!Methodology of cognitive science
!Readings
* [Required] http://plato.stanford.edu/entries/cognitive-science/
* Thagard, Paul (1996). ''[[http://library.hku.hk/search/t?SEARCH=Mind%20%3A%20Introduction%20to%20Cognitive%20Science|Mind : Introduction to Cognitive Science]]'' Cambridge, Mass: MIT Press. [accessible from netlibrary.com]
!What is cognitive science?
!!Definition: Cognitive science is the science of mind and behavior.
!!Feature #1: Cognitive science studies mind and behavior.
* All sorts of [[mental states]] (beliefs, emotions), processes (reasoning, speech), phenomena (consciousness), and behavior (motion, facial expressions, speech).
* Both normal and abnormal (prosopagnosia, autism) cases, human and animal minds are studied.
!!Feature #2: Cognitive science is a science.
* Empirical testability: Theories and hypotheses in cogsci are not armchair speculations. They should be [[thinkweb:sci/hd.php|supported by strong evidence]]. [Questions to ask: Can theory X explain data Y? Are the predictions of theory X correct? Are there other theories that provide better explanations and predictions than theory X?]
* Varieties of experimental approaches: brain scans, psychophysics experiments, studies of cognitive deficits, reaction time, computer simulation, ...
!Themes in explanation
!!1. Cogsci is materialist
* Mental phenomena are explained in terms of physical processes in the brain. Most cognitive scientists are PHYSICALISTS (or MATERIALISTS) - everything in the world is made up of physical substance.
* PHYSICALISTS would deny SUBSTANCE DUALISM - the view that the mind is a soul, some kind of non-extended and non-physical object. Substance dualism is of course a part of most religious doctrines.
* We have no a priori reason to think that substance dualism must be wrong. Only experiments can help us decide which approach is better. What is true is that the physicalist approach has been more successful in improving our understanding of the mind.
!!2. Cogsci is interdisciplinary
The mind is extremely complicated
* Around 100 billion inter-connected neurons
Vertical and horizontal division of labour is needed to understand the mind.
* Horizontal division of labour: Mental phenomena involves language, perception, reasoning, emotions, etc. Different scientists focus on different areas.
* Vertical division of labour: Each mental phenomena can be investigated at [[Main.Levels of Description|various levels]] - the task level, the level of algorithm, and the level of neural mechanism.
Some of the disciplines of cogsci:
* Psychology - cognitive psychology, developmental psychology
* Linguistics - syntax, semantics, phonology
* Neuroscience - brain structures, localization
* Computer science - AI, computer models
* Philosophy - theoretical foundations
!!3. The mind is modular
* The brain is a complex system with different functional parts, e.g. visual areas, language, reasoning, ...
* Cognitive science is more like reverse engineering - understanding a complex system by identifying the functions of different parts and see how they interact.
* SPECIALIZATION not incompatible with PLASTICITY.
!!4. Mental processes are explained in terms of parallel computations in the brain
Information processing in the mind
* Perception - acquiring real-time information about the surrounding environment.
* Language use - making use of information about syntax, semantics and phonology.
* Reasoning - combining different sources of information, deriving new information, testing consistency of information, etc.
* Action - making use of information in action planning and guidance.
* Memory - storing and retrieving information
The distinctive feature of a lot of mental processes is that they involve complex information processing. But complex information processing is best explained by computations and representations. So we have reasons to believe that mental processes should be explained by computations in the brain. There are mental representations that encode information, and there are mental processes that operate on such representations.
!!5. Most mental processes are unconscious
We are not consciously aware of much of our mental processes.
* We have lots of different beliefs at any given time, but we are not aware of all of them at the same time.
* We are not aware of how we retrieve information from memory, how we recognize faces, ...