Archive for the 'Neuroscience' Category

Is perception memory?

I’ve talked quite a bit about the how the brain perceives sensations, particularly pain. My general take has been that our sensory processes are not totally honest – sometimes you feel something is cold when it isn’t, sometimes you see things that aren’t there or vice versa (“I looked on the couch three times for my missing keys, and on the fourth, there they were.”) To some degree, our senses can’t be trusted.

I’ve been reading an interesting book called “World Wide Mind” which covers various topics related to integrating technology into our brain and bodies. It has a section on perception that is thought provoking. The book argues that our sensory experience of doing something is based on more than just the information we get from our nerves, but from our memories of similar experiences! (From pages 81-82.)

When your fingers touch [a doorknob], confirmatory signals flow up the nerves. But… the signals from your hand constitute only a fraction of your conscious experience of the doorknob. Your brain already knows that the doorknob is round, metallic and slightly warm, so it fills in those perceptions from memory rather than generating them from your finger nerves. The reason it does this is because it is more efficient to do so. Analyzing raw perceptions takes a lot of time and energy. It is much simpler for the brain to evoke the memory you have of the doorknob and let that constitute most of your conscious experience of it.

Obviously this theory can explain subjective experience during a short term period, like when you touch a doorknob, but I wonder if it explains a longer term human behavior. We’ve all seen people who say things like, “I can’t believe I let you talk me into going to Disneyland. The last three times I was there, I hated it and I know I’m going to hate it this time.” And hate it they do. But are they really experiencing Disneyland in the now, or the Disneyland of their memories? (I’m not saying they are actually lost in some reverie of the past, but that their memories are in some way coloring their current experience.)

Our canine brothers

An interesting NY Times article argues that canine neurological function is – at least in some ways – similar to our own.

Although we are just beginning to answer basic questions about the canine brain, we cannot ignore the striking similarity between dogs and humans in both the structure and function of a key brain region: the caudate nucleus.

Specific parts of the caudate stand out for their consistent activation to many things that humans enjoy. Caudate activation is so consistent that under the right circumstances, it can predict our preferences for food, music and even beauty.

In dogs, we found that activity in the caudate increased in response to hand signals indicating food. The caudate also activated to the smells of familiar humans. And in preliminary tests, it activated to the return of an owner who had momentarily stepped out of view. Do these findings prove that dogs love us? Not quite. But many of the same things that activate the human caudate, which are associated with positive emotions, also activate the dog caudate. Neuroscientists call this a functional homology, and it may be an indication of canine emotions.

It is a bit of a stretch to conclude that because dog brain components activate in a way similar to ours then they must experience life in the same manner as we do. But it is a step towards that conclusion. And if science does determine that dogs (and likely other animals of similar sentience) feel emotions as humans do, then mankind is going to have to breath in a collective gasp at how we’ve often treated dogs throughout history.

The piece reminds me of an article I once wrote on the topic of morality. It was entitled, “You Think You’re a Good Person? You’re Not!” At one point I said:

By studying the past, and gaining a sense of the evolution of morality, perhaps we can intuit where it is headed. I’ve long felt that there will be a wide expansion of animal-rights in the coming centuries. As animals are revealed to be more and more intelligent and emotive, and as the possibility of “growing meat” becomes reality, there will be increased pressure on the meat industry to soften its ways, or even dissolve completely. (The Spanish government is even currently debating vastly increased legal protections for gorillas.) And some scientists are already arguing that plants have an emotional life, so plant rights may not be far behind. Of course many a science fiction author has painted futuristic scenarios where pieces of technology — computers and robots — demand protection under the law. And in this future era, they will look back at citizens of our age — meat eating, gardening, robot abusing bastards — and be shocked at our cruelty much the same way we are appalled at the behavior of slave owning aristocrats of the 1800s.

Our defining years

Though it’s long, this Daily Beast article arguing that the Millennial generation is to the left of even the Democratic Party makes sense to me. Its core argument is that Millennials came of age in a decade of unending economic insecurity and, as a result, expect the hand of government to address this.

