When 91探花 President Ana Mari Cauce launched the Population Health Initiative in 2016, she spoke in soaring, ambitious terms. 鈥淲e have an unprecedented opportunity to help people live longer, healthier, more productive lives 鈥� here and around the world,鈥� she said. 91探花researchers have leapt at that opportunity, forging connections across the university, working side by side with community partners and breaking down traditional barriers to improving public health. 听

In just eight years, the Initiative has funded 227 innovative, interdisciplinary projects. Many are focused right here in Western Washington, where projects have helped in South Seattle, identified soil contaminants in community gardens in the Duwamish Valley, and improved how community leaders along the Okanogan River . Other projects have reached across the globe, targeting health disparities in Somalia, Peru, Brazil and more.听听

鈥淚n this relatively short period of time, we鈥檝e demonstrated the power that accrues when faculty and staff across the various areas of our campuses are working together and also exposing students to the cutting-edge work of tackling grand challenges,鈥� Cauce said in her most recent .听

And they’re just getting started. Many PHI-funded projects are still in their earliest stages, leveraging initial funding to show proof-of-concept for their ideas and setting the stage for future work. Fourteen projects so far have received much larger grants to empower researchers and community partners to expand successful projects and scale up for greater impact.听

With the Initiative now a third of the way into its 25-year vision, 91探花News checked in with three projects that recently received funding to scale their efforts.听

Spotting potential memory health issues in rural Washington

Diagnosing memory health issues in the best of circumstances is extraordinarily difficult. Patients typically make multiple visits to their doctor and take a many of which can produce flawed results 鈥� people who take the same test more than once, for example, will often score higher, potentially masking memory loss. 听

It鈥檚 even harder in rural America, which has a Patients seeking memory care might have to make a long, expensive trip to a major city, which leads many people to wait until a problem becomes apparent. By then, it鈥檚 often too late 鈥� modern treatments can slow the progress of memory loss, but there鈥檚 no way to regain what鈥檚 been lost.听

鈥淪o, how do you catch it early?鈥� said , a 91探花associate professor of psychology. 鈥淲e give people an app to have them check for themselves.鈥澨�听

Stocco and , director of the 91探花Alzheimer鈥檚 Disease Research Center, together with Hedderik van Rijn of the University of Groningen in the Netherlands, led the development of an online program that can measure a person鈥檚 memory and predict their risk of memory disorders. Like a flash-card app that helps students cram for a test, the program shows pictures and asks the user to recall what they saw a few minutes earlier. The app records how quickly and accurately the user responds to each question and makes the next one a little easier or more difficult.听听

Researchers have long understood that a person鈥檚 ability to recall a specific memory tends to fade over time. This is called the 鈥�.鈥� In听 Stocco and van Rijn found that they could measure individual differences in the slopes of such curves.听 The app works by comparing a person鈥檚 responses to an internal model of forgetting and adjusting the slope of the model until it matches the responses. The resulting slope can be used to estimate the likelihood that their memory is fading faster than normal.听听

By taking the test regularly, a person can track their memory鈥檚 decline over time. But preliminary tests, Stocco said, have shown that even a single use can spot a potential problem.听

鈥淛ust by looking at a single lesson, based on the result, there鈥檚 almost a perfect correspondence between the speed of forgetting and your probability of being diagnosed by a doctor,鈥� Stocco said. 鈥淚t can be as accurate as the best clinical tests but, instead of taking two or three hours, this can be done in eight minutes, and you don鈥檛 need a doctor.鈥�听

A Tier 3 grant from the Population Health Initiative and a collaboration with the will allow the researchers to share the app with up to 500 people in rural and counties. Participants can take the test on their own time, and the results will be shared with researchers. If a potential problem emerges, the researchers plan to invite participants to Seattle for an in-person evaluation.听听

鈥淚t鈥檚 a solution that seems to solve these problems of early access and diagnostic bottlenecks,鈥� Stocco said. 鈥淚f this works, there鈥檚 no problem giving it to everybody in the state. We鈥檙e really interested in expanding and adding people from underrepresented populations and underrepresented areas, and the grant will allow us to do that.鈥�听

Nancy Spurgeon of the Central Washington Area Health Education Center is also a collaborator on the project to test the prototype app, which is not yet available to the public.听

Revamping the Point-In-Time Count to better understand King County鈥檚 unhoused population听

For years, volunteers fanned across King County on a cold night each January, flashlights and clipboards in hand, searching for people sleeping outside. They鈥檇 also gather the shelter head counts for that night. Officially called the , this effort attempted to tally the number of people who lacked stable housing. This endeavor was replicated in cities across the country, and the results were combined to create a national count that influences how the federal government allocates funding.听

