Losing and recovering sight | Olivier Collignon | TEDxUCLouvain

[Music]

[Music] imagine you’re born blind

imagine you’re born blind

imagine you’re born blind you adapt to this condition and you

you adapt to this condition and you

you adapt to this condition and you become very good at navigating with

become very good at navigating with

become very good at navigating with outside at remembering where are places

outside at remembering where are places

outside at remembering where are places object at localizing sounds even at

object at localizing sounds even at

object at localizing sounds even at reading with your fingers in some sense

reading with your fingers in some sense

reading with your fingers in some sense you become with like this Marvel

you become with like this Marvel

you become with like this Marvel superhero daredevil you compensate for

superhero daredevil you compensate for

superhero daredevil you compensate for the lack of vision by developing some

the lack of vision by developing some

the lack of vision by developing some kind of supernatural skills in your

kind of supernatural skills in your

kind of supernatural skills in your remaining senses then someone comes to

remaining senses then someone comes to

remaining senses then someone comes to you and tell you I can fix your eyes and

you and tell you I can fix your eyes and

you and tell you I can fix your eyes and he can provide you the gift of sight

he can provide you the gift of sight

he can provide you the gift of sight a miraculous will that be but is it if

a miraculous will that be but is it if

a miraculous will that be but is it if we looked at the very few cases in the

we looked at the very few cases in the

we looked at the very few cases in the literature of people who recovered sight

literature of people who recovered sight

literature of people who recovered sight after a lifelong experience of blindness

after a lifelong experience of blindness

after a lifelong experience of blindness we see that what was expected to be

we see that what was expected to be

we see that what was expected to be miraculous can sometimes turns out to be

miraculous can sometimes turns out to be

miraculous can sometimes turns out to be a disaster take for example patient s B

a disaster take for example patient s B

a disaster take for example patient s B he was investigated by the famous

he was investigated by the famous

he was investigated by the famous psychologist Richard Gregory as we

psychologist Richard Gregory as we

psychologist Richard Gregory as we regain sight at age 52 and in his

regain sight at age 52 and in his

regain sight at age 52 and in his monograph about the case which art

monograph about the case which art

monograph about the case which art Gregory explained that his case is in

Gregory explained that his case is in

Gregory explained that his case is in some way tragic he lifts with one of the

some way tragic he lifts with one of the

some way tragic he lifts with one of the greatest handicap but yes it lifts with

greatest handicap but yes it lifts with

greatest handicap but yes it lifts with enthusiasm and energy and when his

enthusiasm and energy and when his

enthusiasm and energy and when his handicap was apparently swept away as by

handicap was apparently swept away as by

handicap was apparently swept away as by miracle he lost is peace and

miracle he lost is peace and

miracle he lost is peace and self-respect actually a few years of the

self-respect actually a few years of the

self-respect actually a few years of the recovering sight s be committed suicide

recovering sight s be committed suicide

recovering sight s be committed suicide in my research I’m trying to understand

in my research I’m trying to understand

in my research I’m trying to understand what may happen in the brain of blind

what may happen in the brain of blind

what may happen in the brain of blind individuals that could explain this

individuals that could explain this

individuals that could explain this somehow tragic case stories I’m a

somehow tragic case stories I’m a

somehow tragic case stories I’m a cognitive neuroscientist so during my

cognitive neuroscientist so during my

cognitive neuroscientist so during my work I’m often contemplating this

work I’m often contemplating this

work I’m often contemplating this fascinating but very complex project of

fascinating but very complex project of

fascinating but very complex project of evolution that is the human brain we try

evolution that is the human brain we try

evolution that is the human brain we try to understand oh this brain implements

to understand oh this brain implements

to understand oh this brain implements the mind or cognition and per net

the mind or cognition and per net

the mind or cognition and per net perception emerge from brain activity so

perception emerge from brain activity so

perception emerge from brain activity so for example what we know is that when

for example what we know is that when

for example what we know is that when you see something

you see something

you see something it activates the back part of your brain

it activates the back part of your brain

it activates the back part of your brain what we call the occipital cortex and it

