■ ■ ■■ ■ ■ ■ ■■ (^)
■ ■ ■ ■ ■■ (^)
■ ■ ■ ■ ■■ (^)
■ ■ ■ ■ ■■ (^)
■ ■ ■ ■ ■■ (^)
■ ■ ■ ■ ■■ (^)
■ ■ ■ ■ ■■ (^)
■ ■ ■ ■ ■■ (^)
■ ■ ■ ■ ■■ (^)
■ ■ ■ ■ ■■ (^)
■ ■ ■ ■ ■■ (^)
■ ■ ■
■ ■ ■ ■ ■■ (^)
■ ■ ■ ■ ■■ (^)
■ ■ ■ ■ ■■ (^)
■ ■ ■ ■ ■■ (^)
■ ■ ■ ■ ■■ (^)
■ ■ ■ ■ ■■ (^)
■ ■ ■ ■ ■■ (^)
■ ■ ■ ■ ■■ (^)
■ ■ ■ ■ ■■ (^)
■ ■ ■ ■ ■■ (^)
■ ■ ■ ■ ■■ (^)
■ ■ ■ ■ ■■ (^)
■ ■ ■ ■ ■■ (^)
■ ■ ■ ■ ■■ (^)
■ ■ ■ ■ ■■ (^)
■ ■ ■
■ ■ ■ ■ ■■ (^)
■ ■ ■ ■ ■■ (^)
■ ■ ■ ■ ■■ (^)
■ ■ ■ ■ ■■ (^)
■ ■ ■ ■ ■■ (^)
■ ■ ■ ■ ■■ (^)
■ ■ ■ ■ ■■ (^)
■ ■ ■ ■ ■■ (^)
■ ■ ■ ■ ■■ (^)
■ ■ ■ ■ ■■ (^)
■ ■ ■ ■ ■■ (^)
■ ■ ■ ■ ■■ (^)
■ ■ ■ ■ ■■ (^)
■ ■ ■ ■ ■■ (^)
■ ■ ■ ■ ■■ (^)
■ ■ ■
■ ■ ■ ■ ■■ (^)
■ ■ ■ ■ ■■ (^)
■ ■ ■ ■ ■■ (^)
■ ■ ■ ■ ■■ (^)
■ ■ ■ ■ ■■ (^)
■ ■ ■ ■ ■■ (^)
■ ■ ■ ■ ■■ (^)
1 2
82
83
January/February 2018^ DISCOVER^81
TOP: CALTECH. BOTTOM: REID ET AL., 2017, CURRENT BIOLOGY 27, 1825–1828, CC BY 4.0
Do You Need a Brain to Sleep?
❯
FALLING ASLEEP: So easy,
you don’t even need a
brain. Jellyfish, brainless
creatures with clusters of
neurons throughout their bodies,
display the same behavioral sleep
traits as we do.
Caltech researchers put the
jellyfish Cassiopea through a
series of tests to see if they
fulfilled three requirements
for a sleeplike state: lowered
activity levels, slower reaction
times and impaired performance
after sleep deprivation. They
achieved all three, according
to an October paper in Current
Biology.
The findings indicate the
behavior isn’t the sole province
of brains, suggesting sleep
is important enough to have
survived the hundreds of
millions of years since we
diverged from jellyfish. In
fact, sleep may be an intrinsic
property of neurons themselves.
NATHANIEL SCHARPING
Fetuses Track Facelike Shapes
❯
NEWBORNS TEND to favor
facelike patterns, such as
top-heavy triangles, and
researchers have now shown that
third-trimester fetuses have similar
preferences. Lighting conditions
inside the womb have only recently
been explored, so despite extensive
research on fetal reaction to other
sensory stimuli, visual response had
remained unseen until now.
In a study published in June in
Current Biology, developmental
psychologist Vincent Reid of
Lancaster University and his team
carefully designed an LED array
that penetrates maternal tissue,
showing the fetus an image of a
drifting triangle made of three red
dots. When observed with a 4-D
ultrasound — in which a 3-D image
is in motion — not only were 39
fetuses able to see and track the
image, but they also preferred to
watch the triangle when it was top-
heavy, in the facelike orientation.
Researchers now aim to replicate
in fetuses newborn studies that have
had visual aspects. SYLVIA MORROW
- An illustration depicts lights outside
of the womb. 2. How those lights likely
appear to a third-trimester fetus.