Beyond what our Eyes Perceive

it is often said

that we don’t see through our eyes but

instead

with our brain the eyes enable light to

enter our system

but in order to make sense of the world

around us

the electrically powered piece of meat

we are carrying inside our skulls

needs to get working so what kind of

work does the brain need to do

well the simple answer as in most

psychological research

is pretty straight we are not sure yet

but before i tell you how my institution

spends resources in order for me

to waste hours drinking coffee and

thinking over this

let me give you some examples on how the

brain sees

an obvious example would be dreaming or

imagination

that extraordinary ability of

experiencing images

without them actually being them many

scientists

are curious about understanding this

phenomenon despite

the many practical difficulties but

unfortunately for you unfortunately for

them

i’m not one of those scientists so i

can’t really tell you much on the topic

however i’m kind of curious about stuff

like this

this is the widely known penrose

triangle

it’s quite funny i got this t-shirt

really cheap

because the whole triangle is misspelled

on it

let me make it a bit easier for you to

see

at first glance it looks like an

ordinary triangle

but the more you stare at it the more

you realize that

in reality this shape cannot exist

it’s an optical illusion optical

illusions

are an interesting way to understand

that

beyond one rise perceive beyond the

visual information that’s right in front

of our eyes

the brain does all the hard work to put

that information together

and of course as i know from my personal

life too

hard work does not necessarily mean good

work

sorry boss i know that you’re probably

watching this

arise get constantly bombarded by a huge

influx of visual information and many

times

the brain can get confused distracted

or even miss some of the information

here’s an example of the brain getting

confused

these are the rotating snakes by

akioshikitoka

even though this picture is static our

brains pick up spontaneous movement

as if the snakes are rotating i know

brains are really weird now

of course the way that we perceive the

world

has a lot to do with where and how we

pay attention

where the focus is now

i don’t usually take selfies but i think

there’s

no better way to explain this so i want

you to have a look

here keep going

depending on where you focus your

attention your brain

interprets the perspective of this photo

differently

despite having only one image in front

of your eyes

the brain puts it together in a

prejudiced way

what’s right in front of you in

combination with what we know

about that something for the example

here

the brain has learned that faces can

only have one single perspective

it searches beyond the single image

that’s right in front of

the eyes and puts it all somehow

together

based on what makes sense for the brain

as i mentioned earlier brains can also

get

distracted or even miss some of the

information

for example you probably haven’t noticed

that i switched to what i was wearing

from my right hand to my left hand

there’s a number of reasons why this

happens one reason

is that your brain uses existing

knowledge some sort of

common sense in order to save energy

while figuring things out

if you saw the watch before you know i’m

wearing it

it doesn’t really make sense for me to

switch hands

so why would your brain pay any more

attention to it

it assumes when it sees the watch that

it’s always been

on my left hand

unless of course somebody is trying to

make a point

i know what you’re thinking the screen

is small

the watch is even smaller the setup is

quite big

i have a very pretty face it’s easy to

get away with it

but let me give you a better example our

brains

know that in order to change clothes we

need

to take the ones we’re currently wearing

off and change them with other ones

and one does not simply do that while

giving a speech

or at least that’s what the organizers

told me

that could explain why you probably

haven’t noticed that the word triangle

is now spelled correctly on my t-shirt

trust me this would have been much

cooler if i was doing this on stage

i pointed at my t-shirt before you saw

it you probably read what was written on

it

and your brain processed the information

it knows that the print on it is not

something likely to change

so why give it any more attention the

brain

prefers to save its resources and tries

to avoid

what it thinks is unnecessary it uses

this

common sense to

assume that the t-shirt will remain the

same

or that the watch was always on my left

hand

similarly to how when you see somebody

with glasses

you assume that they have some sort of a

visual impairment

well guess what these glasses

have no lenses in them

well i told you i was trying to make a

point

this brain limitation is something that

magicians have come across and um

often they use this destruction

to impress us with their magic

so try and remember that next time you

spot a magician

now knowing that the brain has all these

capabilities

and limitations we now understand

that somehow the brain using specific

processes

turns all this visual influx into

conscious representations

so beyond polarized perceived

something is happening in some areas of

the brain

that actually allow us to understand the

world around us

such a process is visual short-term

memory

in simple words visual short-term memory

is our brain’s ability

to handle visual information just for a

few seconds

while that information is no longer

available

and therefore we can achieve some goals

to help you understand i want you to

imagine

