As reviewed by Beatson and Gianutsos, it is estimated that 90% of the information processed while driving is taken in through the visual system. Although visual closure in a visual perceptual skill normally associated with reading and writing, it factors into the many visual cognitive judgements that are essential for safe driving. We often associate visual closure with the perceptual skill used in two dimensional tasks such as the subtest of the TVPS-3, but the nature of visual closure used when driving is obivously more dynamic. It also lies at the heart of what we’ve been discussing about Asperger’s Syndrome (AS) in this context: The act of filling in the visual scene is predicated on a number of different possibilities, rather than on “the one correct possbility” as conceived in booklet visual closure subtests. Let’s look at a few different examples of the types of visual closure decisions and judgements made when driving.
As the driver you approach an intersection with a stop sign, stopping at the white line. Cars going through this intersection perpendicular to you do not have a stop sign. They’re expecting you to stop, and not to proceed until they’ve cleared the intersection. The problem is that the hedge on the corner on your left blocks your view of traffic to your left, and you have to inch out to get a complete view. You might use the skill of visual closure and infer where the car will be if you catch the glimpse of the top part of the vehicle beyond the hedge. As you’re watching the car approach from the left, you also have to glance to your right to see if there is oncoming traffic from that direction. At some point, based on your estimate of speed of approaching cars, you make a decision that it is safe to enter the intersection and turn left. If you are an individual with AS you might have a certain algorithm for this situation, and decide that unless there are no cars in sight it is not safe to proceed through the intersection. Although requring extra time, and frustrating the drivers behind you honking their horns to proceed, it is one way to remove the variable of having to judge whether other drivers approaching the intersection will anticipate your turn.
Here’s another example, which happens to be the approach to my office’s back parking lot. Let’s call you Driver A as you proceed to the back lot in the picture above. The wall to the left obscures Driver A’s view of a car that may be approaching from the left (Driver B) toward the exit. The only way to anticipate what might happen is for Driver A to proceed slowly until enough of a view exists beyond the wall to ascertain that there is no car approaching.
Here is the view from the opposite side of the wall. A driver exiting the lot (Driver B) has to make the same judgement, proceeding slowly enough to make sure that no one is approaching as he rounds the corner. It is in essence a double blind situation, requiring some visuial closure as well as mirror neuroning. Let’s presume it’s safe for Driver A to proceed. He now faces another hurdle on the left since the SUV parked on the edge of the row poses the same obstacle that the wall did. He can’t be certain until he inches forward that there isn’t a car coming from the left side.
At some point as he turns left, Driver A will be confident that there is no car approaching from the left, or if there is, Driver B will anticipate the clearance needed for him to make the turn.
Now it looks like you have enough clearance to decide where you’d like to park. Of course, if someone has his rear backup lights on, you can’t assume that he is aware that you’ve just entered the area toward which he’ll be backing up!
If reading other people and their body language is important as a social skill, deciphering what the mind of another person is doing when driving requires reading the body language of their car. It can be done, though it requires some flexibility from different viewpoints.