25% of the people have a 4th cone and see colors as they are

Given the sudden interest for the color of dresses and vision, here some of the fascinating findings we did recently.

The color nuances we see depend on the number and distribution of
cones (=color receptors) in our eye. You can check this rainbow: how
many color nuances do you count?

You see less than 20 color nuances: you are a dichromats, like dogs,
which means you have 2 types of cones only. You are likely to wear
black, beige, and blue. 25% of the population is dichromat.

You see between 20 and 32 color nuances: you are a trichromat, you
have 3 types of cones (in the purple/blue, green and red area). You
enjoy
different colors as you can appreciate them. 50% of the population is
trichromat.

You see between 33 and 39 colors: you are a
tetrachromat, like bees, and have 4 types of cones (in the purple/blue,
green, red plus yellow area). You are irritated by yellow, so this color
will be nowhere to be found in your wardrobe. 25% of the population is
tetrachromat.

You see more than 39 color nuances: come on, you are
making up things! there are only 39 different colors in the test and
probably only 35 are properly translated by your computer screen anyway
🙂

It is highly probable that people who have an additional 4th
cone do not get tricked by blue/black or white/gold dresses, no matter
the background light 😉 (x)

Gorillas make up ‘little food songs’ while they eat: Listen to them here

And it’s not like they “sing the same song over and over,”
commented Luef. “It seems like they are composing their little food
songs.”

According to Ali Vella-Irving of the Toronto Zoo, “Each gorilla
has its own voice: you can really tell who’s singing. And if it’s their
favorite food, they sing louder.”

Gorillas make up ‘little food songs’ while they eat: Listen to them here


Hubert Airy’s drawing illustrates how his
migraine aura grew


There’s still much we don’t know about migraines and migraine auras. One
hypothesis is that a sort of electrical wave sweeps across the visual
cortex, causing hallucinations that spread across the corresponding
parts of the visual field. In a loosely descriptive way, Airy’s time
series drawings—showing an ever expanding shape—jibe with this too.


This detail from Joseph Babinksi’s 1890 drawing of his migraine aura shows a zigzag pattern not unlike the one Hubert Airy saw.