why do we behave so strangely for eight
humans and all of these other animals
are hominoids we are eight I want to
understand why humans they so strangely
phrase I also want to understand why
humans need as you do more generally why
can we be deceived by what we see
why did different people see different
things sometimes can evolutionary
studies inform us about why you see
illusions and to understanding the
perception of illusions inform us about
the peculiarities of the human brain in
the words of the ethology Niko Tinbergen
why do these animals behave what they do
I would like to introduce evolutionary
neuroscience and approach to
understanding human evolutionary
neuroscience is based on a reciprocal
relationship between neuroscience and
evolutionary biology evolutionary
neuroscience might sound like something
new but it’s always been a part of
neuroscience we have long thought we can
learn about our own brains
by studying the brains of other animals
neuroscience has long appreciated that
the brain along with the rest of the
nervous system isn’t an entirely
biological entity the humans share with
other species
physical neural structures have direct
correspondences the process is called
behaviors this has been recognized to
the extent that early on studies seeking
to understand our nervous systems
however light on animals as models
evolutionary neuroscience and provided
an up-to-date biological framework for
understanding brains and behavior
a key aspect of evolutionary
neuroscience is to bridge the findings
of translate
research by using information from
evolutionary constructions here are some
images of a structure in primate brains
called the LGN lateral geniculate
nucleus it is the first place in the
brain most visual information from the
eyes stops before moving on for
processing in the cerebral cortex I
mentioned a lot of these and once notice
that although I had learned in anatomy
class that these structures had six
layers I found that the number of layers
was not consistent across species I was
very surprised because I thought the
macaque visual system was structured and
function just like our own because not
much not much had changed except for the
size of the structures since the time of
our most recent common ancestor with
macaques 30 million years ago
both macaques and humans have six lgn
layers but IPM it shows this similarity
may not be as simple as it seems this is
a phylogenetic tree of some species of
primates a sort of family tree showing
how the species are related to each
other
phylogenetic trees are used to
understand how traits evolve in a group
of related species if they share a
feature the simplest explanation is that
had arisen from a common ancestor and is
thus and such really equivalent in all
those species it would be a shared right
feature but if the feature pops up all
over the place
it must have arisen due to different
evolutionary events and may be a little
bit different every time
many species just as closely related to
humans as macaques and even some which
are even more closely related to us than
in the tacks are how differently shaped
algae and to be fair we cannot be sure
what the functional significance of this
is however it is an important reminder
that make my frames have evolved just as
much as ours have since the time of our
shared most recent comment
and no single species can serve as
simple prototype for understanding human
brains and behaviors to really
understand humans understanding other
species helps but an evolutionary and
phylogenetic approach must always be
taken I’ve always been interested in
human specific behaviors how when and
why they arose these include things like
art tool making the burial of corpses
language and complex social behaviors
human specific behaviors define us human
specific behaviors occur across all
cultures human specific behaviors also
are what sense apart from other species
of course there are a lot of human
behaviors invented every day 25 years
ago it was texting 11 years ago tweeting
with the vended no other species can do
these things but the ones I’m most
interested in really define us out of
species these sorts of behaviors show up
in the hominin archaeological record and
are associated with fossils of the
earliest skeletons that look like our
own they start to appear in earlier
forms even in hominid species that are
more closely related humans than to any
other living animals but are no longer
around today human specific behaviors
tend not to have much of a course bond
as an animal kingdom they can be really
hard to define even they post some
really hard questions what we do know is
that our brains are three to four times
as big as the brains of other ace so
sometime between the time for most
recent common ancestor with tips around
seven million years ago brains got
bigger we have also evidence documents
in brain size over the past seven
million years we can make much better
estimates about the sizes of also
hominids brains and about any other
aspect of brains or behaviors in the
human
canary record but let’s get back to the
visual system a lot of people study the
visual system in a lot of species
because it’s both dominant and most
studied sensory system in humans it is
really relatively easy to identify
histologically and aspects of it may be
detectable in fossils like these in
particular a brain region called the