There鈥檚 just one problem 鈥� the count is Volunteers can鈥檛 possibly find everybody. It captures only a single moment in time, and collects only limited data on people鈥檚 circumstances or personal needs. A person sleeping in their car might need different services than a person who sleeps in a tent, and the count didn鈥檛 fully capture that distinction.听

So, a team of 91探花researchers designed a better way to count. Their method, detailed in a published Sept. 4 in in the American Journal of Epidemiology, taps into people鈥檚 social networks to generate a more representative sample, which the researchers then ran through a series of calculations to estimate the total unhoused population.听听听

Called 鈥渞espondent-driven sampling,鈥� the method stations volunteers in common 鈥渉ubs,鈥� like libraries or community centers, and offers cash gift cards for in-person interviews and peer referrals. Volunteers collect detailed information on people鈥檚 circumstances and needs, giving each person three tickets to share with their unhoused peers. When those peers come in for an interview and show the ticket, the person who referred them receives another small reward. The new person gets a gift card and another three tickets.听

鈥淭his method gives people a more active voice in being counted. It鈥檚 a more humane way to count people, and it鈥檚 also voluntary,鈥� said , a 91探花associate professor of sociology and co-lead on the project. 鈥淭he regular PIT (Point-In-Time) count just counted people. Now we can collect all sorts of information from people on their circumstances and their needs. Should policymakers want to, they could leverage that data to change service offerings.鈥�听

The researchers received a Tier 2 grant to develop the system. They launched it in partnership with King County in 2022 and 2024, and were recently awarded a Tier 3 grant to test out the feasibility of running it quarterly.听听

鈥淩unning the count quarterly allows us to estimate how many people move in and out of homelessness and whether there are seasonal changes, which are rarely measured,鈥� Almquist said. 鈥淎lso, people鈥檚 needs change depending on the time of year, and this method will help us better understand those rhythms.鈥澨�听

Other cities and counties have expressed interest, the researchers said. The team has also begun to expand the effort, aiming to improve data across the broad spectrum of housing and homelessness services.听听

鈥淎 very important byproduct of this work across schools and departments at 91探花is that we can create an ecosystem of people and projects,鈥� said , a 91探花professor emeritus of health systems and population health and co-lead on the project. 鈥淲e鈥檝e spun off projects on sleep assessments, relationships with organizations that collect data on homelessness, and we鈥檙e mapping the sweeps of encampments in relationship to where people choose to be located. We have a whole network of homelessness-related research now.听

鈥淭hese PHI grants gave us the fuel to ignite these projects.鈥�听

Other collaborators are of the 91探花Department of Health Systems and Population Health and of the VA Health Services Research and Development; of the 91探花Departments of Sociology and Statistics; of the Center for Studies in Demography & Ecology and the eScience Institute; and Owen Kajfasz, Janelle Rothfolk and Cathea Carey of the King County Regional Homelessness Authority.听

Engaging community to mitigate flood risk in the Duwamish Valley听

More than a century ago, Seattle leaders set out to control and redirect the Duwamish River. They dredged the riverbed and dug out its twists and turns. Wetlands were filled in, the valley was paved over and a system of hydrology was severed. What had been a wild, winding river valley with regular flooding became an angular straightaway built for industry. But when 91探花postdoctoral scholar looks out at the Duwamish, she sees the river fighting back.听听

鈥淭he water was always there,鈥� Jeranko said, 鈥渁nd now it鈥檚 fighting to come back up.鈥澨�听

The river returned with devastating effect in December 2022, when a king tide and heavy rainfall , submerging homes and shuttering local businesses. The underserved neighborhood faces a significant risk of future floods.听

To mitigate that risk, the City of Seattle has updated the neighborhood鈥檚 stormwater drainage system and launched a new flood-warning system. But the , a nonprofit focused on river pollution and environmental health, saw an opportunity for something greater. The DRCC asked a team of 91探花researchers to help develop flood adaptation plans that are community-based, culturally responsive and that enrich the local environment.听听

鈥淚n the community, people don鈥檛 think there鈥檚 been enough engagement. There鈥檚 all this talk about flood mitigation, but all they see are sandbags,鈥� Jeranko said. 鈥淪o DRCC was like, 鈥楲ook, we really need the people who live in the flood zone to understand the solutions.鈥� Because we have this long-lasting relationship with them, they see us as someone who鈥檚 able to provide a list of solutions, not favor one over the others, and do it in an informative way.鈥�听

Boosted by a Tier 3 grant from the PHI, Jeranko and a team representing five 91探花departments, the Burke Museum and the DRCC are engaging with the community. This fall, the team will present the neighborhood with an expansive list of flood mitigation options and encourage city leaders to consider people鈥檚 preferences. Early work shows the community would favor nature-based solutions, Jeranko said. Floodable parks, for example, would provide ecological, recreational and public health benefits to the entire community, while storing flood water during storms.听听