what we call the occipital cortex and it

what we call the occipital cortex and it does so in an organized fashion you will

does so in an organized fashion you will

does so in an organized fashion you will have some region but some what we call

have some region but some what we call

have some region but some what we call some computational unit that will prefer

some computational unit that will prefer

some computational unit that will prefer to respond to some specific input for

to respond to some specific input for

to respond to some specific input for example you will have some region that

example you will have some region that

example you will have some region that we prefer to respond to faces more than

we prefer to respond to faces more than

we prefer to respond to faces more than to any other object or the region that

to any other object or the region that

to any other object or the region that will refer to respond to places or

will refer to respond to places or

will refer to respond to places or scenes or the region that will prefer to

scenes or the region that will prefer to

scenes or the region that will prefer to response to inanimate object at least if

response to inanimate object at least if

response to inanimate object at least if you don’t drink too much of it and

you don’t drink too much of it and

you don’t drink too much of it and finally other region that will prefer to

finally other region that will prefer to

finally other region that will prefer to response to object in motion more than

response to object in motion more than

response to object in motion more than to any static object and all these

to any static object and all these

to any static object and all these computational units will interact with

computational units will interact with

computational units will interact with each other

each other

each other to create a unified and current

to create a unified and current

to create a unified and current perception of your environment or is

perception of your environment or is

perception of your environment or is this organization emerging what we know

this organization emerging what we know

this organization emerging what we know is that there is a genetic master plan

is that there is a genetic master plan

is that there is a genetic master plan that is at least partly driving this

that is at least partly driving this

that is at least partly driving this organization although we know that first

organization although we know that first

organization although we know that first because this organization is some

because this organization is some

because this organization is some somehow universal is highly similar

somehow universal is highly similar

somehow universal is highly similar between each of us second you can find

between each of us second you can find

between each of us second you can find trace of this organization in very young

trace of this organization in very young

trace of this organization in very young babies and finally you can find this

babies and finally you can find this

babies and finally you can find this organization even in our evolutionary

organization even in our evolutionary

organization even in our evolutionary ancestors like primates all this

ancestors like primates all this

ancestors like primates all this together suggests that there is a

together suggests that there is a

together suggests that there is a genetic determination in the way this

genetic determination in the way this

genetic determination in the way this organization emerge does that mean that

organization emerge does that mean that

organization emerge does that mean that experience plays no role for instance

experience plays no role for instance

experience plays no role for instance what would happen if someone is born

what would happen if someone is born

what would happen if someone is born blind will this region remain silent and

blind will this region remain silent and

blind will this region remain silent and not participate in anything if you

not participate in anything if you

not participate in anything if you actually test that in the laboratory

actually test that in the laboratory

actually test that in the laboratory this is not what you observe we observe

this is not what you observe we observe

this is not what you observe we observe a phenomenon that we call cross model

a phenomenon that we call cross model

a phenomenon that we call cross model plasticity the fact that the region

plasticity the fact that the region

plasticity the fact that the region typically dedicated to process visual

typically dedicated to process visual

typically dedicated to process visual information massively reorganized to

information massively reorganized to

information massively reorganized to process auditory or tactile input and

process auditory or tactile input and

process auditory or tactile input and what is quite fascinating with this

what is quite fascinating with this

what is quite fascinating with this reorganization is someone that it

reorganization is someone that it

reorganization is someone that it follows a division of computational

follows a division of computational

follows a division of computational labour that is similar between blind and

labour that is similar between blind and

labour that is similar between blind and sighted subjects you remember this

sighted subjects you remember this

sighted subjects you remember this region that I said was specific for

region that I said was specific for

region that I said was specific for visual motion in the sighted actually

visual motion in the sighted actually

visual motion in the sighted actually this region remains selective for motion

this region remains selective for motion

this region remains selective for motion in blind people but process motion in

in blind people but process motion in

in blind people but process motion in the auditory or tactile modality so it

the auditory or tactile modality so it

the auditory or tactile modality so it seems that this region maintain is

seems that this region maintain is

seems that this region maintain is function but apply this function to a

function but apply this function to a

function but apply this function to a non visual modality so this kind of

non visual modality so this kind of

non visual modality so this kind of discoveries are very important for us to

discoveries are very important for us to

discoveries are very important for us to understand on nature and nurture

understand on nature and nurture

understand on nature and nurture interact to shape brain development on

interact to shape brain development on

interact to shape brain development on one side we clearly see that experience

one side we clearly see that experience

one side we clearly see that experience plays a dramatic role in case of visual

plays a dramatic role in case of visual

plays a dramatic role in case of visual deprivation those region massively

deprivation those region massively

deprivation those region massively reorganize and play participate in

reorganize and play participate in

reorganize and play participate in another type of processing the

another type of processing the

another type of processing the processing of another sensory modality

processing of another sensory modality

processing of another sensory modality but at the same time we see that there

but at the same time we see that there

but at the same time we see that there are intrinsic forces that constrain the

are intrinsic forces that constrain the

are intrinsic forces that constrain the way this reorganization expresses so

way this reorganization expresses so

way this reorganization expresses so I’ve just said that in early blind

I’ve just said that in early blind

I’ve just said that in early blind people the occipital cortex normally

people the occipital cortex normally

people the occipital cortex normally visual functionally participate in non

visual functionally participate in non

visual functionally participate in non visual processing what would happen if a

visual processing what would happen if a

visual processing what would happen if a blind subject recover site or this newly

