Background
    - Can study the mind from different levels
        ~ Start from the bottom (neurons)
        ~ Start from the top (Theories of cognitive systems)
    - Miller's psychophysics experiemtns on exploring the cognitive capaties and limiations of the subject
    - Kosslyn's focusing on different way

**Marr's Approach**:
    - Distinguished different explanatory tasks at different levels - very influential idea! Integration!
    - Gave a general theoretical framewrok for combining them
    - Aply the frmaework in considerable detail with examples of things like visual

> Marr's Three Types of Analysis:
    - Computational
    - Algorithmic
    - Implementation

**Computation Analysis**:
    Form of 'task analysis' of a cognitive system
        1) Identifies the specific information-processing problem that the system is configured to solve
        2) Identify the general constraints upon any solution to that problem
    `
    Example: How do we go from 'light hitting eyeballs' to 'object/ground'?
        aka: Object recognition

**Algorithmic Analysis**:
    How does the cognitive system actually perform the information-processing task?
    What is the input and output? How is information encoded?
        [Big side note][How much of this is built-in to the system? Not quite hard-wired, but have a 'biological disposition' towards it. There is a lot of parallels with how fast we learn certain things with different species. Evolutionary psychology! Can also use Infants!]
    `
    Example: [Input]{Visual stimulus} - [Output]{Objects in scene}

**Implementation Analysis**:
    Find a physical realization for the algorithm!
    - Identify neural structures realizing the basic represenational states to which the algorithm applies
    - How does the brain make it work?
    `
    Example: Visual Cortex

**Marr's Computational Analysis of Visual System**:
    - Classic example of top-down analysis
    Two basic conclusions from his task analysis:
        - The visual systems job is to provide a 3D representation of the visual environment that can serve as input to other later processes
        - Object-Centered rather than viewer-centered frame of reference. Looking around/moving around doesnt change your representation of the objects in the room.
    `
    Conclusion:
    - Information about the shape of an object must be processed separately from information about what the object is and what it is called
    - The visual system can deliver a specification of the shape of an object even when ---
    `
    Theoretical Considerations:
    - Recognition abilities are constant across changes in how things look to the perceiver due to:
        - Orientation of the object
        - Its distance from perceiver
        - Partial occlusion by other objects