Lecture notes for Jan. 16, 2019 talk
to Univ. of Texas OLLI (Osher Lifelong Learning
Institute) NOVA group.
The ideas I’m going to talk about have
come from reading started while I was running a research laboratory studying
vision at the Univ. of Wisconsin, while also teaching the introductory
neurobiology course. The reading
turned into an interdisciplinary course called the Biology of Mind whose
lecture notes I transformed into a book.
Since retiring from active teaching
and research I’ve been putting newer findings in a blog, Deric’s
MindBlog.
UPSTAIRS/DOWNSTAIRS
I. What is happening as our “I” senses
and acts in the world?
II. What behaviors are coming from upstairs
and downstairs?
III. What is happening in paying attention
versus mind wandering?
IV. How might we observe and influence
what our brains are doing?
Here are the topics I would like to touch
on today. First, how might we
explain or think about our actual lived sense of having a self.
In this first part of the talk I’m going
to be showing you some brain teasers, experiments that
I hope will make your heads spin just a little bit. I’ll give you an advance warning that
this first part of the talk, describing what psychologists and neuroscientists
finding out about the sort of alien seeming things that are really going on
inside our heads, this is a bit strange making, but
I promise then that I will get on to more comfortable and familiar descriptions
of how our upstairs and downstairs run our show.
With the second topic, I get down to some
basic bread and butter descriptions of what goes on in our brains, what roles
are being played by the older downstairs and newer upstairs parts of our
brains.
Then third, I’m going to ask what is going
on when we are paying attention versus ruminating or mind wandering - to what extent do
we really have true mental autonomy.
Finally, how much can we watch and
influence the brain processes I will be describing.
I’m going to be talking about our
awake and aware selves - all of us sitting right here, right now.
This is only one of the kinds of
selves we have. We don’t have this
kind of self during the night when we are in deep sleep and lose
consciousness. And when we are in dreaming sleep we have another kind of
self.
There are clinical conditions, such as
epileptic absence seizures, usually involving our brain’s temporal lobe, in
which a self temporarily vanishes while other faculties persist. A patient will still move, sense, is
wakeful, but is like a zombie, showing no sense of self or interaction, blank
face, eyes, might walk out of a building, down the street, and on recovery have
no recall of intervening time.
This tells us that there are contents
of mind relevant to sensing and moving in a world of objects, but not to normal
consciousness.
We actually have a downstairs
unconscious under mind of a vast number of autopilots with our upstairs actual
awareness being a thin veneer over that.
I want to start by addressing that veneer, our normal
perky awareness, our deciding to do this or that, run our show.
To start then with the first topic, let’s look at what
happens when we are paying attention and decide to do something. I pick up a book and assume my conscious
intention to do that is what causes me to pick it up.... but, it’s not that
simple, and that’s shown by this simple experiment done first by Benjamin Libet, which I never get tired of showing...
- This is an undergraduate psychology student being paid a
few bucks an hour to be a subject, and his instruction is to watch a rapidly
moving clock hand, making a complete rotation every second, and flex his finger
to push the button when he feels like it, and tell us where the hand on the
rapidly moving clock is when he decides to do that.
-Now, the experimenter has previously attached some EEG, or
electroencephalogram electrodes over the part of the brain that activates
movement. The crazy thing is that
if we take the time at which an EEG electrical signal is telling us that brain
activation for movement is starting, take that as being zero time, the kid reports awareness
of his intention to push the button about 350 msec
(0.35 seconds) later, and the actual EKG, the voltage in the finger muscle
doing the push, happens about 200 msec later than
that.
Wow, he is 'late for consciousness', the action had already
started before he thinks he started it.
Many experiments like this have shown that our brain starts on our
acting earlier than our consciousness of intending to act.
Now, this
doesn’t mean we don’t have any control, because we do become aware of our
action before its completion, and can edit or veto it if it is inappropriate.
ACTING
-begins faster than conscious
awareness
-can be edited or vetoed by
awareness
So, the summary at this point is that when you think you
have decided to take an action, your brain has already started working on it a
about third of a second, or even longer, before that. But, our awareness clicks fast enough
for us to alter or veto the activity, like having a ‘free won’t’ editor. [Sept. 2019: More recent work now questions these conclusions. The question of free will is far from solved. More recent experiments, have suggested that the brain signals noted in Libet's original experiment ~500 msec before a movement was made may not be the actual neural initiator of the movement. An artificial intelligence classifier comparing control brain noise in subjects not instructed to move shows divergence from noise in those instructed to move about 150 milliseconds before the movement, the time people reported making the decision to move in Libet's experiment.]
We can make a similar story about our brains being ahead of
our experienced awareness with perception, like when we see things.
Here the undergraduate is told to push the button when the
light flashes on. The button push
occurs about 200 msec after the light comes on. Then the instruction is “be sure you are
seeing the light when you push the button,” or, "slow down your response by the tiniest possible amount."
