What is cognitive psychology?

1. What is cognitive psychology? • Cognitive psychology is the study of perception, attention, memory, language, and thinking in humans...how we know about the world. • ...the scientific study of the human mind and information processing • Related to other fields - linguistics, computer science, philosophy, development, etc.

2. Scientific Study of Info Processing... • Scientific study: Based on the experimental method, empirical, scientific. • Human information processing: People sometimes operate as information processors. • Information comes from the environment, is stored briefly, some is selected for additional processing, something is done to it, it may result in some additional behavior.

3. Some examples of questions of interest: • What is the capacity of short-term memory? • How is short-term memory searched? • How long can memories last? • How do people understand language? • What is attention?

4. Theoretical reasons - to learn more about the processes that underlie our ability to represent information about the world in memory, how language works, and how we solve problems, how we learn things, etc Practical reasons - to develop better human-machine interfaces, develop improved teaching methods, understand where things like stereotypes come from, etc. Why do we study it?

5. Models of Cognition • Current approaches to studying cognition • The primary approach to cognitive psychology today is information processing. • The information processing approach assumes that information from the environment undergoes a series of transformations as it is processed by different cognitive systems

6. Information Processing Approach

7. Assumptions of Info Proc. Approach • Cognition occurs through series of sequential stages • each stage performs unique process on incoming info received from environment (“internal representations”) or other stages • Response is assumed to be the product of these processes

8. 2 Issues Result… • What are the stages through which information passes? • In what form is the information represented in the human mind?

9. Domain of Cognitive Psych • The field draws off research, theory and expertise from at least 12 different areas • Each of these areas are covered in dif chapters throughout the book

10. Cognitive Neuroscience Perception Attention Memory Representation of Knowledge Imagery Language Developmental Psychology Thinking and concept formation Human intelligence Artificial Intelligence Pattern Recognition Areas in Domain

11. pre-20th century history of cognitive psychology • Aristotle - How do we classify objects into groups? • Descartes - What is the relationship between the mind and the body? • Locke - How much do environmental and genetic influences affect perception? • Ebbinghaus - Can we quantify how information is retained and retrieved from memory? • Bryan & Harter - What happens as a task becomes well-learned?

12. early 20th century to late 1940' s • behaviorism - rely only on things that are observable; concept of 'mind' untenable • SR chaining - stimulus®response • verbal learning - SR chaining applied to language; word associations late 1940' s to 1950' s - dissatisfaction with behaviorism and verbal learning

13. Reemergence of Cognitive Psych • The failure of behaviorism • Emergence of communication theory • signal detection , attention, cybernetics, and information theory experimented • Modern linguistics • Memory Research • Computer Science and tech advances • Cognitive Development

14. Cognitive Revolution The changes in American psychology have been so profound over the last 50 years that it has been called the cognitive revolution

15. Levels of description in cognitive psychology • Theories exist at several levels of description: 1.Computational theory - description of processing, input/output, purpose of computation (flowchart) 2.Algorithmic level -implementation of computational theory; exact nature of computation is described 3.Hardware level - physical realization of computational and algorithmic levels; i.e., the brain!

16. Models vs. Theories • theory : comprehensive explanation of a cognitive phenomenon based on a detailed description of the phenomenon that is derived from experimental evidence. • a model is either a mathematical expression derived from a theory that can be used to summarize and predict empirical data, or a computer program derived from a theory that simulates and predicts empirical data.

17. Cognitive Models and Conceptual Science • In general, most hypotheses about the mind come from behavioral studies • i.e., seeing what people do in psychological experiments • However, cognitive psychology also considers information acquired through modeling cognitive processes, analyzing impaired systems, and introspection.

18. Cognitive Psychology and Conceptual Science • Conceptual science - very general, consequences of observations, metaphorical • Cognitive Models - abstract organizational ideas derived from inferences based on observations; part of conceptual science • Specialized forms of scientific concepts that have the same purposes • used to describe the detection, storage and use of information within the “system”

19. Modeling - • makes explicit the assumptions underlying a theory of cognition • tests the theory Ex.) Information Processing Model

20. Computer Modeling • designing a program to run on a computer to simulate what a human does • should be grounded in what humans actually do • caveat - there are sometimes several means to the same end

21. basic types of models Semantic networks • network of interconnected nodes; • nodes stand for characteristics • links between nodes describe relationships between nodes. e.g., robin - bird - animal

22. basic types of models Connectionist networks /neural networks /Parallel Distributed Processing models • attempt to simulate characteristics of information processing among neurons. • Connectionist networks can learn. Cognitive Science (computer science + neuroscience + cognitive psych)

23. basic types of models cognitive neuropsychology - • examining cognitive performance in brain-damaged patients • explain impairment in terms of theories from cognitive psychology • patterns of impairment may also be able to inform theories of normal cognitive functioning • e.g., differential impairment of long-term and short-term memory systems in some patients

24. Problems with cognitive neuropsychology model • extensive (non-local) nature of brain damage • individual differences among patients • ability of other modules to take over functioning of impaired modules

25. basic types of models Cognitive Bionomics evolutionary psychology + biology + cognition • Cognition can be best understood within the context of human physical and social evolution