A common question is pointing to relevant research around this new type of brain sensing technology called functional near-infrared spectroscopy. 

1. A brief history on fNIRS brain sensing, starting out in 1977 then first applied in a research setting in the early 90's

2. An overview of fNIRS related brain sensing, how it works and applied machine learning techniques on the data

3. How fNIRS can be used to measure mental workload; meaning how much effort the mind is under going during a specific task.