# Seeing the Schema

For the past month or two, I’ve been regularly playing a mental rotation game, available here. In the game, the task is to find which two of the six displayed block objects are identical under rotation. I’m not the best at mental rotation, so I figured I’d try and get better at it. But while I’ve gotten better at the matching task, I think I’ve started to see diminishing returns at mental rotations—primarily because, for the most part, I’ve stopped doing them.

The “reward signal” here is success at the matching task—which doesn’t actually require you to perform a mental rotation. In the above image, for example, I run a few basic heuristics: the two blocks on the right are planar, and as one of them has a hook shape and the other doesn’t, they can’t match. Then, the lower centre block doesn’t have a planar hook shape, where the other three do, so it can’t match any of them. Finally, of the remaining blocks, the top centre’s extruded “pole” above the planar hook is two blocks high, where the two on the left have extrusions three blocks high. As such, the two on the left must match.

It’s easier and faster for my brain to run these “checksums” than it is to actually perform the mental rotation task. Early on, I was actually performing mental rotation, but now I’m just running heuristics across the set of shapes. This might seem like a pathological or degenerate solution—I’m not actually training the “thing I wanted” any more—but it’s the path that gives me the highest reward at the end, so that’s the thing my subconscious brain’s started defaulting to.

It’s weird to see a misaligned reward signal from the inside.