arrow optical illusion

I've seen things like this before and I find it super interesting because it seems to indicate the shape of the arrow is somehow automatically recognized by my visual cortex. I have questions:

I've seen submarine sonar maps indicating targets as a circle with a line on one side indicating the direction and speed. The sub is moving in the direction of the line (and of course I can't find an example of this online).

In a sense this is the opposite of a traditional arrow where the indicated direction is towards the complicated portion on the end. My point is maybe the shape of an arrow isn't an universal symbol. Is there some a remote human civilization that doesn't recognize an arrow as a symbol that means to point in a specific direction? What I'm wondering is if the meaning of an arrow symbol is baked into all humans (and by extension other higher mammals) or if it's something I've learned.

Does a baby know what an arrow symbol means? If not, at what age do they recognize the meaning? Would this illusion work on someone who hadn't made that connection?

posted by na on November 15, 2022 20:58