central tendency, or averaged category ideal.
Second, categories have graded membership. Some members are thought of as being better members of the category than others (e.g robin vs penguin).
Finally, members of a category might not be defined by a single set of features. Different features may be shared among several category instances. This is called family resemblance.
Describe an important distinction between two classes of categories. Why is a distinction made here?
Artifact categories (things that people make) and natural kind categories (things that are found in nature). These category classes are served by different brain regions.
First, like most semantic memories, the left hemisphere tends to be more involved than the right. Natural kinds, such as animals, tend to involve more of the medial fusiform gyrus (BA 37) and superior temporal gyrus (BA 41).
In comparison, artifacts involve more of the lateral fusiform gyrus (BA 37) and the posterior middle temporal gyrus (BA 21), near brain regions important for verbs and action
Describe two other differences between these classes of categorisation
While both classes of categories show graded membership, this is more evident in artifact categories. This is because people have more certainty about natural kinds (e.g., what makes something a bird), and have more ambiguity about artifacts (e.g., what makes something a tool).
Also, people make perceptual decisions faster when comparing objects from natural kind categories (what something looks like tells you what it is) but make manipulability (how you use it) decisions faster when comparing objects from artifact categories
What is the classical view of categorisation?
The idea that categories are defined by necessary and sufficient features is the classical view of categorization. They are necessary in that those features must be present and they are sufficient in that, as long as they are present, something is a member of a category.
Describe a study providing evidence for the classical view of categorisation
A study by Bruner, Goodnow, and Austin provided support for the classical view. In this study, people were shown figures where items can be identified along four dimensions: the type of objects, their number, their color, and the number of borders. When people are given subsets of items, along with an indication of whether each one is a member of a category, people can derive the category rules.
How is this classical view limited in its explanations?
The classical view cannot explain central tendency, graded membership, and family resemblance.
Part of this rests on the fact that the brain does not work on the either/or principles of a digital computer. Instead, it makes judgments based on loose and shifting collections of cell assemblies, giving the judgments it produces a fuzzier quality
How can elements, features, or properties that define category members can vary in their importance?
Rarer features are more diagnostic than common features in defining a category. For example, “has a trunk” is more defining of an elephant than is “breathes,” although both are needed.
Describe prototype theory
Categories are organized, in part, using unconscious mental statistics. One idea of how this is done is the prototype model. For this view, categories are determined by a mental representation that is an average of all category members. This averaged representation is a prototype, which may or may not correspond to an actual entity in the world.
Describe a study which attempted to present evidence for prototype theory
An example of prototype extraction using dot patterns: When people first learned the categories, they were shown deviations from the prototypes. The prototypes were never shown during learning. However, when people were later asked to sort both old and new patterns the prototypes were identified and correctly sorted at a high rate of accuracy, suggesting that they were derived and used to make decisions If people can readily derive prototypes from things as meaningless as dot patterns, surely the same mental mechanisms are involved for deriving categories of our everyday experiences with everyday objects.
how is this use of prototypes also seen with meaningful stimuli?
For example, if photographs of faces are used for making preference judgments along with morphed composites of faces, people rate the composite faces, which are closer to the prototype face, as more attractive. That is, people prefer faces that are averages of others. Because they are averages, they have fewer unusual and distinguishing characteristics and so are easier to mentally process. A pretty face is a boring face. This is also part of the reason why attractive faces are harder to remember
What do prototypes provide a clear explanation for?
They provide a clear explanation for the central tendencies of categories (which is the prototype itself) and a graded category structure. The closer an instance is to the prototype, the better a member of the category it is.
What aspects are not accounted for in prototype theory?
For example, people are often aware of a category size —that is, about how many different members are in the category.
Prototypes convey no information about the variability among category members.
Also, a caricature (a category member with exaggerated features) is thought to better represent a category than a prototype when a category is considered in the context of other, related categories. That is because the caricature captures distinctive features and emphasizes them. This helps distinguish one category from other, similar categories.
Name and describe two other approaches to categorisation
Exemplar theory: people use all the category members to make decisions (e.g. thinking of all birds to decide whether something is a bird)
Explanation-based views: people try to have reasons for why things should be grouped together, categories are theories or explanations (feathers and wings tend to go together because feathers are suited for flying).
Describe advantages to exemplar theory
Captures central tendency, graded membership, and family resemblance, as well as information about category size, variability, correlated attributes, and any new information about the category (Because categorization is
always using all of the memory traces, new experiences can have an influence).
They can explain the context sensitivity of categories. For example, the color gray is more similar to white in the context of hair color but is more similar to black in the context of clouds
Previously activated semantic meanings can bias how new information is interpreted. For example, a phrase like “adolescent doctor” is easier to interpret if it follows the phrase “animal doctor” than if it follows “country doctor.”
