Todd Spangler

Perception Is Reality
July 10, 2008

There's a fascinating piece in the June 30 issue of The New Yorker by Atul Gawande, a physician who also happens to be a masterful storyteller.

Mainly, his article, "The Itch," discusses that mysterious sensation and begins with a horrifying account of a woman whose scalp itched so intensely that she scratched through her skull in her sleep -- to her brain.

Yiiiiiiikes.

OK, now connecting the dots back to the multichannel video business (bear with me): Gawande later brings up theories of sensory perception and how they relate to severe itching.

His point here is that our sensory inputs provide a very limited amount of actual external information:

The images in our mind are extraordinarily rich. We can tell if something is liquid or solid, heavy or light, dead or alive. But the information we work from is poor—a distorted, two-dimensional transmission with entire spots missing. So the mind fills in most of the picture. You can get a sense of this from brain-anatomy studies. If visual sensations were primarily received rather than constructed by the brain, you’d expect that most of the fibres going to the brain’s primary visual cortex would come from the retina. Instead, scientists have found that only twenty per cent do; eighty per cent come downward from regions of the brain governing functions like memory. Richard Gregory, a prominent British neuropsychologist, estimates that visual perception is more than ninety per cent memory and less than ten per cent sensory nerve signals. 
 

Gawande terms this the “brain’s best guess” theory of perception.

"Perception is inference," he writes. Talk about Plato's cave. (Top of mind because Multichannel's Ted Hearn referred to it in his post yesterday on an Obama fund-raiser.)

Right. So what does this have to do with cable TV? 

It reinforces a point I made a few weeks ago: That cable companies should place a priority on delivering HD quantity, with the secondary consideration of delivering maximum-possible quality. 

The human visual system is easily fooled. That's why video compression works in the first place.

Verizon and DirecTV have made marketing claims that they have HD quality superior to cable. But all HDTV is highly compressed, regardless of which video service you're using. 

Are there gradations of quality between, say, a 13-Mbps MPEG-2 stream and one at 17-19 Mbps that you might be able to distinguish on a 100-inch high-def plasma TV?

Maybe. But if 80% or 90% of our visual perception is culled from our brains' basements, I wonder how many people can truly differentiate between an HDTV signal that is 1.1% (17 Mbps) of an uncompressed 1080i stream (1.5 Gbps) and one that is 0.8% (13 Mbps) of the uncompressed resolution.

Or whether some think they can tell the difference because that's what they already believe.

Posted by Todd Spangler on July 10, 2008 | Comments (0)