Approaching Scientific Question & How to Model
Marr’s 3 levels of analysis
Brain: hierarchy of complexities
- Computational level - 1
- What is the objective of the system?
- How close is it to optimal?
- Algorithmic level - 2
- What are the data structures?
- What are the approximations?
- What is the runtime?
- Implementation level - 3
- What is the hardware?
- Neurons? Synapses? Molecules?
- What is the hardware?
Diversity of modeling goals
- Useful: good at solving real-world problems?
- Normative: provide the optimal solutions to problems that exist in the real world?
- Clinically relevant: produce insights relevant for developing or evaluating clinical interventions?
- Inspire experiments: change the way we think about a problem, raising interesting new hypotheses & experiments?
- Microscopic realism: describe the microscopic properties of the brain?
- Macroscopic realism: describe properties of brain areas and networks?
- Behavioral realism: can faithfully describe and explain behavioral phenomena?
- Representational: use representations of info that are similar to representations in the brain?
- Compact: can be succinctly expressed in math or code, making them easy for humans to understand?
- Analytically tractable: understandable through equations instead of numerical simulations, therefore generalizable?
- Interpretable?
- Beauty: symmetrical, balanced, or resonate well with the way we think?
1. Asking your own question
- What exact aspect of data needs modeling?
- Answer this question clearly and precisely! Otherwise you will get lost (almost guaranteed)
- Write everything down!
- Also identify aspects of data that you do not want to address (yet)
- Define an evaluation method!
- How will you know your modeling is good?
- E.g. comparison to specific data (quantitative method of comparison?)
- For computational models: think of an experiment that could test your model
- You essentially want your model to interface with this experiment, i.e. you want to simulate this experiment