EVERYTHING WE KNOW,
EVERYTHING WE THINK,
COMES FROM OUR BRAIN.
WE KNOW NOTHING; WE THINK
NOTHING OTHER THAN THAT WHICH
OUR BRAIN CONSTRUCTS.
IN ALL THE UNIVERSE, AS FAR
AS OUR GREAT TELESCOPES SEE,
BRAINS ARE ASTONISHINGLY UNIQUE.
BRACINGLY MOST COMPLEX -
HUMAN BRAINS ABOVE ALL.
ARE BRAINS OUR
WINDOW TO REALITY?
SEEING DEEPLY INTO
WHAT TRULY EXISTS,
OR ARE WE BOUND BY BRAINS,
PRISONERS AND SLAVES OF THE MEAT
IN OUR HEADS.
BRAINS MAY NOT BE
ANSWERS TO BIG QUESTIONS,
BUT IF THERE BE ANSWERS,
BRAINS WILL BRING THEM ABOUT.
THAT'S WHY ALL MY LIFE,
I'VE WONDERED ABOUT THIS:
HOW DO BRAINS WORK?
I'M ROBERT LAWRENCE KUHN, AND
CLOSER TO TRUTH IS MY JOURNEY
TO FIND OUT.
THERE IS NO ONE WAY
THAT BRAINS WORK.
BRAINS WORK ON MULTIPLE LEVELS;
BRAINS ARE BUILT WITH THE
HIERARCHIES OF SCIENCE.
PHYSICS, CHEMISTRY,
MOLECULAR BIOLOGY,
GENETICS, BIOCHEMISTRY,
PHYSIOLOGY, NEUROPHYSIOLOGY,
NEUROPSYCHOLOGY - I COULD
CONTINUE, I OMITTED A LOT.
BRAINS CAN BE
STUDIED AS MOLECULES,
CELLS, STRUCTURES, AND SYSTEMS.
BRAINS QUITE LITERALLY
CHANGED MY LIFE.
IN A SENSE, EVERYTHING
I'VE DONE, I'VE VIEWED
THROUGH THE PRISM
OF BRAIN SCIENCE.
THAT'S WHY I BEGIN AT UCLA,
THE BRAIN RESEARCH INSTITUTE,
WHERE I WAS ONCE
A GRADUATE STUDENT.
I MEET THE CURRENT DIRECTOR OF
THE BRAIN RESEARCH INSTITUTE,
AN EXPERT ON HOW ADDICTIONS
CHANGE BRAINS: DR. CHRIS EVANS.
I START WITH THE NEURON,
THE INDIVIDUAL BRAIN CELL,
THE CORE COMPONENT OF BRAINS.
CHRIS, I FIRST CAME HERE IN
1964 TO DO MY DOCTORATE AT THE
BRAIN RESEARCH INSTITUTE.
AT THAT TIME, NEUROPHYSIOLOGY
WAS THE RAGE AND THAT'S WHAT
I WAS WORKING ON.
HOW CAN WE BEGIN TO UNDERSTAND
THE ENORMOUS GROWTH
IN BRAIN RESEARCH?
I THINK SOME OF THE BIGGEST
CHANGES OF BEING IN GENETICS,
WE NOW KNOW THE STRUCTURE
OF THE MOLECULES WHICH MAKE
UP THE BRAIN.
I THINK THAT'S REALLY
CHANGED OUR APPROACH AND
OUR KNOWLEDGE BASE.
THE BUILDING BLOCKS
ARE THE GENETICS,
BUT, NOW WE HAVE THE
COMPLICATIONS ON TOP OF THE
GENETICS, WHICH ARE INCREDIBLY
DIFFICULT TO SORT OUT.
FIRST, THERE'S THE EPIGENETICS,
WHICH IS THE CONTROL OF
EXPRESSION OF THE
DIFFERENT GENES,
AND THIS CHANGES
THROUGH DEVELOPMENT,
IT CHANGES; IT'S
DIFFERENT IN EVERY CELL.
WE'RE NOW BEGINNING TO
UNDERSTAND A LITTLE BIT MORE
ABOUT HOW THE BRAIN CAN
ENCODE SO MUCH INFORMATION.
THE DIFFERENT COMMUNICATION
BETWEEN THE AXONAL BRANCHES AND
THE DENDRITES, AND THESE SPINES
WHICH FORM IN THE SYNAPSES.
WE'RE NOW UNDERSTANDING THESE
INDIVIDUAL SYNAPSES CAN HAVE
LITTLE BRAINS OF THEIR OWN.
SOME OF THEM EXPRESS RNA,
AND THEY CAN TRANSLATE RNA TO
PROTEINS, AND OF COURSE, THEY
HAVE THEIR INDIVIDUAL MACHINERY
FOR CONTROLLING THE NUMBER OF
RECEPTORS ON THE CELL SURFACE,
AND HOW ARE THEY
GOING TO RESPOND.
