Motion Induced Blindness and Road Safety

Definition and Description:

Motion Induced Blindness (MIB) is a phenomenon of visual disappearance or perceptual illusions. The illusion catches the brain ignoring or discarding information. An on-going debate regarding the causes of MIB is still present in today's vision research, however the purely attentional mechanism explanation has been rejected and new theories were put forward.

The brain seems to have internal theories about what the world is like. It then uses sensory input - which tends to be patchy and disorganized - to choose between these. In some sensory situations, different theories come into conflict, sending our perceptions awry.

In this section we would like to consider the potential threat of Motion Induced Blindness to drivers and what can be done to ensure that we avoid the risks.

 

Research on Motion Induced Blindness:

The illusion, which Bonneh's team calls motion-induced blindness, catches the brain ignoring or discarding information. This may be one of the brain's useful tricks, a deficiency - or perhaps both, says Bonneh.

Jack Pettigrew, a neuroscientist at the University of Queensland in Brisbane, believes that the illusion results from a tussle for supremacy between the left and right halves of the brain. He has found that applying a pulse of magnetism to the brain to temporarily disrupt its function affects the occurrence of motion-induced blindness. When the pulse is applied to the right hemisphere (leaving the left dominant) the dots disappear; zapping the left brings them back2.

The left hemisphere seems to suppress sensory information that conflicts with its idea of what the world should be like; the right sees the world how it really is. Some people with paralysis caused by injuries to their right hemisphere will deny that they are disabled.

"The right hemisphere is the cautious devil's advocate and the left hemisphere is the confident general with a plan of action," says Pettigrew.

 

Example:

The best way to explain Motion Induced Blindness is by way of an example. This phenomenon applies to walking, driving, sailing, flying, hunting, biking, skiing, and so many other activities of daily life.

It’s the affect whereby objects that are stationary, in relation to your eyes, simply vanish from your peripheral sight when near things that is moving, again in relation to your eyes.

In the example you see a grid of blue crosses that are spinning, three stationary yellow dots and a flashing green dot in the centre which is also stationary. Focus your attention on the flashing dot in the middle and you will soon become aware that the yellow dots start vanishing. Sometimes just one vanishes, or in pairs, or all three will vanish from your sight, but they also randomly re-appear without any rhyme or reason. The reality is though…they never actually vanish. They just look like they do.

 

Pilots and Motion Induced Blindness

The importance of Motion Induced Blindness has long been recognized in the aviation industry.

Instructors, some of whom were combat veterans with years of experience, instructed their pilots to continually “keep their eyes moving and head on a swivel” because this was the best way to survive, not only in combat, but from peacetime hazards (like a mid-air collision) as well.

Pilots were taught to alternate their gaze between scanning the horizon and scanning their instrument panel, and never to fix their gaze for more than a couple of seconds on any single object. The reason given is that, if you fix your gaze on one object long enough while you yourself are in motion, your peripheral vision goes blind. That’s why it is called motion induced blindness.

Till about three decades ago, this “heads on swivel & eyes moving” technique was the only way to spot other aircraft in the skies around. Now-a-days they have on-board radars, but the old technique still holds good.

 

Motion Induced Blindness on the Road

Researchers have speculated about whether Motion Induced Blindness occurs outside the laboratory, without being noticed as such. Situations such as driving, in which some night drivers should see stationary red tail lights of the preceding cars disappear temporally when they attend to the moving stream of lights from oncoming traffic may be case points.

The researchers speculate that this phenomenon could happen in everyday life without us noticing it. A highway at night, with drivers staring dully at a mass of moving lights, might recreate the kind of conditions used in the experiments, says Bonneh, causing objects - the tail lamp of the car in the next lane, for example - to temporarily vanish.

Many drivers have claimed not to have seen another vehicle coming from the side, in spite of broad daylight. Drivers often pull in front of vulnerable road users such as motorcycles or a bicycle and say I didn’t see him”. This phenomenon on the car drivers’ part can be part of “Motion Induced Blindness”.

If you are driving at a high speed on a highway and if you fix your gaze on the road straight ahead, you may not be able to see a car, a scooter, a buggy, a bicycle, a buffalo or even a human being approaching from the side. Now reverse the picture. If you are crossing a road on foot and you see a speeding car approaching. There’s a 90% chance that the driver isn’t seeing you, because his/her peripheral vision may be blind! And you may be in that blind zone!!

 

What do we need to know about Motion Induced Blindness and Safe Driving?

It is important to recognize that Motion Induced Blindness applies to everyone, not just pilots, as we all spend time driving and the same concepts apply here! We can also miss things (pedestrians, motorcycles, bicycles other cars) while driving too so we need to remain alert to these dangers.

These risks become a severe liability when flying, driving, or boating when there are moving objects in the field of view which are actually on a collision course with your vehicle, but appear to remain stationary in your field of view.

This is most commonly seen when you are on a highway and another vehicle is coming down an on-ramp at a speed that paces yours. It remains in the same place as viewed through the windshield or side windows.

Your brain will simply erase the other car's image from your view.... until you move your head. This can also occur in your mirrors when a vehicle is overtaking you at a very slow rate. If you simply constantly scan by moving your head or eyes, those important objects will remain visible.

 

Things to do:

  • Remain alert and vigilant on the roads.
     
  • Avoid driver fatigue and the additional pressure it places on your vision.
     
  • Avoid driver distractions and remember that the road and road users need all your attention.
     
  • Do not repeatedly fix your gaze for more than a couple of seconds on any single object. The most dangerous target is the one that has NO apparent motion. This is the one you will hit without evasive action and also the one you will NOT see.
     
  • Keep your eyes moving and scan, scan, scan…!

 

Also view:

Road Safety and the Importance of Clear Vision

Avoiding Distractions while Driving

Avoiding Driver Fatigue

 

Recognition to Sources:

A brain in doubt leaves it out.. John Whitfield

Motorcycle Safety Foundation

Source: www.arrivealive.co.za