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Linear Algebra Refresher Course

Jul 12, 2024

Linear Algebra - Pre-reqs Refresher

Introduction

Lecturer: Ella Batty

  • Lecturer and Curriculum Developer for Computational Neuroscience at Harvard
  • Coordinating Academic Officer for the Comp Neuro course at Neuromatch
  • Interests: Comp neuro education, using Machine Learning to model neurons, methods for understanding complex networks
  • Hobbies: Reading, dogs, binging murder mysteries

Why Linear Algebra is Important

  • Foundational Math: Central to many areas of math and various applications
    • Used in physics, computer science, economics, etc.
    • Especially used in neuroscience, particularly computational and theoretical neuroscience
  • Neuroscience Fit: Linear algebra is the "language of data"
    • Organizes, transforms, analyzes data
    • Essential for over half of the comp neuro course

Example: Neurons and Image Stimuli

  • Recording data from three neurons when showing images to an animal
    • Image 1 (e.g., dog): Neuron 1: 10 Hz, Neuron 2: 50 Hz, Neuron 3: 2 Hz
    • Image 2 (e.g., cow): Neuron 1: 12 Hz, Neuron 2: 8 Hz, Neuron 3: 30 Hz
  • Challenge: Messy data with lots of pairings
  • Solution: Organize data using "Vectors"
    • Vector: Ordered list of numbers (e.g., order here is according to neurons)
    • Example: [10, 50, 2] for the dog image
  • Operations on Vectors: Can perform operations like vector subtraction
    • Example: Difference between responses to dog and cow images
      • (10 - 12), (50 - 8), (2 - 30) results in [-2, 42, -28]

Tutorials Covered Today

  1. Vectors Tutorial:
    • Definition of a vector
    • Vector properties and operations
    • Defining space through vectors
  2. Matrices Tutorial:
    • How matrices transform space
    • Matrix properties and operations
    • Eigenvalues and eigenvectors
  3. Bonus (if time allows): Discrete Dynamical Systems
    • Modeling a simple neural circuit
    • Understanding dynamics using eigenvalues

Note: No need to worry if terms seem complex; understanding will develop through the course.