AND THEN, WE'RE
TALKING ABOUT CIRCUITS.
SO, CIRCUITS WOULD BE
ANOTHER CATEGORY OF
UNDERSTANDING BRAIN CIRCUITRY.
BRAIN CIRCUITRY IS NOW PROBABLY
ONE OF THE BIGGEST CHALLENGES
THAT WE'RE ALL FACING.
WE'RE PARTICULARLY INTERESTED
IN THE OPIATE CIRCUITRY.
WHICH HELPS US UNDERSTAND THE
REWARD SYSTEM OF THE BRAIN.
YES, THERE'S LOTS OF CIRCUITS.
THOUSANDS OF CIRCUITS -
AND THEY CHANGE AS WELL.
CIRCUITS ARE NOT JUST PUT IN
THERE AND STAY AS THEY ARE.
WE KNOW THAT THE REWARD
SYSTEM IS CHANGING MARKEDLY,
SAY WITH PAIN.
SO, THE OPIATE REWARD
SYSTEM CHANGES IN A PAIN STATE,
SO YOU KNOW, OPIATES ARE VERY
GOOD TREATMENTS FOR ACUTE PAIN,
THEY VERY GOOD ANALGESICS.
BUT, WE KNOW THAT PAIN
CHANGES HOW THE OPIATES
PRODUCE THEIR REWARD.
SO, DO YOU SEE INTEGRATION
BETWEEN THESE THREE AREAS?
THE GENETICS, THE SINGLE
CELL, AND THE CIRCUITRY,
SO WE CAN UNDERSTAND THE
TOTALITY OF HOW THE BRAIN WORKS.
YES.
I THINK THIS IS THE GOAL
OF MODERN NEUROSCIENCE,
IS TO ARRANGE ALL OF
THESE DIFFERENT AREAS AND TO
UNDERSTAND THESE
DIFFERENT AREAS,
AND THIS IS WHY I SEE THE
BIGGEST SCIENCE BEING TEAM-BASED
SCIENCE IN THE FUTURE.
SO, HERE EMERGES, AS IF A
TRI-COLORED RAINBOW OF BRAIN
ACTIVITY, THREE PLANES; THREE
LEVELS ON WHICH THE BRAIN WORKS.
GENETICS AND EPIGENETICS - HOW
GENE EXPRESSION YIELDS BRAIN
STRUCTURES AND FUNCTIONS.
NEURONS - THE
INDIVIDUAL BRAIN CELL;
THE SINGLE UNIT
PROCESSING INFORMATION.
BRAIN CIRCUITRIES, COMPRISING
THOUSANDS OR MILLIONS OF
NEURONS, WHICH
PRODUCE SPECIFIC MOTOR,
COGNITIVE, OR CONTROL FUNCTIONS.
I'M PULLED BY THE NATURAL
PROGRESSION FROM GENES TO
NEURONS TO CIRCUITS.
DOES THE PROGRESSION
PROVIDE A WINDOW TO REALITY?
WHAT ABOUT THE CRUCIAL SPACE
OR GAP BETWEEN THE NEURONS,
WHERE MUCH OF BRAIN
ACTIVITY TAKES PLACE?
IT'S CALLED THE SYNAPSE,
AND TO GET THE LATEST,
I VISIT KELSEY MARTIN -
PROFESSOR OF BIOCHEMISTRY AT
UCLA'S BRAIN RESEARCH INSTITUTE.
SO, THE SYNAPSE IS THE SITE OF
COMMUNICATION BETWEEN NEURONS IN
THE BRAIN, AND WITHIN THE BRAIN
THERE ARE CLOSE TO A TRILLION
NEURONS, AND EACH OF THOSE
CONNECT WITH ONE ANOTHER IN
INCREDIBLY COMPLEX WAYS.
AND THERE ARE THREE
COMPONENTS TO THE SYNAPSE,
THERE'S A PRE-SYNAPTIC
COMPONENT, AND THAT
COMES FROM AN AXON OF
THE NEURON, AND THAT
RELEASES INFORMATION IN THE
FORM OF CHEMICALS THAT THEN
DIFFUSE ACROSS THIS VERY SMALL
SPACE AND BIND TO RECEPTORS ON
THE POST-SYNAPTIC COMPONENT.
AND THAT CHEMICAL INFORMATION
THEN GETS CONVERTED
INTO ELECTRICAL
INFORMATION, AND THEN,
THAT CELL, IN TURN, THAT NEURON
CAN COMMUNICATE TO ANOTHER
DOWNSTREAM NEURON, SO.
SO, JUST TO GET AN
ORDER OF MAGNITUDE,
HERE - IF THERE WERE A
TRILLION NEURONS ALTOGETHER;
MAYBE A HUNDRED BILLION
IN THE CORTEX OR WHATEVER.
EACH ONE COULD CONNECT
WITH ROUGHLY HOW MANY OTHERS.
WITH ABOUT A
THOUSAND OTHER ONES.
