Rats may have imaginations
Click on images to enlarge
It's bad enough that rats have such a negative image, from spreading diseases to deserting a sinking ship. They are a commonly used laboratory test animal, though. That's largely because their physiology and genetics are similar to that of humans. They've been used in drug testing, disease modeling, psychological studies, environmental chemical exposure testing, neuroscience research, surgery studies, and more. But recent research is showing some signs that rats may not be the docile creatures we picture them in a lab. They may actually have imaginations similar to humans. What this means is that they might be able to think about objects and places that are not directly in front of them.
From Popular Science article
Two movies from the early 1970s, Willard and Ben, were about an army of rats bonding with a young man for insidious purposes. The highly intelligent rat leader Ben was written with a supernatural element to support his ability to lead.
Once we get to a certain age, humans can envision objects that aren't in front of us; we can create an image of them in our minds. The same goes for places and how to get to them. As for locations, this ability to set them in our minds is part of raw memory coupled to being able to see into a future event (how to go to a place).
The part of our brain that holds this spatial recognition (recognizing space) is called the hippocampus. It is made of 2 curved bodies that look like a seahorse, fatter on one end. They are connected to each other, but it is believed that the right hippocampus deals more with spatial memory and navigation, while the left one is involved more with verbal or language-related memory.
Location of left and right hippocampus (red) in humans (Wikipedia)
The cross-section diagram below shows the location and size of one hippocampus (Hi) in a mouse. Next to it is a dark blue area that feeds it additional information about recognizing what objects are.
Outline of mouse head with light blue brain and hippocampus in center (Boaz Barak)
A team of researchers at the Howard Hughes Medical Institute in Maryland recently set up a series of experiments to test whether rats can use their thoughts to imagine going towards a specific place or to imagine moving an object.
In phase one of the research, they attached electrodes to a rat's hippocampus through a BMI (brain-machine interface). The rat was placed on the top of a blank sphere, but a projector showed images of geometric shapes on a screen around it to give the rat the impression that it was navigating a 1 meter x 1 meter flat field with those shapes on it. There is a water dropper near its mouth, and the rat is rewarded as it moves in the right direction. The BMI records the activity in the rat’s hippocampus, and the researchers can then map it out to see which neurons are activated as the rat moves about.
3D treadmill with projector at the top displaying images on the screen (Howard Hughes Medical Institute)
Samples of what the rat sees (Howard Hughes Medical Institute)
Then, the treadmill is disconnected but the rat is allowed to see the screen image, and the rat must remember and mentally duplicate the recorded images stored in the BMI --- basically, it remembers the pattern of navigation it used to get to the goal the first time. If it's successful, it gets water again. The researchers described the brain signals from the rat brains as a “thought dictionary”.
Phase two of the research is called the "Jedi task". In Star Wars movies, Jedi masters can move objects with their minds. The rat is shown an object on the screen, and through trial and error it learns to imagine directing it to a goal, simulating telekinesis on the screen. The researchers compare this to what we do when we imagine taking a cup next to a coffee machine and filling it. The object is moved, and the rat repeats the digital moving. You can see this from a bird's-eye view of the screen in the video below.
A rat performing a "Jedi mind trick" (Howard Hughes Medical Institute)
As you watch the video, notice how the orange dot represents where the rat imagines the square object should go. It repeatedly puts it there and can hold its thoughts on a given location for many seconds, remarkable considering there is no actual object or physical target location! So much for the short attention span that we think rats have.
Aside from the novelty of this research, it has added information about the hippocampus activity to science. Moreover, the BMI has been used in earlier research on humans and might be improved with this rat data. People may suffer what is called complete locked-in syndrome and be paralyzed suddenly after a stroke or brainstem injury, or slowly as in amyotrophic lateral sclerosis (ALS). They are conscious but unable to move any muscle. Neuroscientist Niels Birbaumer at the Wyss Center for Bio and Neuroengineering in Geneva, Switzerland was able to get such patients to answer yes/no questions in 2017 with a BMI similar to the rat research. Who knows what lies ahead?
Testing the BMI from the Wyss Center (Popular Science)
Similar technology is used to direct the movement of artificial limbs like the Proprio Foot made in Iceland. Most brain-controlled bionic limbs are still only in the lab stage of development right now.
Proprio Foot (Popular Science, 2015)
