As most of us are well aware, virtuality already deprives many children of time spent in the 3-dimensional, natural world. But is there danger in 3D?
Does mediated, 3D exposure alter the area in a child's developing brain responsible for processing 3D images as well?
One major problem is caused by the way movie 3D images trick our visual system.
The eye is hardwired to track and refocus on objects as they approach, but because a 3D display is not actually getting closer, the brain is forced to constantly override this impulse.
Research at the University of Texas at Austin suggests a large set of rich and important functions related to 3D motion perception may be bypassed in the MT+ region of the brain if real cues are consistently absent from objects the brain initially perceives as moving.
Tests revealed how the MT+ area processes 3D motion: It simultaneously encodes two types of cues coming from moving objects.
There is a mismatch between what the left and right eyes see. This is known as binocular disparity. When you alternate between closing your left and right eye, objects appear to jump back and forth. For a moving object, the brain calculates the change in this mismatch over time.
Simultaneously, an object speeding directly toward the eyes will move across the left eye’s retina from right to left and the right eye’s retina from left to right.
“The brain is using both of these ways to add 3D motion up,” says says Alexander Huk, assistant professor of neurobiology at U of T- Austin. “It’s seeing a change in position over time, and it’s seeing opposite motions falling on the two retinas," adds Huk.
Television manufacturers are aware of the potential ill-effects of mediated 3D viewing, with Samsung's Australian website warning that its sets can cause "motion sickness, perceptual after effects, disorientation, eye strain, and decreased postural stability".
The UK's Association of Optometrists echoed Samsung's warnings against excessive use, particularly for children.
"Children need a clear, sharp image in each eye in order for their vision to develop properly. If anything upsets that balance it could affect the visual development resulting in 'amblyopia' (lazy eye) or a squint," said spokeswoman Karen Sparrow.
"Similar to adults using computer screens at work, a sensible regime would be to have a break of five minutes after an hour's use."
The American Association of Optometrists said those who suffer from motion sickness or already have depth perception troubles are likely to come away from a 3D film feeling queasy.
This is one reason why, for adults, a movie playing 3D effect often seems very intense at first -- with characters and images that lunge towards the camera. Though, toward the later part of the film, many seasoned viewers notice the 3D less and less. After the initial wow factor, 3D gimmickry "doesn't mesh" with a brain that has consistently experienced real 3D.
Young children, however, will stay transfixed and seemingly begin to condition the same part of the brain that processes 2D images with ersatz 3D imagery.
see: http://www.futurity.org/science-technology/scans-show-brain%E2%80%9... for more details.
As well as entries in Child and Nature Network discussing Visual tracking of Objects in Nature.