Models of the brain Flashcards
What is artificial intelligence (AI)?
the theory and development of computer systems able to perform tasks normally requiring human intelligence, such as visual perception, speech recognition, decision-making, and translation between languages
-developed out of symbolic logic
What is reasoning with logic?
creating new knowledge from facts we already know/making inferences
-can replace words with symbols (aristotle) and machine makes same inference: symbolic logic
Learning in neural networks
- learning might be changing the strength of neural connections
- conditioning
- which of the connections do we want to change and how?
Why are AI models useful in cognitive psychology?
- ‘what i cannot create, i do not understand’ - building models can help us understand what we haven’t learnt yet
- Data-analysis model: data-driven, descriptive
- Box-and-arrow model: information processing model, conceptual, implicit assumptions e.g. memory model, not functional
- Computational model: information processing model implemented as a simulation, explicit assumptions, various levels of abstraction, model that can do something
Why would we want to build a computational model?
- they make assumptions explicit so they can be tested
- can give specific predictions for outcome of an experiment so helps select which experiment to perform
- models can be explanatory even if not predictive e.g. c models of schiz can indicate causes of disorder without being able to predict individual cases - suggest treatment
- the brain is complicated, abstracted and idealized models can capture broad trends so is still useful
David Marr + his 3 levels of understanding
- worked on visual processing - how can we understand info processing systems like the brain?
- came up with 3 levels of understanding: computation, algorithm, implementation
- we can build models at different levels but experimental techniques favour implementation level
- understanding the brain can cause bottom-up approach: implementation (neural circuits)–>rules–>problem (what we can solve)
Computation
=why (the problem that needs to be solved)
Algorithm
=what (rules to follow) - how can this computational theory be executed?
Implementation
=how (physical action) how can the representation and algorithm be realised physically?
-experimental techniques prefer this level
what does a top-down modelling approach aim to do?
aims to cover algorithmic function and might disregard biological implementation
Epstein argues that computational models are:
often wrong, but can still be illuminating