Early human augmentation startups used Transcranial Direct Current Stimulation (TDCS) to create wearable devices that could induce specific mental states. One version acted as a stimulant, like "digital caffeine," while another induced relaxation, like "digital cannabis," by delivering low-voltage electricity to specific brain regions.

The performance ceiling for non-invasive Brain-Computer Interfaces (BCIs) is rising dramatically, not from better sensors, but from advanced AI. New models can extract high-fidelity signals from noisy data collected outside the skull, potentially making surgical implants like Neuralink unnecessary for sophisticated use cases.

AI devices must be close to human senses to be effective. Glasses are the most natural form factor as they capture sight, sound, and are close to the mouth for speech. This sensory proximity gives them an advantage over other wearables like earbuds or pins.

The sci-fi allure of brain implants and embedded chips often overshadows practical alternatives. Ariel Poler argues that most desired functionalities, from interfacing with AI to carrying identification, can be achieved with less invasive external devices like advanced hearables or wearables, questioning the necessity of risky surgical augmentation for healthy individuals.

Challenging Neuralink's implant-based BCI, Merge Labs is creating a new paradigm using molecules, proteins, and ultrasound. This less invasive approach aims for higher bandwidth by interfacing with millions of neurons, fundamentally rethinking how to connect brains to machines.

While current brain-computer interfaces (BCIs) are for medical patients, the timeline for healthy individuals to augment their brains is rapidly approaching. A child who is five years old today might see the first healthy human augmentations before they graduate high school, signaling a near-term, transformative shift for society.

A common neurofeedback technique involves a user watching a movie that only plays when their brain produces desired brainwaves for focus. When they get distracted, the screen shrinks and the movie stops, providing instant feedback that trains the brain to self-correct and maintain attention.

Neurofeedback is a non-invasive training method that reflects the brain's own electrical activity back to it. This teaches self-regulation and optimization without introducing external energy or compounds, making it a form of biofeedback specifically for the brain.

Current wearables passively track sleep. The next generation of technology will actively induce and manage sleep by 'writing' to our biology—for example, using devices that directly cool the body's core through the palms or eye masks that guide eye movements to accelerate sleep onset.