Things change… now takes approximately 700 msec before the button is pushed. There is a quantum jump of 500 msec, waiting for the conscious perception to develop if a
conscious rather than unconscious response is requested.
ACTING
-begins faster than conscious
awareness
-can be edited or vetoed by
awareness
SENSING
-faster than conscious perception
So, our brain’s actual sensing of something out there is
actually faster than our conscious awareness or perception of it.
The take home message is that both our sensations and
actions are faster than our awareness of them.
-What's the point of this half second
delay for consciousness? There is
one: our downstairs unconscious
mind can shape what we think we are perceiving out
there in the real world.
-We compare the information that comes with our library of
images, and frequently assume that the stored image is the correct one.
Now, I just flashed a playing card briefly, and now am
showing an irrelevant and random picture, called a distractor in the tradition
of psychology experiments.
Now, please recall what kind of card was it, it's suit, its
color. How many think it was a red ace of hearts? What about a black ace of spades?
How many saw something else?
Actually, it was an
impossible card, a red ace of spades.
Our downstairs undermind knows
the history of our development, our learning to sense and name things, the ace
of spades is black, the ace of hearts is red. The
actual experiments do demonstrate that if someone flashes a red ace of spade in
front of people they are more likely to see one of the two choices they are
already familiar with.
We compare the information that comes with our library of
images, and frequently assume that the stored image is the correct one. What you are looking for, rather than
what you are actually looking at, can determine what you see, or what is
obvious.
ACTING
-begins faster than conscious
awareness
-can be edited or vetoed by
awareness
SENSING
-faster than conscious perception
-conscious perception = what ought
to be there
Our summary so far then is that both acting and sensing are
faster than our awareness of them, permitting editing functions to intervene
and shape both our final actions (free won't editor) and perceptions (what
ought to be there).
Let me try another trick. I want you to pick one of the six
playing cards below that you are going to remember, the magic is that I'm going
to tell you which card that one is.
-Slide of cards,
‘picked it out?’
…then Charles Darwin distractor
slide
Yes, this is yet another `distractor' picture, of the
gentleman who described the impersonal mechanisms that led evolution to give us
the sensing devices we are fooling with now.......,
Now I'll ask you to look at the five cards instead of six.. Is the card you picked missing?
OK? let's do it one more time., pick the card you are going to
remember…..got it picked?
-the distractor:
OK,
again, here are five cards instead of six.
Is the card you picked missing?
Amazing.
I’ll bet that some of you can tell me the trick here…. what is it?
Actually
NONE of the original cards are in the second set, but the new five card array is of the same type, for example face cards,
low cards, whatever. The trick capitalizes on the visual brain's laziness (or
efficiency, if you prefer). It seems that the mentally selected one is missing,
because we actually encoded something like 'lots of royal cards including my
mentally selected king of hearts.’
We’ve let ourselves become attentionally
blind.
ACTING
-begins faster than conscious
awareness
-can be edited or vetoed by
awareness
SENSING
-faster than conscious perception
-conscious perception = what ought
to be there
-lazy (i.e. efficient)
So, to my summary slide I have to add this final feature of
our sensing, it
is efficient, or lazy.
In fact, the
current consensus is that what we are actually experiencing all the time is our
prediction of what is out there, or what the sensory consequence of our actions
will be, and the actual inputs from our ongoing sensing of our environment and
the result of our actions serves the function of telling us whether those
predictions are correct.
If that is not
the case, there is a surprise, and that surprise is an error signal that is
used to tweak our ongoing predictions.
This turns out to be the best way for our brains to minimize the amount
of metabolic energy they must use to run our show.
In the 20th century we thought the brain
extracted knowledge from sensations. The 21st century has witnessed a ‘strange
inversion’, in which we now realize that the brain is an organ of inference,
actively constructing explanations and predictions about what’s going on ‘out
there’. Our predictions are what we
are experiencing and seeing, and incoming sensory signals are telling us
whether we are right.
Now, I want to show you another striking experiment that
shows that we can put this predicting self anywhere we like in space. Over the years there have been many
reports of people having out of body experiences, sometimes while entering or
emerging from anesthesia. Turns out
its not that hard to do.
Here is our undergraduate psychology
student on the left in the dark blue trousers. In his goggles he is seeing the picture
being taken of his back projected to be in front of him, so he is looking at
his own back in front of him. Dark
is the actual body, light is the virtual body seen in the head goggles.
Now, he sees the back of the image of
himself being repeatedly stroked at the same time that someone is actually
synchronously stroking his real back with the same rhythm.
This is a multisensory conflict, vision
of the virtual image being stroked is telling him something different from the
felt touching on his back. In a
case like this, vision typically dominates over proprioception and touch, and
the subject starts to feel that the virtual body seen in front of him is his
own body and he mis-localizes himself to
the virtual body, to a position outside his bodily borders.
This indicates an amazing plasticity, with
spatial unity and bodily self-consciousness being computed from
multi-sensory and cognitive processing of bodily information.