SO, THEY'RE ABOUT A
QUADRILLION SYNAPSES.
A THOUSAND TRILLION, OR
A QUADRILLION SYNAPSES.
THAT'S WHAT WE'VE GOT, AND
YOUR JOB IS TO UNDERSTAND
ALL OF THEM.
WELL, MY JOB IS TO
UNDERSTAND HOW ONE WORKS,
AND SO, I'M INTERESTED IN WHAT
ARE THE GENERAL PRINCIPLES OF
HOW A SYNAPSE WORKS, AND ONE OF
THE THINGS THAT'S MOST IMPORTANT
ABOUT IT IS THAT IT'S
WHAT IN BRAIN SCIENCE,
WE CALL "PLASTIC".
SO, IT RESPONDS TO
EXPERIENCE; IT'S DYNAMIC.
IT CHANGES SHAPE,
IT CHANGES STRENGTH.
THERE ARE NEW SYNAPSES BEING
BORN ALL THE TIME AS WE LEARN
NEW THINGS, SO SORT OF A LEADING
HYPOTHESIS IS THAT MEMORIES ARE
STORED AS INCREASES IN THE
STRENGTH OR THE NUMBER OF
SYNAPSES THAT ARE
FORMED IN THE BRAIN.
SO, THERE'S BEEN A LOT OF VERY
BEAUTIFUL WORK THAT HAS LOOKED
AT HOW THOSE CHANGES AT SYNAPSES
HAPPEN OVER VARIOUS TIME FRAMES.
FOR EXAMPLE, WHEN I SAID THAT
THE PRE-SYNAPTIC CELL RELEASES
CHEMICALS, THEY BIND TO A
RECEPTOR IN THE POST-SYNAPTIC
CELL, BUT THERE'S SOME BEAUTIFUL
CELL BIOLOGICAL MECHANISMS WHERE
YOU CAN CHANGE THOSE RECEPTORS.
YOU CAN ADD MORE RECEPTORS, OR
YOU CAN CHANGE THE SENSITIVITY
OF THOSE RECEPTORS, SO THAT WHEN
THE CHEMICAL GOES ACROSS THE
CLEFT - THE AREA BETWEEN THE
TWO PARTS OF THE SYNAPSE - THAT
POST-SYNAPTIC CELL IS
MORE RESPONSIVE TO IT.
SO, YOU COULD HAVE FEWER
CHEMICALS CREATING THE
SAME ELECTRICAL IMPULSE.
RIGHT, AND THAT WILL
TAKE YOUR MEMORY OVER A
CERTAIN TIME DOMAIN.
RIGHT.
BUT, IT WOULDN'T WORK TOMORROW;
YOU WOULDN'T REMEMBER IT,
AND SO, FOR THAT KIND OF MEMORY
TO PERSIST FOR A LONGER PERIOD
OF TIME, ONE OF THE DISCOVERIES
IS THAT YOU NEED TO HAVE NEW
EXPRESSION, NEW
RNA'S, AND NEW PROTEINS,
AND THAT REALLY CAN CHANGE
THE STRUCTURE OF SYNAPSES,
IT CAN CHANGE THE
NUMBER OF SYNAPSES.
AND THAT'S A MUCH
MORE LONG-LASTING CHANGE
THAT CAN OCCUR.
HOW MANY DIFFERENT
KINDS OF MEMORY ARE THERE?
THERE ARE CERTAINLY MORE
THAN JUST SHORT AND LONG-TERM,
AND EVEN SHORT AND LONG-TERM,
THE WAY THAT I DEFINE IT IS,
SHORT IS A FORM OF PLASTICITY
THAT DOES NOT REQUIRE GENE
EXPRESSION, AND LONG
REQUIRES GENE EXPRESSION.
SO, IF GENE EXPRESSION IS
CRITICAL FOR LONG-TERM MEMORY,
HOW DOES THAT WORK?
OKAY, SO EVERY NEURON HAS
THE SAME DNA IN THE BODY.
AS EVERY OTHER CELL?
AS EVERY OTHER CELL IN THE BODY.
THE REALLY BEAUTIFUL THING
IS THAT WHAT HAPPENS IS THAT
EXPERIENCE CHANGES
WHICH GENES ARE EXPRESSED.
SO, NEURONS WILL EXPRESS A
CERTAIN SET OF GENES THAT MAKE
THEM NEURONS AS
OPPOSED TO INTESTINAL CELLS,
BUT IN ADDITION, EXPERIENCE
OR STIMULI - WHETHER THAT'S
SOMETHING THAT WE'RE LEARNING,
WHETHER IT'S AN EMOTIONAL EVENT,
WHETHER IT'S AN ENVIRONMENTAL
EVENT - WILL HAVE AN EFFECT ON
THE GENES THAT ARE
BEING EXPRESSED.
SO, THERE YOU HAVE DNA -
IT GETS EXPRESSED INTO RNA,
AND THE RNA THEN GETS
MADE INTO PROTEINS,
WHICH ARE CALLED SORT OF THE
BUILDING BLOCKS OF THE CELL.
