Researchers recruited 48 adults for the study who were asked to learn and perform a specific fingerpattern (pushing keys on a keyboard in a particular sequence as fast as possible in 30 seconds).
Push lets you add drum hits by tapping the pads on and off as the loop plays, but you can also record a pattern in live if you're a bit of a finger-drummer.
Then the finger joined the girl, the tray banged shut, I was standing by my shopping cart, studying the mesh pattern of the collapsible wire basket, trying to recall what was already slipping away.