You can even experience yourself as
another kind of person.
There have been three separate studies
in which white participants spend around ten minutes in the body of a virtual
black person, learning Tai Chi. Afterward, their scores on a test designed to
reveal unconscious racial bias shift significantly. The effects happen fast,
and seem to last a while. A week later, the white participants still had less
racist attitudes.
These embodied simulations seem to
slip beneath the cognitive threshold, affecting the associative, unconscious
part or our minds. “It’s directly experiential,” “It’s not ‘I know.’ It’s ‘I am.’ ”.
ACTING
-begins faster than conscious
awareness
-can be edited or vetoed by
awareness
SENSING
-faster than conscious perception
-conscious perception = what ought
to be there
-lazy (i.e. efficient)
BEING A BODY
-can be experienced inside or
outside our actual body
So to summarize so far,… our subjective I is late to acting and sensing, it’s
an after the fact report, and we can place our subjective bodies outside our
actual one...
So, the big
question, to end this section of the talk today, is how is it that we have this
experience of having an “I” or self even as experiments like the ones I’ve been
showing prove that most of what is running our show is going on before this
self arrives on the scene to be aware of it.
We are
sensing the world, sound, light, smell, touch, and stuff inside our brains has
to be monitoring all that.
Lets
think of our brains as having circuits like the instruments in a Boeing 777 cockpit that report on pitch, yaw, speed,
fuel, altitude, engine status, and so on..
…there are systems in our brains presenting what is coming into
our senses, and there are circuits in our brains commanding our movements in
response, just like a airplane
pilot moves the different levers you see in the picture.
But,
where is the pilot? Where’s the
little person like in this character from the men in black movie.
If
there is somebody like that in us then what is running it? Another smaller self? We might have a self inside a self
inside a self like a set of Russian dolls, but that doesn’t work out too well.
The
harder we look, the more we find, as in Gertrude Stein’s description of Oakland
Ca. where she grew up, that there isn’t any there there.
Our
best guess is that “We” , in quotes, are the airplane
cockpit instruments. On the instrument panel, there is a light
with a label that says “Pilot Present.” When the light is on, that means that
another kind of instrument has been turned on that is noting the cockpit
workspace and which meters are most relevant, we are self-conscious, that is, we experience
being in the cockpit and monitoring the instruments.
It’s
easy to assume that, while we’re awake, this light is always on. In fact, it’s
frequently off—during daydreams, during a fair fraction of our mental
life, which is largely automatic and unconscious—and the plane still
flies, just like the subject I was mentioning earlier with epileptic
automatism, epileptic absence seizures.
The
harder thing to grasp is that we cannot see the cockpit. Even as we consult its models of the
outer and inner worlds, we don’t experience ourselves as doing so; we
experience ourselves as simply existing. We don’t recognize our
self-model as a model. It is transparent: we look right through
it. we don’t see it. But we see with it.”
Our mental models of reality are like V.R. headsets that we don’t know we are
wearing.
The
best guess is that we are doing with ourselves like what our visual system does
when we look at at this figure, a Kazinsa triangle.
We see it,
but there’s really no triangle there.
We can experience our I-illusion as inside ourselves, or as the
experiments I just shown you demonstrate we can project that illusion out of
our bodies. We have a virtual avatar in our brains.
Should
it upset us that there is not a real “I” like we suppose between our ears? Not really, in a practical sense, our
“I” is an illusion but it is an essential, important, and necessary one… we
couldn’t live without it, without all of us having it to make a society with
other selves we image to be similar.
Illusions piled on top of apparent mental causation are the building
blocks of human psychology and social life… of what we take to be our
responsibility, justice and morality. Evolving the ability to make such an
elaborate illusion is why humans have dominated as a species on this planet.
Well, I
think that is enough mind bending for the moment.
So, a quick summary to wrap up this first section of the talk. Four
major points:
I.
What is happening as our “I” senses and acts in the world?
A. Our subjective “I” is late to sensing
and acting. It is an after the fact report.
B.
What we experience is our prediction of what is out there, or what the
sensory consequence of our actions will be
C. We can place our experienced body
inside or outside our actual one.
D. The “I” or self that we experience is
an illusion, a virtual avatar in our brain.
A repeat
of the talk topics slide:
UPSTAIRS/DOWNSTAIRS
I.
What is happening as our “I” senses and acts in the world?
II. What behaviors are coming from upstairs and
downstairs?
III. What is happening in paying attention
versus mind wandering?
IV.
How might we observe and influence what our brains are doing?
Now, on to part II, our next topic in the
talk, let’s consider what behaviors are coming from upstairs and downstairs in
our brains,.
I haven’t shown you a single picture of a
brain, or mentioned much about the little grey cells between our ears that are
doing all this stuff. So,
here is a picture of a brain that begins to illustrate the upstairs downstairs
distinction:
The
pink portion here is our later evolved version of a simple mammalian brain,
usually called the limbic system. On top of that is our newer, or
neo-cortex. It is hugely folded to
cram a lot of stuff into a small space. This roughly illustrates the
upstairs and downstairs of our cerebral cortex.
