1. Assumptions

This investigation starts with the following key assumptions:

Action in the world is expressed by the position and movements of the bones (of the vertebrates we are considering)

• The change in position of the bones, in general, is caused by rotation in the joints
  • We shall focus on the major bones such as arms and legs, most clearly involved in action
  • We shall greatly simplify the bone structure, and essentially ignore the backbone and the hands
• The rotation in the joints is caused by muscles
  • We shall greatly simplify the muscle mechanism to rotate joints
  • We shall greatly simplify the complexity by focussing on the geometry rather than on actual muscle activity and attachment
• The movement of the muscles to cause rotation in the joints is in turn caused by information transmitted through neural connections
  • We shall greatly simplify muscle activation through neural activity patterns
  • We shall greatly simplify timing relationships in neural activity

To increase the likelihood of successful action, aspects of the action must depend on and integrate the information from perception

• Survivability and thus evolutionary success depend on successful action, whether in feeding, fleeing, fighting, or mating.
  • Relative success or failure is perceived
  • aspects of the perception and action are remembered

Perception is a major source of information about the world. (We will focus on vision, but similar considerations apply to information from other senses, including proprioception.)

• Visual perception illustrates the different forms of encoding
  • the optical source of the information in the world is three dimensional, but transformed by the eyes into two two-dimensional projections
  • the eye rasterizes or pixellates the information using rods and cones, so that the representation is as points in the visual space
• Neuroscience has shown that attributes and features are extracted from the visual image, and motion is detected

Learning increases the likelihood of successful action

• Learning is usually based on memory of past actions and the memory of past perceptions
  • The pattern and sequence of action must be remembered
  • The perceptions and the outcome from the action must be remembered
  • We must be able to find patterns of action that led to the desired outcome
  • We must be able to repeat the pattern and sequence of action that was successful in the past

Action, perception, memory, and prediction are linked by the flow of information

• Muscles to control action are in turn controlled by information flowing through neural fibres
  • Neural activity causes muscles to contract and relax, thus causing rotation about joints
  • Neural firing takes time to propagate from the brain to the muscles
  • The patterns of neural activity may be transformed on the way from the brain to the muscles
• Descriptive information is extracted from perceptual information
  • Features such as lines and motion are extracted from the pixellated retinal image
  • A 3D representation of the world is constructed containing objects

Information is always encoded with some form of (data) representation

• Information is usually transmitted from the place of origin, the source, to one or more places where it is used
  • the transmission can be via dedicated wiring, also known as labelled lines
  • the transmission can be via shared channels such as a network
• Information is commonly transformed from one form of representation to another
  • the transformation can compress the data
  • the transformation can be lossy or lossless