1. A method for retrieving mental images of faces from a human brain, the method comprising: generating a human facial image on a screen, the human facial image including characteristics based on an initial description of a human face; measuring brain activity data from a brain scanner, the brain activity data being measured from a subject viewing the screen; varying the characteristics of the human facial image on the screen; detecting changes in the brain activity data measured from the brain scanner, the brain activity indicative of recognizing the human face; locking certain characteristics that correspond to brain activity that indicated strong recognition of the certain characteristics to reconstruct a final human facial image; reconstructing a final human facial image from the certain characteristics that have been locked based on the strong recognition evidenced by the strong brain activity; and generating a final human facial image on the screen, the final human facial image including updated characteristics based on predetermined brain activity indicative of recognizing the human face; wherein varying characteristics of the human facial image on the screen comprises: in response to varying a first facial characteristic that results in an increase of brain activity as indicated from the brain activity data, fixing the first facial characteristic as part of the final human facial image on the screen; varying a second facial characteristic; and in response to varying a second facial characteristic that results in an increase of brain activity as indicated from the brain activity data, fixing the second facial characteristic as part of the final human facial image on the screen.