WHEN SOMETHING
HAPPENS AT THE SYNAPSE,
THAT HAS TO SEND A SIGNAL ALL
THE WAY BACK TO THE NUCLEUS,
WHICH CAN BE VERY -
BECAUSE THAT'S
WHERE THE GENE IS.
THAT'S WHERE THE GENES
ARE; THAT'S WHERE THE DNA IS,
AND THAT CAN BE A
VERY LONG DISTANCE.
AND NEURONS ARE
SPECIALIZED FOR THAT,
SO THEY UNDERGO THIS SORT OF
ELECTRIC-CHEMICAL SIGNALING
WHERE YOU GET ACTION POTENTIALS,
AND YOU REALLY RAPIDLY SIGNAL
FROM A SYNAPSE
BACK TO THE NUCLEUS.
SO, WE'RE VERY INTERESTED IN
HOW DOES THAT INFORMATION GET
INTEGRATED WITHIN THE NEURON?
I THINK OF NEURONS AS
EXISTING IN CIRCUITS.
I THINK A NEURON ON ITS OWN
DOESN'T HAVE MUCH MEANING
IN ITS LIFE.
THEY REALLY ARE RESPONDING
TO OTHER SIGNALS THAT THEY'RE
GETTING FROM OTHER NEURONS, AND
SO WE WANT TO UNDERSTAND THAT.
YOU KNOW, WHEN I
THINK ABOUT PLASTICITY,
I'M VERY INTERESTED IN HOW
DO THESE SYNAPSES CHANGE TO
EVERYTHING THAT'S HAPPENING?
AND SO, WHAT'S THE
LOCAL CONTROL OF THAT,
AND THEN, HOW IS THAT LOCAL
CONTROL INTEGRATED AT THE LEVEL
OF THE NUCLEUS, AND
THAT'S A SINGLE NEURON.
BETWEEN NEURONS, A
QUADRILLION SYNAPSES.
A THOUSAND TRILLION; A MILLION
BILLION - ALL OF THEM SIGNALING,
ANALYZING, COMPUTING,
AND COMMUNICATING,
DOZENS OR HUNDREDS
OF TIMES A SECOND.
WHILE I RECOGNIZE THAT A SINGLE
NEURON IS THE CORE OPERATING
UNIT OF THE BRAIN, I ALSO KNOW
THAT I MUST UNDERSTAND BEHAVIOR
AND COGNITION IN
TERMS OF WHOLE BRAINS.
BUT, CAN SUCH UNDERSTANDING
IMPROVE HOW OUR BRAINS WORK,
AND CONVERSELY, IF WE
COULD IMPROVE OUR BRAINS,
WHAT WOULD THAT TELL
US ABOUT BRAIN FUNCTION?
WALKING MY OLD HAUNTS AT
UCLA'S BRAIN RESEARCH INSTITUTE,
I MEET COGNITIVE
NEUROSCIENTIST, ROBERT BILDER.
I ASK BOB WHETHER BRAIN RESEARCH
CAN HELP OUR BRAINS WORK BETTER.
THIS IS, IN THEORY, THE NEXT
STAGE OF HUMAN EVOLUTION,
WHERE WE LEARN ENOUGH ABOUT OUR
BRAINS TO BE ABLE TO USE THEM
DIFFERENTLY, AND THEREBY
ENHANCE OUR WELLBEING.
WHAT WE'RE FINDING THROUGH
RECENT RESEARCH IS THAT VERY
SERIOUS MASKED TRAINING
CAN INDUCE SIGNIFICANT
NEURO-PLASTICITY IN THE BRAIN.
IF WE DO THE RIGHT
KINDS OF BRAIN EXERCISE,
AND REPEAT IT ENOUGH THAT IT
ACTUALLY CAN CAUSE PLASTIC
CHANGES IN OUR BRAIN.
EVEN THE IMPACT OF
AEROBIC EXERCISE,
WHICH I MIGHT HAVE BEEN VERY
SKEPTICAL ABOUT JUST A
FEW YEARS AGO.
EVIDENCE HAS ACCUMULATED,
SHOWING THAT THESE KINDS OF
INTERVENTIONS CAN EFFECTIVELY
CHANGE CERTAIN ASPECTS OF
OUR BRAIN FUNCTION.
WHAT ARE THE CATEGORIES THAT YOU
WOULD SAY ARE SERIOUS AND HAVE
EITHER PROVEN OR PROMISED
TO HELP OUR OWN PERSONAL
BRAIN MANAGEMENT?
THE TRAINING OF WORKING MEMORY
FUNCTIONING IS SOMETHING THAT'S
SHOWN, YOU KNOW,
SIGNIFICANT GAINS,
AND IT MAY HAVE GENERALIZATION-
SO WHAT'S A WORKING MEMORY
TRAINING SYSTEM THAT MIGHT
HAVE THIS GENERALIZATION?
