Current text-based prompting for AI is a primitive, temporary phase, similar to MS-DOS. The future lies in more intuitive, constrained, and creative interfaces that allow for richer, more visual exploration of a model's latent space, moving beyond just natural language.

The next frontier for Neuralink is "blindsight," restoring vision by stimulating the brain. The primary design challenge isn't just technical; it's creating a useful visual representation with very few "pixels" of neural stimulation. The problem is akin to designing a legible, life-like image using Atari-level graphics.

The ultimate goal of interface design, exemplified by the joystick, is for the tool to 'disappear.' The user shouldn't think about the controller, but only their intention. This concept, known as 'affordance,' creates a seamless connection between thought and action, making the machine feel like an extension of the self.

Designing for users with motor disabilities who control interfaces with their minds presents a unique challenge. Unlike typical design scenarios, it's impossible for designers to truly imagine or simulate the sensory experience, making direct empathy an unreliable tool for closed-loop interactions.

The best UI for an AI tool is a direct function of the underlying model's power. A more capable model unlocks more autonomous 'form factors.' For example, the sudden rise of CLI agents was only possible once models like Claude 3 became capable enough to reliably handle multi-step tasks.

The team obsesses over perfecting the BCI cursor, treating it as the key to user agency on a computer. However, the long-term vision is to eliminate the cursor entirely by reading user intent directly. This creates a fascinating tension of building a masterwork destined for obsolescence.

Due to latency and model uncertainty, a BCI "click" isn't a discrete event. Neuralink designed a continuous visual ramp-up (color, depth, scale) to make the action predictable. This visual feedback allows the user to subconsciously learn and co-adapt their neural inputs, improving the model's accuracy over time.

Neuralink's initial BCI cursor used color to indicate click probability. As users' control improved, the design evolved to a reticle that uses motion and scale for feedback. This change was more effective because the human eye is more sensitive to motion than color, and it better supported advanced interactions.

A joystick has 'perceived affordance'—its physical form communicates how to use it. In contrast, a touchscreen is a 'flat piece of glass' with zero inherent usability. Its function is entirely defined by software, making it versatile but less intuitive and physically disconnected compared to tactile hardware controls.