Neuro-Electronic Interface (Necklink technology)
The Neuro-Electronic Interface connects a person's brain to into a computer circuit, enabling data transfer between the two. This is used mainly for the purposes of communication between people with necklinks and the download of knowledge and information from a computer system to the brain.
The interface between the necklink and the brain is a complex one, since the principles by which the brain operates are very different from those used in electronics. The necklink is only a part of the Neuro-Electronic Interface: it controls a nanoswarm spread over the celebral cortex. The individual nanobots connect to individual neurons, reading their state and stimulating them when needed. The bots communicate on a bandwidth that doesn't interfere with brain activities.
Each Neuro-Eloctronic Interfece is calibrated to the individual brain it's connected to, and this calibration must be updated regularly as the brain continuously changes its shape. This is achieved by regularly scheduled reading and analysis of the brain activity, followed by adjustments to the settings of the interface.
The User Interface
In addition to knowledge transfer, the Neuro-Electronic Interface acts as the user interface between the colonist and TAU, and by extension, other colonists. In many ways, this resembles telepathy. However, the interface is too simple and clumsy to feel like being truly connected to another mind. TAU's queries and necklink messages feel just like that: queries and messages, albeit complex and versatile in their content.
There are various alternative user interfaces geared to different people. Visual people often choose to represent the interface visually. This doesn't mean covering up their eyesight by popups and dialogs, however - the interface operates purely through the "mind's eye" - the UI components show up in the person's imagination, and they imagine the responses. One can often tell someone is using a visual interface when they close their eyes, stare intently at nothing, or look to the top right.
Most people use a combination of visual, aural, and conceptual user interfaces. Some application only allow one modality, anyway - images the in personnel database can naturally only be viewed visually. The conceptual interface is arguably the most efficient for, for example, TAU queries and necklink messaging: instead of images or sounds you cut straight to the meanings behind. This can, however, be confusing to many. Conceptual interfacing is also the only way to efficiently send feelings over the comms.
In addition to these, there are more exotic modalities: some, for example, prefer tactile elements to their interface, making them operate an imaginary interface through hand movements.