Mind Hacks

Hack #26. Get Adjusted

We get used to things because our brain finds consistency boring and adjusts to filter it out.

My limbs feel weightless. I can’t feel my clothes on my body. The humming of my laptop has disappeared. The flicker of the overhead light has faded out of my consciousness. I know it all must still be happening—I just don’t notice it anymore.

In other words, it’s just another normal day in the world with my brain.

Our brains let us ignore any constant input. A good thing too; otherwise, we’d spend all our time thinking about how heavy our hands are, how exactly our T-shirts feel on our backs, or at precisely what pitch our computers are humming, instead of concentrating on the task at hand.

The general term for this process of adjusting for constant input is called adaptation. Combined with relative representation of input, adaptation gives us aftereffects. The motion aftereffect is a good example of a complex adaptation process, so we’ll walk through a detailed story about that here in a moment.

Note

Both relative representation and the motion aftereffect are described in [Hack #25]. Simply put, how much “movement up” we perceive depends on the activation of up-sensitive neurons compared against the activation of down-sensitive neurons, not just the absolute level of activity.

Adaptation is a feature of all the sensory systems. You’ll notice it (or, on the contrary, most likely not notice it) for sound, touch, and smells particularly. It affects vision [[Hack #25]], too. ...