Why Does a Watch Fade from Awareness After a While?

When a watch is first fastened, the pressure and edges of the strap feel obvious. A little later it is still pressing on the same place, yet we no longer notice it. The sensation has not been switched off. More accurately, the nervous system has reduced its response to stimulation that remains constant, unchanged and apparently harmless, leaving limited resources available for new changes.

Two distinct processes may contribute. Sensory adaptation occurs within sensory pathways. Mechanoreceptors in the skin respond to steady pressure at different rates: some fire strongly when stimulation begins or changes, then respond less while it remains constant. Habituation is a behavioural decline in response caused by repeated stimulation, and cannot simply be attributed to receptor fatigue. Researchers distinguish habituation from sensory adaptation by examining features such as stimulus specificity, recovery after a pause, or whether another stimulus restores the original response.

If the watch suddenly slips, the strap tightens, or you deliberately return attention to your wrist, the sensation often becomes clear at once. The brain has not deleted information about the watch; it has lowered the priority of an unchanging input. This example alone cannot identify exactly where the decline occurs. Peripheral receptors, central processing and attention may all contribute, while the individual, strap material and pressure can change the outcome. The useful conclusion is not that habit makes us numb, but that reducing responses to a stable environment makes change easier to detect.

https://pmc.ncbi.nlm.nih.gov/articles/PMC2754195/
https://pmc.ncbi.nlm.nih.gov/articles/PMC9201416/