Designed for developmental neuroscience and psychology applications, these devices take measurements from the cerebral cortex of the brain. Special attention has been paid to their comfortability and dimensions, to optimize them for use with children and infants. fNIRS stands for functional near infrared spectroscopy, the functional component indicating that these devices are able to assess brain activity. This is done by measuring changes in oxyhemoglobin and deoxyhemoglobin, which reflect local brain activity. fNIRS provides a non-invasive manner to take measurements from the brain with excellent spatial and temporal resolution.