by Grania Spingies
We are such stuff
As dreams are made on, and our little life
Is rounded with a sleep.
The Tempest (4.1.168-170)
I should preface this with my regular caveat: I-am-not-a-scientist, nor do I play one on TV. My level expertise only allows me to say the rough equivalent of “Oh hey, this looks interesting.”
As a child I often used to watch my dogs dreaming. Clearly they were running, sometimes barking and huffing, sometimes panting. It used to fascinate me, and I wondered where in their heads they were running. Was it a field they knew? Were they alone or with companions? Were they chasing prey? Running for the fun of it? What does prey even look like to Canis lupus familiaris who may never met anything particularly prey-like in their modern suburban existence?
Once one of them barked so loud in her dream that she startled herself and woke up with a jump. I’d never seen a Labrador look more sheep-like when her eyes met mine. Unfortunately there was no way to ask her what she had been seeing in her dreams.
But it seems that remarkably a team of scientists has had a glimpse at what rats dream about.
Kiona Smith-Strickland over at Discover Magazine writes about a new study where a team looked at rats and determined remarkably that they dreamed about going places they were aware of but had not yet explored. She explains the process:
First, researchers let rats explore a T-shaped track. The rats could run along the center of the T, but the arms were blocked by clear barriers. While the rats watched, researchers put food at the end of one arm. The rats could see the food and the route to it, but they couldn’t get there.
Then, when the rats were curled up in their cages afterwards, scientists measured their neuron firing. Their brain activity seemed to show them imagining a route through a place they hadn’t explored before. To confirm this, researchers then put the rats back into the maze, but this time without the barriers. As they explored the arm where they had previously seen the food, the rats’ place cells fired in the same pattern as they had during sleep.
Neuroscientist Hugo Spiers, who co-authored the study, notes:
People have talked in the past about these kind of replay and pre-play events as possibly being the substrates of dreams, but you can’t ask rats what they’re thinking or dreaming. There is that really interesting sense that we’re getting at the stuff of dreams, the stuff that goes on when you’re sleeping.
You can read the paper here:
Hippocampal place cells construct reward related sequences through unexplored space by H Freyja Ólafsdóttir, Caswell Barry, Aman B Saleem, Demis Hassabis, Hugo J Spiers