鈥淚t has been wonderful to collaborate with the 91探花team on this to make sure we are centering community voices in every single step of the planning for climate resilience,鈥� said Paulina L贸pez, executive director of the DRCC. 鈥淐ommunity leadership and representation is indispensable to bring climate justice to the Duwamish Valley.鈥�听

Jeranko hopes their community-based model will be replicated by communities across the country facing similar risks from climate change and sea level rise.听

鈥淓ven though 91探花and a lot of other universities really support and invest in community-engaged work, a lot of times it鈥檚 fundamentally hard to make that research happen,鈥� Jeranko said. 鈥淏ut the Population Health Initiative grant was about supporting all those things.鈥�听

Other collaborators on the project are , and of the Department of Environmental & Occupational Health Sciences; of the Department of Landscape Architecture; of the Department of Civil & Environmental Engineering, of the School of Environmental and Forest Sciences; of the Quaternary Research Center and the Burke Museum; and L贸pez and Robin Schwartz of the DRCC.听

For more information on any of the projects mentioned, or to learn more about the 91探花Population Health Initiative, visit the Initiative’s website or contact Alden Woods at acwoods@uw.edu.听听

Say, something like this:

What goes in the last box? (The answer and more puzzles are below.)

You look for a pattern, or a rule, and you just can鈥檛 spot it. So you back up and start over.

That鈥檚 your brain recognizing that your current strategy isn鈥檛 working, and that you need a new way to solve the problem, according to new research from the 91探花. With the help of about 200 puzzle-takers, a computer model and functional MRI (fMRI) images, researchers have learned more about the processes of reasoning and decision-making, pinpointing the brain pathway that springs into action when problem-solving goes south.

鈥淭here are two fundamental ways your brain can steer you through life 鈥� toward things that are good, or away from things that aren鈥檛 working out,鈥� said , associate professor of psychology and co-author of the new , published Feb. 23 in the journal Cognitive Science. 鈥淏ecause these processes are happening beneath the hood, you鈥檙e not necessarily aware of how much driving one or the other is doing.鈥�

Using a decision-making task developed by Michael Frank at Brown University, the researchers measured exactly how much 鈥渟teering鈥� in each person鈥檚 brain involved learning to move toward rewarding things as opposed to away from less-rewarding things. Prat and her co-authors were focused on understanding what makes someone good at problem-solving.

The research team first developed a computer model that specified the series of steps they believed were required for solving the Raven鈥檚 Advanced Performance Matrices (Raven鈥檚) 鈥� a standard lab test made of puzzles like the one above. To succeed, the puzzle-taker must identify patterns and predict the next image in the sequence. The model essentially describes the four steps people take to solve a puzzle:

• Identify a key feature in a pattern;
• Figure out where that feature appears in the sequence;
• Come up with a rule for manipulating the feature;
• Check whether the rule holds true for the entire pattern.

At each step, the model evaluated whether it was making progress. When the model was given real problems to solve, it performed best when it was able to steer away from the features and strategies that weren鈥檛 helping it make progress. According to the authors, this ability to know when your 鈥渢rain of thought is on the wrong track鈥� was central to finding the correct answer.

The next step was to see whether this was true in people. To do so, the team had three groups of participants solve puzzles in three different experiments. In the first, they solved the original set of Raven鈥檚 problems using a paper-and-pencil test, along with Frank鈥檚 test which separately measured their ability to 鈥渃hoose鈥� the best options and to 鈥渁void鈥� the worse options. Their results suggested that only the ability to 鈥渁void鈥� the worst options related to problem-solving success. There was no relation between one鈥檚 ability to recognize the best choice in the decision-making test, and to solve the puzzles effectively.

The second experiment replaced the paper-and-pencil version of the puzzles with a shorter, computerized version of the task that could also be implemented in an MRI brain-scanning environment. These results confirmed that those who were best at avoiding the worse options in the decision-making task were also the best problem solvers.

The final group of participants completed the computerized puzzles while having their brain activity recorded using fMRI. Based on the model, the researchers gauged which parts of the brain would drive problem-solving success. They zeroed in on the basal ganglia 鈥� what Prat calls the 鈥渆xecutive assistant鈥� to the prefrontal cortex, or 鈥淐EO鈥� of the brain. The basal ganglia assist the prefrontal cortex in deciding which action to take using parallel paths: one that turns the volume 鈥渦p鈥� on information it believes is relevant, and another that turns the volume 鈥渄own鈥� on signals it believes to be irrelevant. The 鈥渃hoose鈥� and 鈥渁void鈥� behaviors associated with Frank鈥檚 decision-making test relate to the functioning of these two pathways. Results from this experiment suggest that the process of 鈥渢urning down the volume鈥� in the basal ganglia predicted how successful participants were at solving the puzzles.

