Monkeys Who Meditate

What would the Buddha have said? Monkeys have been trained to put themselves into a Zen-like trance – but out of desire for marshmallows rather than enlightenment.

Neurofeedback involves teaching people to regulate their brainwaves and so control their state of mind by measuring the electrical activity of the brain and showing them that information. It is showing promise for reducing symptoms associated with epilepsy, ADHD and anxiety disorders, but it has been difficult to rule out the possibility that an enhanced awareness of the disease or a placebo effect is responsible, rather than the neurofeedback itself.

Mindful monkeys

To find out, Philippens and her colleague Raymond Vanwersch attached electrodes to the brains of marmoset monkeys to pick up electroencephalogram (EEG) signals from the brain. Rather than showing the monkeys the EEG signal, as might be done in humans, Philippens and Vanwersch simply gave them a marshmallow reward every time they tuned their brain activity to a certain frequency range – in this case, 12 to 16 hertz.

In humans, this frequency is associated with a relaxed but focused state of mind. "It's like meditation," says Philippens. "When you see the monkeys doing it, they look very restful but they have focus, like they are staring at something," she adds.

Two of the four monkeys tested learned to put themselves into this state within two training sessions; the others took four sessions to get the hang of it.

The monkeys may not realise that they are changing their brain activity, but it does show that they can consciously change their mood or state of mind, says Philippens. "This is an initial step for a much-needed scientific basis to neurofeedback."

Journal reference: NeuroReport, DOI: 10.1097/wnr.0b013e3283360ba8