What is cognitive science?
Readings
Cognitive science is an interdisciplinary science of mind and behaviour
- Mind and behaviour
- Mind: Mental states (beliefs, emotions, conscious experience), mental processes (reasoning, speech, dreaming), mental capacities (language)
- Behaviour: actions, facial expressions, speech
- Normal and abnormal (prosopagnosia, autism) cases. Not just humans, animals also.
- Science
- Not based on intuition / authority. Systematic theories have to be supported by experimental evidence.
- Varieties of experimental approaches: brain scans, studies of cognitive deficits, reaction time, computer simulation, ...
- Interdisciplinary
- The mind is an extremely complicated system. Understanding how it works requires expertise from different areas.
- Many types of mental processes: language, perception, reasoning, emotions, ...
- Each type of mental process can be studied at different levels: task, algorithm, neural mechanism.
- Some of the main disciplines of cogsci
- Psychology - cognitive psychology, developmental psychology
- Linguistics - syntax, semantics, phonology
- Neuroscience - brain structures, localization
- Computer science - AI, computer models
- Philosophy - theoretical foundations
- Importance
- Intellectual - the final frontier
- Metaphysical and religious significance
- Practical relevance - education, mental health, management ...
- Future of humanity - AI, human-machine hybrid, singularity ...
Cognitive science is a young science with a long history
- Long history - Philosophers (Plato, Aristotle, Descartes, Hume, Kant ...) and scientists have always been interested in how the mind works.
@Men ought to know that from the brain, and from the brain only, arise our pleasures, joys, laughter and jests, as well as our sorrows, pains, grievances, and tears. Through it...we...think, see, hear, and distinguish the ugly from the beautiful, the bad from the good, the pleasant from the unpleasant.^^^Hippocrates (400BC), Founder of Western medicine@
- Young science - Cognitive science came about in the 1960s as a result of different disciplines coming together. Briefly, it was the result of three main developments:
- The reaction against behaviorism in psychology, linguistics and philosophy
- The emergence of AI and computational theory in computer science
- New discoveries about brain functions in neurophysiology
- The unifying theme was that to explain the mind we need to understand how information is processed in the brain.
@By 1960 it was clear that something interdisciplinary was happening. At Harvard we called it cognitive studies, at Carnegie-Mellon they called in information-processing psychology, and at La Jolla they called it cognitive science.^^^George Miller@
The computer model of the mind
@by reasoning, I understand computation. And to compute is to collect the sum of many things added together at the same time, or to know the remainder when one thing has been taken from another. To reason therefore is the same as to add or to subtract.^^^Thomas Hobbes (1655) De Corpore ("On the Body") @
A main unifying theme in cognitive science is the use of computational explanations. Sometimes this is described as the computer model of the mind. The idea is that the best way to understand mind and behaviour is to explain them in terms of complex information processing carried out by a massively parallel neural network computer. But why?
Claim #1 - The distinctive feature of mental processes is that they involve complex information processing.
- Examples
- 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
- To think about: any aspect of the mind that is distinct from information processing?
Claim #2 - Complex information processing is best explained by computations and representations.
- Complex information processing can be done by simple physical operations on symbols that encode information.
- 2x3 = 2+2+2 ( = 010 + 010 + 010 = 100 + 010 = 110 )
- A cooking recipe is a step-by-step procedure to manipulate ingredients to produce food.
- A program is a set of rules for manipulating symbols, e.g. FOR F=1 TO 10; PRINT F; NEXT F
- The same task can be performed by different programs. The same program can be implemented by different machines.
- Functional organization is the key to explain information processing.
- Most of these processes are unconscious - We are not consciously aware of them, eg memory, facial recognition ...
- To think about: any kind of information processing that cannot be explained by computations?
Claim #3 - Those computations and representations that explain the mind are implemented by neural networks in the brain.
- Physicalism - Mental processes are (identical to / reducible to / constituted by ) physical processes.
- Substance dualism - Universe = physical substances + soul stuff
@I admit it would be easier for me to concede matter and extension to the soul, than the capacity of moving a body and of being moved, to an immaterial being.^^^Letter to Descartes from Elisabeth, Princess of Bohemia@
- Argument from causal interaction
- Mental events are caused by physical events and vice versa.
- Ockham's razor: Physicalism provides the simplest explanation of this causal interaction. (Empirical success of cognitive science)
- Indirect argument: No good evidence for alternatives, e.g. substance dualism
- Science requires publicly verifiable evidence
- SD compatible with the computer model
- Active processor vs cloud storage
- To think about: any mental processes that take place outside of the brain?
Philosophy and cognitive science
What does philosophy have to do with all this? Isn't cognitive science a science (and philosophy is not)?
@The aim of philosophy, abstractly formulated, is to understand how things in the broadest possible sense of the term hang together in the broadest possible sense of the term..^^^Wilfred Sellars "Philosophy and the scientific image of man"@
See Philosophy And Cognitive Science