THE TRAINING, FOR EXAMPLE,
OF SPATIAL LOCATIONS;
BEING ABLE TO MAINTAIN
IN MIND, KEEP IN MIND,
AND THEN MANIPULATE THAT
SPATIAL REPRESENTATION IN MIND,
SO THAT IT CAN THEN BE RETRIEVED
AT A SUBSEQUENT POINT IN TIME.
THESE KINDS OF THINGS ARE
SHOWING THE CAPACITY TO CHANGE
THE FUNDAMENTAL WAY WE
PERCEIVE OTHER STIMULI.
I THINK SOMETHING THAT'S
REALLY AT A EARLY STAGE,
BUT I THINK HAS
ENORMOUS PROMISE,
IS LEARNING HOW WE CAN USE OUR
BRAINS TO BETTER REGULATE OUR
VISCERAL AND AUTONOMIC
NERVOUS SYSTEM.
IT'S REALLY INCREDIBLE THAT
COGNITIVE NEUROSCIENCE HAS
FOCUSED SO MUCH ON THE CONTROL
OF MOTOR ACTIONS AND THE DORSAL
PARTS OF OUR BRAINS.
BUT THE WHOLE VENTRAL
PARTS OF OUR BRAINS,
IN THE PAST, FROM OUR FRONTAL
LOBES TO OUR HYPOTHALAMUS,
AND OTHER LIMBIC STRUCTURES
HAS BEEN MORE IGNORED,
AND I THINK THIS
IS A HUGE THING.
SO, THE PROCESSES OF MEDITATION,
LIKE MINDFUL OF SPACE TO
RELAXATION THERAPY IS MINDFUL
OF SPACE STRESS REDUCTION.
I THINK WE'RE GOING TO SOON
BEGIN TO UNDERSTAND WHAT ARE THE
BRAIN CHANGES THAT ARE
ACCOMPLISHED BY PEOPLE WHO ARE
SERIOUS PRACTITIONERS, AND HOW
DO THEY ACCOMPLISH THE GAINS
THAT THEY DO ACCOMPLISH IN
STRESS REDUCTION AND OVERALL
SENSES OF WELL-BEING.
I MARVEL AT BRAIN PLASTICITY.
THE REMARKABLE CAPACITY OF THE
CENTRAL NERVOUS SYSTEM TO SHAPE
ITSELF; TO CHANGE AND ADAPT
TO MEET NEEDS OR DEMANDS.
BUT ALL BRAINS HAVE PLASTICITY,
SO WHY THE SPECIAL HUMAN
WINDOW TO REALITY?
WHAT CAN COMPARATIVE
BRAIN STUDIES SUGGEST?
WHAT CAN WE LEARN BY COMPARING
THE BRAINS AND BEHAVIORS
OF VARIOUS ANIMALS?
AT UCLA, I HEAD ACROSS
CAMPUS TO MEET JARROD DIAMOND,
PHYSIOLOGIST, ECOLOGIST,
ANTHROPOLOGIST, AUTHOR OF
THE THIRD CHIMPANZEE -
THE EVOLUTION AND FUTURE OF
THE HUMAN ANIMAL.
WE HUMANS ARE OBSESSED WITH THE
IMPORTANCE OF THE BRAIN BECAUSE
WE ARE DISTINGUISHED
BY A BIG BRAIN,
BUT BY LOOKING AT THE
DIVERSITY OF ANIMAL SPECIES,
WE SHOULD LEARN TO BE LESS
OBSESSED WITH THE BRAIN,
BECAUSE REALLY, BIG BRAINS
ARE VERY UNCOMMON AMONG MAMMAL.
AND THE COMMONEST ANIMALS ON
EARTH - THE SUCCESSFUL ANIMALS -
ARE NOT HUMANS, BUT THE
SUCCESSFUL ANIMALS ARE THE
NEMATODE WORMS, RIBBON WORMS.
THEY SAY IF YOU DISSOLVED ALL
THE WORLD AND THE ONLY THING
THAT WAS LEFT WAS
NEMATODE WORMS,
YOU WOULD HAVE AN OUTLINE
OF ALL THE WORLD BECAUSE
NEMATODE ARE EVERYWHERE.
BEETLES, RATS -
THEY'RE VERY SUCCESSFUL.
THE NEXT THING WE LEARNED
ABOUT BRAINS IS THAT
THEY'RE EXTREMELY EXPENSIVE.
THEY'RE A METABOLICALLY
EXPENSIVE ORGAN.
WHEN WE COMPARE DOMESTIC
CHICKENS WITH WILD CHICKENS,
AND DOMESTIC DOGS WITH WOLVES,
AND DOMESTIC CATTLE WITH WILD
CATTLE, A UNIVERSAL TREND
OF DOMESTICATION IS THAT THE
BRAIN GETS SMALLER.
