Abstract: A user-friendly reliable process is provided to help diagnose (assess) and treat (rehabilitate) impairment or deficiencies in a person (subject or patient) caused by a traumatic brain injury (TBI) or other neurocognitive disorders. The economical, safe, effective process can include: generating and electronically displaying a virtual reality environment (VRE) with moveable images; identifying and letting the TBI person perform a task in the VRE; electronically inputting and recording the performance data with an electronic interactive communications device; electronically evaluating the person's performance and assessing the person's impairment by electronically determining a deficiency in the person's cognitive function (e.g. memory, recall, recognition, attention, spatial awareness) and/or motor function (i.e. motor skills, e.g. balance) as a result of the TBI or other neurocognitive disorder.