Living in the Past

My brain hurts. Again. That’s what comes of reading articles on how the, um, brain works.

The brain automatically smoothes our visual input over time.

That doesn’t sound so bad, does it? But try it the way the article’s title says it.

Everything We See Is a Mash-up
of the Brain’s Last 15 Seconds of Visual Information

A mash-up? A stuck-together-collage of visual inputs like those dance videos on YouTube? Yup.

Instead of analysing every single visual snapshot,
we perceive in a given moment
an average of what we saw in the past 15 seconds.

Well, why the heck would our brains do that?

So, by pulling together objects
to appear more similar to each other,
our brain tricks us into perceiving a stable environment.

Stable, good; jerky, bad? I guess so.

If our brains were always updating in real time,
the world would feel like a chaotic place
with constant fluctuations in light, shadow and movement.
We would feel like we were hallucinating all the time.

But is this speculation or can they, you know, prove it? Well, they have some test results that support this idea.

. . . we recruited hundreds of participants and asked them to view close-ups of faces morphing chronologically in age in 30-second timelapse videos. When asked to tell the age of the face at the very end of the video, the participants almost consistently reported the age of the face that was presented 15 seconds before. (emphasis added)

OK, a few thoughts occur.

First, if this visual thing is true, to other people I look a full 15 seconds younger than I am.

Second, this lapse might explain why some of my bird photos are fuzzy. I’m focusing on an average of where the bird was in the last 15 seconds.

Third, maybe our brains have a bias to stability in many ways, not just visually. Maybe we interpret the world we’re experiencing now based more on what we’ve experienced before than on this whole in-the-moment thing. That might mean that as we get older we get steadily worse at “seeing” — believing, understanding — what’s actually in front of us.

But you know, that “almost c0nsistently” caught my attention. Guys, get back to me when you no longer need the “almost.” Until then, I’m going to stick with my impression of the brain from, oh, about 15 seconds before I clicked on this article.

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8 Responses to Living in the Past

  1. Well, that bit about hallucinating isn’t true, so the rest of the theorizing about “stability” leaves me a little unstable as well. My environment is so stable it’s a wonder I’m not hallucinating just to provide some variety. But that environment includes someone who *is* hallucinating with a redundancy of words and images that is so disgusting it’s a good thing the tedium allows me to ignore most of it. Nope, these researchers have no idea what they think they are doing. *I* think I’ll join you in the 15-second reset!

    • Isabel Gibson says:

      Laurna – Indeed, many of us live in environments so stable that our brains could do a check every month or so. Of course, that would make it hard to find waylaid eyeglasses. As for the hallucinator in your house, I wish him better health soon.

  2. John Whitman says:

    Isabel – two thoughts:
    #1 Maybe this is why defense lawyers question eyewitness accounts so closely.
    #2 Military advances in the attack are coordinated with the time-of-flight of artillery and mortar rounds supporting the attack so that the attackers are close behind the falling rounds, but the defenders still have their heads down. You can do a lot in 15 seconds if you have to.

    • Isabel Gibson says:

      John – Re #2 – I seem to remember a retired military colleague informing me that surprise was not a principle of administration, but of war. Diversion likewise, I presume. 🙂

      • John Whitman says:

        Isabel – here are some diversions for you.
        #1 In Defensive Driving Courses they teach that it takes just under 2 seconds for a human being to react to something a driver sees ahead of them. Therefore, a driver should allow a 2-second (as opposed to 2 car lengths) gap between their vehicle and the vehicle ahead. (That rule-of-thumb works regardless of the speed you are travelling. However, I am not certain how advancing age might affect that rule-of-thumb.) Now my question is, does that 15 second thingy shrink to 13 seconds or expand to 17 seconds when driving? Is this another Schrödinger’s Cat thingy, or does it even matter at all? Maybe the 15 second thingy only applies to facial recognition. Just wondering.

        #2 Does that 15 second thingy also help to explain why when you go to another room to get something, you or at least I sometimes can’t remember what it was I went to get when I arrive in that other room.

        #3 Does the 15 second thingy help explain why my brain sometimes hurt when I was a proposal writer, or was that just eye fatigue, or could it have been some of the RFP’s we had to deal with? Again, just wondering.

        • Isabel Gibson says:

          John – Well, it does seem as if 15 seconds might be an over-reach by the researchers. (Maybe it should have been 1.5 seconds?) Otherwise, how would we ever drive safely at all? As for the proposal headaches, maybe it was your colleagues.

  3. barbara carlson says:

    15 seconds is a VERY, VERY long time!

    I also think it’s 1.5 seconds.

    But the brains remembers it all, or else detailed dreams wouldn’t be possible, right
    This morning I woke up at 6:30 and wondered if there was freezing rain, thus putting off grocery shopping… I woke up again 20 minutes later, having dreamed of getting up and checking the balcony for ice — my dreaming mind showed me the entire apartment, the balcony, the siding glass doors which I opened and had me feel the carpeting on the balcony — solid ice. I could feel it.

    I often have detailed dreams. Sometimes waking up and going back to sleep to continue the dream.

    • Isabel Gibson says:

      Barbara – Hahaha. Maybe *your* brain remembers it all. I don’t often have detailed dreams but when I do they eventually degenerate into incoherence. Frustrating – it’s like not finding out the ending to a story.

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