鈥淥ur brains have parallel learning systems for avoiding the least good thing and getting the best thing. A lot of research has focused on how we learn to find good things, but this pandemic is an excellent example of why we have both systems. Sometimes, when there are no good options, you have to pick the least bad one! What we found here was that this is even more critical to complex problem-solving than recognizing what鈥檚 working.鈥�

Co-authors of the study were , associate professor, and Lauren Graham, assistant teaching professor, in the 91探花Department of Psychology. The research was supported by the 91探花Royalty Research Fund, a 91探花startup fund award and the Bezos Family Foundation.

For more information, contact Prat at csprat@uw.edu.

Telepathic communication might be one step closer to reality thanks to new research from the 91探花. A team created a method that allows three people to work together to solve a problem using only their minds.

In BrainNet, three people play a Tetris-like game using a brain-to-brain interface. This is the first demonstration of two things: a brain-to-brain network of more than two people, and a person being able to both receive and send information to others using only their brain. The team April 16 in the Nature journal , though this research previously attracted media attention after the researchers September to the preprint site .

“Humans are social beings who communicate with each other to cooperate and solve problems that none of us can solve on our own,” said corresponding author , the CJ and Elizabeth Hwang professor in the UW鈥檚 Paul G. Allen School of Computer Science & Engineering and a co-director of the . “We wanted to know if a group of people could collaborate using only their brains. That’s how we came up with the idea of BrainNet: where two people help a third person solve a task.”

As in Tetris, the game shows a block at the top of the screen and a line that needs to be completed at the bottom. Two people, the Senders, can see both the block and the line but can’t control the game. The third person, the Receiver, can see only the block but can tell the game whether to rotate the block to successfully complete the line. Each Sender decides whether the block needs to be rotated and then passes that information from their brain, through the internet and to the brain of the Receiver. Then the Receiver processes that information and sends a command 鈥� to rotate or not rotate the block 鈥� to the game directly from their brain, hopefully completing and clearing the line.

The team asked five groups of participants to play 16 rounds of the game. For each group, all three participants were in different rooms and couldn鈥檛 see, hear or speak to one another.

The Senders each could see the game displayed on a computer screen. The screen also showed the word “Yes” on one side and the word “No” on the other side. Beneath the “Yes” option, an LED flashed 17 times per second. Beneath the “No” option, an LED flashed 15 times a second.

“Once the Sender makes a decision about whether to rotate the block, they send ‘Yes’ or ‘No’ to the Receiver鈥檚 brain by concentrating on the corresponding light,” said first author , a student in the Allen School’s combined bachelor’s/master’s degree program.

The Senders wore electroencephalography caps that picked up electrical activity in their brains. The lights’ different flashing patterns trigger unique types of activity in the brain, which the caps can pick up. So, as the Senders stared at the light for their corresponding selection, the cap picked up those signals, and the computer provided real-time feedback by displaying a cursor on the screen that moved toward their desired choice. The selections were then translated into a “Yes” or “No” answer that could be sent over the internet to the Receiver.

“To deliver the message to the Receiver, we used a cable that ends with a wand that looks like a tiny racket behind the Receiver’s head. This coil stimulates the part of the brain that translates signals from the eyes,” said co-author , a 91探花assistant professor in the Department of Psychology and the Institute for Learning & Brain Sciences, or I-LABS. “We essentially ‘trick’ the neurons in the back of the brain to spread around the message that they have received signals from the eyes. Then participants have the sensation that bright arcs or objects suddenly appear in front of their eyes.”

If the answer was, “Yes, rotate the block,” then the Receiver would see the bright flash. If the answer was “No,” then the Receiver wouldn’t see anything. The Receiver received input from both Senders before making a decision about whether to rotate the block. Because the Receiver also wore an electroencephalography cap, they used the same method as the Senders to select yes or no.

The Senders got a chance to review the Receiver’s decision and send corrections if they disagreed. Then, once the Receiver sent a second decision, everyone in the group found out if they cleared the line. On average, each group successfully cleared the line 81% of the time, or for 13 out of 16 trials.

The researchers wanted to know if the Receiver would learn over time to trust one Sender over the other based on their reliability. The team purposely picked one of the Senders to be a “bad Sender” and flipped their responses in 10 out of the 16 trials 鈥� so that a “Yes, rotate the block” suggestion would be given to the Receiver as “No, don’t rotate the block,” and vice versa. Over time, the Receiver switched from being relatively neutral about both Senders to strongly preferring the information from the “good Sender.”