Actually, Upstairs/Downstairs
is an oversimplification, our
brains have multiple stories, or levels.
The
author and writer Arthur Koestler quipped that when we lie down on the
psychiatrist’s couch, an alligator and a horse lie down with us.
The
bulges at the top of our spinal cord, our brain stem, are our evolved derivative of a
reptilian brain, regulating breathing,
swallowing, body temperature, heart beat, visual tracking, hearing, drives,
motivations, and the medical
student’s four F’s feeding, fighting, fleeing, and fornicating.
A new
kind of cortex appears in mammals, that regulates
nurturing and emotional behaviors, and our subsequent version of this simple
mammalian brain is the pink stuff in the slide I just showed, the limbic
system.
These
older parts, that I’ve labeled brain stem basement and middle brain or limbic
downstairs are rapid, the upstairs is slower, what we
use to think about things.
As
mammals develop more complex social groups and communication, the top layer of
the cortex, called the neocortex, that covers both the limbic system and the brain stem
becomes much larger. This is our upstairs, housing our higher functions,
thoughts, language, logic, etc.
Animals
that form social groups have larger cortices. An extrapolation of brain size
correlations with group size suggests that the optimal size of a human group,
or tribe, when you can know everybody and everybody knows you, is about 150
individuals, which is about the size of the few remaining stone
age tribes that still exist.
150 is also the average number of personal
relationship, from close to distant, that people in society today maintain.
In general, the older downstairs parts of our brains can react
more rapidly to what is happening than the more thoughtful upstairs. You might
find yourself jumping to avoid a sudden looming overhead movement, or a
squiggly object in your peripheral side vision just in case they might be due
to a large object about to fall on you, or a snake on the ground beside you, nothing
lost if it your upstairs machinery perceives just a bit later that it is
actually a cloud darkening the sun or a twisted rope rather than a snake.
Things we see take a fast unconscious route route
through a part of the brain called the amygdala, sort of where my thumbnail is
if I make a fist with my hand in the shape or our brain, this route can command
a rapid unconscious behavior like jumping away. More slowly, the upstairs part of our
brain forms our conscious perception of what is there.
Remember the experiment I showed you earlier with the kid
pushing a button very rapidly when a light came on, this was going through this
lower brain system, but if upstairs perception of the light was requested, it
was half a second slower.
We have upstairs cognitive frontal inhibitory controls that can
regulate more rapid medial lower areas like the amygdala where habitual
routines and learned emotions reside. It takes increased activity in our
frontal cortex to override addictions and cravings fueled by deeper structures
in our old mammalian brains, or to dampen inappropriate reactivity of our
amygdala.
Once a fear reaction or emotional
aversion is established it can become permanent unless the cortex learns that
it is no longer relevant and inhibits the amygdala’s reactivity, by sending
chill it signals down nerve fibers connecting it to the amygdala. In post-traumatic stress syndrome
this cortical inhibition has been impaired.
Now, a very important point: The normal
condition, the default condition - for this fearful threat seeking part of our
brain, the amygdala - is to be turned on more than it really needs to be,
better to be safe than sorry. This
leads to a feeling of anxiety, one of the best definitions of anxiety being that
it is fear in search of a cause. To
feel safe, when there is actually no realistic threat present, continuous
suppression or inhibition of this amygdala activity by the upstairs frontal
part of our brain is required, using the nerve fibers it sends downstairs.
The amygdala is part
of a sort of "command central" network that can program our overall
emotional reactivity, our bias toward being apprehensive and anxious.
Its opponent is a
"positive-making system" that correlates with enhanced left frontal
activity that connects down to and can suppress amygdala activity, allowing
more positive appetitive behavior.
Ideally we find an upstairs downstairs balance that doesn’t let
either inhibited limbic emotional reactivity or a frontal control freak run the
show.
I need to mention some other
downstairs/upstairs systems that can be tweaking our behaviors or explanations
without our being aware of it.
Our downstairs brainstem and basal forebrain has clusters
of cells that send axons all over the upstairs to diffusely spritz different
areas with neurotransmitters to chill or arouse them, to toggle attention,
alertness, anxiety, elation, depression, aggression, appetite and motivation.
You’ve probably heard the names of the neurotransmitters,
small molecules that carry messages between nerve cells, doing this:
acetylcholine, dopamine, serotonin, norepinephrine. The details aren’t important for what I
want to say today.
All of these systems are regulated by our
conscious cognitive response to aspects of our environment, especially whether
it is safe or threatening.
But they all can also have reasons of
their own. There can be internal explanations for why we feel this or that
particular way. These systems have daily cycles, alternating periods of
activity with intervals of rest and renewal of their neurotransmitter systems.
There is a cyclical activation of cholinergic versus adrenergic systems in
sleep versus wakefulness.
