How to Insert a Memory Into the Brain of a Sleeping Mouse

Researchers create synthetic memories through brain stimulation

2 min read
How to Insert a Memory Into the Brain of a Sleeping Mouse
Photo: Oktay Ortakcioglu/Getty Images

The lab mice awoke with happy memories… that researchers had inserted into their brains while they slept. New research in Nature Neurscience is the latest proof that we may soon live in a Philip K. Dick short story, where synthetic memories can be created via neural stimulation. 

Hyperbole aside, here’s how they did it. The researchers set out to test the following hypothesis: Animals consolidate memories while sleeping by reactivating neurons associated with the remembered experience. In five mice, the researchers used a clearly defined spatial memory. Each mouse had electrodes implanted in its hippocampus, the structure associated with memory. The electrodes recorded neural activity while the mouse explored a new environment. By monitoring the recorded signals, the researchers could identify spikes of electrical activity in certain neurons that were associated with a certain place in the chamber.


Then each mouse took a one-hour nap. During that snooze the researchers continued to watched the signals from the hippocampus. They waited for moments when those place-associated neurons lit up with activity, suggesting that the mouse was recalling its experience. (Interestingly, this didn’t occur often during the REM sleep in which we dream.) On that activity cue, the researchers used a second set of electrodes to stimulate the brain’s medial forebrain bundle, a structure associated with the sensation of pleasure. Essentially, the scientists were teaching the mouse to associate that certain location with a reward. 

When each mouse awoke, it was sent back into the chamber, while the researchers watched to see where it would hang out. These five mice did not wander at random, but instead showed a clear preference for the place now associated with good feelings. 

It’s a small study, but a fascinating contribution to the new field of memory hacking. Another recent experiment showed a way of turning bad memories into good ones in mice, and DARPA is funding research on memory prosthetics for humans. One day we may look back on these early experiments, and remember them fondly—thanks to the electrodes implanted in our brains. 

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Are You Ready for Workplace Brain Scanning?

Extracting and using brain data will make workers happier and more productive, backers say

11 min read
A photo collage showing a man wearing a eeg headset while looking at a computer screen.
Nadia Radic

Get ready: Neurotechnology is coming to the workplace. Neural sensors are now reliable and affordable enough to support commercial pilot projects that extract productivity-enhancing data from workers’ brains. These projects aren’t confined to specialized workplaces; they’re also happening in offices, factories, farms, and airports. The companies and people behind these neurotech devices are certain that they will improve our lives. But there are serious questions about whether work should be organized around certain functions of the brain, rather than the person as a whole.

To be clear, the kind of neurotech that’s currently available is nowhere close to reading minds. Sensors detect electrical activity across different areas of the brain, and the patterns in that activity can be broadly correlated with different feelings or physiological responses, such as stress, focus, or a reaction to external stimuli. These data can be exploited to make workers more efficient—and, proponents of the technology say, to make them happier. Two of the most interesting innovators in this field are the Israel-based startup InnerEye, which aims to give workers superhuman abilities, and Emotiv, a Silicon Valley neurotech company that’s bringing a brain-tracking wearable to office workers, including those working remotely.

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