The team hopes that these results pave the way for future brain-to-brain interfaces that allow people to collaborate to solve tough problems that one brain alone couldn’t solve. The researchers also believe this is an appropriate time to start to have a larger conversation about the ethics of this kind of brain augmentation research and developing protocols to ensure that people’s privacy is respected as the technology improves. The group is working with the at the Center for Neurotechnology to address these types of issues.

“But for now, this is just a baby step. Our equipment is still expensive and very bulky and the task is a game,” Rao said. “We’re in the ‘Kitty Hawk’ days of brain interface technologies: We’re just getting off the ground.”

Co-authors include , a graduate student at Carnegie Mellon University who completed this research as a 91探花undergraduate in computer science and neurobiology; , a research assistant at I-LABS; and , an associate professor in the Department of Psychology and I-LABS. This research was funded by the National Science Foundation, a W.M. Keck Foundation Award and a Levinson Emerging Scholars Award.

###

For more information, contact Jiang at prestonj@cs.washington.edu, Stocco at stocco@uw.edu or Rao at rao@cs.washington.edu.

Grant number: EEC-1028725

In the Matrix film series, Keanu Reeves plugs his brain directly into a virtual world that sentient machines have designed to enslave mankind.

The Matrix plot may be dystopian fantasy, but 91探花 researchers have taken a first step in showing how humans can interact with virtual realities via direct brain stimulation.

In a published online Nov. 16 in , they describe the first demonstration of humans playing a simple, two-dimensional computer game using only input from direct brain stimulation 鈥� without relying on any usual sensory cues from sight, hearing or touch.

The subjects had to navigate 21 different mazes, with two choices to move forward or down based on whether they sensed a visual stimulation artifact called a , which are perceived as blobs or bars of light. To signal which direction to move, the researchers generated a phosphene through , a well-known technique that uses a magnetic coil placed near the skull to directly and noninvasively stimulate a specific area of the brain.

鈥淭he way virtual reality is done these days is through displays, headsets and goggles, but ultimately your brain is what creates your reality,鈥� said senior author , 91探花professor of and director of the

鈥淭he fundamental question we wanted to answer was: Can the brain make use of artificial information that it鈥檚 never seen before that is delivered directly to the brain to navigate a virtual world or do useful tasks without other sensory input? And the answer is yes.鈥�

The five test subjects made the right moves in the mazes 92 percent of the time when they received the input via direct brain stimulation, compared to 15 percent of the time when they lacked that guidance.

The simple game demonstrates one way that novel information from artificial sensors or computer-generated virtual worlds can be successfully encoded and delivered noninvasively to the human brain to solve useful tasks. It employs a technology commonly used in neuroscience to study how the brain works 鈥� transcranial magnetic stimulation 鈥� to instead convey actionable information to the brain.

The test subjects also got better at the navigation task over time, suggesting that they were able to learn to better detect the artificial stimuli.

鈥淲e鈥檙e essentially trying to give humans a sixth sense,鈥� said lead author , a 2016 91探花graduate in computer science and neurobiology who now works as a staff researcher for the .听 鈥淪o much effort in this field of neural engineering has focused on decoding information from the brain. We鈥檙e interested in how you can encode information into the brain.鈥�

The initial experiment used binary information 鈥� whether a phosphene was present or not 鈥� to let the game players know whether there was an obstacle in front of them in the maze. In the real world, even that type of simple input could help blind or visually impaired individuals navigate.

Theoretically, any of a variety of sensors on a person鈥檚 body 鈥� from cameras to infrared, ultrasound, or laser rangefinders 鈥� could convey information about what is surrounding or approaching the person in the real world to a direct brain stimulator that gives that person useful input to guide their actions.

鈥淭he technology is not there yet 鈥� the tool we use to stimulate the brain is a bulky piece of equipment that you wouldn鈥檛 carry around with you,鈥� said co-author , a 91探花assistant professor of psychology and I-LABS research scientist. 鈥淏ut eventually we might be able to replace the hardware with something that鈥檚 amenable to real world applications.鈥�

Together with other partners from outside UW, members of the research team have co-founded , a startup company aimed at commercializing their ideas and introducing neuroscience and artificial intelligence (AI) techniques that could make virtual-reality, gaming and other applications better and more engaging.

The team is currently investigating how altering the intensity and location of direct brain stimulation can create more complex visual and other sensory perceptions which are currently difficult to replicate in augmented or virtual reality.

鈥淲e look at this as a very small step toward the grander vision of providing rich sensory input to the brain directly and noninvasively,鈥� said Rao. 鈥淥ver the long term, this could have profound implications for assisting people with sensory deficits while also paving the way for more realistic virtual reality experiences.鈥�

The research was funded by the W.M. Keck Foundation and the Washington Research Foundation.

Co-authors include I-LABS research coordinator .

