Why the Brain Under Your Hat is Like a Brain in a Vat.

Lee Frank

© 2003, Lee Frank

Problems for Brains (in vats and under hats)

• A brain in a vat must access the data of the world despite no direct connection.

• How to persuade the envatted brain that it is acquiring data and acting in the real world?

Problems for Brains

• Preselecting data for the brain would interfere with the normal functioning of an envatted brain.

• Better to remove a brain, place it in a vat, and have it control its body, transmitting internal and external data to the brain.

• Impractical, not to mention difficult, and probably illegal.

Problems for Brains

• A robotic body might perform all of the actions, data acquisition, and transmissions of a normal body––except for the body’s somatosensory system.

• But robots and data transmissions are impractical computer ideals.

• The body sends much more than neural signals to the brain.

Problems for Brains

• There is also chemical information from hormones, the immune system, enzymes, pH levels, and varying amounts of glucose, oxygen, and carbon dioxide in the blood.

• Computer signals cannot substitute for all bodily data.

• While we cannot provide a brain in a vat with real bodily data, we can still examine how simulation could take such data and create a world.

How to Deal with Too Much––and Bad––Data

Real world data can be excessive, insufficient, and erroneous.

Excessive data can be reduced, simplified, or abstracted.

Insufficient and erroneous data can be smoothed or filled-in.

Comment on “Filling-in”

“Filling-in” is a non-controversy. Of course, the conscious mind does not

fill-in. Data is “filled-in” before it reaches

consciousness, perception, or even sensation.

“Filling-in” is just another way to smooth data.

Methods for Data Solution

1. Compression (with and without loss)• jpeg, gif, mpeg• zip, stuffit, tar

2. Filtering using Invariance Under Transformation

The Example of Body Temperatures

• There are numerous body temperature sensors, internal and external.

• Multiplied by different temperatures at each of these various sensors.

• Multiplied by number of times a given sensor records a temperature.

• Yet, despite the volume of information, simplification is easy.

• Once a baseline is determined, a sensor only needs to transmit the amount of change.

• Given the normal stasis of the body, change is rare.

• Most people only notice when their feet are cold while their head may be warm.

• This is a miniscule amount of information compared to how much data our temperature sensors are collecting.

• Many recorded temperatures are immediately simplified before being passed to the next higher level.

• Each sensor on your forearm is saying simply “same.”

• The area of the brain monitoring your entire forearm is probably saying, “all the same.”

• This next level reports the temperature of all our extremities: “arms and legs the same, but feet are cold.”

• The next level monitors the entire body, inside and out, and is aware your head feels warm but your feet are cold.

• Four levels, from skin sensor to forearm monitor to extremity monitor to awareness of the entire body.

• As information moves up each level in this hierarchy, it is easily simplified (reduced) so that finally consciousness can focus on the simple fact that our head is warm but our feet are cold.

• Without reduction, consciousness would be overwhelmed by all the information arriving from our many senses.

• Without hierarchical reduction, consciousness alone would not be able to filter all this sensory information and push it into the background––so it can focus on what’s important.

• “I may be developing a cold or I may just need to put on my socks and shoes.”

Advantages of Indirect Contact with Real World

Acquiring data indirectly permits levels of data reduction and data correction.

This reduced and corrected data can be used to recreate the world.

The mechanism needed by the brain in a vat to achieve this is simulation.

The Brain in a Vat Needs Simulation to Create

a Virtual Reality

• The brain in a vat must believe it moves in the real world just as we do, who (believe we) are not in a vat.

• It must be aware of its legs, will those legs to move, feel them move, feel them make contact with ground as they move––and feel its body move as its legs carry it along.

Simulation of Virtual Reality

• To believe it is a brain in the real world, an envatted brain has to experience sensations, perceptions, and conceptions about that real world.

• It not only has to have conscious thoughts about its body and the real world, but it has to believe its body is acting in that real world.

Simulation of Virtual Reality

There has to be a correspondence between the world the envatted brain believes it is in and the real world.

