Can You Experience Déja Vu of a Place or Situation You’ve Never Encountered?

Can You Experience Déja Vu of a Place
or Situation You’ve Never Encountered?

by Ellen Smucker-Green

Alan Brown, professor in the department of psychology at Southern Methodist University, Dallas, responds:

Déjà vu is a startling mental event. The phenomenon involves a strong feeling that an experience is familiar, despite sensing or knowing that it never happened before. Most people have experienced déjà vu at some point in their life, but it occurs infrequently, perhaps once or twice a year at most.

Although déjà vu often feels supernatural or paranormal, glitches in the brain might be to blame. One possibility is that a small seizure occurs in brain regions essential for memory formation and retrieval—the hippocampus and parahippocampal gyrus, areas deep in the middle of the brain. When you see your grandmother, for example, spontaneous activity in these regions creates an instant feeling of familiarity. With déjà vu, a brief synaptic misfiring might occur in these areas, creating the illusion that the event has occurred before. In support of this idea, studies show that some individuals with epilepsy have a brief déjà vu episode prior to a seizure, with the focal area of the seizure often falling in the hippocampus and parahippocampal gyrus.

Other phenomena might also help explain déjà vu, such as inattentiveness. Because we often navigate the world on autopilot, we take in much of our surroundings on an unconscious level. People who text on their cell phones while walking are only superficially aware of the shops and pedestrians they are passing. Perhaps an episode of déjà vu begins during such a moment. When we emerge into full awareness, we might do a perceptual double take. We are struck by a strange sense of familiarity because we saw the scene just moments before, unconsciously.

In a recent study, Elizabeth Marsh of Duke University and I investigated this idea. We showed participants dozens of unique symbols. Some of them were flashed too quickly for participants to consciously detect before they were revealed for longer viewing. Our participants were significantly more likely to identify a novel symbol as familiar if they had subconsciously glimpsed the image before.

A third possibility is that we have forgotten the prior experience. The psychology literature is replete with stories of adults visiting a notable place, such as a castle, and becoming overwhelmed by an uncanny sense of having been there before. Their parents, however, clued them in: they had been to the castle as a very young child. Similarly, television and photographs can breed a false sense of familiarity later on. For example, having watched a documentary on a castle a decade ago might lead to a sense of déjà vu when you visit it.

So, yes, it is possible to experience déjà vu related to a completely new place. Our brain is always searching for connections. As a result, we can sometimes make links that simply aren’t there.

The internet of you: How wireless medical implants will change medicine

The internet of you: How wireless
medical implants will change medicine

By Signe Brewster

Summary:In the future, patients and doctors will monitor health with data collected
constantly inside the body and beamed directly to their mobile device or computer.Strap on a Fitbit (see disclosure) and you can track your physical activity and sleep patterns over weeks, months and years, generating long-term personal data and potential health insights that otherwise might have been missed. But what if there was a personal health tracker that could go deeper?

That’s the promise of future medical implants that will continuously collect data and transfer it wirelessly. From the bloodstream, stomach and deep inside the brain, they could someday warn of heart attacks before they happen and administer just the right doses of medicine. They’ll also communicate among themselves, creating an internet of you.

“Pacemakers for a long time have had the ability to download data through fairly primitive methods, such as a phone modem. I’m sure that will get more and more continuous, so instead of downloading the data once a week it will be more of a continuous link,” said Joshua Smith, an associate professor of computer science and engineering at the University of Washington. “There are going to be more and more devices implanted and this will become more and more common.”

People might at first feel squeamish about letting a device live inside them and wirelessly transmit large amounts of personal data, but implants open up treatment resources that quickly outweigh any risks and drawbacks. And researchers are spending lots of time trying to make implants impervious to hacking. Giovanni de Micheli, director of the Institute of Electrical Engineering at the Ecole Polytechnique Federale in Lausanne, Switzerland, said safety concerns are already being addressed in current technology like pacemakers. As a result, measures will be in place by the time the next generation of implants hits the market.

Current applications

Wirelessly communicating medical implants are already common, particularly for short-term use. If someone has an epileptic seizure, they can have electrodes placed on the surface of their brain to spot the origin of the seizure, Smith said. The system is currently only used for a week or two, but Smith foresees monitoring people for longer in the future.

