1. A method for enhancing cognition in a participant, utilizing a computing device to present visual stimuli for training, and to receive responses from the participant, the method comprising: utilizing the computing device to perform: providing one or more scenes, each having a background and at least one foreground object, wherein the one or more scenes are available for visual presentation to the participant; visually presenting a scene from the one or more scenes to the participant, wherein said visually presenting comprises visually presenting the at least one foreground object and/or the background with a specified visual emphasis that visually distinguishes the at least one foreground object with respect to the background; requiring the participant to respond to the scene; determining whether the participant responded correctly; modifying the specified visual emphasis based on said determining, wherein said modifying the specified visual emphasis comprises adjusting the degree of visual emphasis according to one or more visual emphasis techniques; and repeating said visually presenting, said requiring, and said determining one or more times in an iterative manner to improve the participant's cognition.