4 - models in cognitive psychology Flashcards
what is a model?
a simplified (or idealised) representation of a thing
what is a statistical model?
a mathematical relationship between variables, that hold under specific assumptions
what is a theoretical model (in cognition)?
a description of the relationship between different mental processes, that makes assumptions about the nature of these processes
what is behaviourism?
sees brain as a black box that we don’t know what’s happening inside
all we can observe are the inputs and outputs
what are cognitive “box-and-arrow” models?
describe the relationship between different mental processes
under the assumption that the mind operates like multi-staged information-processing machines
how can cognitive models be tested?
manipulating the input and observing the output can provide a glimpse into the machination of our mind and allow us to test our models
what are formal cognitive models?
similar to cognitive models but includes a mathematical description of the relationship between mental processes
usually represented through computer code
what are characteristics of models?
simplification - not everything is described in a model, only critical parts
abstraction - generating general rules and concepts from information
what is the purpose of models in science?
must produce predictions and/or explanations
predictions can be directional or numerical
cognitive models give an explanation of what is happening unlike statistical models
what is the difference between a theory and a model?
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
what is the difference between informal and formal cognitive models?
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)
what do Guest and Martin add to the theory building chain?
specification - formal description of relations described by a theory
implementation - specific instantiation of a specification (computer program)
why use formal models?
- more accurate (precise) predictions
- counter-intuitive predictions
- benefits of explicit assumptions
why are formal models more accurate (precise)?
- 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
why are formal models better?: counter-intuitive predictions
formal models can more clearly describe which predictions follow a model
with informal models, hard to notice when they make counter-intuitive predictions
why are formal models better?: benefits of explicit assumptions
makes assumptions transparent for others to see
so we can reveal unanswered questions, flaws in reasoning, contradictory or unreasonable assumptions
how was David Marr?
mathematician and neuroscientist
worked on how to understand information processing systems like the brain?
what was David Marr’s idea?
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)
what is the bottom-up approach used by AI and classic neuroscience?
- implementation - machinery of neural circuits
- rules - what representations can we generate?
- problems - what problems does this solve?
what did David Marr say about theory and implementation?
we cannot focus on implementation without theory and vice versa
we need to have feedback and focus on everything, theory and implementation