For more information, contact Losey at loseydm@uw.edu, Stocco at stocco@uw.edu or Rao at rao@cs.washington.edu.

Imagine a question-and-answer game played by two people who are not in the same place and not talking to each other. Round after round, one player asks a series of questions and accurately guesses the object the other is thinking about.

Sci-fi? Mind-reading superpowers? Not quite.

91探花 researchers recently used a direct brain-to-brain connection to enable pairs of participants to play a question-and-answer game by transmitting signals from one brain to the other over the Internet. The experiment, detailed today in , is thought to be the first to show that two brains can be directly linked to allow one person to guess what鈥檚 on another person鈥檚 mind.

鈥淭his is the most complex brain-to-brain experiment, I think, that鈥檚 been done to date in humans,鈥� said lead author , an assistant professor of psychology and a researcher at UW鈥檚 .

鈥淚t uses conscious experiences through signals that are experienced visually, and it requires two people to collaborate,鈥� Stocco said.

Here鈥檚 how it works: The first participant, or 鈥渞espondent,鈥� wears a cap connected to an (EEG) machine that records electrical brain activity. The respondent is shown an object (for example, a dog) on a computer screen, and the second participant, or 鈥渋nquirer,鈥� sees a list of possible objects and associated questions. With the click of a mouse, the inquirer sends a question and the respondent answers 鈥測es鈥� or 鈥渘o鈥� by focusing on one of two flashing LED lights attached to the monitor, which flash at different frequencies.

A 鈥渘o鈥� or 鈥測es鈥� answer both send a signal to the inquirer via the Internet and activate a magnetic coil positioned behind the inquirer鈥檚 head. But only a 鈥測es鈥� answer generates a response intense enough to stimulate the visual cortex and cause the inquirer to see a flash of light known as a 鈥�.鈥� The phosphene 鈥� which might look like a blob, waves or a thin line 鈥� is created through a brief disruption in the visual field and tells the inquirer the answer is yes. Through answers to these simple yes or no questions, the inquirer identifies the correct item.

The experiment was carried out in dark rooms in two 91探花labs located almost a mile apart and involved five pairs of participants, who played 20 rounds of the question-and-answer game. Each game had eight objects and three questions that would solve the game if answered correctly. The sessions were a random mixture of 10 real games and 10 control games that were structured the same way.

The researchers took steps to ensure participants couldn’t use clues other than direct brain communication to complete the game. Inquirers wore earplugs so they couldn’t hear the different sounds produced by the varying stimulation intensities of the “yes” and “no” responses. Since noise travels through the skull bone, the researchers also changed the stimulation intensities slightly from game to game and randomly used three different intensities each for “yes” and “no” answers to further reduce the chance that sound could provide clues.

The researchers also repositioned the coil on the inquirer’s head at the start of each game, but for the control games, added a plastic spacer undetectable to the participant that weakened the magnetic field enough to prevent the generation of phosphenes. Inquirers were not told whether they had correctly identified the items, and only the researcher on the respondent end knew whether each game was real or a control round.

“We took many steps to make sure that people were not cheating,” Stocco said.

Participants were able to guess the correct object in 72 percent of the real games, compared with just 18 percent of the control rounds. Incorrect guesses in the real games could be caused by several factors, the most likely being uncertainty about whether a phosphene had appeared.

鈥淭hey have to interpret something they鈥檙e seeing with their brains,鈥� said co-author , a faculty member at the and a 91探花associate professor of psychology. 鈥淚t鈥檚 not something they鈥檝e ever seen before.鈥�

Errors can also result from respondents not knowing the answers to questions or focusing on both answers, or by the brain signal transmission being interrupted by hardware problems.

“While the flashing lights are signals that we’re putting into the brain, those parts of the brain are doing a million other things at any given time too,” Prat said.

The study builds on the 91探花team鈥檚 in 2013, when it was the first to demonstrate a direct brain-to-brain connection between humans. Other scientists have connected the brains of rats and monkeys, and transmitted brain signals from a human to a rat, using electrodes inserted into animals鈥� brains. In the 2013 experiment, the 91探花team used noninvasive technology to send a person鈥檚 brain signals over the Internet to control the hand motions of another person.

The experiment evolved out of research by co-author , a 91探花professor of computer science and engineering, on that enable people to activate devices with their minds. In 2011, Rao began collaborating with Stocco and Prat to determine how to link two human brains together.

In 2014, the researchers received a $1 million grant from the that allowed them to broaden their experiments to decode more complex interactions and brain processes. They are now exploring the possibility of 鈥渂rain tutoring,鈥� transferring signals directly from healthy brains to ones that are developmentally impaired or impacted by external factors such as a stroke or accident, or simply to transfer knowledge from teacher to pupil.