The article also makes an interesting point I can relate to psychology and brain science. (I’m sure everyone is excited by that.)

For Mannheim, generations were born from historical disruption. As he argued—and later scholars have confirmed—people are disproportionately influenced by events that occur between their late teens and mid-twenties. During that period—between the time they leave their parents’ home and the time they create a stable home of their own—individuals are most prone to change cities, religions, political parties, brands of toothpaste. After that, lifestyles and attitudes calcify. For Mannheim, what defined a generation was the particular slice of history people experienced during those plastic years. A generation had no set length. A new one could emerge “every year, every thirty, every hundred.” What mattered was whether the events people experienced while at their most malleable were sufficiently different from those experienced by people older or younger than themselves.

On one hand this is hardly news – it’s well known that a person’s (or generation’s) character is largely defined by the culture of their late teens to mid-twenties. I, for example, will always be defined by and partial to the music of Guns-n-Roses, Nirvana (even if I’m not a fan) and movies like “Die Hard” or “Pulp Fiction.” The article is simply carrying idea this over to politics, making the claim that political events that occur in your teen/twenty-something years have a stronger effect than political events that occur earlier or later. (This makes sense. Whenever I hear people older than me ranting about Reagan I think, “Jesus, get over it!”)

But there’s an interesting question here: Why? Why are our tastes and politics defined by experiences in our teens and twenties? I would argue it’s because that is a period when our brain is primed to most richly experience life. At that point our brains have become sharpened in the sense that we’ve learned much of what we need to become adults, but we still have an active emotional system (the somewhat controversial limbic system.) We are thinking and reasoning better than we ever have, but we are also enjoying the emotional depth of life in ways we will likely lose in coming years. Because of these brain changes, life is exciting and thus the events of those years – personal, cultural, historical and political events – have a pronounced effect on us. As a result, when we get older and jaded and tired, we don’t fully appreciate how the current teen/twentysomething generation is reacting to events.

Put your left brain in, put your left brain out…

Educated readers doubtless recall my old Acid Logic article “What is Morality?” in which I argued that our sense of morality is less a thought out, reasoned set of rules and more an ethereal sense that is actually physically felt in our body. We avoid doing bad not because we are intellectually opposed to it, but because contemplating bad acts makes us feel uncomfortable.

As mentioned, I’ve been reading Mike Gazzaniga’s book on free will, “Who’s In Charge?”, and he discusses some observations relevant to the morality issue. Gazzaniga is most famous for studying “split brain patients.” These are people, usually epileptic, who’ve had the series of neural fibers that connect their left and right brain hemispheres separated (for therapeutic reasons.) Gazzaniga came to find that in subtle ways these people are really of two minds. The right hemisphere is very literal and has no language function. The left hemisphere is the interpreter (e.g. it can construct stories and explanations – often incorrectly – from observed events), and has rich language functionality.

In the book, Gazzaniga notes the work of another neuroscientist who discovered that when we use our knowledge of other people’s beliefs and intent, we use a particular brain area in the right hemisphere. Gazzaniga was surprised by this because he presumed this would mean that the left brain in split brain patients (the talky brain) would be incapable of keeping track of people’s intentions. He designed a series of experiments to suss this out. Basically this involved asking patients questions like, “If Susie gives what she thinks is sugar but actually is poison to her boss, is she bad?” or the inverse, “If Susie gives her boss sugar that she thinks is poison, is she ok?” These questions, as you can see, are all about Susie’s intent. And, as Gazzaniga’s predicted, the split brain patients (or at least their talking left side) focused on the outcome of the actions, not the intent. It didn’t matter that Susie was trying to kill her boss if it all worked out okay.

It would seem that morality is a series of brain functions. If a piece is missing (or inaccessible), our moral function gets warped, at least by the standards of society.

Synaptic re-calibration

The premise of this “Connectome” book I’ve been reading is that we can get to the very essence of a person by mapping the specific way their neurons connect within their brain. Neurons connect with each other, as you probably know, via points called synapses. At a synapse, one neuron fires a blast of chemicals (neurotransmitters) to a receiving neuron. If the second neuron gets enough of these sorts of signals it will fire an electrical signal and send its own signals to other neurons down the line. Thus, “Connectome” argues, if we can map out all these synaptic connection points we can basically map out a personality. (There’s more to it than that but that’s the big picture.)