Do people tend to use prototype or exemplar based processes?
it seems that both are used, though in different circumstances. Specifically, it is more adaptive in a natural environment to move early on from a more exemplar-based form of categorization to a more prototype based form of categorization.
This allows people to deal with the family resemblance of many natural kinds and be less led astray by more peripheral and irrelevant features of individual category members
Describe a serious problem with both prototype and exemplar theories
An inherent circularity. Specifically, categories are defined by experiences with members of that category. That is, the members of the category all contribute to defining it. However, the memory traces that are selected are those that conform to the criteria of the category. In short, how can memory traces be selected to define a category if the category is needed to select them in the first place?
Describe two tendencies which people have that is consistent with the idea that they are creating explanations for what makes something a category
In general, people place an emphasis on causal factors as compared to the effects. For example, knowing that an animal swims is a more fundamental characteristic than knowing that an animal has webbed feet (presumably they have webbed feet because they swim).
Also, categories are defined, in part, by how people interact with things not just statistical regularities. For example, what makes something a chair has more to do with your sitting in it than with the materials used to make it.
What are ad hoc categories? What makes them interesting?
People can make new categories on the fly. These are ad hoc categories. For example, coffee, perfume, leather, and skunks are all members of the category things with a distinctive smell. Ad hoc categories are interesting because people generate them off the cuff but they have many of the same properties as standard categories. They have a central tendency, graded structures, and family resemblance. Thus, some semantic memory structures are generated spontaneously. This raises questions about the stability of semantic memory in general.
What is meant by psychological essentialism?
Consistent with the idea that we create categories in the pursuit of explanations is psychological essentialism. This is the idea that members of a category share an underlying essence, of which people may or may not be aware.
Does psychological essentialism generally apply to natural or artefact categories?
It usually applies to natural kind categories, which can be defined by chemical structure or DNA, such as water or skunk. That said, some artifact categories, such as scientific instruments, are treated as though they have essential qualities, and some natural kind categories, such as humans, are not.
When can categorisation cause problems?
When we engage in stereotyping. Stereotypes are categories for groups of people. When you stereotype people, you are treating them as if they are essentially the same as other members of that group. These stereotypes are activated automatically and we use this semantic knowledge to make assumptions about people and are surprised when those assumptions are violated
What is meant by linear order effects?
Another characteristic of semantic memory is the influence of knowledge that is ordered along some dimension, such as size, intelligence, or age. These are linear order effects and reflect the organization of information as it is stored or processed in semantic memory.
Name and describe three classic ordering effects
Semantic distance effect: people make faster judgments about the order of two items as the distance between them increases (size of rabbit and elephant vs dog and rabbit, more likely to confuse adjacent days of the week rather than days that are separated from one another).
Semantic congruity effect: people are faster to judge the relationship between two items if the valence of the comparison term matches the end of the dimension they are on (easier to judge that Jefferson was president before Monroe than it is to judge that Monroe was president after Jefferson because both are at the “early” end of the dimension)
Serial position effect, people are faster to make judgments about two or more items at the extremes of a dimension than those in the middle (e.g cork is bigger than castleblayney vs sligo is bigger than Clare).
Give a possible explanation for why there is a semantic congruity effect
Dimensional information is stored in semantic memory along with the concepts. Jefferson and Monroe are both thought of as early U.S. presidents, so the attribute “early” is stored directly with them. When this information is needed, if the attributes match the judgment people respond faster than if there is a mismatch. With a mismatch, people need to do more thinking to get the information lined up properly.
Give an example of how we use our bodies to interact with the world can influence semantic order knowledge
The spatial-numerical association of response codes, or SNARC effect. When people made judgments about numbers, such as whether they were odd or even, judgments about smaller numbers were made faster with the left hand. The reverse was true for the larger numbers
The SNARC effect is consistent with the idea that people have a mental number line in semantic memory going from left to right with small numbers on the left and large numbers appearing as one moves to the right, although this may be due to relative, rather than absolute, magnitudes
Give two examples of how the SNARC effect is not strictly visual
It is also observed in
blind people, suggesting that it is not strictly visual.
Moreover, the SNARC effect is not limited to numbers.
Researchers also found a similar pattern with musical pitches. People respond
faster to lower tones with the left hand and higher tones with the right
What is meant by a schema
In life, there are many situations that are fairly regular in how they unfold and operate, and how we react to them. That is, common experiences shared some framework that unites them. We are able to capitalize on this to help us
understand new situations, much as we use categories to understand new objects
or creatures.