These cycles can generate feelings for
which "there is no reason" in the usual sense, not withstanding our
tendency always to invent a reason for the way we are feeling.
During some feelings and emotions, the
brainstem systems are calling the shots, and our fertile imaginations are
merely supplying a cover-up story.
Numerous experiments have shown that we
will cheerfully confabulate bogus reasons for a behavior if the real cause is
not accessible to our consciousness.
Some patients with damage to the right
parietal lobe display a condition called anosognosia,
and will deny the existence of the left side of their body. “Oh, that’s not my
arm, it must belong to someone else.”
The language system in our left brain, which is not damaged, is making
up the best cover story it can to preserve the sense of an intact self.
Thinking
about what comes first, emotions or reasons, presents us with the same problem
as the ‘which comes first the chicken or the egg’ question. There is no action or reason that is not
informed by emotion,
there is no emotion that is not informed by cognition.
OK, enough on
downstairs. Now I want to go to our our newer neocortical upstairs
that is running our most advanced human functions, what we see looking at the
external surface of our brain.
In the
1800s if you wanted to know about how your brain was working you went to a
practitioner of the science, or pseudoscience, of phrenology which localized
cognitive functions to specific areas of the brain, and a professional
examination of the bumps and indentations of your skull was supposed to reveal
the strengths and weaknesses of your domesticity, conscientiousness,
spirituality, combativeness and so on.
But, a more
scientific identification of the functions of various brain areas was happening
in the 19th century as physicians were observing that strokes that damaged
specific parts of the brain could damage specific functions like hearing,
vision, language.
These first crude PET, or positron emission tomography images of the
activities in living brains from over 40 years ago began to show us brain
activities that increased in the same areas as those functions were going
on.
Assigning
functions to brain areas has come from correlating brain lesions, damage from
strokes or tumors, with electrical recordings from brains or from imaging those
areas with more modern techniques.
The figure labels the
primary visual, auditory, somatosensory, and other areas. In general information coming in first
projects to the back of the brain and then moves forward in a dorsal (top, or
upstairs) stream that is figuring out the spatial relationships in the
environment so that it can act on them and a ventral stream (bottom, or
downstairs) that is concerned with the identity and meaning of what is coming
in.
The frontal lobes that
are focusing attention actually feed back to the primary sensory areas to
enhance processing of what’s most relevant.
Our brains generate a
constant prediction of what they expect to see, and are mainly stimulated by
deviations from this prediction.
Remember the card experiment from earlier where I was hoping some of you
saw a card you expected rather than the one I actually projected.
One model for what’s
going on, proposed by a well know brain researcher, Steve Kosslyn,
is that the upstairs or dorsal top brain system is what formulates and executes
plans. The downstairs or ventral pathways are a bottom brain system that
classifies and interprets information from the world.
He suggests that the
relative strengths of these upstairs and downstairs systems might account for
four basic personality types…
The Movers are your
winners, top brain action people who actually also use
the bottom to pay attention to the consequences of their actions and use the
feedback.
The stimulator is more a
‘damn the cannons, full speed ahead’ kind of person, less inclined to attend to
bottom pathway, the consequences of their actions and know when enough is
enough.
Does that sound like a
prominent figure we all know?
The Perceiver is mainly a
bottom brain interpreter, unlikely to initiate top brain detailed or complex
plans.
Finally, the people with
lazy top and bottom brains are your ‘whatever…’ types, absorbed by local events
and immediate imperatives, responsive to ongoing situations…more like a large
fraction of the U.S. electorate.
By now I’ve mentioned at
least four different levels or stories of the upstairs/downstairs motif, any
one of which, at a given moment might be dominant in running our show. Cool rational reasons from the highest
levels at some times, at other times downstairs primitive emotions actually
controlling while the unaware upstairs makes up the best cover story it
can.
So, a brief summary of this second
section of the talk:
II. What behaviors are coming from upstairs
and downstairs?
A. Downstairs dominates rapid
actions and judgements.
B. Upstairs modulates this with
slower reasoned responses.
C. Reasons and emotions cause each
other.
D. Different personality types
have different upstairs profiles.
A
repeat of the talk’s topics:
UPSTAIRS/DOWNSTAIRS
I.
What is happening as our “I” senses and acts in the world?
II. What behaviors are coming from upstairs
and downstairs?
III. What is happening in paying attention
versus mind wandering?
IV.
How might we observe and influence what our brains are doing?
I want to move
my third topic now and talk about another kind of self, the self that is
focused inward, daydreaming, maybe thinking about the past and future. And it’s not
all that engaged or paying attention to the outside world.
I suspect
we’ve all had the experience of lapsing into thoughts while we are driving, and
all of a sudden, with a start, we realize that we have gone
maybe gone eight blocks, through two traffic lights, and have no recall of
having done so, we were paying no conscious attention to what we were doing,
the self that normally pays attention to driving has vanished and a daydreaming
self is in place.