blind subject recover site or this newly

blind subject recover site or this newly required visual input will interact or

required visual input will interact or

required visual input will interact or even interfere with this auditory or

even interfere with this auditory or

even interfere with this auditory or tactile input that are no rooted in the

tactile input that are no rooted in the

tactile input that are no rooted in the occipital cortex of this blind subject

occipital cortex of this blind subject

occipital cortex of this blind subject actually a few years ago we had the

actually a few years ago we had the

actually a few years ago we had the unique opportunity to explore this

unique opportunity to explore this

unique opportunity to explore this question by investigating the case of a

question by investigating the case of a

question by investigating the case of a patient which was born with massive

patient which was born with massive

patient which was born with massive visual impairment up to the moment she

visual impairment up to the moment she

visual impairment up to the moment she recovered side at age 47 and what we did

recovered side at age 47 and what we did

recovered side at age 47 and what we did is that we tested this person at least

is that we tested this person at least

is that we tested this person at least all the brain of this person react

all the brain of this person react

all the brain of this person react before and after site recovery and what

before and after site recovery and what

before and after site recovery and what we saw before site recovery is that

we saw before site recovery is that

we saw before site recovery is that because she was highly visually impaired

because she was highly visually impaired

because she was highly visually impaired her brain reaction the reaction of our

her brain reaction the reaction of our

her brain reaction the reaction of our occipital cortex to visual input was

occipital cortex to visual input was

occipital cortex to visual input was highly clumsy but because she lived as a

highly clumsy but because she lived as a

highly clumsy but because she lived as a blind subject she had massive activity

blind subject she had massive activity

blind subject she had massive activity in this region for auditory information

in this region for auditory information

in this region for auditory information for example after the reacquisition of

for example after the reacquisition of

for example after the reacquisition of sight what we saw is that this region

sight what we saw is that this region

sight what we saw is that this region progressively became tuned to the visual

progressively became tuned to the visual

progressively became tuned to the visual input but what was probably the most

input but what was probably the most

input but what was probably the most striking discovery is that even seven

striking discovery is that even seven

striking discovery is that even seven months

months

months after site recovery we could still find

after site recovery we could still find

after site recovery we could still find trace of auditory activity in this

trace of auditory activity in this

trace of auditory activity in this region so it means that if you are born

region so it means that if you are born

region so it means that if you are born blind and live a life as a blind subject

blind and live a life as a blind subject

blind and live a life as a blind subject and get vision restored as an adult you

and get vision restored as an adult you

and get vision restored as an adult you have an occipital cortex that

have an occipital cortex that

have an occipital cortex that simultaneously react to vision and to

simultaneously react to vision and to

simultaneously react to vision and to audition and we believe that this

audition and we believe that this

audition and we believe that this interaction in the occipital cortex may

interaction in the occipital cortex may

interaction in the occipital cortex may potentially create some interference can

potentially create some interference can

potentially create some interference can challenge the optimal reacquisition

challenge the optimal reacquisition

challenge the optimal reacquisition of sight actually you do not need a full

of sight actually you do not need a full

of sight actually you do not need a full experience a full life of blindness to

experience a full life of blindness to

experience a full life of blindness to experience that those kind of

experience that those kind of

