
How the Brain Creates a Timeline of the Past - chmaynard
https://www.quantamagazine.org/how-the-brain-creates-a-timeline-of-the-past-20190212/
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noobiemcfoob
"Just a few months after Howard and Shankar started to flesh out their theory,
other scientists independently uncovered neurons, dubbed “time cells,” that
were “as close as we can possibly get to having that explicit record of the
past,” Howard said. These cells were each tuned to certain points in a span of
time, with some firing, say, one second after a stimulus and others after five
seconds, essentially bridging time gaps between experiences."

Most relevant idea from the article for me

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rconti
We know that entering a new room in your house impacts your thinking -- like a
new "window" of thought opens. There is, in fact, a concrete reason why you
will forget what you were looking for as soon as you enter the room you
intended to search for said object.

It's interesting, as mentioned, how you can recall other things that happened
in temporal or spatial proximity to another memory you're recalling.

My mother has an uncanny ability to unwind a series of connected memories --
"I know that was in 1973 because that's when so-and-so got married, and we had
traveled to such-and-such location that year, which is why I had the new
suitcase that..."

Fascinating research.

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galaxyLogic
As a programmer I think I forget a lot because programming keeps my brain busy
thinking about things. I forget features and solutions I've done before. I
think it's because the space inside the brain is limited. I'm thinking hard
about a new problem every day. Whereas my boss can remember things I did a
year ago I can't easily.

~~~
9dev
Maybe its just you being in the business longer than me, but I've had pretty
much the opposite thought: I'm learning new stuff every day, wondering when I
will start to actually forget chunks of it. Currently, it seems like most
technical knowledge tends to stick in my brain, with no apparent limit yet. I
can still recall most of the Redis protocol commands despite not having used
it in more than six years.

~~~
pandapower2
After almost 20 years as a commercial developer I forget entire projects,
entire jobs even. Someone will mention a company name and it takes me a few
seconds to realize that the reason the name is familiar is because I briefly
worked there 15 years ago. Jobs I held for multiple years are fine but any
short stints are a blur.

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sizzle
I've experienced this as well and the phenomenon is more pronounced if the
role/company was unremarkable at the time, and it was as if I overwrote the
memory with the excitement of the next job, then rinse and repeat with every
new job.

~~~
galaxyLogic
I guess something like that is going on in my brain too. The code I come up
with often feels exciting because it is a solution to a problem, but then the
next several 100 code-solutions overwrite the memory of what once felt
important. It is no longer important, so I think it's good my brain let's go
of it. But often I lament having not much documented why I wrote some code the
way I did

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ralusek
I actually think it's much simpler than all of this. I may be extrapolating
from my own brain a bit, I'm fairly certain that the brain creates a timeline
of the past by running a garbage collection function every night that goes
something like:

    
    
        if (memory.timestamp < YESTERDAY) delete(memory);

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vokep
I think its a bit more complex than that, maybe something like

    
    
      if (memory.timestamp < YESTERDAY && memory.significance < 0.1) {
        delete(memory);
      } else {
        dream_playback(memory).then((score) => {
          memory.significance = score;
        })
      }

~~~
therein
So if I understand correctly, you are suggesting that the dream playback is
used as a way to determine the significance of a memory?

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jimfleming
Hopefully this leads to better temporal priors for machine learning models.
Sequence encoding frequently uses position coding[0] but the typical
approaches (e.g. low frequency sin waves) are fairly naive. In reinforcement
learning we have (somewhat obvious) works that show that providing explicit
time representations help[1]. Simply throwing a recurrent model at a sequence
may pick up simple ordering but improving the temporal representation would
improve data efficiency.

[0] [https://arxiv.org/abs/1706.03762](https://arxiv.org/abs/1706.03762)

[1] [https://arxiv.org/abs/1712.00378](https://arxiv.org/abs/1712.00378)

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empath75
Lots of people have suggested time distortion effects from psychedelics have
to do with altering how this system works -- if time input decays more slowly,
that would explain things like visual trails and so on.

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ausbah
Are there any research groups who are actively investigating how insights into
the human mind may be applied to artificial intelligence methods? If that's
even applicable?

Edit 0: I should clarify that I am well aware that neuron architecture already
has influenced modern AI methods, I was leaning more towards non-neuron based
methodologies.

~~~
jplayer01
This is what everybody has been working on for the past ten years.

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nshm
The journalist failed to explain "Laplace transform" part unfortunately. How
something like complex variable operation happens in the brain. Most likely
the original researchers meant something different.

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chdaniel
Maybe a bit unrelated but I thought of this as I was reading through the
article: I think it'd be _very_ interesting to invest in a dreams research
centre and I'll definitely do so as well eventually

