What is cognitive psychology?

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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.

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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.

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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?

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Why do we study it?

• 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.

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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

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Information Processing Approach
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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

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2 Issues Result

• What are the stages through which information
  passes?
• In what form is the information represented in
  the human mind?

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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

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Areas in Domain

• Cognitive Neuroscience
• Perception
• Attention
• Memory
• Representation of Knowledge
• Imagery

• Language
• Developmental Psychology
• Thinking and concept formation
• Human intelligence
• Artificial Intelligence
• Pattern Recognition

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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?

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early 20th century to late 1940' s

• behaviorism - rely only on things that are
  observable concept of 'mind' untenable
• SR chaining - stimulusresponse
• verbal learning - SR chaining applied to
  language word associations
• late 1940' s to 1950' s - dissatisfaction with
  behaviorism and verbal learning

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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

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Cognitive Revolution

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

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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!

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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.

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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.

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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

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Modeling -

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

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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

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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

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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)

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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

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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

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basic types of models

• Cognitive Bionomics
• evolutionary psychology biology cognition
• Cognition can be best understood within the
  context of human physical and social evolution