At dinner today I couldn’t remember what the article I planned to write afterwards was about. Minutes later when I realized what it was, I couldn’t stop laughing, and I think people may have thought I’d finally lost it.
For millions of people suffering memory loss, the thought of the U.S. military developing a brain implant to restore memory to veterans who suffered from brain injuries is quite exciting. Certainly the average civilian will have to wait, but it still offers hope for the future.
The program in question, Restoring Active Memory, or RAM, is part of the Defense Advanced Research Projects Agency’s branch of the Department of Defense. They have been charged with developing a wireless, fully implantable neuroprosthetic device, accoring to Program Manager Justin Sanchez. Two teams of researchers are set to the memory loss implant task, one at UCLA, and the other at the University of Pennsylvania.
Brain Injury can have a huge affect on those who suffer from it, as it did to Larry Miller last year, but perhaps one of the most disconcerting of all symptoms is memory loss. More than 270k veterans, and over a million civilians, are affected in the United States each year by a traumatic brain injury. TBI interferes with the ablitiy to recall memories, or to form or retain new memories.
Implants have proven successful for stimulating the brain to help with other chronic brain conditions, so it’s now a matter of location and stimulus delivery. To better understand where such implants would likely be placed to regain memory, one must first understand where and how different types of memories are stored.
As the article above explains, memories are encoded and stored for later retrieval. Depending on the nature of a brain injury, one of more of these processes could be affected. There are several types of memories, including sensory, short-term, and long-term memories. People with damage to the short-term memory can’t remember things that were said or done recently–such as what story was just pulled up on the screen for later reading. In that case, I had to wait a bit until somehow the data I could not recall hit long-term status, at which point it was available to me again (and still will be twenty years from now for some weird reason…)
Short term memories are obtained mostly from acoustic settings, and to a lesser extent using visual cues. Generally the short term memory holds only 5 items at a time, but can be enhanced by chunking together bits of code. For example, recalling a ten-digit telephone number by three or four numbers at a time. This type of memory is typically housed in the frontal lobe, so if you got hit upside the front of the head like I did seven years ago, this is they type of loss you would suffer, assuming you followed the norms.
Long-term memory, however, stores much larger quantities of information given from sensory and short-term memories. These bits of data are stored for a potentially unlimited duration. This is where those telephone numbers you recall at will are kept. It is housed throughout the brain, and as such different injuries may affect different types of that memory.
Another important factor in storing memory is the hippocampus, which is part of the limbic system. It plays an important role in the consolidation of information from short to long-term memory as well as spatial navigation. It’s hidden deep inside the brain, but if you hit your head hard enough or it gets damaged by swelling, you’re likely to get some serious memory issues.
People affected with long-term memory loss can’t remember much of their past, and many of them are unable to retain memory of the new events that happen to them beyond a few hours or even a few minutes. As you can imagine, this type of memory loss can be much more troubling over time.
Within the long-term memories there are several types. Recognition memories allow people to know whether they’ve seen an object or heard an idea before. Recall goes a bit deeper, requiring the person to retrieve information they have previously learned. This could involve the ability to orient oneself geographically, remember an event that evoked highly charged emotions, or be a fact that is needed for some reason.
This means that if one were trying to treat short-term memory loss, placement of an implant would likely be to the front of the brain, but other than that it’s still going to be a bit of hit and miss. Before they would know where to plant the device, they’d have to probe further into the types of functions that are being problematic, as well as whether or not the loss was complete or mild. Below is a video describing brain trauma a bit better.