“In general, you’ll see more data that’s collected continuously that’s used more for wellness than just for acute interventions with problems,” Smith said.

Communicating through implants is especially powerful for patients who need continuous control to treat a disorder. Smith, who is a principal investigator at the university’s Sensor Systems Laboratory, works with deep brain stimulation systems, which can be used for diseases like Parkinson’s.

“[Doctors] tend to give a little more control to the patients because they need to be a little more adaptive. There’s sort of a doctor remote control and a patient remote control,” Smith said.

Paul Berger, an electrical and computer engineering professor at Ohio State University, sees all kinds of applications for implants. Along with advancing devices that provide deep brain stimulation, researchers could build a heart stent capable of wirelessly transmitting the health of an artery.

One of his colleagues at OSU is building an artificial neuron out of transistors. Damaged nerves could be patched immediately, “rather than injecting stem cells and hoping and praying in a few months time there is a restoration,” Berger said.

de Micheli thinks transplants could also serve more mundane purposes. Take bike racing, for example, a sport where athletes frequently turn to performance enhancing drugs. An implant would monitor constantly and make tampering with results more difficult.

“We may come to a situation in a five-to-10 year time where every athlete will have to have something implanted or in contact with their body,” de Micheli said.

Monitoring diabetes with a smartphone

Smith said he sees smartphones as a logical future resource for monitoring brain implants. A hospital in the U.K. is already developing them as a tool for people with diabetes.

People with diabetes must manage their diet and rely on synthetic insulin to prevent life-threatening complications. Most people monitor their blood sugar levels by pricking their finger and feeding a drop of blood into a glucose meter. Then a syringe is used to inject the necessary amount of insulin.

Medical devices are already beginning to automate this process. A sensor inserted under the skin can monitor glucose levels constantly and alert users when their blood sugar is too high. Insulin pumps use a tiny tube inserted into the body to deliver insulin without a syringe.

Product development firm Cambridge Consultants and the Institute of Metabolic Science at Addenbrooke’s Hospital in Cambridge are working on an artificial pancreas system that would connect the glucose meter and insulin pump wirelessly, creating an autonomous system that monitors and corrects blood sugar levels. No input from a patient or doctor would be necessary. The devices’ data would be relayed via a smartphone or tablet, which would make minute-by-minute analytics available.

“You’re getting much tighter control. Tighter control means less complications,” said John Pritchard, a commercial director at Cambridge Consultants. “Ultimately, once this makes it to marketplace, a type 1 diabetic will find it much easier to control the disease. They hopefully will have fewer trips to the hospital, trips to the doctor, and a better standard of living.”

An in-home, long-term trial of the artificial pancreas system will start later this year.

Putting electronics inside the body

Developing an artificial pancreas system that can be entirely enclosed in the body will take much longer. Right now, glucose meter sensors only last a few days or a week before they need to be replaced, according to the National Diabetes Information Clearinghouse.

“I think there’s a misconception maybe by the public and the community that bioelecronics exist,” Berger said. “There’s a dearth of that at present and it’s extremely ripe for exploration.”

de Micheli developed a chip earlier this year that monitors blood protein and acid levels. Its perfect for just after emergency situations, when a patient is particularly vulnerable to shifts in their condition and could benefit from constant monitoring.

The chips’ probes degrade quickly, however, meaning they need to be replaced every few weeks or month.

“That’s not desirable,” de Micheli said. “I think we should be bold and think of materials that can last longer.”

Berger recently developed a coating that allows cheap silicon sensors to be inserted into a person for up to 24 hours. Several common molecules in the body interfere with silicon sensors, so without some kind of protection they are useless.

Even with the coating, the body eventually wraps devices in a fibrous cocoon and pushes them out through the skin like a splinter. To survive inside the body, electronics must be enclosed in a steel jacket, as is the case with current pacemaker models. Just a few electrodes are allowed to poke out into the surrounding tissue.

Berger hopes that someday this kind of barrier won’t exist. He has approached researchers working on brain implants for people with Parkinson’s and epilepsy about working on ways to move intelligent electronics out of metal boxes and directly into body tissue.

“They seemed to like the idea,” Berger said. “I don’t find that much (research) going on yet. I feel I’m just taking my first baby steps in this.”