Phase precession

This amazing video has something to do with phase precession in magnetic resonance imaging (MRI). Discuss...

Are chimps closer to humans or gorillas?

This question occurred to me recently. Which species do chimps share a more recent ancestor, humans or gorillas? So I looked it up. According to the paper

Rannala, B. and Yang, Z, "Probability distribution of molecular evolutionary trees: A new method of phylogenetic inference", Journal of Molecular Evolution, 43(3): 304-311, 1996.

the most likely phylogenetic tree (based on genetic nucleotide sequencing data) looks like this,

Hominidae is the family of great apes, containing us (genus Homo), chimpanzees (Pan), gorillas (Gorilla), and orangutans (Pongo). As you can see, the chimps share a more recent ancestor with us than with the gorillas. In other words, chimpanzees are more closely related to humans than they are to gorillas.

Neural Adaptation

This is a demonstration of neural adaptation. When a neuron is continuously excited by a stimulus, its firing rate decreases after a while; this is called adaptation. But when you remove the stimulus, the neural adaptation affects your perception.  Here are two demonstrations of the effect.

Colour Adaptation
Stare at the red nose on the left for about 30 seconds. Then shift your gaze to the white panel. What do you see?

Motion Adaptation
Click on the image below and follow the instructions.

Nerd jokes

A Mathematician, a Biologist and a Physicist are sitting in a street cafe watching people going in and coming out of the house on the other side of the street. First they see two people going into the house. Time passes. After a while they notice three people coming out of the house.
The Physicist says, "The measurement wasn't accurate".
The Biologists says "They have reproduced".
The Mathematician says, "If a person enters the house, then it'll be empty again."

Three statisticians went duck hunting and they saw a duck flying.
The first statistician fired his gun, but the shot went a metre too high.
The second fired his gun but the shot went a metre too low.
The third statistician cried, "Bullseye!"

Timecube

If you think the brain is infalible, check out the Time Cube web page. Dr. Gene Ray, the author, is the self-proclaimed "greatest philosopher" and "greatest mathematician", and I think even his title of "doctor" is self-assigned. Enjoy.