primary visual area is the first place
in the cerebral cortex most information
goes after having that stopped in the
lateral geniculate nucleus it is the
biggest brain region and it aches its
extent is marked by a fold in the brain
called in the lunate sulcus as you’ll
see in the orangutan brain on the left
the lunate sulcus has been the focus of
a nine-year-old debate about false
hominins such as this fossil an
Australopithecus africanus child
I studied the visual system to get some
basic idea about how our human minds
work we can start with understanding the
visual system and perhaps then try to
understand the rest of the brain
illusions reveal quirks in the visual
system that enable us to understand how
it works
we do not see in a photographic way we
are constrained by the features of our
cognition human brains and behaviors are
full of surprises and an evolutionary
framework is what might be needed to
crack that code these quirks also remind
us that our brains were not designed by
engineers simply for accuracy or even
for efficiency they’re not everything is
happy or to make us healthy or to help
us know the correct answer brains are a
product of reproductive success and the
way they perform is influenced by the
evolutionary history of our species some
features of human cognition like
language seem to sense apart from other
species however illusory perception is
something
share with a lot of other species as
well within our species their
differences and how different people
perceive things and allusions reveal
these five solutions their causes are
cases where external features cause
objects of identical size to appear to
have different sizes like this one first
identified the muller-lyer in this
figure the context influenced how long
the line seemed rows up to each other
the illusion is that the arrowheads make
the line appear shorter the tale makes
it appear longer the strength of the
mule or life illusion actually differs
between individuals more generally
people differ introduces susceptibility
to all spider lesions illusion strength
is higher in people with a smaller size
primary visual cortex so as I mentioned
non-human species also perceive
illusions demonstrating that similar
cognitive processes are at work in their
brains as well however there are also
species differences in the perception of
illusions and the strength of sign
delusion such as Mueller Liars
unfortunately most of what we know about
the behavior has been limited to a few
model species just that species vary in
susceptibility to illusions they also
vary in the sizes of their visual areas
with larger Villiers visual areas
containing more neurons
across primate species visual acuity is
related to the size of the visual cortex
so having bigger v1 with more neurons in
it could allow for a more detailed
representation of visual images which
are processed in the brain a model based
on the work of else suggests that having
more neurons to cover the perception of
an object means the person be perceived
in more detail Aleutians could result
when there are fewer neurons to cover
the perception of an image an illusion
is perhaps a more neuron economical way
of perceiving the world however note
that illusions are not merely economical
trade-offs they can be better at
summarizing information about what we
see and directing appropriate behavior
that is illusions to be an advantage and
it could even be an event of having
fewer neurons so this might be another
way in which evolution and neuroscience
can potentially inform each other’s
fields a trend within species may give a
hint to a trend across species
if the similar mechanism is that place
this framework suggests have sensory
perception may influence or constrain
the size of sensory regions and could
even result in differences in the
modular organization of cognition so
it’s not quite clear why humans have
such big brains and whether brain size
can explain human specific behaviors
we’re now in an era of big data we’re in
a better position than ever before to
use comparative methods to help uncover
the origin and adaptive basis for
behaviors cognitive abilities and
features of the brain take for example
this phylogenetic trees reconstructed
from the genetic data of 301 primate
species and showing how they are related
to each other
here are 301 species of interest which
can be studied to help us understand why
and how we behave as we do but we are
still faced with the problem of very
little data about the neuroanatomy and
behaviors which can be compared across
species we lack data from Jeff Serena’s
tarsiers most of the new world monkeys
except for one species of capuchin
most of the old world monkeys expect
except for one species a baboon and a
species of macaque and most of the age
except for chimps and ourselves so this
brings us back to an earlier point to
increase the reliability of the
framework which I’ve described that of
evolutionary neuroscience and best
extrapolate findings across these it
helps to know more about the
evolutionary history of illusory
perception we can have a better idea of
what is going on in our own hands by
studying the diversity of species which
still have today these are all species
of interest and relevant when
understanding the origin of the human
mind the more we can learn about them
the more we can understand about
ourselves why do we behave the way we do
