CS 448 Lecture - cognition

1. Programming questions?
2. Modelling cognition
   1. Wholism -- human nature
      Observations about humans
      1. fascinated by sex and violence
      2. hate confusion/need to understand
      3. need meaning/purpose
      4. build internal, predictive models
      5. use metaphor easily
      6. detect patterns everywhere
      7. generalize (and overgeneralize) automatically
      8. like to tell/hear stories
      9. learn quickly (and like it!); routine activities become unconscious (5+/-2!)
      10. tend to (if not paying attention) divide the world into us and them
      11. imitate better than other primates
      
      Theories of mind/cognition
      1. Jung's archetypes
      2. Buddhism
   2. Reductionism -- neurons and their connections
      1. neurons
         • McCollough-Pitts
         • Real neurons
           1. Sodium pumps (one molecule at a time)
           2. Voltage gated sodium channels.
           3. Resting firing rate
           4. Synchrony! Fireflies, leaky toilet metaphor
      2. connections
         • Hebb's rule -- "When an axon of cell A is near enough to excite a cell B and repeatedly or persistently takes part in firing it, some growth process or metabolic change takes palce in one or both cells such that A's efficiency, as one of the cells firing B, is increased.". (D.O.Hebb, The Organization of Behavior, p62, 1949).
         • Over time, with repeated experience with a particular object, this rule can cause the neurons which become active in its presence to form strong enough connections that they can function as a group. This "cell assembly" is an active symbol which stands for that thing and is capable of activity in its absence; this is the basis of cognition.
      3. activity control
         1. fatigue
         2. inhibition
            • local/lateral
            • regional (Milner)
            • global (dopamine/norepinepherine)