Information Processing Model of Cognition

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Information Processing Model of Cognition

• First Meta-theory in cognitive science a all
  encompassing theory designed to explain cognition

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The Use of Models

• Hydraulic models of human behavior- Romans
  believed the heart pumped fluids that caused
  movement
• Descartes mechanical model, the body functions
  like a machine
• British empiricists- model base upon physics
• Associationists model based upon chemistry
• 1950s computer model information processing
  model
• 1980 brain model - connectionism

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7 Themes of Cognition

• Attention different types are important
• Automatic and conscious processing
• Data driven versus conceptually driven processing
• Representations how memories are stored
• Implicit versus explicit memory
• Metacognition
• The Brain

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Research Methods Used

• Correlational studies are two or more factors
  or variables related
• Experimental studies manipulate one or more
  variables and control others
• Quazi-experimental the variable of interest
  cannot be manipulated, usually involves subject
  variables
• Single case use of one subject most
  frequently used in neurocognition

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Methods for Measuring Cognition

• 1. Reaction time measure time between stimulus
  and response
• 2. Accuracy measurements
• Simple how many mistakes were made
• Complex look for a pattern of errors
• 3. Trials to criterion
• 4. Relearning learn a task. After a delay how
  long did it take to relearn the task

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Guiding Analogies

• Channel Capacity
• An early analogy for the limited capacity of the
  human information-processing system.
• The Computer Analogy
• Human information processing may be similar to
  the sequence of steps and operations in a
  computer program, similar to the flow of
  information from input to output when a computer
  processes information.

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The Atkinson and Shiffrin Model

• The Atkinson and Shiffrin Model of Human Memory
• Encoding The act of taking environmental
  stimulation and converting it to a usable mental
  form (electrical signals).
• Three memory components sensory memory,
  short-term memory, and long-term memory.

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Examples

• Multiplying 2 X 3
• Lexical Decision Task A timed task in which
  people decide whether letter strings are or are
  not English words.
• Takes longer to decide if a non-word is real than
  a real world
• Word Frequency Effect The effect which states
  that it takes significantly longer to judge words
  of lower frequency than it does to judge
  high-frequency words.

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The Strict Information Processing Approach

• Sequential Stages of Processing An assumption
  in most process models that the separate stages
  of processing occur in a fixed sequence, with no
  overlap of the stages.
• Independent and Nonoverlapping Stages The
  assumption in the strict information processing
  approach that the stages of processing are
  independent of one another in their functioning,
  and that they do not overlap in time.

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Some Problems

• Parallel Processing Any mental processing in
  which two or more processes or operations occur
  simultaneously.
• Model could not explain how context could speed
  up processing such as during priming tasks

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The Modern Cognitive Approach Cognitive Science
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Cognitive Science

• The study of human thought, using all available
  scientific techniques and including all relevant
  scientific disciplines for exploring and
  investigating cognition.

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Updating the Standard Theory
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Two Types of Processing

• Bottom-up or data driven
• Top-down or conceptually driven

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Summary

• The strict-information processing approach to
  cognition was replaced with a broader, more
  inclusive approach now known as cognitive
  science. This approach described cognition as
  the coordinated, often parallel operation of
  mental processes within a multicomponent memory
  system. The approach is deliberately
  multidisciplinary, accepting evidence from all
  the sciences interested in cognition.

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Brain Anatomy
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Brain Anatomy (cont.)

• Neocortex or cerebral cortex The top layer of
  the brain responsible for higher-level mental
  processes.
• The lobes of the neocortex the frontal lobe,
  parietal lobe, occipital lobe, and temporal lobe

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Four Lobes of the Neocortex
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Lower Brain Structures
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Brain Anatomy (cont.)

• Three other subcortical (below the neocortext)
  structures are especially important to
  neurocognition
• thalamus the gateway to the cortex almost
  all messages entering the cortex come through
  the thalamus
• corpus callosum the primary bridge across
  which messages pass between the left and right
  halves or hemispheres of the neocortex
• hippocampus an internal brain structure
  strongly implicated in the storing of new
  information into long-term memory

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Principles of Functioning

• Contralaterality The principle that control of
  one side of the body is localized in the
  opposite-side cerebral hemisphere.
• Hemispheric Specialization The principle that
  each cerebral hemisphere has specialized
  functions and abilities.

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Split-Brain Research and Lateralization

• Research on split-brain patients
• Principle of lateralization

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Basic Neurology

• Neurons The basic building block of the brain
  and the entire nervous system, a neuron is a cell
  that is specialized for receiving and
  transmitting a neural impulse.

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The various structures of the neuron
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Basic Neurology (cont.)

• Synapses The region where the axon terminals of
  one neuron and the dendrites of another come
  together is the synapse.
• Neurotransmitter The chemical substance
  released into the synapse between two neurons,
  responsible for activating or inhibiting the next
  neuron in sequence.

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Methods of Investigation

• Lesions Used by Sperry the site and extent of
  the brain lesion are important guides to the kind
  of disruption in behavior that is observed and
  vice versa.
• Direct Stimulation Pioneered by Penfield the
  patient in brain surgery remained conscious
  during surgery and was administered minute
  electrical charges to the exposed brain, thus
  triggering very small regions.

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Exposed cortex of one of Penfields patients
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Methods of Investigation (cont.)

• Imaging Technology
• Magnetic Resonance Imaging (MRI) Gives clear
  pictures of the structure of the brain.
• Functional MRI Image shows regions of the brain
  with heightened neural activity, with different
  colors reflecting high or low levels of blood
  flow, oxygen uptake, and the like.
• PET scans- use or radioactive labels attached to
  glucose

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Methods of Investigation (cont.)

• Electrocephalograms (EEG) Electrodes are
  attached to the subjects scalp, and the device
  records the patterns of brain waves.
• Event-Related Potentials The momentary changes
  in electrical activity of the brain when a
  particular stimulus is presented to the subject.

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Neural Net Models Connectionism

• Connectionist models are often called neural net
  models or parallel distributed processing (PDP)
  models the three terms are synonymous. All
  refer to a computer-based technique for modeling
  complex neural based systems.

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An early connectionist model by McClelland and
Rumelhart