humans and all of these other animals
are hominoids we are eight I want to
understand why humans they so strangely
phrase I also want to understand why
humans need as you do more generally why
can we be deceived by what we see
why did different people see different
things sometimes can evolutionary
studies inform us about why you see
illusions and to understanding the
perception of illusions inform us about
the peculiarities of the human brain in
the words of the ethology Niko Tinbergen
why do these animals behave what they do
I would like to introduce evolutionary
neuroscience and approach to
understanding human evolutionary
neuroscience is based on a reciprocal
relationship between neuroscience and
evolutionary biology evolutionary
neuroscience might sound like something
new but it’s always been a part of
neuroscience we have long thought we can
learn about our own brains
by studying the brains of other animals
neuroscience has long appreciated that
the brain along with the rest of the
nervous system isn’t an entirely
biological entity the humans share with
other species
physical neural structures have direct
correspondences the process is called
behaviors this has been recognized to
the extent that early on studies seeking
to understand our nervous systems
however light on animals as models
evolutionary neuroscience and provided
an up-to-date biological framework for
understanding brains and behavior
a key aspect of evolutionary
neuroscience is to bridge the findings
of translate
research by using information from
evolutionary constructions here are some
images of a structure in primate brains
called the LGN lateral geniculate
nucleus it is the first place in the
brain most visual information from the
eyes stops before moving on for
processing in the cerebral cortex I
mentioned a lot of these and once notice
that although I had learned in anatomy
class that these structures had six
layers I found that the number of layers
was not consistent across species I was
very surprised because I thought the
macaque visual system was structured and
function just like our own because not
much not much had changed except for the
size of the structures since the time of
our most recent common ancestor with
macaques 30 million years ago
both macaques and humans have six lgn
layers but IPM it shows this similarity
may not be as simple as it seems this is
a phylogenetic tree of some species of
primates a sort of family tree showing
how the species are related to each
other
phylogenetic trees are used to
understand how traits evolve in a group
of related species if they share a
feature the simplest explanation is that
had arisen from a common ancestor and is
thus and such really equivalent in all
those species it would be a shared right
feature but if the feature pops up all
over the place
it must have arisen due to different
evolutionary events and may be a little
bit different every time
many species just as closely related to
humans as macaques and even some which
are even more closely related to us than
in the tacks are how differently shaped
algae and to be fair we cannot be sure
what the functional significance of this
is however it is an important reminder
that make my frames have evolved just as
much as ours have since the time of our
shared most recent comment
and no single species can serve as
simple prototype for understanding human
brains and behaviors to really
understand humans understanding other
species helps but an evolutionary and
phylogenetic approach must always be
taken I’ve always been interested in
human specific behaviors how when and
why they arose these include things like
art tool making the burial of corpses
language and complex social behaviors
human specific behaviors define us human
specific behaviors occur across all
cultures human specific behaviors also
are what sense apart from other species
of course there are a lot of human
behaviors invented every day 25 years
ago it was texting 11 years ago tweeting
with the vended no other species can do
these things but the ones I’m most
interested in really define us out of
species these sorts of behaviors show up
in the hominin archaeological record and
are associated with fossils of the
earliest skeletons that look like our
own they start to appear in earlier
forms even in hominid species that are
more closely related humans than to any
other living animals but are no longer
around today human specific behaviors
tend not to have much of a course bond
as an animal kingdom they can be really
hard to define even they post some
really hard questions what we do know is
that our brains are three to four times
as big as the brains of other ace so
sometime between the time for most
recent common ancestor with tips around
seven million years ago brains got
bigger we have also evidence documents
in brain size over the past seven
million years we can make much better
estimates about the sizes of also
hominids brains and about any other
aspect of brains or behaviors in the
human
canary record but let’s get back to the
visual system a lot of people study the
visual system in a lot of species
because it’s both dominant and most
studied sensory system in humans it is
really relatively easy to identify
histologically and aspects of it may be
detectable in fossils like these in
particular a brain region called the
primary visual area is the first place
