In a lab at MIT, a rat enters a T-shaped maze, hears a tone, and runs down the left arm towards a piece of chocolate. It’s a habit. The rat has done the same thing over so many days that once it hears the tone, it’ll run in the same direction even if there’s no chocolate to be found. Humans are driven by similar habits. Every morning, I hear my alarm go off, put some clothes on, and shamble into the kitchen to brew some coffee.
Habits, by their very nature, seem permanent, stable, automatic. But they are not, and the MIT rat tells us why. Earlier, Kyle Smith had added a light-sensitive protein to one small part of its brain – the infralimbic cortex (ILC). This addition allows Smith to silence the neurons in this one area with a flash of yellow light, delivered to the rat’s brain via an optic fibre. The light flashes for just three seconds, and the habit disappears. The rat hears the tone, but no longer heads down the chocolate arm.
The experiment shows that even though habits seem automatic, they still depend on ongoing supervision from the ILC and possibly other parts of the brain. They’re ingrained and durable, but subject to second-by-second control. And they can be disrupted in surprisingly quick and simple ways.
“We were all stunned by how immediate and on-line these effects really are,” says Smith. “Changing the activity of this small cortex area could profoundly change how habitual behaviour was, in a matter of seconds.”
By cutting out bits of a rodent’s brain, or inactivating them with chemicals, other scientists had already identified parts of the brain, including the ILC, that are important for habits. But these are somewhat clumsy methods. Smith’s team wanted some more refined, something that could inactivate the ILC on demand for short bursts of time.
They turned to optogenetics. This revolutionary technique takes light-sensitive proteins from around the tree of life, and uses viruses to introduce them into an animal’s neurons. By choosing the right protein, and targeting the right part of the brain, scientists can now excite or silence a chosen group of neurons with astounding precision, using little more than flashes of coloured light.
Working with supervisor Ann Graybiel and optogenetics founder Karl Deisseroth, Smith filled his rats’ ILCs with halorhodopsin – a protein that comes from salt-loving microbes, and silences neurons when hit by yellow light.
Smith then trained rats to run down one arm of his T-shaped maze towards some chocolate, or down the other towards a sugary drink. One tone set them off, and a second one told them which arm to run down. After days of practice, the habits became ingrained. Even when Smith started “devaluing” one of the rewards by lacing it with a nauseating chemical, the rat would still run towards it the next time it was tested, even if it didn’t drink. That’s a habit – a behavioural reflex. The tone sets off a chain of actions, regardless of what the rat gets out of them.
Sweden may be at war "in a few years" - top brass in leaked document 2016-02-13 5:24
In a few years Sweden may be engaged in a war with a “qualified opponent” after two centuries of peace, a senior Swedish commander has told soldiers in an internal brochure.
The alarming message was reportedly sent by Major General Anders Brännström, the Army chief, in a brochure distributed among the participants of a major annual event that is to open ...
Danish imam urges govt to accept child marriages among refugees 2016-02-13 4:57
A high-profile imam has urged the Danish government to accept child brides, as the practice is part of the culture of many refugees arriving in the country. It follows an announcement by Denmark that such couples will be separated under Danish law.
Imam Oussama El-Saadi, of the Aarhus mosque in Denmark, said that child brides should be looked at from a ...
White Parents in Virginia Shutdown White Guilt Video! 2016-02-13 4:56
You see folks? This is what happens when you stop blaming the Joo, and you get the fuck off your favorite bitch corner and start taking action! This is what happens when parents start parenting again! What? You’re gonna brainwash our kids with your filth and lies? We don’t think so. How would you like an empty school with no ...
Hungarian Top Economist: Civil War is Coming to Europe 2016-02-13 2:36 Zsolt Bayer, Hungarian journalist, publicist, and co-founder of Hungary's currently ruling political party, and Dr. László Bogár, former politician and leading economist, discuss the Cologne sexual assualts committed by migrants on New Year's Eve, 2016.
This short part of the 60-minute long television program that aired on Echo TV on January 8, 2016, is of a rant by Mr. Bogár warning ...
British scientists granted permission to genetically modify human embryos 2016-02-12 23:48 The Francis Crick institute will genetically edit the leftover embryos from from IVF clinics
British scientists have been granted permission to genetically modify human embryos by the fertility regulator.
The scientists want to deactivate genes in leftover embryos from IVF clinics to see if it hinders development.
It will only be the second time in the world that such a procedure has ...