Distant!

October 11th, 2025| Topic: RaMbLeS | 0

We use lots of cues to make sure we don’t get lost. Familiar landmarks, general sense of direction, an estimate of how far we have walked, etc. Apparently the last is very important—there is a portion of the brain dedicated to that estimation. Yup, a milometer in the brain.

Thus saith researchers from the UK, US, and Australia in “Grid Cell Distortion Is Associated with Increased Distance Estimation Error in Polarized Environments,” published this month in Current Biology.

These folks got rats to run a specific distance in a rat arena to get a reward. They then made electrical recordings of individual cells (called “grid cells”) in the brain’s navigation system as the rats performed the task. There were cells there “fired” in a pattern that looked like a mileage clock—ticking with every few steps the animal travelled. The regularity of the pedometer-like signal was correlated with accuracy of distance estimation, suggesting that this was the neural signal that allowed those rodents to keep track of how far they had run.

Prof. Ainge, lead author:

The more regular that firing pattern was, the better the animals were at estimating the distance they had to go to get that treat.”

Crucially, when the scientists altered the shape of the rat arena, that regular firing pattern became erratic and the rats struggled to work out how far they needed to go before they returned to the start for their chocolate treat.

And not just in rats.

To test this in humans, the researchers scaled up their rat-sized experiment. They built a 40 × 20-feet arena and asked volunteers to carry out the same task as the rats—walking a set distance, then returning to the start. Just like rats, human participants were consistently able to estimate the distance correctly when they were in a symmetrical, rectangular box. But when the scientists moved the walls of their purpose-built arena to change its shape, the participants started making mistakes.

I.e., if you disrupt the ticking of that mileage clock by changing the environment, say when it is dark or foggy (or when walls around you start shifting!), both rats and humans start getting their distance estimation wrong. It suddenly becomes much more difficult to estimate how far we have travelled, because our mileage counter stops working reliably in obscure and unfamiliar surroundings.

Ainge, again:

The fact that humans and rats show the same type of errors in distance estimation in different environments gives us confidence that the brain mechanisms are the same in both species. Rats and humans learn the distance estimation task really well; but then, when you change the environment in the way that we know distorts the signal in the rats, you see exactly the same behavioral pattern in humans.”

Estimation of distance is a good thing, the Bible says, particularly of distance from God. The psalmist was particularly conscious of this, especially in his days of turmoil, trouble, and turbulence. He pleads (often):

My God, my God, why have You abandoned me?
Far from my deliverance are the words of my groaning.
Be not far from me, for distress is near, for there is no one who is a helper.
But You, Yahweh, be not far; my strength, hasten to my help.
Psalm 22:1, 11, 19

God, do not be far from me; my God, hurry to my help.
Psalm 71:12

It is not safe for those who are distant from God.

For, behold, those far from You perish;
You terminate all those who are unfaithful to You.
Psalm 73:27

SOURCE: Current Biology; BBC