Now if, while you were lost in thought, a light had turned red, or a kid
had run out into the street, the part of your brain that was paying attention
would hopefully have snapped you back into focusing on your driving. For a while you were on autopilot, being
run by a downstairs unconscious undermind of learned
routines.
Our normal awareness is
a thin veneer over this larger process.
Our
brains are in a very different space when we are paying attention, focusing,
versus being focused inward in reflection, or letting our minds wander.
Our brains
have two major systems, the attentional and default
mode systems.
When we are paying attention and controlling things, the blue
areas in this graphic are more active… that’s in the more frontal and side, or
lateral part of the cortex. The top figure is looking at the left side of our
cortex.
When we turn inside of the top half hemisphere around to face us
we see the red and yellow areas, part of what is called the default mode
network.
Summary :
attentional: direct experiential focus, task focused network, mechanical physical cause/effect
reasoning
default: mind wandering, stimulus independent, narrative focus,
phenomenal, social reasoning, self referential, introspective
Our attentional network is active when are are
actively focusing on external tasks, trying to figure out external things,
causes and effects.
Our default
mode network is our inner life, our ‘this is me’ system, independent of what’s
going on the outside world, creating narrative about who we are, past and
future, randomly wandering, thinking about ourselves and others.
Each of these default mode network activities recruit slightly
different but highly overlapping brain areas.
One of the best descriptions you can
read of the attentional and default mode networks is
in the recent book by Michael Pollan, “How to Change Your Mind”, which is a
description of what psychedelics teach us about how our minds work. Psychedelics dampen down our default
mode networks that are maintaining our constant sense of our self, who we are,
allowing more open and novel experiences of reality. Young children, whose default mode
networks have not matured, are closer to being in this kind of open naive
space. During meditation by
experienced meditators the activity of the default mode network also
diminishes.
Our switching back and forth between attentional
and default modes seems to be based on a cyclically recurring process in our
brains. The ebb and flow of autonomy is a kind of attentional
see-sawing between our inner and outer worlds, caused by a constant competition
between the brain networks underlying spontaneous sub-personal thinking and
goal-oriented cognition.
Mind wandering is a transient loss of mental autonomy, via the
loss of our sense of ourselves as an active agent. A
daydream just happens to you – there is
ownership, but no control over the event. It is not something you do, but
something in which you ‘lose yourself’.
Just as with our upstairs/downstairs behavior drivers there is
an optimal balance between attentional and default or
mind wandering modes. They both
have strong points and weak points.
Our attentional mode gives our control
to more frontal cognitively and metabolically demanding activities. When its
active, like when we are focusing on some external task, it dials down the
default mode network.
Its downside comes if we get into being control freaks, with so
much attentional control that we suppress our
spontaneity and creativity.
The attentional
upstairs frontal stuff
that we have to engage to do novel and new things is more
susceptible to aging, most of us find it more of an effort to do novel actions
as we age. These frontal areas of
our brain are the first to begin slipping as we age, they were the last to form
during brain development, continuing to mature and change through our mid to
late twenties. As we age we play in
reverse the steps that formed our brains.
Our default mode or wandering mind has turned inward, is less
focused on actively engaging what is going on in the outside world right
now. It has its virtues and
constructive aspects: self-
awareness, creative incubation, improvisation and evaluation, memory
consolidation, autobiographical planning, goal driven thought, future planning,
retrieval of deeply personal memories.
The basement stuff that is wandering
around in the absence of focused effort more easily makes novel associations, I’ll bet that
a lot of you have had my experience of having a solution to an unresolved
intellectual or personal issues seem to click into place or appear from nowhere
during the period of mind wandering that occurs in the transition from sleeping
to waking, or dreaming.
Our
mind-wandering network and the DMN basically serve to keep our sense of self stable and in good shape. Like an automatic maintenance
program, they constantly generate new stories, weaving back and forth between
different time-horizons, each micro-narrative contributing to the illusion that
we are actually the same person over time. Like night time dreaming,
mind-wandering seems to be a process by which our brain and body consolidate
our long-term memory and stabilize specific parts of our self model.
Two Yale psychologists have pointed to another feature of mind
wandering. They published a clever study in Science Magazine several years ago showing that
we are likely to be less happy when we are ruminating or mind wandering than we
are focused on some activity. Their
paper’s title was: “A wandering
mind is an unhappy mind.”
They developed an iPhone App, which thousands of people in
different countries downloaded, and then when their cell phones ‘pinged’ they
answered a number of questions like “How are you feeling right now?” on a scale
from 1 (very bad) to 10 (very good).
Or, ‘are you thinking about something other than what you are currently
doing, is it pleasant, neutral, or unpleasant, and so on.
Mind wandering was occurring half the time, in half their
samples, and regression analysis showed that people were less happy when their
minds were wandering than when they were not, this was true during all
activities.
This and many other studies point to the fact that thinking is
not so much something we do as it is something that
happens to us. Almost all of us, for half to two thirds of our conscious
lifetime, are not in control of our conscious thought processes…Many hundred
times a day, all of us experience a sudden diminution of inner autonomy,
periods when we are no longer directing an outer focus on some activity.