experience that those kind of reorganization even if the blindness is

reorganization even if the blindness is

reorganization even if the blindness is very short but early in life in the most

very short but early in life in the most

very short but early in life in the most sensitive period of blind development

sensitive period of blind development

sensitive period of blind development like in the case of these babies born

like in the case of these babies born

like in the case of these babies born with dense bilateral cataract that got

with dense bilateral cataract that got

with dense bilateral cataract that got operated very early in life few weeks of

operated very early in life few weeks of

operated very early in life few weeks of humans after birth if you test them when

humans after birth if you test them when

humans after birth if you test them when they are adults actually even in these

they are adults actually even in these

they are adults actually even in these people you can find trace of auditory

people you can find trace of auditory

people you can find trace of auditory activity in the occipital cortex and

activity in the occipital cortex and

activity in the occipital cortex and again this may potentially explain why

again this may potentially explain why

again this may potentially explain why these people never react wire perfect

these people never react wire perfect

these people never react wire perfect vision even in adulthood so what I

vision even in adulthood so what I

vision even in adulthood so what I wanted to tell you today is that you can

wanted to tell you today is that you can

wanted to tell you today is that you can look at brain plasticity in two ways

look at brain plasticity in two ways

look at brain plasticity in two ways there is obviously the adaptive side of

there is obviously the adaptive side of

there is obviously the adaptive side of plasticity the fact that the brain can

plasticity the fact that the brain can

plasticity the fact that the brain can reorganize to interact with is in the

reorganize to interact with is in the

reorganize to interact with is in the environment to potential eyes is

environment to potential eyes is

environment to potential eyes is capacity but there is also a maladaptive

capacity but there is also a maladaptive

capacity but there is also a maladaptive way of looking at the palate plasticity

way of looking at the palate plasticity

way of looking at the palate plasticity the fact that reorganization that are

the fact that reorganization that are

the fact that reorganization that are put in place early in life are very

put in place early in life are very

put in place early in life are very difficult to undo and potentially could

difficult to undo and potentially could

difficult to undo and potentially could interfere with the reacquisition of

interfere with the reacquisition of

interfere with the reacquisition of sensory information later in life so I

sensory information later in life so I

sensory information later in life so I hope I’ve convinced you today that the

hope I’ve convinced you today that the

hope I’ve convinced you today that the study of brain plasticity is an

study of brain plasticity is an

study of brain plasticity is an important topic it’s also a very timely

important topic it’s also a very timely

important topic it’s also a very timely topic why because we are living

topic why because we are living

topic why because we are living exponential increase in the medicine of

exponential increase in the medicine of

exponential increase in the medicine of sensory restoration so it’s very

sensory restoration so it’s very

sensory restoration so it’s very important to tackle this question now

important to tackle this question now

important to tackle this question now what we hope is that we can use

what we hope is that we can use

what we hope is that we can use neuroscience to predict who will be the

neuroscience to predict who will be the

neuroscience to predict who will be the good or the bad candidate for sensory

good or the bad candidate for sensory

good or the bad candidate for sensory restoration and potentially also that we

restoration and potentially also that we

restoration and potentially also that we can leverage all knowledge

can leverage all knowledge

can leverage all knowledge about brain plasticity to design better

about brain plasticity to design better

about brain plasticity to design better tailored rehabilitation procedure thank

tailored rehabilitation procedure thank

tailored rehabilitation procedure thank you

you

you [Applause]