This opens up an interesting sci-fi concept. Could we get to a point where we could perform a kind of synaptic re-calibration – going into the brain and strengthening or removing synaptic connections to create more desirable personalities? Perhaps this would be done under court order – pedophiles would be calibrated to lose their dark urges, for example. Or perhaps we could chose to do so – introverts could become less shy.

Dream girls

I had an interesting dream last night in which I was talking to a girl I used to know. It was definitely her, even though she didn’t exactly look like her. One difference was that the dream girl had this weird bent tooth which the real girl does not have. She did have, however, the large breasts that I so fondly remember.

I woke up and was thinking about the dream. It struck me that I have another female friend who has large breasts and also has that weird bent tooth. My dream factory sort of borrowed this trait from one friend and glued it onto another.

This ties into my earlier post about the discovery of a neuron that only fires when people see pictures of Jennifer Anniston. I’ve seen this explained as follows: the Jennifer Anniston neuron is at the end of a long chain of neural “units” that individually recognize certain traits. Maybe one unit recognizes blue/grey eyes, another a pointy chin, another a diminutive physique, another tan skin etc. When all these units are active they end up firing off this neuron at the end of the chain which says, “Yay! Jennifer Anniston!”

So what happened in my dream? It seems like some wires got crossed and neural units from Girl B (big tits, funny tooth) got fired while thinking about Girl A (big tits, no funny tooth.)

The mind is fascinating.

Here’s some pictures of Jennifer Anniston.

Eternal life via Connectomics

As I’ve mentioned, I’ve been reading a book called “Connectome” which argues that the essence of a human being can be understood to be the way their billions of neurons hook up to each other. The idea presumes that if you can map someone’s neural structure and recreate it (in a biological or electronic model), you would essentially be creating a clone of their mind.

With this idea in mind, we can contemplate ways of living forever. If we can maintain the map of our connectome after we die, we (conceivably) could be re-animated in some form via future technology and be the same person. The problem is that it’s hard to maintain the connectome after death – cellular damage can destroy the map. One way to get around this might be to “freeze” our brains in plastic soon after death – so soon that we would have to do it in a controlled situation; essentially we would have to choose to kill ourselves to have a chance at living forever.

That’s what Kenneth Hayward, a futurist with impressive science credentials, would like to do.

That case is deeply speculative. Here’s how Hayworth envisions his own brain-preservation procedure. Before becoming “very sick or very old,” he’ll opt for an “early ‘retirement’ to the future,” he writes. There will be a send-off party with friends and family, followed by a trip to the hospital. “I’m not going in for some back-alley situation. We need to get the science right to convince the medical community. It’s a very clear dividing line: I will not advocate any technique until we have good proof that it works.”

After Hayworth is placed under anesthesia, a cocktail of toxic chemicals will be perfused through his still-functioning vascular system, fixing every protein and lipid in his brain into place, preventing decay, and killing him instantly. Then he will be injected with heavy-metal staining solutions to make his cell membranes visible under a microscope. All of the water will then be drained from his brain and spinal cord, replaced by pure plastic resin. Every neuron and synapse in his central nervous system will be protected down to the nanometer level, Hayworth says, “the most perfectly preserved fossil imaginable.”

His plastic-embedded brain will eventually be cut into strips, perhaps using a machine like the one he invented, and then imaged in an electron microscope. His physical brain will be destroyed, but in its place will be a precise map of his connectome. In 100 years or so, he says, scientists will be able to determine the function of each neuron and synapse and build a computer simulation of his mind. And because the plastination process will have preserved his spinal nerves, he’s hopeful that his computer-generated mind can be connected to a robot body.

Easy as pie.

Powerful tools

The neuroscience book I’m currently reading, “Connectome,” makes an interesting point about scientific discovery. Technology is just as much a driver of discovery as the scientists themselves. Without microscopes, telescopes, MRIs etc. none of the discoveries about the brain (and others areas of scientific study) we’ve made would have been possible.

