Rid­ing ..............................................

Shift­ing fo­cus from speedome­ter to the car ahead we ‘lose’ 0.7 sec­onds of smooth track­ing in the road and rid­ing en­vi­ron­ment.

Fast Bikes - - CONTENTS -

Scan­ning is fre­quently touted as the ul­ti­mate form of vis­ual con­trol when rid­ing a mo­tor­cy­cle or even driv­ing a car. Let’s de­con­struct this piece of con­ven­tional wis­dom...

First, try this quick vis­ual ex­per­i­ment: find two ob­jects about 5ft in front of you and 2ft apart. Rapidly scan your eyes back and forth be­tween the two ob­jects, fo­cus­ing briefly on one and then the other. Ob­serve that, un­like a still or video cam­era, there is no mo­tion blur as you shift your eyes from one ob­ject to the other. A par­tic­u­larly good ob­server will also no­tice a very brief blank pe­riod while shift­ing be­tween the two ob­jects – a quick fade-in fade-out of the vis­ual field. That blank pe­riod is the re­sult of some­thing called ‘vis­ual sac­cadic sup­pres­sion’ or ‘sac­cadic mask­ing,’ which elim­i­nates blur­ring and any po­ten­tial ghost im­age that might dirty your vi­sion like the ‘af­ter­im­age’ that lingers fol­low­ing a bright flash of light.

Taken to its ex­treme, where the eyes would main­tain a con­tin­u­ous scan-fo­cus-scan pat­tern, we would, based on the prin­ci­ple of sac­cadic sup­pres­sion, ac­tu­ally miss a fair bit of in­for­ma­tion – like watch­ing a very fast slide show. This leaves much to be de­sired com­pared to what I would con­sider the ideal sit­u­a­tion of a con­tin­u­ous flow of vis­ual in­for­ma­tion.

Con­sid­er­ing that we re­quire a min­i­mum elapsed time of 0.35 sec­onds be­tween each fo­cus­re­fo­cus cy­cle, we can be­gin to cal­cu­late just how de­fi­cient for a rider’s needs our sys­tem re­ally is. For ev­ery one se­cond with two fo­cus changes – say, from the speedome­ter to the car just ahead – we ‘lose’ 0.7 sec­onds of smooth track­ing of the road and rid­ing en­vi­ron­ment.

That rep­re­sents a lot of time and a lot of space. At 30mph we’ve gone 30ft dur­ing that time; at 60mph it is more than 60ft of lost vis­ual flow.

In all crit­i­cal cir­cum­stances, vi­sion is the source of our most vi­tal in­for­ma­tion. The hu­man vis­ual ap­pa­ra­tus is a mar­vel in so many ways, but, un­for­tu­nately, some key as­pects of its op­er­at­ing sys­tem are in­suf­fi­cient for a rider’s needs. When rid­ing a mo­tor­cy­cle, the ever-chang­ing vis­ual en­vi­ron­ment de­mands a spe­cial­ized strat­egy on how to best use our eyes to by­pass or mit­i­gate these frail­ties.

We work around sac­cadic sup­pres­sion; it’s al­ways been a part of the oper­a­tion. The al­ter­na­tive – a blurred vis­ual field each time we shift our eyes – is cat­e­gor­i­cally un­ap­peal­ing. We can use our present vis­ual sys­tem as ei­ther a Johnny-on­the-spot fix-it or, prefer­ably, as a highly evolved tool that pre­vents us from get­ting trapped in crit­i­cal sit­u­a­tions. As a quick-fix tool it is left want­ing. As a pre­ven­ta­tive mea­sure, once prop­erly har­nessed and trained, it can be supreme.

How can you har­ness the power of your eyes? You have two op­tions: mov­ing your eyes in a slow-track­ing fash­ion or pick­ing a vis­ual plane far enough out in front that it al­lows you to main­tain a ‘wide view’ that fills your vis­ual screen com­pletely while still main­tain­ing a good con­nec­tion to your pe­riph­eral field.

The pe­riph­eral field is pri­mar­ily used to iden­tify mo­tion and give you ad­vance warn­ing of any­thing that might re­quire your aware­ness. Our cen­tral, sharp­fo­cus field is ac­tu­ally quite nar­row – only 2º – and does not de­tect move­ment as well. If the eyes are scan­ning about fran­ti­cally, the valu­able func­tion of our pe­riph­eral field is sig­nif­i­cantly im­paired. This is not to say that you should blankly stare off into space. You need to ac­tively fill your vis­ual screen, but you should be aware not to make so many in­vol­un­tary vis­ual jumps. In this case, less is more.

Over­com­ing the eyes’ in­nate ten­dency to dart around may not be easy, but it is doable. De­mand­ing that the eyes sweep smoothly, rather than flit around, is a skill that only im­proves with prac­tice. Eyes are both vol­un­tar­ily and in­vol­un­tar­ily con­trolled; prac­tice gain­ing con­scious con­trol of them at ev­ery op­por­tu­nity, start­ing now.

‘He went that way!’

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