Study shows differences in brain waves between people who recall dreams and those who don't

August 15, 2013 by Bob Yirka report
Credit: Maurajbo/Wikipedia.

(Medical Xpress)—Researchers at Lyon Neuroscience Research Center and University Lyon in France, have found that people who regularly recall their dreams have different alpha brain wave patterns than do people who rarely recall their dreams. They have published a paper describing their research in Frontiers in Consciousness Research.

Despite hundreds of years of study, scientists still know very little about why people , how it comes about or why some recall their dreams quite vividly while others rarely remember them at all. To find out if there are any measurable differences between groups of people who recall their dreams and those that don't, the researchers in this latest effort enlisted the assistance of 36 young volunteers—half of whom were described as high recallers (those that remember their dreams almost every night) and half whom were described as low recallers (those that remember their dreams just once or twice a month). Each was connected to an EEG machine and given headphones to wear while they slept. As they did so, the researchers monitored their , but added a as well. Each of the volunteers had their first name spoken to them while they were sleeping to see how their brains reacted. To provide an example to compare against, each was also monitored while hearing their name spoken to them while wide awake.

In studying the data, the researchers found that both groups responded when their names were called when they were sleeping, but the high recallers responded more. Quite unexpectedly, the same group also showed wave spikes when hearing their name spoken when wide awake. The team also found that the high recallers spent more time awake on average during their sleep cycle than did low recallers (30 minutes compared to 15).

The researchers speculate that high recallers are more reactive to in general, which explains why their brains would respond more in response to hearing their name called when awake. Why they respond more when sleeping, they add, likely means they are more responsive when dreaming as well, which may or may not be connected to why the same group spends more time awake at night.

Explore further: Researchers devise a way to manipulate a rat's dreams

More information: Alpha reactivity to first names differs in subjects with high and low dream recall frequency, Front. Psychol., 13 August 2013 DOI: 10.3389/fpsyg.2013.00419

Abstract
Studies in cognitive psychology showed that personality (openness to experience, thin boundaries, absorption), creativity, nocturnal awakenings, and attitude toward dreams are significantly related to dream recall frequency (DRF). These results suggest the possibility of neurophysiological trait differences between subjects with high and low DRF. To test this hypothesis we compared sleep characteristics and alpha reactivity to sounds in subjects with high and low DRF using polysomnographic recordings and electroencephalography (EEG). We acquired EEG from 21 channels in 36 healthy subjects while they were presented with a passive auditory oddball paradigm (frequent standard tones, rare deviant tones and very rare first names) during wakefulness and sleep (intensity, 50 dB above the subject's hearing level). Subjects were selected as High-recallers (HR, DRF = 4.42 ± 0.25 SEM, dream recalls per week) and Low-recallers (LR, DRF = 0.25 ± 0.02) using a questionnaire and an interview on sleep and dream habits. Despite the disturbing setup, the subjects' quality of sleep was generally preserved. First names induced a more sustained decrease in alpha activity in HR than in LR at Pz (1000–1200 ms) during wakefulness, but no group difference was found in REM sleep. The current dominant hypothesis proposes that alpha rhythms would be involved in the active inhibition of the brain regions not involved in the ongoing brain operation. According to this hypothesis, a more sustained alpha decrease in HR would reflect a longer release of inhibition, suggesting a deeper processing of complex sounds than in LR during wakefulness. A possibility to explain the absence of group difference during sleep is that increase in alpha power in HR may have resulted in awakenings. Our results support this hypothesis since HR experienced more intra sleep wakefulness than LR (30 ± 4 vs. 14 ± 4 min). As a whole our results support the hypothesis of neurophysiological trait differences in high and low-recallers.

Related Stories

Researchers devise a way to manipulate a rat's dreams

September 6, 2012
(Medical Xpress)—Cognitive scientists working at MIT have devised a means for not only altering the dreams of rats, but of demonstrating a way of testing what they've achieved, offering evidence that it can be done, and ...

Scientists in sleep-wake tests decode dreams

October 29, 2012
What's in a dream? For Yukiyasu Kamitani, the question is important. He has been testing how dreams relate to brain activity and what really is the function of dreaming, He leads a team of researchers at the ATR Computational ...

New study shows how seals sleep with only half their brain at a time

February 19, 2013
(Medical Xpress)—A new study led by an international team of biologists has identified some of the brain chemicals that allow seals to sleep with half of their brain at a time.

Lesson in sleep learning: Associations formed in brains of sleeping volunteers remained intact when subjects were awake

August 26, 2012
Is sleep learning possible? A new Weizmann Institute study appearing today in Nature Neuroscience has found that if certain odors are presented after tones during sleep, people will start sniffing when they hear the tones ...

Could scientists peek into your dreams? (w/ video)

April 4, 2013
(HealthDay)—Talk about mind reading. Researchers have discovered a potential way to decode your dreams, predicting the content of the visual imagery you've experienced on the basis of neural activity recorded during sleep.

Recommended for you

'Residual echo' of ancient humans in scans may hold clues to mental disorders

July 26, 2017
Researchers at the National Institute of Mental Health (NIMH) have produced the first direct evidence that parts of our brains implicated in mental disorders may be shaped by a "residual echo" from our ancient past. The more ...

Laser used to reawaken lost memories in mice with Alzheimer's disease

July 26, 2017
(Medical Xpress)—A team of researchers at Columbia University has found that applying a laser to the part of a mouse brain used for memory storage caused the mice to recall memories lost due to a mouse version of Alzheimer's ...

Cognitive cross-training enhances learning, study finds

July 25, 2017
Just as athletes cross-train to improve physical skills, those wanting to enhance cognitive skills can benefit from multiple ways of exercising the brain, according to a comprehensive new study from University of Illinois ...

Brain disease seen in most football players in large report

July 25, 2017
Research on 202 former football players found evidence of a brain disease linked to repeated head blows in nearly all of them, from athletes in the National Football League, college and even high school.

Zebrafish study reveals clues to healing spinal cord injuries

July 25, 2017
Fresh insights into how zebrafish repair their nerve connections could hold clues to new therapies for people with spinal cord injuries.

Lutein may counter cognitive aging, study finds

July 25, 2017
Spinach and kale are favorites of those looking to stay physically fit, but they also could keep consumers cognitively fit, according to a new study from University of Illinois researchers.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.