1. sensory systems
   1. What are their functions?
   2. How do they work?
      1. common sense
      2. individual senses
         1. receptors: chemical, light, mechanical
         2. localization
         3. perception and recognition
         4. a sense of time?
   3. How do they differ among the primates, especially humans?
      1. different functions?
      2. different structures?
      3. different phenomenal experience?
      4. For humans, we have three specific questions:
         1. loss of sensitivity of smell?
         2. adaptations for speech perception?
         3. how does our consciousness or phenomenal experience differ from a chimp's?
   4. How and why did they evolve that way?
      1. external
         1. hearing
         2. vision (depth, acuity, color, recognition)
         3. touch
         4. smell
         5. taste
      2. time
         1. circadian
         2. interval
      3. consciousness?