# EmotivBCI Brain Computer Interfaces (BCI) is a system that allows you to control machines using your brain activity directly, rather than through intermediary interfaces like a mouse, keyboard, touchscreen or voice. EMOTIV technology converts brain waves to digital signals that can be used to control an endless number of digital outputs such as games, IoT devices, communication devices and audio/visual content. EmotivBCI is a desktop application for Mac and Windows that allows you to view and train the EMOTIV data streams used for BCI. These data streams are the following: * [Mental Commands](https://emotiv.gitbook.io/emotivbci/mental-commands) allow active control with specific thoughts that you have trained the system to recognize. You can train up to 4 commands per training profile with an unlimited number of profiles. * [Performance Metrics](https://emotiv.gitbook.io/emotivbci/performance-metrics) allow passive and continuous control based on your real time cognitive state, including measurements of focus, excitement, interest, engagement, stress and relaxation. No training is required. We also offer two additional data streams that are not from the brain directly, but can be applied to enhance your BCI system. * [Facial Expressions](https://emotiv.gitbook.io/emotivbci/facial-expressions) trigger events with movements of your facial and eye muscles. No training is required, but you can train some expressions to make them more accurate and personalized. * [Motion Sensors](https://emotiv.gitbook.io/emotivbci/motion-sensors) capture your head movements which you can apply to move a mouse or trigger other commands. The personalized training profiles that you create in EmotivBCI can be used with our Node-RED toolbox to control a wide array of outputs including social media, IoT devices and robotics. Your BCI profile can also be used in other third party applications connected to EMOTIV via our [Cortex](https://www.emotiv.com/cortex-ui/) service. This document is intended to help you to get started with EmotivBCI and to understand how to use the various features that it offers. If you have any queries beyond the scope of this document, please contact us through our [online support](https://www.emotiv.com/contact-support/). --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://emotiv.gitbook.io/emotivbci/undefined.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.