Introduction
The
aim
of
this
text
is
threefold
:
Firstly
,
to
prove
to
the
Teacher
that
the
author
of
this
article
(
i
.
e
.
Student
)
have
sufficiently
internalized
all
the
facts
presented
during
UE
Neuroimagery
.
Secondly
,
Student
aims
to
introduce
the
notion
of
«
invasivity
»
as
something
which
should
be
considered
wery
seriously
by
someone
who
seeks
an
«
ideal
method
»
of
conducting
his
future
(
neuro
)
scientific
experiments
towards
success
.
But
the
ultimate
aim
si
to
show
that
certain
«
philosophical
schools
»
who
point
out
to
«
invasivity
-
related
aspects
»
of
current
neuro
-
scientific
research
are
not
doing
so
from
the
position
of
moralizing
savants
locked
in
their
ivory
towers
,
but
they
do
so
because
of
concrete
and
highly
-
pragmatic
reasons
related
to
purest
expressions
of
highest
scientific
practice
.
Principal
thesis
of
this
text
states
that
«
invasivity
»
and
«
reversibility
»
aspects
of
a
chosen
experimental
method
should
determine
experimentator
'
s
choice
at
least
as
significantly
as
other
aspects
like
spatial
/
temporal
resolution
characteristics
,
signal
/
noise
ratio
or
economical
feasibility
.
First
part
of
the
text
is
dedicated
to
highly
invasive
techniques
tissue
extraction
and
analysis
by
means
of
electron
,
multiphoton
or
confocal
microscopes
.
Post
mortem
autopsy
and
chirurgical
interventions
like
vivisesction
or
lobotomy
will
be
mentioned
when
discussing
this
group
.
Common
demoninator
of
these
approaches
is
that
their
condition
sine
qua
non
of
their
realisation
is
nonreversible
and
fatal
degradation
of
one
vital
functions
of
the
organism
under
study
or
...
death
.
Second
part
of
the
text
is
dedicated
to
somewhat
more
reversible
,
nonetheless
still
very
brutal
«
in
vivo
»
techniques
like
that
of
calcic
imaging
,
optic
imaging
or
electrode
implantation
.
Because
it
is
evident
that
such
approaches
can
inflict
severe
injuries
and
suffering
of
the
organisms
under
study
,
they
will
be
labeled
as
«
partially
reversible
quasi
in
vivo
techniques
».
Contrary
to
common
categorisation
of
these
days
,
even
techniques
like
PET
(
positron
emission
tomography
)
or
X
-
ray
imaging
will
be
included
into
this
middle
group
of
partially
invasive
techniques
.
This
is
due
to
their
high
-
energy
kinship
with
radioactivity
which
can
without
any
doubt
induce
mutations
resulting
in
the
disequilibrium
of
a
living
system
which
is
commonly
known
as
«
loss
of
health
».
The
loss
of
this
precious
equilibrium
is
the
reason
why
we
'
ll
include
all
the
luminescence
/
fluorescence
marker
techniques
into
this
category
as
well
.
The
third
part
of
the
text
aims
to
bring
hope
.
It
will
be
fully
devoted
to
techniques
which
can
be
considered
as
fully
reversible
:
focus
will
be
definitely
on
Magnetic
Resonance
Imaging
(
MRI
)
and
Electroencephalography
(
EEG
)
while
other
non
-
invasive
techniques
(
NIRS
,
echography
or
TCD
)
will
be
excluded
from
the
list
due
to
lack
of
Student
'
s
personal
experience
with
these
techniques
.
The
small
part
of
this
final
part
will
be
dedicated
to
«
what
if
?»
speculation
proposing
to
use
these
pure
and
elegant
techniques
not
only
for
imaging
,
but
as
well
as
a
tool
of
healing
practice
.
These
three
parts
can
be
considered
as
a
core
of
Student
'
s
homework
demanding
him
to
«
highlight
the
advantages
and
limits
of
these
techniques
depending
from
the
scientific
question
You
'
ll
pose
».
The
question
posed
by
student
is
this
:
«
According
to
what
criteriae
could
we
possibly
quantify
invasivity
of
an
experimental
tool
or
method
?
»
This
text
will
try
to
answer
this
question
by
introducing
the
term
which
we
label
hereby
as
«
Information
/
Invasivity
Quotient
»
(
IIQ
).
We
'
ll
analyse
this
notion
from
more
ethical
perspective
in
Discussion
section
,
while
Appendix
will
summariz
IIQ
-
based
ranking
of
4
presented
methods
.