Cognitive Psychology Lecture 7-10 Flashcards
How do we understand the world?
Through automatic and effortless evocation of categories.
we understand categories rather than individual stimuli.
How do we test categorisation?
by slowing down categorization by making very difficult.
What 2 theories do we need to understand theories of categorization?
we need to understand that features may vary in salience (attract attention) and validity (how important they are for categorization)
What type of features are there?
features may be:
Perceptual (Not everyone see the same features)
Functional (features need not be physical)
Relational, Emotion, Causal
Intergral or seperable (Colour-hue, saturation &brightness and Faces)
What are the benefits of categorization?
- Reduce complexity of environment
- enable us to relate classes of objects and events (3 levels-superordinate, basic, subordinate)
- Provides means for identification
- Allows for generalization
- Provides basis for deciding what is an appropriate action
- In real life- recommender systems that predict what we might like to buy
When are generalisation of categories greater?
Similarity: the more similar we think it is, the more likely we are able to generalize.
Typicality: the more typical the thing is to the category, then it allows for greater generalization (Osherson et al., 1990).
Specificity: the smaller the category is from the thing, the better we are able to generalize (Osherson et al., 1990).
Variablity: Generalization is greater when examples are more variable
Name the 3 levels of categorisation and give an example of each.
Hierachical category levels Superordinate: highest - fruit. listed slightly more basic level categories. often functional terms Basic: normal - apple. listed most often. Children speal this first- most used type of terms @ 2 years old during 2 hr recording of MLU based on morpheme count (1-2 morphemes) Often nouns and adjectives Subordinate: specific - granny smith
Category levels are not definite and may change depending on context.
How do similar events/things get categorized?
similar things get clustered together on a map/grid thing.
but the further the things get in the category, may become a whole new category. in this case, there will be no more generalizability
Are concept subtle/obvious? Are concepts simple/complex?
concepts are subtle and complex
Do categories have a large/small degree of variation?
categories have a large degree of variation
What is the classical view of concepts according to Plato, Aristotle, and Jerome Bruner?
Plato: world possess natural partitions, concept representation involves learning the rules that govern the structure of partitions
Aristotle: concepts are mentally represented as definitions which provide the necessary and sufficient conditions for category membership (any member is equal to every other member, no in-between cases, either in the category or not)
Jerome Bruner: Categorization involves discovering the defining attribute in the environment
Do complex or simple rule take longer to learn?
complex rules take longer to learn
number of stimuli determines complexity
Are categories definite or can they change?
categories can change.
categories can be made on the fly (Ad hoc)
prototype enhancement effect: prototype is falsely remembered with same rate as old items
new items that have not been seen before are falsely remembered according to typicality
What is a “prototype”? + Person
Eleanor Rosch: average of all category members
Problem: average may not be an accurate representation. Examplar theory solves this
What is an “Examplar”? +Person
Rob Nosofsky: all category members, similarity based on distance.
In examplar theory, there would be no prototypical bird.
on the surface, it would appear that it did not reduce cognitive complexity, but it does if we allow for selection attention mechanisms to influence how similarity is determined across the category
What categorical theory best describes our understanding of how people categorise?
Examplar theory- most of the time.
but sometimes it changes.
How do we Learn?
Selective attention
neural mechanisms of learning
cognitive phenomenon
What is knowledge and how does it affect our interpretation of new information?
Knowledge = things we have already acquired
influences our interpretation of new info by explanation, fitting to our thinking, and learning about causes
What are the types of learning?
- Habituation: Decrease to stimuli after repeated exposure w/o reinforcement
- Sensitization: Increase in response to stimuli after strong stimulation
- Associative Learning: Classical conditioning (association of originally neutral stimulus with later salient event), Operant Conditioning (learning based on modification of behaviour due to consequences.
Who studied Aplysia and why did he study it?
Also name the features of a typical Aplysia.
WHO: Eric Kandel
WHY: Big neurons therefore easy to insert electrodes so can study neurons easier. studied Aplysia when they encountered danger by tickling their gills and siphon with paintbrush b/c they use it for respiration
WHAT: Sipon, Tail, Gill, Mantle
Describe an Action Potential and its related details.
-70mV resting membrane potential
Electrotonic conduction = depolarization = influx of Na+
AP is all or nothing
Sodium potassium pump = Na+ out, K+ in
Ca2+ facilitates neurotransmitter docking in synaptic cleft
Outline Habituation in Aplysia
Test gill tickling reflex
after 10 mins stimulation –> 15 mins habituation
after 4 days stimulation –> 1 week habituation
What they thought:
Sensory neuron does not react as strongly
motor neuron does not react as strongly
increase inhibition from interneuron
The actual reason:
with successive stimulation, less neurotransmitter released
different wiring so there are less and less connections between siphon and gill
Outline Habituation in infants
presented infants with 2 pictures each time, measure how often infant looked at repeated pattern. Discovered it manifests in humans as boredom or ignoring cue.
1-2 month old infants: looked at old pattern equal amount of time
Older infants: decrease in amount of time looking at old pattern, increase amount of time looking at novel pattern
What can memory be described as in terms of learning?
memory can be described as long term sensitization
What is a classic example of sensitization?
Learned food aversion
Know Classical conditioning + Person + Experiment
Pavlov, Dog, UCS, UCR, CS, CR
classical conditioning produces a series of molecular changes at the pre and post synaptic gap of the motor neurons
AP more likely to be produced because of change in cell membrane permeability
What is Latent inhibition?
Latent inhibition is the pre-amptive introduction to the conditioned stimulus before classical conditioning commences
Pre-amptive introduction does not transfer over contexts
slows down learning of conditioned response
Is learning context specific or broad? What evidence is there to show this? + Person
What percentage of people knowledge partition?
specific
Latent inhibition and habituation is evidence of context specificity
Roediger & Kaepicke (2006): matching context between self test and final test predicted better scores
Lewandowsky & Kirsner (2000): Firefighters partioning in fires and backburns
~ 2/3 of people knowledge partition
dependent on attention to cus or components of cues.