IT'S NOT THAT THE FIRST FARMERS
TRIED TO MAKE DOGS DUMBER THAT
WOLVES, OR TRIED TO MAKE
CHICKENS DUMBER THAT WILD
CHICKENS, IT'S THAT IF
YOU'RE IN A BARNYARD,
YOU DON'T NEED A BRAIN AS
MUCH AS IF YOU'RE SCAVENGING
AROUND OUT THERE.
SO, THE REASON THAT THE BRAIN
GETS SMALLER IN DOMESTICATION IS
NOT THAT IT WAS INTENTIONAL,
BUT IT'S A VERY EXPENSIVE
PIECE OF MACHINERY.
IF THAT PIECE OF
MACHINERY IS REDUCED,
THEN THERE'S MORE ENERGY
TO PUT INTO CHICKEN BREAST,
AND INTO A DOG
WHO'LL WAVE ITS TAIL.
OKAY.
WHAT ABOUT THE RELATIONSHIP
BETWEEN BRAIN SIZE
AND INTELLIGENCE.
IF WE LOOK AT THE
MAMMALIAN EXAMPLES.
INSOFAR AS ONE CAN
MEASURE INTELLIGENCE,
YES, IT DOES INCREASE
WITH BRAIN SIZE,
BUT ONE HAS TO TALK
ABOUT RELATIVE BRAIN SIZE.
I WOULD EXPECT A BLUE WHALE
WOULD HAVE A LARGER BRAIN THAN
US HUMANS, BUT A BLUE WHALE
DOESN'T HAVE THE COMPLEX SOCIAL
STRUCTURE; IT CAN'T DESIGN
A SPACE CRAFT AS WE HUMANS.
THAT LARGE BRAIN DOES A
SPECIFIC GOOD IN MANY WAYS.
IT'S NOT JUST THAT WE CAN FIGURE
OUT WHERE THE DEER IS RUNNING,
BUT OUR BRAIN SERVES TO
TRACK OUR VERY COMPLICATED
SOCIAL RELATIONSHIPS.
SO, IN A TRIBAL SOCIETY,
EVERY PERSON KNOWS HUNDREDS
OF OTHER PEOPLE.
THERE'S ALL THIS ENORMOUS
THAT HAS TO BE MASTERED.
IT'S ALSO TO INTERPRET THINGS
THAT OTHER ANIMALS WITH SLIGHTLY
BIG BRAINS CAN'T INTERPRET.
FOR EXAMPLE, HERE'S A
REAL PUZZLE - MONKEYS.
MONKEYS HAVE
RELATIVELY LARGE BRAINS;
NOT AS BIG AS OURS.
YOU TAKE VERVET MONKEYS: THEY'VE
GOT A PRIMITIVE LANGUAGE,
THEY HAVE A SEPARATE GRUNT, A
SEPARATE WORD FOR LEOPARD AND
PYTHON AND EAGLE.
SO, HERE'S A SMART
ANIMAL WITH A BIG BRAIN.
A SIGNIFICANT PREDATOR FOR
VERVET MONKEYS IS PYTHONS;
VERVETS HAVE A WORD,
A GRUNT, FOR PYTHON.
AND YOU WOULD THEREFORE EXPECT
THAT THIS SMART ANIMAL WOULD BE-
WHEN HE SEES A PYTHON
TRACK IN THE GRASS,
WOULD FIGURE, THAT'S A
PYTHON, AND WOULD GET SCARED.
NO.
THE VERVET MONKEYS DON'T MAKE
THE ASSOCIATION BETWEEN THE
TRACK IN THE
GRASS AND THE PYTHON;
THAT'S WHAT WE HUMANS DO WITH
THE EXTRA 1,000CC OF OUR BRAIN
OVER ABOVE A CHIMPANZEE BRAIN.
WE CAN FIGURE OUT THINGS THAT
A CHIMPANZEE CAN'T FIGURE OUT,
AND AGAIN, THAT'S WHY YOU AND I
ARE HAVING THIS CONVERSATION,
AND CHIMPS ARE OFF IN ZOOS.
HOW ABOUT COMPARING THE VERY
CLOSE SPECIES TO THE HUMAN
SPECIES - NEANDERTHAL MAN,
WHOSE BRAIN WAS EVEN BIGGER,
AT LEAST ON A QUANTITATIVE
BASIS, THAN OUR BRAIN.
WHAT CAN WE SAY ABOUT THAT?
YOU AND I ARE SAPIENS AND WE
EXTERMINATED THE NEANDERTHALS.
THAT IMPLIES THAT
THERE'S SOMETHING,
QUALITATIVELY "BETTER".
SOMETHING QUALITATIVELY ABOUT
THE SAPIENS' BRAIN THAT ALLOWED
US TO SURVIVE AND NOT
NEANDERTHALS TO SURVIVE.
MY PERSONAL
SPECULATION IS LANGUAGE.
HUMAN LANGUAGE,
IT'S COMPLICATED.
IT'S NOT JUST A
FUNCTIONING BIG BRAIN,
BUT YOU GOT TO HAVE
THE RIGHT ANATOMY.
