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A small amount of electricity delivered at a specific frequency to a particular point in the brain will snap a monkey out of even deep anesthesia, pointing to a circuit of brain activity key to consciousness and suggesting potential treatments for debilitating brain disorders.

Macaques put under with general anesthetic drugs commonly administered to human surgical patients, propofol and isoflurane, could be revived and alert within two or three seconds of applying low current, according to a study published today in the journal Neuron by a team led by University of Wisconsin–Madison brain researchers.

“For as long as you’re stimulating their brain, their behavior — full eye opening, reaching for objects in their vicinity, vital sign changes, bodily movements and facial movements — and their brain activity is that of a waking state,” says Yuri Saalmann, UW–Madison psychology and neuroscience professor. “Then, within a few seconds of switching off the stimulation, their eyes closed again. The animal is right back into an unconscious state.”

A key exception: The brains of people who exhibited anti-social behavior as teenagers but not as adults showed no such abnormalities. That’s good news for reformed bullies, but bad news for the lifers.

“Most people who exhibit antisocial behaviour primarily do so only in adolescence, likely as a result of navigating socially difficult years, and these individuals do not display structural brain differences,” Carlisi said. “It is also these individuals who are generally capable of reform and go on to become valuable members of society.”

What remains hazy is the question of causation — are the brains of bullies small because they’re bullies, or do they become bullies because of their small brains?

An auditory illusion thought to synchronize brain waves and alter mood is no more effective than other sounds, according to research in adults recently published in eNeuro. The effect reported in other studies might be a placebo but could still have helpful effects for some people.

Binaural beats are an auditory illusion caused by listening to two tones of slightly different frequency, one in each ear. The difference in frequencies creates the illusion of a third sound — a rhythmic beat. Neurons throughout the brain begin to send electrical messages at the same rate as the imaginary beat. Many unsupported claims surround binaural beats, including that listening to them decreases anxiety, increases focus, and improves mood.

Orozco Perez et al. played binaural and monoaural beats to healthy adults and measured their brain activity with electroencephalography. Monoaural beats don’t rely on the illusion to create the beats because they consist of edited audio tracks of the two different tones together. Both ears hear all three sounds. Brain activity synchronized with both types of beats, but the effect was stronger with monoaural beats. Neither type of beat affected mood. When the binaural beat played, far apart brain areas synchronized with each other at a different frequency than the beat. This may be how binaural beats improve memory and focus.