A semantic memory that captures commonly encountered aspects of life is called a schema. A schema can be thought of as a blueprint for events that people can draw upon to understand a specific case.
Name and describe the five primary schema processes
selection: process to sort out which things are likely to be central and which are peripheral (which are important; e.g time elapsed in football v baseball)
abstraction: converting the surface form of information (e.g., verbatim wording) into a more abstract representation that captures the underlying meaning
interpretation: allows people to fill in the gaps for things that were missed
integration: sometimes we come across event descriptions that are given out piecemeal, and we need this schema process to guide us in putting these pieces together into a coherent whole (e.g clues of a murder)
reconstruction: Memories are not complete records of the past. Instead, they are fragmentary. Sometimes there are a lot of fragments, enough to recover almost the entire memory, whereas in other cases the fragments are few and far between. With reconstruction, people fill in the memory gaps.
What can knowing which schema is relevant have an effect on?
Knowing which schema is relevant can greatly influence performance. E.g people read an ambiguous passage. If people are told ahead of time that the passage is entitled “Washing Clothes,” then they remember more of it later. The title allows them to activate the appropriate schema and they can then select what is relevant in the passage and interpret it. This occurs during encoding because this title benefit is only observed when it is given before reading
Describe three experimental effects which demonstrate abstraction
when people hear sentences and comprehend them, within a few minutes they are not be able to distinguish verbatim sentences from paraphrases.
Similarly, if people see a picture, they are less likely to notice a change, such as adding or subtracting elements, rearranging entities in the scene, or changing the orientation of entities in the picture, if the rearranged picture fits their abstract, schematic memory of what they saw
People see ambiguous line drawings with one of two labels (e.g curtains/ diamond in square). Each of these labels is placed next to the drawing. After a period of time, people were asked to draw what they remembered seeing. People tended to distort their drawings to conform to the label that was provided. People used their schemas to abstract away and lose the ambiguous information. Thus, what is remembered is more schema-consistent.
How can interpretation have a powerful effect on memory?
People may misremember having encountered things that they only inferred using a schema.
Which schema processes are important for encoding and which for retrieval?
The first four are for the encoding of new information, and the fifth is important during retrieval.
Describe a study which demonstrates reconstruction
In one set of experiments, he gave British Cambridge University students a Native American folktale to read, called “The War of the Ghosts.” Sometime after reading—often several days, weeks, or months later— people were asked to recall the tale. People not only forgot parts of the story but they added new elements. Often this new information was less consistent with the original story but more consistent with typical English folktales.
What is meant by scripts?
When knowledge refers to a sequence of events that occurs in a stereotyped fashion, these scripts are temporally ordered schemas that are structured according to the major components of the event with a preference for using script information in a forward order (e.g what to do at a restaurant.)
How are the cognitive effects of scripts observed in research? Give a possible explanation for this effect
The use of scripts influences how information is retrieved and used. For example, when people read a text of a scripted event they take longer to read a sentence when the action is further along in the script from the prior sentence than if it is closer
When the information is close in the script, less effort is required. However, when the information is far in the script, more effort is required because more of the script needs to be scanned to bring the person up to date. More knowledge must be inferred.
While schemas and scripts have a large influence on memory, they are not always used.
Describe an example of a consistent limit of schema usage
People are likely to make causal inferences because understanding causal relations is important for understanding how the world is structured and operates. However there is a bias to infer causes but not effects because people can easily infer how they may have gotten to a current point in time (what caused this) if they access the appropriate schema. However, knowing what will happen next (what effects to predict) is more difficult because in many cases any number of possible outcomes could exist. This is not to say that people never use schemas to make predictions about the future—only that they are much less likely to do so.
Describe a study which demonstrates that it is possible to get people to disregard schema-generated information when the schema has been discredited
Students were given ambiguous texts, (e.g could be either about an escaped convict or a deer hunter.) Students were first asked to read this text from one perspective. After a brief delay, the students were asked to recall the story. Some did this from the same perspective as they read it. In contrast, others were led to believe that the experimenter had given them the wrong title initially. They were then given the “correct” other title.
When there was a title switch, people recalled the same amount of information as when there was no switch. However, there were important differences. When there was a title switch, people made fewer intrusions, whereas those who did not have the switch made a large number of schema-consistent intrusions. Thus, people can disregard schemas and use more detailed, verbatim memories.
Name and describe two semantic memory problems/ errors
Semantic illusions- inappropriate retrieval of information when there is overlapping lexical information, such as a similar name (e.g moses illusion/ moses’ ark)
Naive physics- memory can incorporate physical principles of the world, such as gravity and friction. Some naïve physics knowledge is stored in semantic memory. However, when we consciously try to apply this knowledge, misunderstandings can be revealed
What are the three accounts/ explanations of the moses illusion?