That speaks to, I think, a bias build into the human species. We become fixated on the people making the discoveries but not the devices. You see this in politics too. We get fixated on Anthony Weiner and his downfall but don’t seem that aware of the sea changing effects on society that technology is poised to bring.

The one theme I’ve been thinking about very the past several months is that technology is going to disrupted our lives more and more from now on. And to fixate on people – to expect politicians or scientists or entrepreneurs to slow or stall that disruption (to “save us”) – is a mistake.

We are doomed.

The Jennifer Aniston neuron

Though I spend a lot of time following brain news, I somehow missed this announcement when it first went around. Scientists have discovered a neuron that fires when a person sees pictures of Jennifer Aniston!

In brain surgery, patients are often kept fully conscious, even when they have a probe implanted in their heads. Brains don’t hurt when they’re open, and this is standard procedure; the doctor needs to map the area where there’s going to be surgery, the patient needs to answer the doctor’s questions.

Fried asked his patients if they wouldn’t mind doing a little exploratory science while on the operating table, and a bunch of them said yes.

So he showed them a set of photographs, and he noticed when they came to a picture of Jen, very often a particular neuron would begin to flash, multiple times. When he showed these same patients pictures of Julia Roberts or random (not famous) people, or animals, or places, the neuron was quiet. Back to Jen? Back came the flash. He found this Aniston-specific brain cell in a number of people, and he wondered, what is going on?

A “Halle Berry neuron” was also discovered. A book I’m reading, “Connectome” makes an interesting point about this discovery.

[The] “Halle Berry neuron” was activated by an image of the actress Halle Berry, suggesting that it plays a role in perceiving her. But the neuron was also activated by the written words Halle Berry, indicating that it participates in thinking about her as well. So it seems the “Halle Berry” neuron” represents the abstract idea of Halle Berry…

Mmmm, there’s nothing abstract about Halle Berry and you know what I mean!

The Brain telegraph

The New York Times blog has an interesting post about brain-to-brain and brain-to-computer interfaces. The concept is that we could eventually pass signals from our brain directly to a computer and from there to another brain. (Interestingly, this was a premise in the movie “Pacific Rim” which I saw last night.) The article says…

Writing to the brain could allow us to interact with our computers, or other human beings, just by thinking about it.

In February, Dr. Miguel A. Nicolelis, a neuroscientist at Duke University successfully connected the brains of two rats over the Internet, allowing them to communicate with their minds so when one rat pressed a lever, the other one did the same. The rats were in different locations, one at Duke University, in North Carolina, and another in a laboratory in Natal, Brazil.

Dr. Nicolelis said he has recently performed other experiments in his lab where he has connected the brains of four mice in what he calls a “brain net” allowing them to share information over the Internet. In another experiment, he took two monkeys and gave them both half of a piece of information to successfully move a robotic arm, which required them to share the information through their brain.

Last week scientists at Harvard Medical School created a brain-to-brain interface that enables a human to move a rat’s tail just by thinking about it.

A couple years ago I read a book by Nicolelis and he makes a strong case that a lot of science fiction ideas could become reality.

This is a very interesting section of the article:

In 2011, scientists working in collaboration with Boston University and A.T.R. Computational Neuroscience Laboratories in Kyoto, Japan, published a paper on a process called Decoded Neurofeedback, or “DecNef,” which sends signals to the brain through a functional magnetic resonance imaging machine, or FMRI, that can alter a person’s brain activity pattern. In time, these scientists believe they could teach people how to play a musical instrument while they sleep, learn a new language or master a sport, all by “uploading” information to the brain.

If we presume (correctly, I think, though it’s hard to verify) that a person’s brain changes in a predictable way after learning to play a song, and that we can notate those changes, then, in theory, we should be able to affect those changes in someone else’s brain (via some kind of electrical or magnetic stimulation?) and teach them the song. However, it’s not that simple since no two brains are exactly the same. It’s possible that enacting brain changes to teach a person how to play “Greensleeves” could instead turn them into a cannibalistic killer with lasers for eyes.