Marr’s Levels
Last modified on May 29, 2022
Stole this frame from various classes, most notably PSYCH 50: Cognitive Neuroscience.
Marr’s Levels is one example of viewing the system that is the human brain-mind-thing at three different layers of abstraction.
Computational level
What is the goal?
Algorithmic level
What are the representations/frames/ways of thinking/procedures?
Right now, I’m kind of using this as like the “middleware” between goals and concrete realizations. They are sort of the idea playground, the habit loops, the states of mind, etc.
Implementation level
What are the physical mechanisms that bring about these changes? What are the current things I’m doing?
See: , frames
I feel like Input systems in the brain ascend Marr’s Levels (from physical reality => representations => meaning / goal of perceiving), whereas Output (motor) systems descend them (prefrontal decides a lofty goal, and that gets translated into concrete movement/reality.)
Links to “Marr’s Levels”
Intro (Intro)
How does our brain allow us to do what we do? – that is, cognitive neuroscience = how cognition is implemented in the brain, whereas cognitive science = how we think and behave.
different “scales” of the same system – genes => intracellular signals => neurotransmitters/receptors => synapses => neurons => local circuits => populations => areas => interacting brains
different processes: input · output · feedback · broadcast
Key framework: Marr’s Levels. What goal? What algorithm? What implementation? – interesting bit from Marr here. We can’t study the brain just by looking at neuron implementation – we need to ask what they’re trying to accomplish, and how.
Experiment types: observe brain, add something to brain, remove something from brain. observe is cheaper, but add/remove can establish causality (since you’re essentially doing the “wiggle” test.) So, when FB/Twitter/whatever do A/B testing, they’re basically doing add/remove (psych not neuro) experiments lol…
Consciousness (Consciousness)
Feels like…we’re going with a neuroscientist’s definition of consciousness here. One that presupposes Identity Theory…
I think he tried to apply the Marr’s Levels construct here – top points are the physical / algorithmic ways consciousness happens, bottom is big picture, what’s the purpose of consciousness?
system (Interesting phenomena: > Redundancy)
Everyone has their “own road to Rome.” i.e., People in different fields reproduce many of the same algorithms or goals or whatever with different implementations. (Marr’s level stuff…)