YOU HAVE YOUR VOCAL TRACT, AND
THEN YOU HAVE TO HAVE YOUR BRAIN
CIRCUITS TO HAVE GRAMMAR, SO
NEANDERTHAL BRAIN MIGHT SIMPLY
HAVE BEEN LACKING
SOME SMALL AREAS,
OR THOSE SMALL AREAS MIGHT
HAVE BEEN UNDERDEVELOPED,
WITH THE RESULT THAT
NEANDERTHALS COULD GRUNT,
BUT THEY DIDN'T HAVE
PREPOSITIONS AND THEY COULDN'T
INFER CAUSATION, WHEREAS WE,
WERE THE LITTLE MORE - FEW MORE
GRAND - SOME WAVES IN OUR BRAIN,
BECAUSE WE HAD A SLIGHTLY BIGGER
OR BETTER SMALL AREA OF THE
BRAIN THAT GAVE US PREPOSITIONS,
AND IT WAS PREPOSITIONS THAT LET
US WIPE OUT THE NEANDERTHALS.
WAS IT JUST SOME SMALL
DIFFERENCE IN OUR BRAINS,
SOME SIZE AND STRUCTURE,
THAT DELIVERED HUMAN
DOMINANCE ON EARTH?
SMALL DIFFERENCES CAN
HAVE MASSIVE EFFECTS.
DID SMALL DIFFERENCES IN
OUR BRAINS UNLATCH OUR
WINDOW TO REALITY?
WHAT'S BEYOND WHOLE BRAINS?
ARTIFICIAL INTELLIGENCES?
WHAT CAN WE LEARN ABOUT
BIOLOGICAL BRAINS BY STUDYING
NON-BIOLOGICAL BRAINS
- MASSIVE COMPUTERS,
SOPHISTICATED ROBOTICS?
I GO TO MIT, MY
OTHER ALMA MATER,
TO VISIT A FORMER DIRECTOR
OF THE COMPUTER SCIENCE AND
ARTIFICIAL INTELLIGENCE
LABORATORY, RODNEY BROOKS.
LOOKING AT BRAINS, TO
ME, THAT'S LIKE LOOKING AT
TRANSISTORS AND YOU'VE GOT
A MODERN COMPUTER, AND YOU
PUT A FEW ELECTRODES IN AND
YOU'RE TRYING TO UNDERSTAND
THE C-PROGRAMMING
LANGUAGE FROM THAT.
IT'S A VERY HARD SHIFT TO MAKE,
BUT I THINK WHAT ARTIFICIAL
INTELLIGENCE HAS GIVEN US IS
A WAY OF DOING THE STUFF AT A
HIGHER LEVEL, PROPAGATES DOWN ON
THE SILICON INSTEAD OF THE WET
STUFF THAT'S IN OUR
BRAINS, AND SO, AT LEAST
WE HAVE SOME IDEAS OF WHAT
SORTS OF THINGS MIGHT HAPPEN.
WHAT ARE THE ANALOGS IN A.I.?
WELL, THERE'S
VARIOUS FLAVORS OF A.I.
THE FLAVOR THAT I FOLLOW TRIES
TO TAKE SOME OF THOSE COGNITIVE
MODULES THAT WE'VE DISCOVERED,
WHERE WE'RE COMING
FROM TWO WAYS.
ONE IS LOOKING AT,
OVER EVOLUTIONARY TIME,
WHAT THINGS ARE COMMON IN
DIFFERENT ANIMALS AND THEN
TRYING TO SAY - AH, THERE'S A
MODULE THAT DIRECTS EYE GAZE,
OR WHERE MY EYES ARE POINTING.
AND WE CAN SEE THAT THAT MODULE
MIGHT BE A WAY OF DESCRIBING,
AND THEN WE LOOK
AT THE INDIVIDUALS,
MAYBE INFANTS, AND SEE OVER TIME
HOW THEY'VE DEVELOPED THEIR
EYE GAZE CONTROL.
SO, EARLY ON, INFANTS'
EYE GAZE IS JUST LOOKING
AT THEIR MOTHERS.
LATER, WHEN THEIR MOTHER LOOKS
AT SOMETHING ELSE IN THE WORLD,
THEY START TO THINK, OH -
SHE'S LOOKING SOMEWHERE ELSE,
AND THEIR EYES GO,
WHAT'S GOING ON?
AND THEN A LITTLE LATER, THEY
START TO LOOK AT THE DIRECTION
HER EYES ARE, AND JUST A
LITTLE LATER THAN THAT,
THEY JUMP DIRECTLY FROM
ESTIMATED GAZE DIRECTION,
TO WHERE THE MOTHER IS LOOKING.
SO, WE SEE THOSE DEVELOPMENTS
HAPPEN IN THE INDIVIDUAL,
AND THAT GIVES US SOME CLUES
ABOUT WHAT WE MIGHT BE ABLE TO
BUILD A MACHINE.