Increasing activity of the default mode network can correlate
with passive reactivity and using environmental support rather than focused
frontal self initiation.
Environmental support can be both good and bad: it provides
structure that helps aging individuals like ourselves to chose and carry out
activities, but this can go with a decrease in our self initiated more energy
requiring upstairs frontal brain activities, with letting go of our internal
control.
A decrease in active goal directed attentional
behavior is associated with various kinds of fronto-temporal
dementias.
So, a list of a few of
the points I’ve just made:
III.
What is happening in paying attention versus mind wandering?
A. Mind wandering is a transient loss of
mental autonomy.
B. Mind wandering and default mode
networks stabilize our self model.
C. Mind wandering facilitates creative
incubation.
D. A wandering mind can be an unhappy
mind.
UPSTAIRS/DOWNSTAIRS
I. What is happening as our “I”
senses and acts in the world?
II. What behaviors are coming from upstairs
and downstairs?
III. What is happening in paying attention
versus mind wandering?
IV. How might we observe and
influence what our brains are doing?
OK, here is the summary slide again,
the first three topics describe
three different kinds of control, that are collaborating in running our
show. Most of us, most of the time, are not paying attention to which of these
are managing us, how they are doing it. In this final section of the talk
I want to talk about what can happen if we do pay more attention to these
things going on.
Part I
was about systems that start up before our awareness to influence our acting
and sensing. The question is: Can we nudge our awareness into those
earlier time windows before we are aware of acting or sensing
to check on our actions better, to sense what is really there
rather than what we expect to be?
Part II
was about our upstairs and downstairs brain. Can we develop an awareness that notes
when a not very useful emotion is about to override our more reasonable
responding?
Part III
has been about our attentional versus default or mind
wandering brains. Can we develop
better awareness of whether we are attending to a task or letting our minds
wander?
The
answer to all these questions is yes. We can observe and influence all of these
processes by training our attentional muscle to watch
what is going on in our mind.
Observing
our own minds working not something that ‘just happens’ like upstairs versus
downstairs, attentional versus default
activities. We have to work at it.
We have
to slow down and quiet ourselves enough to notice things appearing in our
awareness as soon as they happen.
Now, let's take a break from the constant stream of information I've been throwing at you. Let's do an experiment. What I’m going to ask you to do may seem
a bit strange, but bear with me. I
want you to get comfortable in your seats, put your hands in your laps, and, no
cheating, close your eyes. Please
just sit with your eyes closed. Now
I want you to pay attention to your breathing, in and out, and see if you can
slow it down just a bit. Let the
muscles around your eyes soften. When I say go we begin a period of silence for
30 seconds during which I want you to follow a simple instruction. Continue to pay attention just to your
breathing, and have no thoughts or images in your mind. Begin now……
Now, take your time to slowly open
your eyes and tune back into our session. I would like a show of hands, how
many of you were able to have no thoughts for 30 seconds? Unless you are an experienced meditator,
I suspect you were not able to have an empty mind.
Most of us find thoughts popping into
your head in spite of our best intentions. If I had just explicitly told you to
return your awareness to your breathing when you noticed thoughts or emotions
intruding, I would have been giving you the instructions for one form of
mindfulness meditation.
In an
exercise like this thoughts or emotions just keep popping up from somewhere, that's the martian inside, a brain that is is
generating this stuff in spite of “our” conscious best intentions. This is what it is designed to do,
generate stuff,
regardless of whether “we” in quotes, want it to or not. This, like earlier examples I’ve given,
is saying that in spite of our best intentions, we are not entirely running our
own show.
Here
I’ve pulled a figure from my book to illustrate the epochs of
processing that
are occurring in the time frames you have just been paying attention to
- the first second after a new thought or sensory perception
appears in your mind...
Remember from the first section of the talk that after the
first 100--200 milliseconds of processing a new sensory input or starting up an
action, there is a delay period of 400--500 milliseconds, which we are usually
unconscious of,
before actual awareness of what we are sensing or intending comes to us, a delay during which editing, revision, or vetoing can occur.
One
point of an
exercise like the one we just did is to let our awareness expand into
the this previously unconscious editing and revision period, Sometimes making us more able to
perceive what is really there, rather than what we think should be, or inhibit
an action that has been initiated.
Observing in the sub second time windows
can let us note that upstairs thoughts and the downstairs emotions associated
with them can occur at slightly different times. Brain imaging experiments have
observed this time difference. Our
observing awareness can sometimes uncouple an association between a thought and
an emotion, or an emotion and a thought, if it is not useful.
Think about this for a moment. In doing an
exercise like this we are placing ourselves in the position of both being a
brain process (generating thoughts and emotions) and at the same time being
another process observing this first one, and deciding whether to turn the
thoughts or emotions off and return to awareness just of breathing. We switch
from moments of quiet without thoughts or emotions to suddenly being the
thoughts or emotions, and then on noting that fact can try to switch back to
quiet again.
