Rat's Cannot Use Color For Spacial Orientation?

I’m listening to one of The Great Courses audio lecture series entitled: “Scientific Secrets for Raising Kids Who Thrive”.

In lecture 6, Professor Vishton refers to a 1986 study by Ken Cheng. The experiment revealed that rats do not use color when collecting environmental data for spacial orientation.


I’m completely intrigued!

First - it would seem like any visual input would necessarily be tied to spacial orientation (granted that sentence is loaded with bias). However, thinking through the process of evolution - I began to see how this could happen in that rats are nocturnal. Obviously, this indicates a slim likelihood that such an evolutionary trait would find itself useful in the gene pool.

It could be genetic, but it could also be just a matter of making those neural associations. Their lack of color-spacial associative capacity might just be a result of their nocturnal behavior. If you raised a rat with constant light in an extremely colorful environment, might their brains begin to process color as an effective contributing factor for spacial orientation? Isn’t that all part of how HTM works anyway? Shouldn’t the neural substrate eventually build horizontal associations between color, geometries, and spacial orientation & reasoning?

So is it that the neural structures don’t appear because the rats are not equipped with the necessary genetics or is it due to some specific processing anomalies?

btw - I’m not expecting anybody to answer my questions - I just found this incredibly interesting from an HTM standpoint.

I’m curious - if it is a neural/processing issue, would the associations have to develop in childhood -or- given enough training, might adult rats be capable of building such associations?

Anyway - interesting little rabbit-hole