OUR BRAINS CONTINUE TO SURPRISE

Two news stories about the human brain are worth passing along this week.

The first is a potential breakthrough by Australian researchers in the treatment of Alzheimer’s disease. One of the primary causes of Alzheimer’s is the build-up of what’s known as amyloid plaques between the nerve cells of the brain (neurons) that interfere with the transmission of signals. Drug-based treatments for Alzheimer’s have had limited success partly because the body’s own blood-brain barrier, meant to protect the brain from invaders, does a good job of keeping out helpful chemicals too. The new treatment involves using focused therapeutic ultrasound—gentle sound waves that nudge the blood-brain barrier open to help the body’s clean-up crew (microglial cells) to remove the offending plaques. So far, test results in mice have been very promising, restoring 75% of memory function without causing damage. That’s still a long way from curing humans, true. But having witnessed the ravages of dementia up close in the last years of my mother’s life, I appreciate any good news in the fight against it.

The second story involves a new calculation of the data processing capability of the human brain. Signals pass between neurons via special structures called synapses, so it’s not hard to understand that the ability of a neuron to pass signals will be affected by the number and size of the synapses it has. It was thought that there are only a few different types and sizes of synapses in our brains, but when a team led by the Salk Institute recreated brain tissue down to the nanometre scale for the first time, they discovered that synapses change according to how they’re used, and how often. The Salk scientists and their partners calculated that there could be as many as twenty-six different categories of synapses, adjusting themselves as needed, which goes a long way toward explaining how the brain accomplishes so much using so little energy (the power consumption of a dim light bulb, they say). But it also means that our brain’s capacity for storing information could be ten times greater than previously thought—possibly in the range of a petabyte (a million gigabytes) which is the equivalent of all the storage in the World Wide Web.

Are you feeling impressed with yourself yet?

A long-lived urban myth suggested that we only use about ten percent of the capacity of our brains. That claim has been thoroughly discredited by neuroscientists, but the Salk Institute findings have to make you wonder if there isn’t a way we could somehow make even better use of all the brainpower we have. It’s a vast amount of storage, yes, but what if we could improve our information processing, filing, and retrieval systems? For one thing, we might never again lose our car keys (!), but we also might have less and less need for digital computers. Since synapses respond to need, picture flicking a mental switch to turn on “mathematics mode” or “language mode” to temporarily divert cognitive resources to a specific task. We could be specialized  geniuses on demand! The idea of someday using a human brain to store secret data archives (like in the TV show Chuck or the movie Johnny Mnemonic) seems more plausible too.

But doesn’t it also make you wonder if there aren’t other potential capabilities within our brains that we’ve either forgotten how to use or just haven’t learned yet? Most scientists would scoff at the idea of so-called “paranormal” powers like telekinesis and telepathy, and most science fiction writers relegate such things to fantasy instead of SF. I’m not so sure. For one thing, I accept that there are dimensions of existence that we don’t currently perceive, but mathematicians and physicists readily include them in their theories about the universe. And I can accept that the universe includes an underlying level of information, call it what you will. Human beings don’t normally tap into such things because we haven’t needed to for our survival, but that doesn’t mean it’s beyond our ability if we only knew how.

I believe that each new discovery about the human body and mind in physical terms leads to a deeper understanding of ourselves in a holistic and even philosophical context. So news stories  like these reinforce my conviction that the human adventure is far from over and there are many wonders yet to come.

THANKS FOR THE MEMORIES...AGAIN

A scientist at M.I.T. has been working on a way to decipher our memories and encode them like data for a computer. The goal is to be able to restore memories in cases where Alzheimer’s disease or some other damage to the brain has caused neuron failure and memory loss.

Dr. Ed Boyden uses a protein extracted from algae that produces electricity when struck by light. By inserting the protein into brain neurons and then triggering them with light, he and his team are hoping to be able to map out brain pathways, learning more about how the brain functions and possibly even translating the neural paths of memories into binary code, which would allow them to be stored like other computer data. So far there have been promising results from testing with mice.

Obviously the storage and re-implantation of memories (or implantation of new ones) could have a lot more applications than just helping dementia victims, and there have been all kinds of science fiction stories covering that ground, including movies like Total Recall and Johnny Mnemonic. I suspect the reality, when it comes, won’t be nearly so cut and dried. After all, much of what we “remember” is edited and rewritten by our conscious minds, taking pieces of actual memory and combining them with experience and knowledge we’ve acquired along the way. The result can’t possibly be like the precise and well-organized data computers like to receive, and it certainly won’t “play back” like a piece of video. At best, a replay would be like a dream state, where we often jump from one scene or setting to another without any linking moments between. The continuity and context could easily be lost. So I suspect the closest anyone will come to returning a lost memory will be to take the retrievable highlights, and then string them together with manufactured filler in a way someone or some machine thinks will make sense. Kind of like one of those Hollywood movies “based on a true story”. Entertaining, maybe. But a preservation of a real past? Not hardly.