Verfasst von: Dr. Who | 12.5.14

882 | Lucid dreams through brain stimulation can alter way of sleeping

by Olga Yazhgunovich

Controlling your dreams – this may come true, as scientists on Sunday said they have found the way to modify sleep so that an individual has „lucid dreams,“ a particularly powerful form of dreaming considered by many psychologists to be an intermediate stage between two forms of consciousness. According to a study it can be done by applying mild electrical currents to the scalps.Lucid dreaming is the process in which a sleeper recognizes they are dreaming i.e. they may even be able to control their dream’s plot and manipulate their behavior.

The discovery provides insights into the mechanism of dreaming – an area that has fascinated thinkers for millennia, The Voice of America reports.

Lucid dreams lie between so-called rapid eye movement (REM) dreams – which are concerned with the immediate present and have no access to past memories or anticipated events in the future – and being awake, which brings into play abstract thought and other cognitive functions.

In lucid dreaming, a state believed to be unique to humans, elements of secondary consciousness combine with REM dreams.

Researchers led by Ursula Voss at the J.W. Goethe University Frankfurt, used a technique called transcranial alternating current stimulation (tACS) to explore the causes of lucid dreaming.

The gadget comprises two small boxes with electrodes that are placed next to the skull and send a very weak, low-frequency electrical signal across the brain.

The team recruited 15 women and 12 men aged 18 to 26, who spent up to four nights in a sleep laboratory.

After the volunteers had experienced between two and three minutes of REM sleep, the scientists applied tACS for around 30 seconds. The current was below the sensory threshold, so that the subjects did not wake up.

They then woke up the volunteers and asked them what they had been dreaming.

„The dream reports were similar, in that most subjects reported to ’see myself from the outside‘ and the dream was watched from the outside, as if it was displayed on a screen,“ Voss told AFP.

„Also, they often reported to know that they were dreaming.“

The volunteers were tested at frequencies of two herz (Hz), six Hz, 12 Hz, 25 Hz, 60 Hz and 100 Hz.

„The effect… was only observed for 25 and 40 Hz, both frequencies in the lower gamma frequency band,“ Voss said.

It induced further gamma frequency activity in the frontal and temporal lobes. These types of brain waves have only been known to occur when a person is experiencing a higher level of thinking.

„I did not have much hope that this experiment would actually work,“ said Voss. „For us, it was surprising that you can actually force the brain to take on a new brain rhythm – that the brain really adapts and the neurons begin to fire at the new frequency with just this mild stimulation.“

„This band has linked with conscious awareness, but a causal relationship had so far not been established. Now it is,“ she added.

When the volunteers were stimulated with 25 HZ, „we had increased ratings for control of the dream plot, meaning they were able to change the action at will,“ Voss said.

The study, reported in the journal Nature Neuroscience, gave several anecdotes from the recruits about what they had dreamt. An example described in the article suggested they could choose their outfit before leaving the house, Reuters reported. The volunteers also often reported feeling like they were watching themselves instead of being in the first person.

„I am driving in my car, for a long time,“ said one. „Then I arrive at this place where I haven’t been before. And there are a lot of people there. I think maybe I know some of them but they are all in a bad mood, so I go to a separate room, all by myself.“

The study suggests that frontotemporal tACS might help to restore dysfunctional brain networks which are fingered in schizophrenia and obsessive-compulsive disorder.

Applied during REM sleep, it could also one day help victims of post-traumatic stress disorder to overcome recurrent nightmares by placing them in charge of the dream plot, the paper theorises.

The tACS gadget itself is a recognised medical invention designed to be used only for research purposes.

Voss said, though, that it seemed inevitable that a similar device would one day be invented for consumers, enabling sleepers to latch onto lucid dreaming, for better or worse.

„Although this is not something I am personally interested in, I am certain that it won’t take long until such devices come out. However, brain stimulation should always be carefully monitored by a physician,“ she cautioned.

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