that you’re building one of those model

aeroplanes or a model boat

you have all these pieces laid in front

of you in the table and of course you

have this huge

booklet with instructions you open up

the instruction manual to the first page

and have a look at the first piece

you’re going to need

what you’re doing is you’re trying to

remember the image

of the first piece in your mind

and you put the instructions away you

turn to all the pieces on the table

trying to find the one that you’re

holding into your memory

trying to remember and handle all this

visual information

which is no longer present is what the

visual short-term memory process

is in our lab

we don’t really build mobile aeroplanes

or model boats but part of our work

relates to which brain areas are

involved during visual short-term memory

specifically we study the primary visual

cortex

which is an area on the back of the

brain somewhere around here

the primary visual cortex is the first

brain area

that processes visual information right

after the light

passes through our eyes and the optic

nerve

it even consists of special cells

special neurons

which have been shown to be particularly

responsible for processing some basic

visual features

in other words some neurons in the

primary visual cortex

are exclusively there to process some

basic

visual characteristics such as contrast

and orientation

however we are still not sure whether

this brain area

is able to hold on to this visual

characteristics

let’s say whether the primary visual

cortex

is able to remember them or whether

other brain areas need to be recruited

in order to do so

so how do we find out well

the first thing we need to do is design

some tasks

computer tasks which will present to

people

visual information and people will have

to remember it

think of it as some sort of a very

boring video game

so basically what we do is we present

an image to the participants

the image then disappears and the

participants are trying to remember it

after a few seconds a second image

appears

then participants need to tell us if the

second image

is the same as the first one or if it’s

a different one

so far so good

these kinds of computer tasks have been

used in cognitive science for decades

and it is something we use in our lab as

well

apparently part of my job is to spend

hours

designing these very boring memory games

while of course

making sure the whole lab’s computer

system doesn’t crash

these tasks help us gather evidence

about visual short-term memory enabling

us to study it

and explore it but

that’s the easy part we still need to

figure out a way

to investigate how the primary visual

cortex

is involved during the process of visual

short-term memory

now the most reliable way to do this

and bear with me that’s the best way to

do it

is the following we bring people to the

lab

to play these very boring video games we

design which the goal is to remember

something visually so

we show them the first image and when

the first image disappears

we slice open the skulls surgically

remove the primary visual cortex

completely from the brain

and put it right back just before the

second image appears

while of course keeping them conscious

and alive

and uh by the way we only have about

two seconds to do so before the second

image

appears of course when i told my lab

team this idea

they were staring at me as if i was

standing naked in the room

i almost lost my job and some people

won’t talk to me anymore

so obviously this is not a realistic

scenario

it might indeed be the best way to find

out

but clearly is not something that can be

done

so what now after the shock of that

meeting called down

and my supervisor decided to start

talking to me again

we turned to state-of-the-art technology

to find the answers we were looking for

non-invasive

brain stimulation science and technology

have developed amazing techniques that

today

allow us to interfere with the brain’s

regular activity

as if we are removing a brain part in a

safe

non-invasive and reliable way we use

magnetic stimulation

to target the primary visual cortex

disrupt its regular activity

and study how this temporal disruption

affects cognitive processes

such as visual short-term memory

at the start of this talk i mentioned

that the brain is electrically powered

this exact fat is what makes brain

stimulation

possible we use magnetic energy

which we know is safe for humans because

this energy can manipulate electrical

fields

such as the one our brain generates

therefore by manipulating the brain’s

regular activity

during visual short-term memory we can

study how the primary visual cortex

is involved during this process

now as in all sciences a very important

question needs to be asked

which is probably something you’re

thinking right now

so what what’s the importance of this

why do we do it well first of all

it is because we are curious scientists

want to know why

or how the world works

this is what has driven science

throughout the years and this is what

drives

many scientists around the world today

the brain is very difficult to

understand

these experiments add a very small piece

to the puzzle

of unraveling how the brain works

they help us better understand

mesmerizing questions

like why or how are we conscious

further this kind of work can be

translated into the practical world

helping us solve everyday problems

for example many accidents are caused by

the human factor

and often by how our brains get confused

distracted or even misinformation

with this said i want to close by saying

that

beyond every scientist work was an

infinite stream of curiosity

and a dream of making the world a better

place

thank you