In a nutshell: Conducting the Dream Catcher test for the first time suggests that we don’t understand electroencephalography (EEG) data enough to explain how our minds work.

View Paper Abstract

One of the biggest challenges in neuroscience is understanding human consciousness. How can we use what we know about the workings of the brain to explain our subjective experiences – awareness, perception, thoughts and feelings?

The Dream Catcher test was designed to link patterns of brain activity directly to specific features of consciousness. The test, which was originally developed as a thought experiment, requires researchers to ‘read’ a person’s dreams based purely on observations of their brain activity. The test focuses on dreams because they are created entirely by the brain with minimal influence from any external stimuli.

An international group of researchers, led by William Wong from Brain Function CoE investigator Naotsugu Tsuchiya’s laboratory at Monash University, have attempted the Dream Catcher test for the first time. The group split into two teams: a data team at the University of Turku in Finland, and an analysis team at Monash University.

The data team used electroencephalography (EEG) to record the brain activity of nine people who slept in the laboratory over five nights. Whenever the EEG data showed that the participants had entered non-REM sleep, they were woken up and asked detailed questions about their dreams. People dream about half of the time during non-REM sleep, so this sleep stage is useful for differentiating between dreamful and dreamless sleep. Once the participants had answered the questions, they could fall back asleep.

At the end of this experiment, the data team prepared 54 short EEG recordings – half of which were from dreamful sleep and half from dreamless sleep – for the analysis team. Using unsupervised machine-learning algorithms, the analysis team tried to classify the EEG recordings as either dreamful or dreamless.

Apart from the EEG recordings, the analysis team did not receive any other information from the data team about the participants or their dreams. Unfortunately, their predictions were no better than chance – they could find no clear association between brain activity and dreams.

The data team then gradually revealed more information about the EEG recordings, such as which participant they came from. Even with these clues, the analysis team still couldn’t reliably distinguish dreamful sleep from dreamless sleep.

This suggests that we still don’t understand enough about the brain and EEG recordings to explain what goes on in our minds during sleep.

Next steps:
The researchers plan to assemble an international, open-science consortium to obtain much more data for further analysis.

Wong, W., Noreika, V., Móró, L., Revonsuo, A., Windt, J., Valli, K., & Tsuchiya, N. (2020). The Dream Catcher experiment: Blinded analyses failed to detect markers of dreaming consciousness in EEG spectral power. Neuroscience of Consciousness, 1, niaa006. doi: 10.1093/nc/niaa006

Republish this article:

We believe in sharing knowledge. We use a Creative Commons Attribution 4.0 International License, which allows unrestricted use of this content, subject only to appropriate attribution. So please use this article as is, or edit it to fit your purposes. Referrals, mentions and links are appreciated.