free will experiments

Champions of free will, take heart. A landmark 1980s experiment that purported to show free will doesn't exist is being challenged.

In 1983, neuroscientist Benjamin Libet asked volunteers wearing scalp electrodes to flex a finger or wrist. When they did, the movements were preceded by a dip in the signals being recorded, called the "readiness potential". Libet interpreted this RP as the brain preparing for movement.

Crucially, the RP came a few tenths of a second before the volunteers said they had decided to move. Libet concluded that unconscious neural processes determine our actions before we are ever aware of making a decision.

Since then, others have quoted the experiment as evidence that free will is an illusion – a conclusion that was always controversial, particularly as there is no proof the RP represents a decision to move.

Sound decisions

Long sceptical of Libet's interpretation, Jeff Miller and Judy Trevena of the University of Otago in Dunedin, New Zealand, attempted to tease apart what prompts the RP using a similar experiment, with a key twist.

They also used scalp electrodes, but instead of letting their volunteers decide when to move, Miller and Trevena asked them to wait for an audio tone before deciding whether to tap a key. If Libet's interpretation were correct, Miller reasoned, the RP should be greater after the tone when a person chose to tap the key.

While there was an RP before volunteers made their decision to move, the signal was the same whether or not they elected to tap. Miller concludes that the RP may merely be a sign that the brain is paying attention and does not indicate that a decision has been made.

Miller and Trevena also failed to find evidence of subconscious decision-making in a second experiment. This time they asked volunteers to press a key after the tone, but to decide on the spot whether to use their left or right hand. As movement in the right limbs is related to the brain signals in the left hemisphere and vice versa, they reasoned that if an unconscious process is driving this decision, where it occurs in the brain should depend on which hand is chosen. But they found no such correlation.

[the rest of this interesting piece, on the NewScientist.com]

charity: water & schools

School is officially back in full swing. At least it is for our kids.

But at half of all schools around the world, students are going to class without access to clean water.

No cold drinks at the water fountain.
No bathrooms.
No place to wash hands.

Millions of children with untold potential spend their mornings walking up to four hours to fetch water before school, then arrive to class late and exhausted. The water they find often makes them sick, causing them to miss even more valuable classroom time. Over the next few months, many students will fall too far behind in their studies to continue attending class.

We think that's a terrible cycle. A cycle that we're determined to break.

That's why this fall, we're launching Water for Schools, a student-led campaign to raise awareness and funds for water projects at schools in developing nations.

Last year, students from elementary schools and universities, swim teams and church groups raised over $160,000 to give water to schools in developing nations. This year as we launch the Water for Schools campaign, we're aiming to bring clean, safe drinking water, private latrines and hand-washing stations to at least 100 schools in developing nations in the first year.

It'll take $2 million to get there and we're going to need everyone's help to do it. In fact, you don't have to be a student to fundraise for clean water in schools. We've created a fundraising kit for all ages and it has everything you need to get started.

Clean water gives kids the opportunity to attend school and get an education. With education comes more opportunity and a chance for future generations to escape poverty. Clean water offers kids improved health, a better quality of life and hope for a brighter future.

Here's how you can help.

Students: start a campaign >
Parents: Ask your kids to sign up >
Teachers and school leaders: Sign up your school, group or team > or
write us here if you'd like to help us develop curriculum.

- the charity: water team