Pigeons Explain SMIDSY - a SOBS update?

[Horse]

[iansoady]

Quite interesting. Nice to reprise some of the old ads as well. And of course the fundamental message is right - we need to take responsibility ourselves not depend on other people.

[slowsider]

Love the reference at the end: Kathryn Knight. "Head bobbing gives pigeons a sense of perspective".

[Horse]

And the little-known, but incredibly useful, 'Hills' also gets a name check too.

[The Spin Doctor]

Quite interesting. Nice to reprise some of the old ads as well. And of course the fundamental message is right - we need to take responsibility ourselves not depend on other people.

I think he's probably been through 'Science Of Being Seen' over at www.scienceofbeingseen.org.uk!

[The Spin Doctor]

I'll have to do some background digging but as far as I know, we only use stereoscopic vision at very short distances - around five metres max, which of course is way shorter than the kind of distances that Ryan is talking about in terms of collision detection. My own understanding is that we use other cues to estimate distance, and thus speed and 'time to collision'.

This is the paper I was aware of:

http://www.hitl.washington.edu/projects ... 20distance.

I'd also think the 'one eyed' issue isn't a factor unless we're talking about perceptual vision either, because we need to turn our eyes to point directly at an object to bring it into the foveal zone. It's actually quite tiring to move your eyes in the socket, so we swing our heads which brings both eyes into play.

Generally, the stuff Ryan produces on visual perception is accurate (if sensationalised) but I am far from convinced he's right on this.

I'll have a read of the papers he's provided for background and get back to you.

[Scootabout]

I'd have liked to see mention of the importance of lateral movement, too.

[Horse]

I'd have liked to see mention of the importance of lateral movement, too.

To be fair to Ryan & F9, I'm not aware of too much research evidence that he could use.

Oullet was theoretical only.

There is a US paper comparing different lane position approaches to a junction, but not lateral movement.

[Scootabout]

Wot, you mean you made all that Z line stuff up?!

[Horse]

Wot, you mean you made all that Z line stuff up?!

Nope, none of it - but credited everyone so can't even be accused of plagiarism

http://the-ride-info.blogspot.com/2008/ ... s.html?m=0

First off: I didn't 'invent' Z Line, all I've done is give a name to something other people were already doing. Indeed, I first read about 'dramatic' positioning changes across the lane width in a UK motorcycle magazine 'Motorcycle and Workshop', in articles written by Ed Reid of Oxford Motorcycle Engineers. This would have been in the mid-late 1980s.

More recently, science has 'caught up' with research on how some animals hunt by maintaining a position relative to their prey

....

By moving across the lane away from the driver you - according to Ouellet - reduce your 'worst case' zone. By moving when the driver is most likely to see you, you attract their attention - you make yourself more conspicuous.

So . . . what is "Z Line"?

Thank you for asking

"Z Line combines the 'best' of Ouellet, with 'active' positioning.

...

[The Spin Doctor]

More recently, science has 'caught up' with research on how some animals hunt by maintaining a position relative to their prey

Actually, that's been known about for decades... probably back to the early 20th century. It's the relevance to how drivers detect motion that's new.

Incidentally, on the original pigeon vision issue, whilst reading around the topic, I found a paper that suggested that very significant numbers of people have defective eyesight which renders them unable to use stereoscopic vision. I'll do a bit more reading when I get a moment, but my feeling is that Ryan's not actually correct with his conclusions in this particular video...

[Scootabout]

I found this with a quick Google, so no idea how good a study it is, but FWIW they claim to have found depth perception effects from stereoscopic vision to 'at least 18 metres'.

https://jov.arvojournals.org/article.as ... id=2122030

[The Spin Doctor]

I found this with a quick Google, so no idea how good a study it is, but FWIW they claim to have found depth perception effects from stereoscopic vision to 'at least 18 metres'.

https://jov.arvojournals.org/article.as ... id=2122030

I was reading that one a couple of days ago and struggling to make sense of it. In the discussion, they talk about "observers were likely using monocular cues to scale depth from disparity", which seems to contradict their other conclusions.

Anyway, even if binocular vision does allow depth perception to 18 metres, that's pretty irrelevant on the road.

If a vehicle - even a motorcycle - is 18 metres away and something goes wrong with visual perception, it's not likely a speed and distance miscalculation that came about from poor depth perception.

It's likely to be either the bike wasn't visible when the driver looked (one in five of collisions) or looked but failed to see, via mechanisms such as the terribly-named 'inattentional blindness' which means we've focused on something else happening around us and haven't detected the motorcycle, or it's a workload related event including the issue described a couple of years ago - looked, saw then forgot again - when a cluttered environment means other objects overwrite the visual memory that held the image of the motorcycle.