VISUAL PATHWAYS AND SPATIAL FREQUENCIES

What is Retinotopic Mapping?

In short: Retinotopic mapping means your brain organizes sight like a physical map—what is next to each other in the real world is processed by cells next to each other in your brain.

A: The way the brain organizes visual information by creating a literal geometric "map" of the visual world on the surface of the cortex, where adjacent points on the retina are represented by adjacent neurons.

• basically, the layout of the world you see is mapped out in the back of your brain

Compare "View Invariant" and "View Dependent" object recognition in the "What" pathway.

A:

• View Invariant: Recognizing an object from any angle (e.g., knowing a car is a car from the front, side, or top).

• View Dependent: Recognizing an object only from a specific, familiar angle; if it's flipped or rotated oddly, processing takes longer

Define Low Spatial Frequencies (LSF) vs. High Spatial Frequencies (HSF).

A:

• LSF: Provides a quick overall "blurry gist" with low detail, processed very rapidly.

• HSF: Provides fine, high-level details, but requires extensive cortical processing time.

• BSF (Broad Spatial Frequencies): LSF + HSF combined, representing normal, everyday vision.

Why do cats act startled or scared when presented with a cucumber suddenly placed behind them?

A: The cat's subcortical "Low Road" quickly processes a blurry, snake-like shape via LSF before the slow "High Road" can process full details, triggering an instantaneous defensive reaction.