Large number of Americans suffer from PTSD. PTSD is a condition in which individuals feel anxiety and panic when reminded of a traumatic event. Current statistics suggest that between 6.8 and 10.1 percent of Americans will develop PTSD in their lifetimes making it the 5th most common psychiatric illness. “For perspective, that’s somewhere between the population of Texas and California who will require treatment. By contrast, rates are much lower in other westernized countries like Germany (2.3%) or Spain (.56%),” write Judith Edersheim and Kenneth M. McCullough in The Huffington Post.
Military service members are particularly susceptible to PTSD as a reaction to the traumas of war. About 2.7 million Americans served in the Iraq and Afghanistan wars, and at least 20 per cent of them have Post Traumatic Stress Disorder (PTSD). It also continues to occur at high rates among civilians because of high incidents of trauma such as an assault, traffic accident, or natural disaster.
The US Defense Advanced Research Project Agency (Darpa) says it can reduce this number by treating war veterans using chip implants. Researchers at the organisation say wireless ‘neuroprosthetic’ brain implants will also help restore memory functions and heal traumatic brain injuries. Scientists have already tested these implants in individuals suffering from brain injuries to improve their memory, the defense agency announced at a conference in September. Darpa said it had implanted temporary sensors into patients undergoing brain surgery that were able to detect signals in the brains during the process of forming and recalling memories.
Brain implants that deliver electrical pulses tuned to a person’s feelings and behaviour are being tested in people for the first time. Two teams funded by the US military’s research arm, the Defense Advanced Research Projects Agency (DARPA), have begun preliminary trials of ‘closed-loop’ brain implants that use algorithms to detect patterns associated with mood disorders. These devices can shock the brain back to a healthy state without input from a physician.
“What it really boils down to is precision interaction with neurons of the brain that are involved in neuropsychiatric illness,” said Justin Sanchez, director of DARPA’s biological technologies office. ‘As the technology of these fully implantable devices improves, and as we learn more about how to stimulate the brain ever more precisely to achieve the most therapeutic effects,’ Justin Sanchez, Darpa’s biological technologies program manager, said in a recent interview. ‘I believe we are going to gain a critical capacity to help our wounded warriors and others who today suffer from intractable neurological problems.’
Existing drugs for brain disorders are often ineffective and frequently produce troublesome side effects. One reason is that drugs alter the chemistry of the entire brain, not just the area of interest, modulating the behavior of otherwise healthy neurons, writes Adam Piore in MIT technology review.
However, experts express fears that this technology can also be used to manipulate soldier’s thoughts, remove their guilt and make them fearless soldiers.
Deep Brain Stimulation for treating psychiatric disorders
Deep brain stimulation (DBS) has been used for almost two decades to treat patients with severe forms of Parkinson’s (and since 2009 to treat a far smaller number of patients with OCD). As many as 125,000 people are living with electrodes implanted in their brains.
Under this technique, 42 centimeter electrodes are surgically inserted into the gray matter of the brain through holes in the top of the patient’s skull. These electrodes electrically stimulate the neurons through a device incorporating a pulse generator and battery and implanted into the skin of patient. In 50 percent of Iskandar’s cases, a miracle follows: the obsessions and compulsions fade and then disappear.
As part of President Obama’s Brain Initiative, Eskandar is co-leading a team of doctors, scientists, and engineers that is one year into a five-year, $30 million effort to use DBS to treat severe psychiatric disorders, most of which have been considered too complex and mysterious for any such system currently on the market.
Conditions like schizophrenia, PTSD, and depression are characterized by unpredictable changes in the brain that lead to intermittent episodes. Taming them will require a new kind of device capable not just of stimulating the brain but of monitoring brain activity in real time and detecting anomalies that, in many cases, neuroscientists have not yet identified.
Deep Brain Stimulation can impair memory
DARPA-funded study, published in the journal Neuron, concluded that deep-brain stimulation failed to improve memory—and in fact actually worsened memory. But a previous study, a few years ago, found the opposite: that stimulation helped memory. The findings of a 2012 New England Journal of Medicine study that showed significant improvement in memory following stimulation at 50 Hz—a high frequency—through tiny probes embedded in the brains of seven patients. These new findings temper the hope that deep brain stimulation, which has shown success in treating Parkinson’s disease and some psychiatric disorders, might also soon be useful in Alzheimer’s disease and dementia.
