Scientists 'read dreams' using brain scans

Scientists have found a
way to "read" dreams, a
study suggests.
Researchers in Japan used
MRI scans to reveal the
images that people were
seeing as they entered
into an early stage of
sleep.
Writing in the journal
Science, they reported
that they could do this
with 60% accuracy.
The team now wants to
see if brain activity can be
used to decipher other
aspects of dreaming, such
as the emotions
experienced during sleep.
Professor Yukiyasu
Kamitani, from the ATR
Computational
Neuroscience
Laboratories, in Kyoto,
said: "I had a strong belief
that dream decoding
should be possible at least
for particular aspects of
dreaming... I was not very
surprised by the results,
but excited."
Brain wave
People have been trying
to understand dreams
since ancient Egyptian
times, but the researchers
who have carried out this
study have found a more
direct way to tap into our
nighttime visions.
The team used MRI scans
to monitor three people
as they slept.
Just as the
volunteers
started to
fall asleep
inside the
scanners,
they were
woken up
and asked
to recount
what they
had seen.
Each image
mentioned, from bronze
statues to keys and ice
picks, was noted, no
matter how surreal.
This was repeated more
than 200 times for each
participant.
The researchers used the
results to build a
database, where they
grouped together objects
into similar visual
categories. For example,
hotel, house and building
were grouped together as
"structures".
The scientists then
scanned the volunteers
again, but this time, while
they were awake and
looking at images on a
computer screen.
With this, they were able
to see the specific
patterns of brain activity
that correlated with the
visual imagery.
Dream machines?
During the next round of
sleep tests, by monitoring
the brain scans the
researchers could tell
what the volunteers were
seeing in their dreams.
They were able to assess
which broad category the
images were in with 60%
accuracy.
"We were able to reveal
dream content from brain
activity during sleep,
which was consistent
with the subjects' verbal
reports," explained
Professor Kamitani.
The researchers now want
to look at deeper sleep,
where the most vivid
dreams are thought to
occur, as well as see
whether brain scans can
help them to reveal the
emotions, smells, colours
and actions that people
experience as they sleep.
Dr Mark Stokes, a
cognitive neuroscientist
from the University of
Oxford, said it was an
"exciting" piece of
research that brought us
closer to the concept of
dream-reading machines.
"It's obviously a long way
off, but there is no reason
why not in principle. The
difficult thing is to work
out the systematic
mapping between the
brain activity and the
phenomena," he
explained.
However, he added that a
single dream-reading
system would not work
for everyone.
"All of this would have to
be done within individual
subjects. So you would
never be able build a
general classifier that
could read anybody's
dreams. They will all be
idiosyncratic to the
individual, so the brain
activity will never be
general across subjects,"
he said.
"You would never be able
to build something that
could read other peoples
thoughts without them
knowing about it, for
example."