Cognitive Science, an introduction
1995 Stillings, Weisler, Chase, Feinstein, Garfield, Rissland
Second edition
Chapter 1. What is cognitive science.
- Information processes are contentful and purposeful.
- Information processes are representational. Information must be represented somehow, and there must be rules related to that. ie "253" represents 2*100+5*10+3*1. These rules are the "syntax". some representational schemes include rules to build structures out of simple ones (combinatorial, aka productive)
- A Semantic interpretation, of a complex symbol is built up from the meanings of each syntactic symbol. A semantic interpretation of a multiplication can illustrate about the goals, but not about the implementation, the 'how'.
- Information process can be described formally. Thus, can be described and implemented without any awareness of their meaning (ie: a calculator can multiply without "knowing" what multiplication is). However, the more specialized implementations (ie complex sw) have very well defined representational relationship to their particular domains.
- In Human Language, there are multiple languages, but there is experimental proof that some "linguistic universals" do exist. See Chomsky.
- Information process can be analyzed at several levels (*like OSI layers.) ie multiplication can be analyzed:
Abstract -> what; Representative -> what does it represent; formal -> mechanics.
- The implementational mapping ties together the different layers.
Cognitive Psychology / Architecture of the mind
- Intelligence is not homogeneous, but it consists of subsystems.
- Vision and language are probably the most specialized information processing subsystems.
- The architecture of a system may or may not give it the potential to acquire information-processing capabilities that are not specifically built in.
- In humans, there are architectural differences form individual to individual. ie: a deaf person would have different architecture than a hearing one.
- GLOBAL VIEW
Think of it as a black box, with 3 stages.
Input: Sensory input is the input to the first stage.
1. Sensory systems: Vision, hearing, taste, smell, touch...
those in turn provide input to
2. Central systems: Thinking, attention, memory, learning and Language.
Those inturn provide input to
3. Motor systems.
Output: Motion, motor output.
- Sensory systems are "informationally encapsulated", they provide input to the central processes, but central processes are not engaged in the ellaboration of such input. (ie, no feedback)
- Two theories that may be complementary, may be exclusive:
a. Central Systems Theories. Classical view, connections, parallel distributed processing, artificial neural networks.
b. Physical Symbol systems. this hypothesis says that cognition can be analyzed as a formal symbol manipulation process.
- Yet, a physical symbol system does not necessarily have survival mechanisms, so is not sufficient to define intelligence at the human level.
- Distal access symbols, (ie: reliable calling subroutines, or making associations between symbol).
CHAPTER 7
7.2 Organization of Central Nervous System
Levels of description
1m > Central Nervous System
10 cm > Systems
1 cm > Maps
1 mm > Networks
100 um > Neurons
1 A > Molecules
(Sejnowki and Churchland)
- Amnesic patients don’t see affected procedural memory, only declarative memory, this would mean that there are two clearly different neurobiological implementations of these two types of memory.
- Imbalance between right and left hemisphere