"Computers also appear to have an effect on visual intelligence. For example, playing Marble Madness, a game requiring children to visualize and manipulate objects in their minds, was found to enhance spatial skill (Subrahmanyam & Greenfield, 1994), although playing a game that requires the visual tracking of an object on a screen also improved this type of spatial skill outside of the computer environment (Greenfield, De Winstanley, & Kilpatrick, 1994); playing the computer game Concentration-a learning game-improved iconic representation skills (Greenfield et al., 1996). Therefore, there is some evidence that computers, even computer game play, can improve visual skills outside of the computer environment. However, for long-term positive effects to occur in the classroom, computers must be integrated into the classroom and not simply placed in it. Similarly, much research is needed on the use of computers in the home in terms of their influence on cognitive and academic growth in children."