The team is also working on transmitting brain states 鈥� for example, sending signals from an alert person to a sleepy one, or from a focused student to one who has attention deficit hyperactivity disorder, or ADHD.

鈥淚magine having someone with ADHD and a neurotypical student,鈥� Prat said. 鈥淲hen the non-ADHD student is paying attention, the ADHD student鈥檚 brain gets put into a state of greater attention automatically.鈥�

Many technological advancements over the past century, from the telegraph to the Internet, were created to facilitate communication between people. The 91探花team鈥檚 work takes a different approach, using technology to strip away the need for such intermediaries.

鈥淓volution has spent a colossal amount of time to find ways for us and other animals to take information out of our brains and communicate it to other animals in the forms of behavior, speech and so on,鈥� Stocco said. 鈥淏ut it requires a translation. We can only communicate part of whatever our brain processes.

鈥淲hat we are doing is kind of reversing the process a step at a time by opening up this box and taking signals from the brain and with minimal translation, putting them back in another person鈥檚 brain,鈥� he said.

Other co-authors are听 91探花computer science and neurobiology undergraduate student , 91探花bioengineering doctoral student Jeneva Cronin, 91探花bioengineering doctoral student Joseph Wu, and , a research assistant at the 91探花Institute for Learning & Brain Sciences.

91探花 researchers have successfully replicated a direct brain-to-brain connection between pairs of people as part of a scientific study following the team’s a year ago. In the , which involved six people, researchers were able to transmit the signals from one person’s brain over the Internet and use these signals to control the hand motions of another person within a split second of sending that signal.

At the time of the first experiment in August 2013, the 91探花team was the first to demonstrate two human brains communicating in this way. The researchers then tested their brain-to-brain interface in a more comprehensive study, published Nov. 5 in the journal PLOS ONE.

“The new study brings our brain-to-brain interfacing paradigm from an initial demonstration to something that is closer to a deliverable technology,” said co-author , a research assistant professor of psychology and a researcher at UW’s . “Now we have replicated our methods and know that they can work reliably with walk-in participants.”

Collaborator , a 91探花professor of computer science and engineering, is the lead author on this work.

The research team combined two kinds of noninvasive instruments and fine-tuned software to connect two human brains in real time. The process is fairly straightforward. One participant is hooked to an machine that reads brain activity and sends electrical pulses via the Web to the second participant, who is wearing a swim cap with a coil placed near the part of the brain that controls hand movements.

Using this setup, one person can send a command to move the hand of the other by simply thinking about that hand movement.

The 91探花study involved three pairs of participants. Each pair included a sender and a receiver with different roles and constraints. They sat in separate buildings on campus about a half mile apart and were unable to interact with each other in any way 鈥� except for the link between their brains.

Each sender was in front of a computer game in which he or she had to defend a city by firing a cannon and intercepting rockets launched by a pirate ship. But because the senders could not physically interact with the game, the only way they could defend the city was by thinking about moving their hand to fire the cannon.

Across campus, each receiver sat wearing headphones in a dark room 鈥� with no ability to see the computer game 鈥� with the right hand positioned over the only touchpad that could actually fire the cannon. If the brain-to-brain interface was successful, the receiver’s hand would twitch, pressing the touchpad and firing the cannon that was displayed on the sender’s computer screen across campus.

Researchers found that accuracy varied among the pairs, ranging from 25 to 83 percent. Misses mostly were due to a sender failing to accurately execute the thought to send the “fire” command. The researchers also were able to quantify the exact amount of information that was transferred between the two brains.

Another research team from the company Starlab in Barcelona, Spain, recently published in the same journal showing direct communication between two human brains, but that study only tested one sender brain instead of different pairs of study participants and was conducted offline instead of in real time over the Web.

Now, with a new $1 million grant from the , the 91探花research team is taking the work a step further in an attempt to decode and transmit more complex brain processes.

With the new funding, the research team will expand the types of information that can be transferred from brain to brain, including more complex visual and psychological phenomena such as concepts, thoughts and rules.

They’re also exploring how to influence brain waves that correspond with alertness or sleepiness. Eventually, for example, the brain of a sleepy airplane pilot dozing off at the controls could stimulate the copilot’s brain to become more alert.

The project could also eventually lead to “brain tutoring,” in which knowledge is transferred directly from the brain of a teacher to a student.

“Imagine someone who’s a brilliant scientist but not a brilliant teacher. Complex knowledge is hard to explain 鈥� we’re limited by language,” said co-author , a faculty member at the Institute for Learning & Brain Sciences and a 91探花assistant professor of psychology.

Other 91探花co-authors are Joseph Wu of computer science and engineering; Devapratim Sarma and Tiffany Youngquist of bioengineering; and Matthew Bryan, formerly of the UW.

