In my
previous entry on the topic of free will, I ended by saying that free will happens at the level of the neuron. It’s probably more correct to say that free
will should be apparent at the level
of the neuron. Anyway, that statement is
surely worth further consideration.
First, let me
acknowledge a statement I made that I don’t think I can prove. I said that “there is no thinking without
neurons firing.” I make that statement
because I don’t know of any alternative hypothesis and there is no other
physiological candidate for thought.
Therefore, I think it is a pretty good assumption, but I would be open
to other alternatives.
Second, what
I want to consider here are the implications of free will with respect to the
neuron. The implications are important
to someone like me, because I believe there is more to a person than material
stuff. I believe every human has a
mind/soul/spirit[1]
that is the ultimate source of decision-making, moral responsibility, and probably
even consciousness and imagination. But
my belief – assertion even – has very important implications when it comes to
physiology and I’ve never heard anyone address the issue. So, I’m about to dive right in.
As I have
stated before, I think that free will is real and not just a figment of our
imagination. For the purposes of
discussion, I use the term “mind” to refer to that entity where decisions
involving free will are made (or at least initiated). How does that happen? Let’s start with an example. I know I previously used the example of moving
your hand to the left or right, but, to be honest, that’s a pretty lame example. I’m not sure that kind of “decision” even
requires a will of any sort. Let’s use a
more human example: you go to an ATM
outside a bank to withdraw money. You
type in a withdrawal of $60 and you hear the machine clunking as it counts out
the $20 bills and you hear a lot more clunks than there should be. When the drawer opens there is over $200 in there! You take the money, complete the transaction
and look at your receipt. It states
plainly that you withdrew only $60. Bank
error in your favor – collect $140! This
really happened to me – it happened to me back when I was a very poor graduate
student. In fact, it happened about two
months after I ran out of money at the end of my first month in Cleveland and
had to live on lemonade crystals for a few days before the next paycheck. So, what do you do with the money? Keep it?
Give it back to the back? Leave
it in the drawer? This is a decision of the will. This involves your mind. Your character. This is uniquely human, isn’t it? I mean, what would a cow do in this
situation?[2]
For our
purposes, we are not concerned with what is right or wrong here. What I want to do is consider how a decision
is made and carried out. Let’s boil it
down to an action. When you pull out of
the ATM spot after collecting the money, you can either turn right and into a
parking spot so you can go into the bank, or you can turn left and on to the
street to go on to whatever is next in your day. How do you physically make that happen? Well, your arms move across the steering
wheel in either a clockwise or counterclockwise direction. How does that happen from a physiological
standpoint? Neurons fire in your brain to
direct other neurons to fire the muscles in your arms in the correct
coordinated pattern. It is quite
complex, and involves the sensations your hands and arms feel from the steering
wheel. Some of the movement is modified
in your spinal cord and in your cerebellum and, for the most part, you are not
really conscious of all of those details.
Most of that movement is orchestrated by motor pattern generators in the
brain – neurons that store information about the millions of times you’ve made
that same motion before. You push the
button for “steering wheel motor pattern turn left” and the program runs
without much conscious effort on your part, unless you decide to alter the
pattern midstream.
The point is,
lots of neurons fire to make that action happen. But notice the phrase “you push the
button.” Who pushes the button? Somewhere in the brain, a decision has to be
made to initiate either the left turning or right turning motor pattern. I do not know whether that “decision signal”
resides in a single neuron or in a network of neurons, but I do know this: ultimately
the decision has to be encoded in neuronal firing because that is the only
way that the signal can be communicated to the motor pattern to your brain and
eventually to the muscles in your arms.
My assertion
is that the decision as to whether to go back into the bank or drive away is
made by your will. I say further that your
“will” is “free” in the sense that it is ultimately up to the unique
“you”. You are responsible for the
decision. Lots of things factor into
that decision, such as how poor you are at the moment and so on, but that does
not change the fact that it is a decision nonetheless. We can assign a moral value to your decision
because it is truly a decision. It is not
random and it is not inevitable.
What it all
means from a physiological standpoint is that there must be at least one neuron
in your brain that is influenced by your will (your mind). As we have established before, neurons
respond to the various inputs they get in one of two ways: they either fire an action potential or they
do nothing. Let’s say in your brain that
there is one neuron whose output initiates the “left turning motor pattern” and
another neuron that initiates the “right turning motor pattern”. These two neurons are mutually inhibitory, which
means that when one fires, the other is inhibited. This keeps your arms from fighting against
each other and causing you not to be able to turn either way, and so you would drive
straight ahead into the curb (you could kind of see how that might happen in
this case, as you struggled to make a decision). These two neurons have many different inputs
from other neurons in the brain. But
when it comes right down to it, the tendency of one neuron to fire is enhanced by your will and the tendency
of the other neuron to fire is not-enhanced
by your will. The decision is
encoded in the two neurons. It has to
be.
If you could
zoom down onto those two single neurons and measure the inputs to each neuron,
you would find that the firing of at least one of those neurons is not directly related only to its inputs. The same set of inputs, given over and over
again to that neuron, produces different results, and those results are not random. This can only happen if there is another
input to the neuron – an input that you can’t measure. That “other” input is the mind. At least that’s what belief in a mind comes
down to.
In summary,
our decisions are ultimately encoded in the neuron. So, the
connection between the material (physical body) and non-material (mind) has to
occur in the neuron. That’s why I
called the neuron the “center” of the universe.
I know my
assertion is hard to accept at first.
For those who subscribe to a purely material universe, you laugh and say
“I’m glad I don’t have to accept that idea.”
Instead, you are happier accepting the premise that free will is a
figment of our imagination. I can’t do
that – I can’t accept that the most compelling thing that I observe in myself
at every moment of every day – that sense that I can decide things – is a
figment of my imagination. For those
who, like me, subscribe to some concept of a “mind” or “will” or “soul” or “spirit”…you
probably haven’t thought much about the practical implications at the
physiological level, so you’re probably saying “hmmm – that seems a bit crazy.”
I will stop
here for the moment, but I want to make two final statements that will be the
topics of future entries. First, note
that in the scenario I’ve put forth, the mind is not the only thing that
influences a particular neuron – it’s just one of many influences. As a result, most of what we do – even our
“decisions” – don’t require the will or are hardly influenced by the will. Things we have done in the past, our
environment, etc. etc. all have strong influences on neurons because these
things are all stored or sensed by other neurons. If anything, the will is a “weak force”. This has a lot of implications when we
observe human behavior. Second, it would
seem that my hypothesis should be testable since we have the technology to
record signals from single neurons. In
the future I’ll talk about why such a test would be really really really
difficult to do, if not impossible.
OK – you can
return to your originally scheduled thoughts!
Let those neurons fire away!
P.S. Oh – to complete the story – yes, I did take
the money back to the bank. The teller
looked at me like I was an alien!
[1]
For now, I am lumping these terms together to represent one concept. Specifically, they represent the concept that
there is something non-material that is part of every human being. It’s easier, for the moment, to just use the
term “mind”, but I’m sure I will have to come back to this topic at some later
date.
[2]
Well, I know for a fact that cows can’t count, so they would have no clue they
got extra money.
No comments:
Post a Comment