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

Scientific Study of Info Processing... zScientific study: Based on the experimental method, empirical, scientific. zHuman information processing: People sometimes operate as information processors. yInformation 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.

Some examples of questions of interest: zWhat is the capacity of short-term memory? zHow is short-term memory searched? zHow long can memories last? zHow do people understand language? zWhat is attention?

Why do we study it? zTheoretical 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 z Practical reasons - to develop better human-machine interfaces, develop improved teaching methods, understand where things like stereotypes come from, etc.

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

Information Processing Approach

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

2 Issues Result… zWhat are the stages through which information passes? zIn what form is the information represented in the human mind?

Domain of Cognitive Psych zThe field draws off research, theory and expertise from at least 12 different areas zEach of these areas are covered in dif chapters throughout the book

Areas in Domain zCognitive Neuroscience zPerception zAttention zMemory zRepresentation of Knowledge zImagery z Language z Developmental Psychology z Thinking and concept formation z Human intelligence z Artificial Intelligence z Pattern Recognition

pre-20th century history of cognitive psychology yAristotle - How do we classify objects into groups? yDescartes - What is the relationship between the mind and the body? yLocke - How much do environmental and genetic influences affect perception? yEbbinghaus - Can we quantify how information is retained and retrieved from memory? yBryan & Harter - What happens as a task becomes well-learned?

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

Reemergence of Cognitive Psych zThe failure of behaviorism zEmergence of communication theory ysignal detection, attention, cybernetics, and information theory experimented zModern linguistics zMemory Research zComputer Science and tech advances zCognitive Development

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

Levels of description in cognitive psychology zTheories 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!

Models vs. Theories ztheory : comprehensive explanation of a cognitive phenomenon based on a detailed description of the phenomenon that is derived from experimental evidence. za 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.

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

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

Modeling - zmakes explicit the assumptions underlying a theory of cognition ztests the theory Ex.) Information Processing Model

Computer Modeling zdesigning a program to run on a computer to simulate what a human does yshould be grounded in what humans actually do ycaveat - there are sometimes several means to the same end

basic types of models Semantic networks znetwork of interconnected nodes; ynodes stand for characteristics ylinks between nodes describe relationships between nodes. e.g., robin - bird - animal

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

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

Problems with cognitive neuropsychology model zextensive (non-local) nature of brain damage zindividual differences among patients zability of other modules to take over functioning of impaired modules

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