The research published in PLOS ONE was initially funded by the U.S. Army Research Office and the UW, with additional support from the Keck Foundation.

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For more information, contact Stocco at stocco@uw.edu or 206-685-8610, Rao at rao@cs.washington.edu or 206-685-9141 and Prat at csprat@uw.edu or 206-685-8610.

Using electrical brain recordings and a form of magnetic stimulation, sent a brain signal to on the other side of the 91探花campus, causing Stocco’s finger to move on a keyboard.

While researchers at Duke University have demonstrated brain-to-brain communication between two rats, and Harvard researchers have demonstrated it between a human and a rat, Rao and Stocco believe this is the first demonstration of human-to-human brain interfacing.

“The Internet was a way to connect computers, and now it can be a way to connect brains,” Stocco said. “We want to take the knowledge of a brain and transmit it directly from brain to brain.”

The researchers captured the full demonstration on video recorded in both labs. The following version has been edited for length. This video and high-resolution photos also are available on the听.

Rao, a 91探花professor of computer science and engineering, has been working on brain-computer interfacing in his lab for more than 10 years and just published a on the subject. In 2011, spurred by the rapid advances in technology, he believed he could demonstrate the concept of human brain-to-brain interfacing. So he partnered with Stocco, a 91探花research assistant professor in psychology at the UW’s听.

On Aug. 12, Rao sat in his lab wearing a cap with electrodes hooked up to an machine, which reads electrical activity in the brain. Stocco was in his lab across campus wearing a purple swim cap marked with the stimulation site for the coil that was placed directly over his left motor cortex, which controls hand movement.

The team had a Skype connection set up so the two labs could coordinate, though neither Rao nor Stocco could see the Skype screens.

Rao looked at a computer screen and played a simple video game with his mind. When he was supposed to fire a cannon at a target, he imagined moving his right hand (being careful not to actually move his hand), causing a cursor to hit the “fire” button. Almost instantaneously, Stocco, who wore noise-canceling earbuds and wasn’t looking at a computer screen, involuntarily moved his right index finger to push the space bar on the keyboard in front of him, as if firing the cannon. Stocco compared the feeling of his hand moving involuntarily to that of a nervous tic.

“It was both exciting and eerie to watch an imagined action from my brain get translated into actual action by another brain,” Rao said. “This was basically a one-way flow of information from my brain to his. The next step is having a more equitable two-way conversation directly between the two brains.”

The technologies used by the researchers for recording and stimulating the brain are both well-known. Electroencephalography, or EEG, is routinely used by clinicians and researchers to record brain activity noninvasively from the scalp. Transcranial magnetic stimulation is a noninvasive way of delivering stimulation to the brain to elicit a response. Its effect depends on where the coil is placed; in this case, it was placed directly over the brain region that controls a person’s right hand. By activating these neurons, the stimulation convinced the brain that it needed to move the right hand.

Computer science and engineering undergraduates Matthew Bryan, Bryan Djunaedi, Joseph Wu and Alex Dadgar, along with bioengineering graduate student Dev Sarma, wrote the computer code for the project, translating Rao’s brain signals into a command for Stocco’s brain.

“Brain-computer interface is something people have been talking about for a long, long time,” said , assistant professor in psychology at the UW’s Institute for Learning & Brain Sciences, and Stocco’s wife and research partner who helped conduct the experiment. “We plugged a brain into the most complex computer anyone has ever studied, and that is another brain.”

At first blush, this breakthrough brings to mind all kinds of science fiction scenarios. Stocco jokingly referred to it as a “Vulcan mind meld.” But Rao cautioned this technology only reads certain kinds of simple brain signals, not a person’s thoughts. And it doesn’t give anyone the ability to control your actions against your will.

Both researchers were in the lab wearing highly specialized equipment and under ideal conditions. They also had to obtain and follow a stringent set of international human-subject testing rules to conduct the demonstration.

“I think some people will be unnerved by this because they will overestimate the technology,” Prat said. “There’s no possible way the technology that we have could be used on a person unknowingly or without their willing participation.”

Stocco said years from now the technology could be used, for example, by someone on the ground to help a flight attendant or passenger land an airplane if the pilot becomes incapacitated. Or a person with disabilities could communicate his or her wish, say, for food or water. The brain signals from one person to another would work even if they didn’t speak the same language.

Rao and Stocco next plan to conduct an experiment that would transmit more complex information from one brain to the other. If that works, they then will conduct the experiment on a larger pool of subjects.

Their research was funded in part by the 听at the UW, the 听and the .

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For more information, contact Rao at rao@cs.washington.edu or 206-685-9141, and Stocco at stocco@uw.edu or 206-685-8610. Video and high-resolution photos are available on the .