4 - models in cognitive psychology

Question 1

what is a model?

Answer 1

a simplified (or idealised) representation of a thing

Question 2

what is a statistical model?

Answer 2

a mathematical relationship between variables, that hold under specific assumptions

Question 3

what is a theoretical model (in cognition)?

Answer 3

a description of the relationship between different mental processes, that makes assumptions about the nature of these processes

Question 4

what is behaviourism?

Answer 4

sees brain as a black box that we don’t know what’s happening inside

all we can observe are the inputs and outputs

Question 4

what are cognitive “box-and-arrow” models?

Answer 4

describe the relationship between different mental processes

under the assumption that the mind operates like multi-staged information-processing machines

Question 5

how can cognitive models be tested?

Answer 5

manipulating the input and observing the output can provide a glimpse into the machination of our mind and allow us to test our models

Question 6

what are formal cognitive models?

Answer 6

similar to cognitive models but includes a mathematical description of the relationship between mental processes

usually represented through computer code

Question 7

what are characteristics of models?

Answer 7

simplification - not everything is described in a model, only critical parts

abstraction - generating general rules and concepts from information

Question 8

what is the purpose of models in science?

Answer 8

must produce predictions and/or explanations

predictions can be directional or numerical

cognitive models give an explanation of what is happening unlike statistical models

Question 9

what is the difference between a theory and a model?

Answer 9

theory - scientific proposition that provides relations between phenomena e.g. early-selection theory

model - schematic representation of a theory, more limited in scope e.g. Broadbent’s filter model

Question 10

what is the difference between informal and formal cognitive models?

Answer 10

informal - a verbal description of relationship between different cognitive procedure (implicit, directional)

formal - mathematical description of relationship between different cognitive procedure, often via computer program (explicit, numerical)

Question 11

what do Guest and Martin add to the theory building chain?

Answer 11

specification - formal description of relations described by a theory

implementation - specific instantiation of a specification (computer program)

Question 12

why use formal models?

Answer 12

1. more accurate (precise) predictions
2. counter-intuitive predictions
3. benefits of explicit assumptions

Question 13

why are formal models more accurate (precise)?

Answer 13

• numerical simulation allows us to see if model provides unreasonable predictions (easy to reject bad models)
• help select which experiments to perform
• better hypothesis testing, how close a model is to predicting actual result

Question 14

why are formal models better?: counter-intuitive predictions

Answer 14

formal models can more clearly describe which predictions follow a model

with informal models, hard to notice when they make counter-intuitive predictions

Question 15

why are formal models better?: benefits of explicit assumptions

Answer 15

makes assumptions transparent for others to see

so we can reveal unanswered questions, flaws in reasoning, contradictory or unreasonable assumptions

Question 16

how was David Marr?

Answer 16

mathematician and neuroscientist

worked on how to understand information processing systems like the brain?

Question 17

what was David Marr’s idea?

Answer 17

to make sense of brain data we have to break it into 3 levels:
1. computation - problem being solved
2. algorithm - steps/rules to solve it
3. implementation - actual machinery
(Top down approach)

Question 18

what is the bottom-up approach used by AI and classic neuroscience?

Answer 18

1. implementation - machinery of neural circuits
2. rules - what representations can we generate?
3. problems - what problems does this solve?

Question 19

what did David Marr say about theory and implementation?

Answer 19

we cannot focus on implementation without theory and vice versa

we need to have feedback and focus on everything, theory and implementation