Semantic processing is very general unless people focus on the information of interest (we only do a cursory check of knowledge in semantic memory to see if the information is broadly consistent.)
People engage in only a partial assessment of semantic information (people retrieve some of the information from semantic memory and, so long as it is a close fit, they are willing to go with it.)
Similar language elements, such as a similar name, can inappropriately activate information in semantic memory, giving the illusion that it is known (if it sounds close, people are often willing to disregard some smaller inconsistencies)
Describe a study which demonstrates naive physics
Students were given diagrams (google docs). The task was to indicate (1) the trajectory of a ball shot out of the tube, (2) the trajectory of the ball when the string broke, and (3) the path of the bomb when the plane dropped it.
Although people do give the correct responses in some cases, they also give incorrect responses using incorrect knowledge in semantic memory. What is interesting is that people are responding as if they are holding medieval impetus theories of motion. Such responses are more likely when people use static diagrams and are less likely when viewing moving displays although not always
Can people overcome their naive beliefs about emotion through education?
With education, people can overcome their naïve beliefs about motion. That said, these beliefs never seem to go away completely. For example, if people are asked to verify statements that are inconsistent with early childhood beliefs, such as the idea that the earth goes around the sun, people respond more slowly compared to statements that are consistent with early beliefs, such as the idea that the moon goes around the earth. This is because there is some interference from older, incorrect knowledge. I
What is meant by the galileo bias?
While education improves performance, it can also get in the way. Researchers reported what they called the Galileo bias, in which people mistakenly believed that if two balls of different weights dropped from 10 meters they will hit the ground simultaneously. However, this does not take into account air resistance. Even with extensive practice dropping these balls, students at Arizona State University continued to make errors based on semantic knowledge of what they had learned in elementary school about Galileo and gravity.
Evaluate the ‘encyclopedia’ idea of semantic memory
Not a good model because we cannot simply grab one section and we have all that knowledge in one place in the brain however it is a good model to an extent in that libraries tend to have a classification system (e.g hobbies, skiing, alpine skiing etc)
What was the first approach in psychology in modelling the semantic memory?
Networks of connections between concepts.
Name two underlying assumptions regarding artificial intelligence and comment on their accuracy
Assumption 1: If we know how a computer generates knowledge and uses it, we will know how human memory works
Assumption 2: If we know how human memory works, we can make a super-powerful computer
These have largely been refuted and is not how it works in practice
describe how a model of semantic memory inspired by artificial intelligence works
A network representation showing how concepts are tied to different concepts through many rules and relationships via coding type language e.g My dog Isa Dog Isa animal. agent, dog; relation, eats; Object; meat.
Diagram in notes
rather than being very fast and nimble in thinking, how is it posited that you become a ‘good thinker?’
By having many many rules for many many instances/ cases (e.g chess, fighting)
Describe a classic study which demonstrates the requirement of having many many rules for many many instances/ cases rather than being a quick or nimble thinker
Herbert Simon studied chess grandmasters and low level students. He first placed pieces on the board to represent a game situation. He would show them, take it away and have them set it up again. The grandmasters were extremely good at this, students were a lot worse, showing an effect of expertise. Simon then set up the boards in ways which would never naturally occur in a game (e.g extra horses). The difference in performance disappeared between the students and masters.
What did Herbert Simon develop inspired by these studies
Expert systems in which, given a situation, one consults their database of what can be done in certain situations they know and applying one which is suitable.
Name and describe a model which attempts to explain why some sentences are easier to comprehend than others i.e
A baguette is a form of bread vs
An elevator is a vehicle
The Collins & Quillian Model is a hierarchal network model in which there are both categories and characteristics. Categories of animals could include birds, fish etc which could include canary, ostrich; shark, salmon as subcategories. These categories have associated characteristics such as bird- wings, fly, feathers and ostrich- long thin legs, feathers, can’t fly.
Connections between categories are called links and the categories they connect are called buttons.
How does this model answer why some sentences are easier to comprehend than others
The sentence ‘the seahorse has eyes’ takes longer to comprehend than the ‘male seahorse carries the baby’ because eyes are something that is not unique to seahorse but you have to travel back up to fish and animals to access that characteristic, however a male seahorse carrying the child is something uniquely associated with them and not fish or animals so it is accessed more quickly.
Describe the limitations to this hierarchal network model
It was found through later studies that this theory did not hold up and makes several incorrect predictions.
It has no explanation for “typicality’ effects e.g a robin being one of the first birds when you think of a robin, thought of faster than a chicken or a penguin because it is more typical of a bird.