In the new study, during the encoding periods of both tasks, subjects received electrical stimulation at 50 Hz. Neurosurgical patients with implanted electrodes performed spatial and verbal-episodic memory tasks. In contrast to earlier work, electrical stimulation impaired memory performance significantly in both spatial and verbal tasks.
“People got really excited about deep brain stimulation and started applying it in a lot of different areas…But for the purposes of memory, it’s much more challenging,” said Joshua Jacobs, a bioengineer at Columbia University and the study’s first author. “We were disappointed.”
Nanthia Suthana, a neuroscientist at the University of California, Los Angeles, is also “absolutely” hopeful that DBS can still be used as treatment for such conditions. Enhancing memory can depend on the region targeted, the frequency of electrical pulses used to incite brain activity, and what the brain is doing at a particular point in time, experts said.
“When you map out what’s going on in the brain, we’ve found that if you don’t send the right codes into the brain you don’t get a facilitation of memory—and you can even impair memory. The flip story is that if you do send the right codes in, you can get huge improvements in declarative memory. The program has also seen that side of the work turn out. So when I take a step back from seeing all of this and do an assessment of it, we have both sides of the coin. We understand the codes that impair memory and facilitate memory. I think it prompts deeper investigation for the next generation of brain exploration,” explained director of its BTO, neuroprosthetic researcher Justin Sanchez.
“The code is a couple of things. It is the precise firing of individual neurons. Let’s say you have 100 neurons and they all fire at different times in different locations—it’s interpreting all that turning-off and turning-on when trying to remember the word “Nancy” or “tree”—we can understand what those firing patterns mean and how they relate to the outside world. All those neural firing patterns collectively produce brain waves or rhythms, and we are studying the brain at that level, too. It’s important to understand all those different facets of the brain because that’s how it works. Without the ability to go in and make these measurements we would never have this understanding. That’s why it’s so important that an organization like DARPA can go forward and develop neurotechnology to do this. We have some teams on the program that are seeing huge improvements on memory performance in humans when you use the right kinds of codes.”
“Neurotechnology is a very big area in our office. We have made great strides on the medical side of things, showing direct neural interfaces [connections between the brain and a device like a neurostimulator, computer or prosthetic] can restore movement, sensation and health with neuropsychiatric disorders.”
Prosthetic device improves short term memory
Michael Kahana, professor of psychology at the University of Pennsylvania, in collaboration with medical technology company Medtronic Plc. has developed a device called a ‘prosthetic memory’, according to a paper recently published in the Journal of Neural Engineering. The work was partially funded by DARPA (the U.S Defense Advancement Research Projects Agency).
The device is a neural implant connected to the left temporal cortex that can recognize your brain activity when you recall new information correctly. It can replicate that activity via electrical signals, so as to give your short-term memory a bit of a kick. “Just like meteorologists predict the weather by putting sensors in the environment that measure humidity and wind speed and temperature, we put sensors in the brain and measure electrical signals,” Kahana told Bloomberg.
A few tests were conducted on 15 epilepsy patients at the Wake Forest Baptist Medical Center, which showed a 35% improvement on their short-term memory and, though that might not sound like much, according to study author Robert Hampson, professor of physiology, pharmacology and neurology at the Wake Forest School of Medicine in North Carolina, that 35% is actually a massive achievement.
The patients that underwent testing were also already taking part in a brain-mapping procedure for treating seizures which required them to have electrodes surgically implanted in their brains, the hippocampus -the part of the brain that plays a big role in creating new memories- included.
The test saw the patients playing a memory challenge game where they had to identify a number of images that had been shown on the screen previously. Initially, the delay in recognizing the images was at about 2 minutes and then went all the way up to 75 minutes.