in the cerebral cortex most information
goes after having that stopped in the
lateral geniculate nucleus it is the
biggest brain region and it aches its
extent is marked by a fold in the brain
called in the lunate sulcus as you’ll
see in the orangutan brain on the left
the lunate sulcus has been the focus of
a nine-year-old debate about false
hominins such as this fossil an
Australopithecus africanus child
I studied the visual system to get some
basic idea about how our human minds
work we can start with understanding the
visual system and perhaps then try to
understand the rest of the brain
illusions reveal quirks in the visual
system that enable us to understand how
it works
we do not see in a photographic way we
are constrained by the features of our
cognition human brains and behaviors are
full of surprises and an evolutionary
framework is what might be needed to
crack that code these quirks also remind
us that our brains were not designed by
engineers simply for accuracy or even
for efficiency they’re not everything is
happy or to make us healthy or to help
us know the correct answer brains are a
product of reproductive success and the
way they perform is influenced by the
evolutionary history of our species some
features of human cognition like
language seem to sense apart from other
species however illusory perception is
something
share with a lot of other species as
well within our species their
differences and how different people
perceive things and allusions reveal
these five solutions their causes are
cases where external features cause
objects of identical size to appear to
have different sizes like this one first
identified the muller-lyer in this
figure the context influenced how long
the line seemed rows up to each other
the illusion is that the arrowheads make
the line appear shorter the tale makes
it appear longer the strength of the
mule or life illusion actually differs
between individuals more generally
people differ introduces susceptibility
to all spider lesions illusion strength
is higher in people with a smaller size
primary visual cortex so as I mentioned
non-human species also perceive
illusions demonstrating that similar
cognitive processes are at work in their
brains as well however there are also
species differences in the perception of
illusions and the strength of sign
delusion such as Mueller Liars
unfortunately most of what we know about
the behavior has been limited to a few
model species just that species vary in
susceptibility to illusions they also
vary in the sizes of their visual areas
with larger Villiers visual areas
containing more neurons
across primate species visual acuity is
related to the size of the visual cortex
so having bigger v1 with more neurons in
it could allow for a more detailed
representation of visual images which
are processed in the brain a model based
on the work of else suggests that having
more neurons to cover the perception of
an object means the person be perceived
in more detail Aleutians could result
when there are fewer neurons to cover
the perception of an image an illusion
is perhaps a more neuron economical way
of perceiving the world however note
that illusions are not merely economical
trade-offs they can be better at
summarizing information about what we
see and directing appropriate behavior
that is illusions to be an advantage and
it could even be an event of having
fewer neurons so this might be another
way in which evolution and neuroscience
can potentially inform each other’s
fields a trend within species may give a
hint to a trend across species
if the similar mechanism is that place
this framework suggests have sensory
perception may influence or constrain
the size of sensory regions and could
even result in differences in the
modular organization of cognition so
it’s not quite clear why humans have
such big brains and whether brain size
can explain human specific behaviors
we’re now in an era of big data we’re in
a better position than ever before to
use comparative methods to help uncover
the origin and adaptive basis for
behaviors cognitive abilities and
features of the brain take for example
this phylogenetic trees reconstructed
from the genetic data of 301 primate
species and showing how they are related
to each other
here are 301 species of interest which
can be studied to help us understand why
and how we behave as we do but we are
still faced with the problem of very
little data about the neuroanatomy and
behaviors which can be compared across
species we lack data from Jeff Serena’s
tarsiers most of the new world monkeys
except for one species of capuchin
most of the old world monkeys expect
except for one species a baboon and a
species of macaque and most of the age
except for chimps and ourselves so this
brings us back to an earlier point to
increase the reliability of the
framework which I’ve described that of
evolutionary neuroscience and best
extrapolate findings across these it
helps to know more about the
evolutionary history of illusory
perception we can have a better idea of
what is going on in our own hands by
studying the diversity of species which
still have today these are all species
of interest and relevant when
understanding the origin of the human
mind the more we can learn about them
the more we can understand about
ourselves why do we behave the way we do
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