In one moment we might suddenly feel an
emotion like anger, be an angry person, in next moment we might step aside and
observe ourselves as angry-ing. And maybe decide to do something else
instead.
-being an angry, afraid, or
desiring person
-observing oneself angry-ing, fear-ing, desire-ing
-choosing whether to cease or continue
the emotion
This is not rocket science. From this third person like distance -
something simple that I’m sure you have all done for yourself, putting yourself in the shoes of
someone looking at you, observing your behavior - we have more freedom to
choose whether we are going to be an angry person versus observing ourselves
angry-ing.
There is a subtle difference or distance
results from using the “-ing” suffix for familiar
emotions. I’m afraid versus I
observe myself fear-ing, or I desire versus I see
myself desire-ing.
We are thinking about, observing ourselves, thinking and
feeling. The psychologists’ fancy
word for that is metacognition.
Many regimes of training and practice can
be used to train our attentional muscle to do this,
from modern psychotherapies, especially cognitive therapy, to different forms
of meditation that have very ancient origins. Fourth century texts give instructions for
indexing mindfulness of breathing by breath counting.
It is
interesting that of the various religious traditions that have developed
meditation techniques,
acient buddhist
procedures and texts offer descriptions of what a human mind is like that are the
closest correlate of what modern neuroscience is telling us.
Meditation
wasn’t originally developed so we could lead less stressful lives or improve
our wellbeing, its primary purpose was more radical - to rupture your idea of
who you are; to shake to the core your sense of self
so that you realize there is ‘nothing there’. Which is what the experiments I showed
you earlier are saying.
But
that’s not how we see meditation courses promoted in the West. Here, meditation has been revamped as a
natural pill, a Buddha pill, that will quiet your mind
and make you happier.
Here is
a laundry list of the good things meditation has been claimed to do
Partial
laundry list of assertions, that meditation practice:
-reduces
stress, emotional arousal, pain, expression of genes involved in HPA stress
axis and inflammation
-improves
working memory, cognitive performance, attentional
expertise and stability, cognitive and emotional plasticity, connectivity in
both attentional and default networks, left frontal
activation and positive emotions.
On
balance it seems that expert meditators, of different meditation styles - such as focused
attention, open monitoring, compassion - show deactivation of the main nodes of
the mind wandering default-mode network.
Changes in the brain areas shown in this
slide that correlate with meditation practice are not
surprising. Any specialized
training, of either a skilled physical or introspective ability, causes long
lasting changes in brain activity and usually also structural changes (an
increase in the volume of the relevant area) that persist as long as the
activity in question is practiced and maintained. I have been an accomplished pianist
since childhood, do recitals and recordings, and the part of my motor cortex
that is running my hands and fingers is larger than in an average person. Motor areas of the brain regulating leg movement are
enlarged in skilled soccer or football players.
All of these change in the activity and size of particular brain
areas can slowly return to the average if the skilled activity is discontinued.
It’s as simple as “Use it or lose it”. It’s what happens to all of
us senior folks if we don’t keep mind and body active.
A few points from this fourth section
of the talk:
IV. How might we observe and influence
what our brains are doing?
A. Attention can be trained
by meditation-like activities
B. Attention training, like
training for other skills, causes brain changes.
C. Skilled awareness allows more autonomy in choosing actions,
perceptions, and emotions, making us more pilot than passenger of our ship.
So, I have now touched on my four topic
areas and here is a grand summary slide (which for the spoken lecture is TMI,
too much information, but is put on this web version to collect together the
main points).
Upstairs/Downstairs - Who or what is
running our show?
I. What is happening as our “I” acts and
senses in the world?
A. Our subjective “I” is late
to sensing and acting. It is an after the fact report.
B. What we experience is our prediction of
what is out there, or what the sensory consequence of our actions will be
C. We can place our
experienced body inside or outside our actual
one.
D. The “I” or self that we
experience is an illusion, a virtual avatar in our brain.
II. What behaviors are coming from upstairs
and downstairs?
A. Downstairs dominates rapid
actions and judgements.
B. Upstairs modulates this with
slower reasoned responses.
C. Reasons and emotions cause each
other.
D. Different personality types
have different upstairs profiles.
III. What is happening in paying attention
versus mind wandering?
A. Mind wandering is a transient loss of mental autonomy.
B. Mind wandering and default mode networks stabilize our self model.
C. Mind wandering facilitates creative incubation.
D. A wandering mind can be an unhappy mind.
IV. How might we observe and influence
what our brains are doing?
A. Attention can be trained
by meditation-like activities
B. Attention training, like
training for other skills, causes brain changes.
C. Attention training can
allow more autonomy in choosing actions and emotions, making us more pilot than
passenger of our ship.
pay
attention!
So the self help
take-home message from this talk would be simply to pay attention. Maintaining and exercising focused attentional mechanisms is very important to our mental
vitality and longevity.
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