spend five minutes in any forest and you'll probably hear birds chirping the
kind of vocal communication which are sounds animals make with their mouth or
throat parts like talking roaring or meowing and there are tons of papers out
there about birdsong and how it can mean anything from look how cool my feathers
are to run away but about a hundred and fifty years ago Charles Darwin had a
thought what if the non vocal sounds that birds make like by flapping their
wings mean something to scientists have been looking into this question for a
while and this week a study from the Australian National University seems to
give more evidence that Darwin was right if you've spent any time on mainland
Australia you'll have heard the crested pidgin whistle except it isn't a mouth
sound they whistle when they flap their wings which got them the nickname
whistle winged pigeons say that five times fast in the 2009 paper researchers
had noticed something important other pigeons seem to react to the whistle so
a group of biologists including one of the previous paper's authors wanted to
do more tests to see if the noise actually communicated something in the
2009 research they measured crested pigeon wing feathers and discovered a
weirdly thin one specifically the eighth primary feather measurements in both
studies showed that the pigeons produced two distinct notes as their wings flap
and vibrate the feathers one is much higher than the other also when the
birds were flying away in a hurry they flapped faster and the sound was louder
so the researchers carefully removed the weird feather from some birds all in the
name of science it's okay they grow back without the narrow feather the highest
note disappeared and wind tunnel experiments confirmed that the feather
makes the noise when it's vibrating on its own most importantly the researchers
compared the reaction of other crested pigeons to recordings of birds flying
away with and without the special feather and there was a clear difference
when the other birds heard the high-pitched sound they were more likely
to get out of there in a hurry as if there were an alarm blaring but if they
heard the recordings without that alarm they were more likely to stick around or
take off more leisurely this gives some solid evidence for Darwin's nonverbal
communication idea showing how the sound is produced and how other birds respond
to it and the researchers say it makes sense evolutionarily to these pigeons
are always going to make a sound if there's danger nearby so more birds know
to escape and stay alive unless a scientist comes along and takes away
some of their feathers but enough about birds let's talk about
humans because if you're a student a parent or really anyone you've probably
been sleep-deprived before you feel sluggish like your mind is swimming
through fog to make decisions and everything just seems harder and this
week researchers from UCLA took a deep look into the biology behind this
feeling when you're tired your neurons sort of go to sleep - in a paper
published in the journal Nature Medicine this team of neuroscientists monitored
the brain activity of 12 patients who had electrodes in their heads before you
get too weirded out by that the patients were already in the hospital to get
treatment for epilepsy epilepsy is a super broad term for abnormal brain
activity that causes seizures there's a lot of variation in causes and symptoms
which means treatments can vary a lot - sometimes it's hard to pinpoint the
exact brain region that's affected so doctors can implant electrodes to keep
track of the electrical signals throughout the brain when a seizure
happens and this can help doctors decide if brain surgery is worth the risk to
remove something that might be causing the seizures like scar tissue and when
doctors want to cause a seizure in a controlled hospital setting sleep
deprivation is key electrical activity in the brain changes when you're asleep
or awake so messing with that cycle can influence seizures this worked out well
for these researchers - they had a group of probably bored sleep-deprived people
with their brain signals being monitored so they can see what happens to neurons
when we force ourselves to stay awake at different times the patients were given
a set of images to categorize as quickly as they could while the researchers
monitored brain activity in a region called the temporal lobe among other
things the temporal lobe translates sensory information into conscious
thoughts basically information processing like if I see a roundish red
thing with a brown stem on top my temporal lobe helps me recognize that
it's an Apple the scientists noticed that the neurons in the temporal lobe
actually fired more slowly and passed along weaker signals as the patients did
this task after staying awake longer the researchers also measured brain waves
the repeating cycles of many neurons firing and these brain waves slowed down
in certain regions - so they kind of looked like the ones linked with sleep
we've known for a long time that sleep deprivation can mess with how you act
but this is the first study in humans that might explain what's going on
biologically the researchers say the effects of these basically sleeping
neurons are similar to being drunk which has huge implications for things like
driving like it's going to take longer for your brain to process an unexpected
pedestrian on the road and react so that's maybe something to
think about next time you're watching Netflix until 3 a.m. thanks for watching
this episode of scishow news and thanks especially to all of our patrons on
patreon who make this show possible if you want to help us keep making episodes
like this go to patreon.com/scishow and don't forget to go to
youtube.com/scishow and subscribe
you