While the patients played the game, the researchers kept a close watch on their brain activity via their implants. Whenever they recognized an image correctly, the researchers were offered more information about how their mental activity looked when their short-term memory was being put to use.
During subsequent trials, the researchers used this information (which was unique to every patient) to stimulate parts of the patient’s brain, which in turn resulted in improved recall. However, the study was ‘sample-sized’ and every patient involved in it already had electrodes surgically implanted to treat other, unrelated conditions, so there is a significant amount of research that still needs to be done before these sort of implants would become procedures we’ll be able to undergo without batting an eyelash.
The next steps the researchers plan to undertake is to first build smaller implants and then work on receiving the necessary approvals from the U.S Food and Drug Administration in order to bring them to the market.
The US military fund research into brain implants for treating depression, PTSD
In 2014, Defense Advanced Research Projects Agency, or DARPA, awarded two large contracts to Massachusetts General Hospital and the Chang’s group at University of California, San Francisco, to create electrical brain implants capable of treating seven psychiatric conditions, including addiction, depression, and borderline personality disorder. Each team hopes to create a system of implanted electrodes to track activity across the brain as they stimulate the organ.
The project builds on expanding knowledge about how the brain works; the development of microlectronic systems that can fit in the body; and substantial evidence that thoughts and actions can be altered with well-placed electrical impulses to the brain.
The effort could lead to cures for brain-based illnesses and diseases like Alzheimer’s, epilepsy, autism and diseases that disproportionately affect troops, such as post-traumatic stress, brain injury and associated memory loss. The technology will use sensors to watch for unusual neural activity at multiple parts of the brain. If something’s wrong, the implants will use deep electrical stimulation to restore healthy activity — permanently, if possible.
DARPA and the Presidential Commission for the study of Bioethical Issues also will investigate the ethical, legal and societal concerns raised when scientists begin tinkering in peoples’ brains, according to administration officials.
DARPA Director Arati Prabhakar said that “DARPA hopes to build tools that can view, measure and control the brain from the cellular and neuronal to the macroscopic levels”. “We’re driving toward clearer models of how memory is encoded in the brain and how lesions that lead to memory loss can be circumvented in order to restore memory that may have been damaged due to post traumatic stress or brain injury”, according to Prabhakar.
US military funds AI brain implants to treat veterans’ post-traumatic stress disorder
The groups are developing their technologies in experiments with people with epilepsy who already have electrodes implanted in their brains to track their seizures. The researchers can use these electrodes to record what happens as they stimulate the brain intermittently ― rather than constantly, as with older implants.
UCSF Mood map
The scientists behind the DARPA-funded projects say that their work might succeed where earlier attempts failed, because they have designed their brain implants specifically to treat mental illness — and to switch on only when needed. “We’ve learned a lot about the limitations of our current technology,” says Edward Chang, a neuroscientist at the University of California, San Francisco (UCSF), who is leading one of the projects.
At the SfN meeting, electrical engineer Omid Sani of the University of Southern California in Los Angeles — who is working with Chang’s team — showed the first map of how mood is encoded in the brain over time. He and his colleagues worked with six people with epilepsy who had implanted electrodes, tracking their brain activity and moods in detail over the course of one to three weeks. By comparing the two types of information, the researchers could create an algorithm to ‘decode’ that person’s changing moods from their brain activity. Some broad patterns emerged, particularly in brain areas that have previously been associated with mood.
Massachusetts General Hospital
The MGH team is taking a different approach. Rather than detecting a particular mood or mental illness, they want to map the brain activity associated with behaviours that are present in multiple disorders — such as difficulties with concentration and empathy. At the SfN meeting, they reported on tests of algorithms they developed to stimulate the brain when a person is distracted from a set task, such as matching images of numbers or identifying emotions on faces.
The researchers found that delivering electrical pulses to areas of the brain involved in decision-making and emotion significantly improved the performance of test participants. The team also mapped the brain activity that occurred when a person began failing or slowing at a set task because they were forgetful or distracted, and found they were able to reverse it with stimulation. They are now beginning to test algorithms that use specific patterns of brain activity as a trigger to automatically stimulate the brain.
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