Doing Psychology Flashcards
What is the goal of the quantitative approach?
To develop formal (explicit) theories that can be tested
How would the quantitative approach define a theory?
A principle or set of principles that explains a body of facts
Theories (ideally) make mathematical predictions, which can be tested by collecting data and submitting that data to formal statistical analysis
In logic/maths = A theory is a set of sentences in a formal language
What makes a good theory?
Specifies the relations (often casual) between states
E.g. Evolution explains change or organisms over time due to mutation and selection
What are the features of a theory?
Theory has a goal of understanding
Theory is expressed as an explanation
Theory set of principles that explain a system
Set of axioms
Set of inferences to explain existing data & predict new data
Theory must predict or it is not useful
What are not features/aspects of a theory?
Theory is not a description
Specify structures of of interest & relations between them
Must specify relations between entities via transformative function
Theory is not a set of data
Theory is not a diagram (unless it includes a description of the logic underlying the specified relationships)
What is good science?
Produces ‘good’ and testable theories
What do theories of cognition believe about the mind?
That the mind is an intelligent system
Who proposed a way to understand intelligent systems?
David Maar 1980 - Answered the question of how intelligent systems work?
What were the three different components of David Maar’s explanation of intelligent systems? (Name only)
Computational theory, Representation and Algorithm, Physical implementation
What is the computational theory of understanding intelligent systems?
What problem is it solving (& why)?
What are the constraints on its solution?
What, in general terms, is the nature of the problem that is getting solved or the function that’s being computed?
What is the representation and algorithm explanation of understanding intelligent systems?
What information does the system represent and how does it represent that information?
What does it do with that information?
What algorithm is it running on the information in order to get something useful out of it?
What is the input to the system, what is its output, and what stages does it go through in between?
Why are the three different levels important in understanding a system?
In order to understand a system fully, it needs to be described at all three levels
What is the physical implementation view of intelligent systems?
How are these representations and algorithms realised in the hardware of the device itself (e.g. in the neurons in the brain)
How does an example of a cash register demonstrate the different levels of Maar’s explanation?
Example of a Cash register
Computational - Problem is arithmetic
Representation and algorithm - Representation is arabic numerals & algorithm operation is on least significant digits
Implementation - Series of 10 notch metal wheels turned by a control structure
What level do we want to study cognition at?
Implementation level can be too abstract or complicated at first so representation level easier as well as being abstract
What is an example of a model that works on the level of computational theory?
Rescorla-Wagner model that explains learning via association as it specifies a function mapping input state to output state
What features would a model of the level of representation and algorithm have?
Specify representations for input and output
- Content
- Format (e.g. spoken)
Specifies algorithm for transforming input representations into output representations
Precise series of operations
How would physical implementation look like in application? (e.g. what features of the brain would be focussed on)
How do real neurons behave?
How do real neurons learn connections?
How are items encoded by real neurons?
How is association implemented in real neurons?
What are the two types of models used in Psychology?
Mathematical models
- e.g. Rescorla-wagner model
- Many models of personality specify which traits interact to produce
things like preferences or behaviours
Process models
- Most common in cognitive and behavioural neuroscience
What are the two broad classes of process model?
Symbolic
Represent knowledge as symbolic data structures
Manipulate data structures with variablised rules
Connectionist
Represent knowledge as nodes in a network
Processing is carried out by passing activation between nodes
What is representation like in symbolic models?
Symbolic data structures
Basic (or atomic elements)
Rules for composing elements to make more complex structures
Basically a language
E.g.
Basic elements → Variables (S,T,U,V) & Operators (& or !)
Rules for making propositions → Any variable is a legal proposition (any two legal propositions can be combined by an operator)
What are processes like in symbolic models?
Symbolic operations on the data structures & application of symbolic rules
In general → Cognition is like a traditional computer program
Mental representations are just like the data structures in a computer program
Procedures are just like the functions or methods that operate on data structures in a computer program
What is the prototypical symbolic model (example of production system)?
- A database is a set of known facts (represented as data structures)
- Set of inference rules is created (if a proposed rule (e.g. cat smaller than elephant) fits a known fact in the database then the rule can be ‘fired’ and become part of the database)
- Executive control structure (decides which rules to fire when; hard question; requires specific algorithm)
(Look at diagram in lecture notes for better understanding)
What are the different states of operation for a production system?
Current state → The current contents of the database (e.g. known facts about the system, current state of chess board)
State space → Set of all possible states (all possible legal states of pieces on a chess board)
Goal state → The state you want the database to be in (e.g. checkmate)
State transition → Moving from one state to another (check-mate opponent)
Search - Algorithm for traversing the state space and finding the best path for moving from current state to goal state (which rules, in which order)
What are the advantages of symbolic models?
Computational power
You can define variablized and universally quantified rules
What are the disadvantages of symbolic models?
Symbolic rules are often too rigid to capture human behaviour
We don’t always apply a rule we know
Fail to capture shades of meaning
Not very automatic processing
How are structured representations learned? (example of disadvantage of symbolic model)
New representations are combinations of existing representations that are already structured (e.g. by size - lion and dog)
Production systems assume these representations
How are rules learnt? (example of disadvantage of symbolic model)
No graceful degradation with damage
No obvious neural implementation
What are connectionist models?
Models compared of networks of interconnected nodes
Nodes are simple processors that mimic neurons or populations of neurons
Connections are weights between nodes
Representation - Patterns of activation on modes or neurons
How does processing occur in connectionist models?
Processing - Nodes pass activation over weighted connections
Positive weights are excitatory connections
Can teach the network for something to have positive connection between units
Creating a negative connection - node will have negative weight so won’t activate
Using different types of connections we can teach the network things
What are the advantages of connectionist models?
Flexible processing (parallel constraints)
Flexible representations
Distributed representations capture semantic content
Permit automatic generalisation
Graceful degradation with damage
Transparent neural implementation
What are the disadvantages of connectionist models?
Not symbolic
Ability to generalise depends on similarity of examples
What you know about chasing can only generalise to objects like one’s you’ve seen chasing before
Cannot represent or use variablised rules:
∀ x, y, z if larger (x, y) and larger (y, z) then larger (x, z)
Must learn about different instances
But even children generalise to utterly dissimilar examples sometimes
What is ‘vulnerable’ defined as?
Adult is ‘vulnerable’ when she/he is unable to take care of her/himself (Department of Health, 2004)
‘Vulnerable’ individuals are those who have enhanced risk of suicide, self-harm or harming others (Smith,2007)
There is innate, person vulnerability and then structural/contextual/environmental definitions
Safeguarding Vulnerable Groups Act (2006) - Based on way groups are
Marginalised
Socially excluded
Limited opportunities
Suffer abuse (physical, sexual, psychological and financial)
Hardship
Prejudice
Discrimination
What is social exclusion and why can is occur?
What can happen when people or areas suffer from a combination of linked problems
E.g. Unemployment, lack of skills, low incomes, poor housing, high crime
Occurs because problems are linked, mutually reinforce each other - clustered in particular areas (‘Vicious cycle’)
Linked to disadvantages individuals face at birth & persist from generation to generation
Causes/consequences
E.g. Poverty,low income, unemployment, poor education attainment, poor mental/physical health