Thync:

The forehead and the neck piece generate impulses, controlled by the program you've loaded via a companion smartphone app, that actively jolt the neurons in those two sensitive areas; these programs generate mood shifts that Thync calls "Vibes." At present, there are two sets of Vibes available: One designed to produce relaxation, and another designed to produce alertness. [...]

I barely wait before jacking the setting to 100. There's no point in experiencing something unless you're doing it to the max. At 70, the sensation the device produces is like ants crawling on the surface of your skin. At 100, the ants are on the inside of your skin and dancing a wild myrmecoid folk dance. [...]

The 20 minutes are up sooner than I imagined. I peel the device from my forehead, remove the underlying disposable electrodes, replace my glasses. The difference, I must admit, is palpable: Everything seems more finely etched, crisper. I notice more details in the world around me, and the sense of dullness that three days spent listening to press pitches from moribund industry giants has draped over my brain seems to have been peeled away.

Previously, previously, previously, previously, previously, previously.