AND THEN, WE BUILD IN
THE MACHINE, AND IT
WORKS SURPRISINGLY WELL.
MY VERSION OF O.A.I., THEN
PUTS A WHOLE BUNCH OF
THOSE TOGETHER, AND LETS
THEM INTERACT IN REAL TIME,
AND OUT OF THAT EMERGES
WHAT, TO THE OUTSIDE OBSERVER,
IS A DIFFERENT LEVEL OF
OPERATION IN THE WORLD.
YOU'VE NOTED THAT
VISION IS SOMETHING THAT,
IN THE EARLY DAYS OF A.I.,
PEOPLE THOUGHT WAS SORT OF EASY
AND OBVIOUS, AND TURNED OUT TO
BE ONE OF THE MOST DIFFICULT.
YEAH, IN FACT, AT MIT IN 1969,
SOME OF THOSE FOUNDERS OF THE
FIELD HAD A
SUMMER VISION PROJECT,
AND THEY PUT A SOPHOMORE -
WHO'S NOW A PROFESSOR AT MIT,
WHO I'VE SEEN IN PERSON - WAS A
SOPHOMORE IN CHARGE OF SOLVING
VISION OVER THE SUMMER.
AND 50 SOME YEARS LATER, WE'RE
NOT CLOSE TO THE GOALS THAT THEY
SET UP IN MAY TO PLANNED
TO HAVE FINISHED BY AUGUST.
IF YOU GOT A TWO YEAR OLD
AND YOU SHOW THEM A KEY,
YOU KNOW, IT MIGHT BE A
DIFFERENT SHAPED KEY THAN
THEY'VE EVER SEEN BEFORE,
THEY'D SAY THAT'S A KEY.
YOU SHOW THEM A CUP, AND THEY'VE
NEVER SEEN THAT PARTICULAR SORT
OF CUP, YOU KNOW, IT MAY
HAVE CLOWNS ON IT OR SOMETHING,
THEY'VE NEVER
SEEN - THAT'S A CUP.
AND, IF YOU DO THIS
EXPERIMENT WITH TWO YEAR OLDS,
THEY SORT OF, WHY IS THIS PERSON
ASKING ME THESE DUMB QUESTIONS?
IT'S A KEY!
IT'S A CUP!
AND THEY CAN DO
THAT EFFORTLESSLY;
OUR COMPUTER VISIONS, HOWEVER,
STILL ARE NOT GOOD AT THAT.
OUR FAILURE TO HAVE ROBUST
COMPUTER VISION - AS ROBUST AS A
TWO YEAR OLD CHILD - TELLS ME
WE STILL HAVEN'T FIGURED OUT THE
BASIC WAY THAT
ANIMALS EVEN DO IT.
I'M STILL WAITING.
AT SOME POINT, SOMEONE'S
GOT TO GET IT RIGHT, BUT IT
HASN'T HAPPENED YET.
NOW, I THINK WE MAY GET A LITTLE
TO ENGINEERING-CENTRIC IN A LOT
OF SCIENTIFIC THINKING, IN
THAT WE THINK ABOUT THERE BEING
MODULES PER SE.
WELL, EVOLUTION DIDN'T
NECESSARILY DESIGN A MODULE
AND PERFECT IT.
EVOLUTION IS WILLING TO DO ANY
MUCKY THING THAT HAPPENS TO BE
A LOCAL ADVANTAGE.
OUR COMPUTATION SYSTEMS ARE
NOWHERE NEAR AS ROBUST OR
IMPACTED AS EVEN
SIMPLE BIOLOGY SYSTEMS.
ARTIFICIAL INTELLIGENCE
IS A WILDCARD.
WE DO NOT KNOW WHERE
A.I. WILL TAKE US.
THIS WE DO KNOW: BRAINS
WORK ON MULTIPLE LEVELS.
NEURONS, INDIVIDUAL NERVE
CELLS, EACH DAUNTINGLY COMPLEX;
A TRILLION OF THEM.
SYNAPSES, THE GAPS BETWEEN
NEURONS WHERE COCKTAILS OF
CHEMICALS FLOW AND EBB;
A QUADRILLION OF THEM.
BRAIN CIRCUITS, MILLIONS OF
NEURONS LINKED TOGETHER IN
ORGANIZED PATHWAYS, EACH
WITH SPECIFIC FUNCTIONS
SUCH AS MOVEMENT.
BRAIN SYSTEMS - MASSIVE
BRAIN AREAS WORKING TOGETHER TO
CONDUCT MAJOR TASKS SUCH
AS LEARNING OR EMOTIONS.
I'VE THOUGHT ABOUT
BRAINS MY WHOLE LIFE.
I NEVER WEARY.
IN THE COSMOS, WHETHER
BRAINS ARE ROUTINE OR RARE,
BRAINS OPEN OUR
WINDOW OF REALITY,
AND BRING US CLOSER TO TRUTH.
