Scans of sleeping brains reveal what we dream about
Using a combination of neuroimaging and EEGs, scientists have decoded the visual content of our dreams. Nature News reports.
“Knowing more about the content of dreams and how it relates to brain activity may help us to understand the function of dreaming,” says study author Yukiyasu Kamitani of the ATR Computational Neuroscience Laboratories in Kyoto.
- They scanned the brains of three people as they slept using functional neuroimaging, and brain waves were recorded using electroencephalography (EEG).
- They woke the participants up whenever patterns of brain waves associated with sleep onset were detected.
- Then they asked them what they just dreamed about, and let them go back to sleep.
- From about 200 dream reports, the researchers extracted key words and picked 20 categories -- car, male, female, computer -- that appeared most frequently in the reports.
- They selected photos for each category, and scanned the participants’ brains again while they viewed those.
- They compared brain activity patterns with those recorded just before the participants were woken up.
- Finally, they analyzed activity in brain areas involved in the earliest stages of visual processing, along with regions involved in higher order visual functions, such as object recognition.
From this, they built a model to predict whether each category of content was present in the dreams. And they found that activity in the higher order brain regions could accurately predict the content of the participants’ dreams.
The findings were presented at the Society for Neuroscience meeting in New Orleans last week.
[Via Nature News]
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