It also does not take into account that frequency of association is more important than distance in the hierarchey- i.e a cat is an animal is quicker registered of than a cat is a mammal.
Describe a later version of this model
Collins & Loftus made a spreading activation model in which, for example, if you think of the a firetruck, then the concept of red could be activated and therefore red objects such as cherries, fire etc could be more easily reached (primed.)
How long does semantic priming usually last?
ms to s
What is the does a distinction made in priming
Associative priming- e.g ‘cats and dogs’ may prime ‘weather’ from the expression; found together in the real world
Semantic priming- when there is a semantic bond between the too e.g Labrador primes dog.
Compare the effects of expected RT in a lexical decision task to stimuli robin, arm, and box if primed with the word bird or no prime.
Robin- quicker RT if primed with the word bird or not: semantic prime.
Box- quicker RT if primed with word bird: associative prime
Arm: Slower RT if primed with word bird: slower response due to unrelated prime
What factor in a LDT design can affect the extent to which a prime affects RT?
SOA or Stimulus Onset Asynchrony: interval between prime and target
Facilitation = RT non-primed trial -RT primed trial
How can the priming effect be turned around
By informing the participant that when there is a e.g a body part, there will be part of a building. Then there will be a faster RT for ‘door’ than ‘heart’. There is then a slower RT as if it is an unrelated prime
Describe the learning regularities
- A good classification is reached after many examples
- This learning is pretty difficult
- The prototype is typically misrecognised as ‘seen’, even if it was not
- This was taken to suggest that subjects induce a type of prototype
How to anterograde amnesia patients perform in these category tasks?
(Anterograde) amnesia patients can also learn this type of categories, suggesting that this learning is implicit
What categorisation theory holds up best in research and what likely incorrect assumption does it make?
Examplar theory holds up the best compared to prototype but makes the really weird remember-all items in the category that is likely wrong
What kind of models are able to incorporate aspects of both?
Neural network models
Describe a study utilising a location which displays the effect of schemas in memory
Subjects had to sit and wait in an office until a study began. When they got into the study, participants had to remember everything they could about the office. Since it was quite a typical office setting, it activated this schema and participants would add stuff that they would expect to find in an office but were not present such as books and did not report some items which are not typical of offices such as the notice board.
What are the benefits and disadvantages to schemas?
Benefits:
- Creates expectations
- Makes it much easier to make inferences
- You remember more
Disadvantages
- Distorts memory (without realising it)
- Allows manipulation by others (e.g magicians, politicians and advertisers)
Describe the observed symptoms of someone with semantic dementia
They have a progressive loss of semantic knowledge. You can speak to thme completely fine and then mention grandchildren and they could say “what are grandchildren?” If you explore further you will find that whole categories of knowledge are missing from their index. If getting them to talk about a topic in which they have lost a lot of information on, they may use words like ‘thingy’ and try to talk around it (word finding problems and some comprehension difficulties). However there are no problems with new learning.
What lesions are associated with semantic dementia?
infero-lateral temporal cortex but (early in the disease) with sparing of the disease. It is considered a sub-type of fronto-temporal dementia
How may a semantic dementia patient still have certain knowledge about certain things without it being ‘true’ semantic knowledge?
It may be a bunch of episodic knowledge that they can use as if it were semantic knowledge e.g e.g., ‘ducks’ are ‘those animals that I sometimes feed in the park’ withno generalization (e.g., lays eggs???). This is also context dependent (toothbrush in kitchen drawer may not be recognized; only in bathroom)
Describe a task which demonstrates how patients use and integrate existing knowledge
E.g you could show them a camel. Then take it away for a few minutes then ask them to draw a camel or the thing they just seen and often it will not look like one, instead integrating different aspects such as wheels instead of legs or a human head.
Describe how you could observe the pattern of progressive loss of semantic knowledge in a patient
Picture naming responses to the same stimuli can also be recorded such as (over three years):
Swan: swan, bird, animal
Rooster: chicken, chicken, dog
What pattern do these Picture naming tasks demonstrating the pattern of progressive loss of semantic knowledge in a patient show?
First the very specific knowledge (subordinate) leaves and is replaced by the more general knowledge (superordinate) which survives longer. And then this can go and can be replaced by some kind of (high frequent) prototypical response (e.g dog for rooster or duck) or even something non-living for something which is living for example (e.g vehicle for peacock).
What model do these findings reflect?
Quillian’s hierachical model could not predict reaction times correctly in many important cases. But it seems that knowledge erodes in a hierarchical manner with semantic dementia–From the subordinate to superordinate levels
