
How Does the Brain Represent the Objects We Touch? - laurex
https://www.technologynetworks.com/neuroscience/articles/how-does-the-brain-represent-the-objects-we-touch-307051
======
cromulent
It's more complicated than that - other senses such as sight are also part of
the representation. Blind people who regain their sight do not recognise cubes
and spheres that they would recognise by touch.

[https://www.newyorker.com/tech/elements/people-cured-
blindne...](https://www.newyorker.com/tech/elements/people-cured-blindness-
see)

~~~
escherplex
True. Also have to factor in the proprioceptive sense, EG, index finger in
neurologically mapped space pressing on the arm of a chair. But what about the
condition where an index finger is pressing against an adjacent thumb? Here
percepts involve two conjoined sensors reporting as both sensors and objects
being sensed. What's the priority source of the sensation?

~~~
AstralStorm
Why should there be any? Advanced neural networks can easily take in such
ambiguous inputs. Heck, even contradictory, explaining a few illusions in the
process.

------
al_ramich
Fascinating approach. To evolve the current AI methods more study is required
on how the human brain works and doing studies on the very early stages of the
human brain at its infancy has the most potential to move us forward. What
comes after Deep Learning? Probably a version of biotech, a synthetic
capability that can learn based on the external sensory input.

------
mattbierner
Interesting. My sense of touch has gotten messed up for week or so a few times
and those experience really made me appreciate how the brain integrates the
senses to create the feeling of "normal" existence. You don't even realize
this until the system breaks down. The closest thing I compare my experiences
to is: imagine interacting with the world using a pair of super awesome VR
gloves. Not muted exactly, just somehow unreal feeling.

Even though my muscles worked just fine, the differentness of sensation made
it very to manipulate objects without concentration. This was especially true
for fabrics and soft objects, which my brain found fascinating to play with
but utterly incomprehensible. The unreal sensation slowly faded throughout the
week but certain experiences—like trying to use pockets—would make the feeling
of unreality come roaring back. I don't know if this fading was just my brain
returning to normal or if it was my brain re-leaning and adjusting to what
normal is.

~~~
taneq
> The closest thing I compare my experiences to is: imagine interacting with
> the world using a pair of super awesome VR gloves. Not muted exactly, just
> somehow unreal feeling.

Wow, this is really interesting because one of the side effects of excessive
VR usage that I've read about is "hands not feeling real". Otherwise 'normal'
people spend a ton of time in VR (where your hands are represented by largely
immobile mitts at the location of your controllers) and start to feel like
their actual hands 'aren't real'.

If you don't mind saying, how did your perception of touch get affected in
this way?

------
ggm
I think it's very unlikely we will ever concretely define how the brain
represents reality in its intrior model.

Given that I can conceptualize the existence of the letter "A" on the back
face of a red square box sitting on a black floor and hypothetically view it
face on,reflected in a mirror behind, through the box backwards if it's
translucent, and _the box doesn 't even have to exist_ ... And then intrude
being asked to put my hand into some three-space simulating feedback
environment and "feel" the box which isn't there, or add VR glasses and "see"
the box which isn't there...

Now consider a classic nuclear hot box, and put a real cube inside it and
interact through the remote sensor waldoes.

Is that feeling any different? Is the brain model any different?

------
axilmar
It would make sense that any information is stored as a key-value pair in the
brain. In this case, the key is the sensory input, and the value is the type
of surface that is being touched.

Could the simplistic key-value pair work in creating more complex systems?
perhaps it does, if keys are complex input structures which be divided into
more keys in a tree-like fashion.

~~~
pjc50
I don't think it's established that either "keys" or "values" exist in the
brain. It's more "stimulus-response", where similar stimulus produces similar
response. There's a nonlinear classifier going on which tends to create
categories for us, but it's definitely possible to produce cross-category
stimulus.

~~~
eli_gottlieb
There isn't a classifier in the brain, and there _certainly_ isn't a key-value
store. The brain mostly runs the sensorimotor systems based on top-down
Bayesian prediction, not bottom-up classification or regression.

~~~
axilmar
The way living organisms behave certainly points towards a simple key-value
store, where key is the current experience and value is the response.

~~~
eli_gottlieb
Scientifically speaking, no, that's not even remotely true. What on _Earth_
gave you that impression?