Acting in the real world automatically refines this correspondence through feedback.

Representation and the Cartesian Theater

• It is only our visual bias that causes representation to imply viewer.

• Close your eyes. Be aware of all you touch and all that touches you.

• If there is a representation here, is it not of your whole body?

• Is there a theater or is your mind simply aware of your whole body?

Active versus Passive

• Theater and viewer also imply passivity.• The simulation actively seeks

correspondence with the real world.• The simulation must include what it’s like to

act in the world.• Our senses are active not passive. • An even better word would be “exploratory”

(after Gibson).

Filter and Focus

The simulation gives both

FILTER

and

FOCUS

Filter and Focus

• Consciousness is what it is, and works as well as it does, only because of the things we are not conscious of.

• The mechanism that keeps things from our consciousness is at least as important as that which informs our consciousness.

• There are not two separate mechanisms, filter and focus, but two sides of the same mechanism.

Background and Foreground

In standard figure-ground illusions, it is not possible to see both figures simultaneously.

Background and Foreground

Simulation says the simpler interpretation is most likely.

Therefore, we have no reason to see both figures simultaneously.

This explains static pictures, but what about moving?

What About the “movie-in-the-brain” Problem?

“. . . first problem of consciousness is the problem of how we get a ‘movie-in-the-brain’ . . .” Damasio

The problem is we think of our visual experience as a “movie-in-the-brain.”

What About the “movie-in-the-brain” Problem?

It is not at all like a movie, with full detail in every frame.

What About the “movie-in-the-brain” Problem?

It is more like an animation: a changing foreground against an unchanging background.

Expectation• To be ignored in detail but available as

background, data must be simplified when excessive and expanded when insufficient.

• It must also be made consistent when imperfect or incorrect.

• To achieve this, the system seeks data expecting correspondence with previous data.

• This matching is not exact but a seeking of invariance under transformation.

• In other words, the simulator is looking for things not to see.

Focus

• The other side of this filtering mechanism is focus.

• It is the non-conscious reduction and simplification of the rest of our virtual world that allows consciousness to focus on one small part of it.

• Aware this is done automatically, we learn how to do it better intentionally.

Making Sense and Making Nonsense

At each level the simulator makes sense out of the data of the previous level.

Sometimes it does this too well, e.g., when we think we can drive when drunk.

Making Sense and Making Nonsense

• Aoccdrnig to a rscheearch at Cmabrigde Uinervtisy, it deosn't mttaer in waht oredr the ltteers in a wrod are, the olny iprmoetnt tihng is that the frist and lsat ltteer be at the rghit pclae.

• The rset can be a total mses and you can sitll raed it wouthit porbelm. Tihs is bcuseae the huamn mnid deos not raed ervey lteter by istlef, but the wrod as a wlohe.

Making Sense and Making Nonsense

Even simple magician’s tricks can fool us into believing that what cannot be so must be so.

We have to believe because the system’s intent is to give us workable representations with imperfect information.

Brain in a Vat Like Brain Under a Hat

Our mind functions like the brain in a vat in that it simulates the real world so it can interact with it.

Our brain, too, is incapable of handling every detail of all the data it encounters in the world.

Brain Under a Hat• You may think you’re doing this, but do you

really believe a tiny bird’s brain capable of processing all the data it encounters as it flies through a forest?

• Nor do we process all the world’s data we encounter when we run, jump, ski, drive a car, or fly a plane.

• Like the bird in the detail-burdened macro-world, we use only a fraction of its data to simulate a version of the complete world we experience: a virtual reality.

Brain Under a Hat

This is what the simulator does.

Brain Under a Hat

This is what the simulator does.

And it does it for a brain––our brain–– that, like the brain in the vat, is not directly connected to that real world.

Brain Under a Hat

This is what the simulator does.

And it does it for a brain––our brain–– that, like the brain in the vat, is not directly connected to that real world.

A brain not unlike a brain in a vat.

In Vat

Under Hat

Under Hat . . . . In Vat

© 2003, Lee Frank