Tuesday, November 12, 2013

Where Does "Identity" Come From?

 (You, Your Brain, and the Nature vs. Nurture Debate)




Imagine your life is a tape, and we rewind it. All your accomplishments, awards, and graduations are erased. Your experiences move in reverse, and you grow smaller and smaller, as you were as a child. Your adult teeth turn back into baby teeth, and eventually retract completely, while all of your traits and quirks start to fade away. Pretty soon language goes away too, and you’re no longer you, but potential you. The tape continues rewinding, halving colonies of your cells until finally we arrive at the amazing singular miracle: the one cell that will evolve to become you.

Now, the question is this: what happens when we press “play” again? The common battle between nature versus nurture arises – the question that psychologists and scientists everywhere are prodding, probing, and researching to figure out. Are your talents, traits, and personal characteristics deeply embedded in your genes? Is what makes you you implanted in the DNA of our cells? Or could things completely change who we are with a few simple nudges? To put it simply – how much of your fate do you believe depends on your genes, your surroundings, or merely just by chance?

Since we can’t rewind time, Julia Freund and her colleagues found another way to better answer this question in a simple but remarkable recent study. To test the nature-versus-nurture phenomenon, Freund and her investigators placed genetically identical mice in a common environment, and tested to see whether systematic behavioral differences still could emerge. By answering “yes,” it would mean that there are sources of behavioral variability (intrinsic individuality, if you will) that could be unaccounted for by a combination of common genes and a common environment.

For the experiment, 40 genetically identical mice were placed in an “enriched” environment, where Freund monitored their behavior for a period of three months (which, for mice, is about 10-15% of their entire lifespan). The enriched environment was about 36 square feet, engineered to include multi-tiered platforms, nesting boxes, and interconnected tubes in order to promote exploratory behaviors in the mice that would not exist in a normal confined cage. What makes this study different from one of human twins is that by using mice, the subjects’ movements could be recorded with extraordinary detail over a major period of their lifespan. A radiofrequency ID transponder was placed on every mouse, measuring their every movement, chase, and sedentary period.

In order to measure the differences in behavior between the mice, the investigators used a gage called “roaming entropy.” Roaming entropy captures how often you get out, and with how much variety – so basically if you are someone who just darts back and forth (say from your dorm room to Van Pelt…) your roaming entropy is low. But if you’re the type of person who could pretty much be anywhere at any given time, you have a high roaming entropy. At the beginning of the study, the mice all had fairly similar roaming entropies… however, as the weeks progressed, the population diverged significantly, with some mice being much more exploratory and active than others. If you take the tendency to explore as a characteristic trait, then this is obviously one that elaborates and changes over time in a way that isn’t strictly determined by genes or the environment.

However, the most interesting part of the study arose when Fruend and her team examined the changes in brain activity that went along with the changes in exploratory behavior. Before the experiment was over, the mice were injected with a compound that selectively incorporates itself into dividing cells. This basically means that the compound can show researchers which neurons are formed in adulthood, and which neurons the mice were born with. While most of our neurons are formed during early development, there are a good number of well-studied brain areas that continuously produce new neurons throughout our adult lives.

Surprisingly, the mice that were the most exploratory throughout the study (who exhibited the most outgoing behavior) were also those who experienced the greatest production of adult-born neurons. While we can’t say this particularly proves anything, the results are still pretty intriguing. Even after your genes are set in stone from birth, and the majority of your environmental surroundings are laid firm throughout your early development, your brain maintains the raw potential to grow its own new neurons. The investigators of this study propose that these neurons are involved in tailoring and tuning our behaviors, implying that the way we live our lives may make us who we are.


So, how does this happen? We don’t actually know. No disrespect intended to these researchers, but any experiment addressing such a controversial, profound, and metaphysically-tangled problem as the nature-vs.-nurture debate is going to generate more questions than answers. It could be that epigenetic changes, where experience modifies gene expression, gives rise to completely different life paths. It can also be questioned just how substantial the differences in roaming entropy could actually be, and whether it was actually statistically significant. Regardless of the specifics and questions left to be answered, this experiment is a reminder that our lives are truly a work in progress. Whether it is our genes, our environments, or generation of adult born neurons, the nature versus nurture debate is yet to be solved. But it seems that if we are living out our lives as a sort of tape, then it’s a tape in which the tracks can be tweaked as they’re read, as our genes can be modified as we live. As your brain is shaped by your life and vice versa, there is so much room for chance and noise – room for you to become you.

Saturday, November 9, 2013

The Prophetic Brain: Foretelling Your Future

The act of fortune telling is an ancient practice. Chinese diviners burnt turtle shells and studied the resulting cracks to make a host of predictions, including future crop conditions and weather forecasts, and ancient Greeks read animal entrails in their divinatory practices. While the modern scientific community regards fortune telling as mere hogwash, brain science is starting to use genetic information, environmental conditions, and brain structure to predict an individuals future actions. Neuroscientists could become the oracles of our era.
One such scientist is Penn professor and neurocriminologist Adrian Raine. In his controversial research, Dr. Raine proposes that the structure of the brain may provide insight into an individual’s propensity to commit a violent crime. In fact, he argues that future criminal offending can be predicted in children as young as three years. In one experiment, Dr. Raine studied 1,800 three-year-old children from the tropical island of Mauritius in the Indian Ocean. In his longitudinal study, he followed subjects for 20 years, noting any criminal convictions. He then compared the criminals with the noncriminals and discovered that the former demonstrated a lack of fear as children.*
Although the findings of Dr. Raine's research are intriguing, the environmental and biological affects on brain and behavior ought to be examined. Child abuse, cigarette smoking and alcohol consumption during pregnancy, and poor nutrition give scientists great predictive power regarding individuals' outcomes. For example, children of moms who smoked tobacco while pregnant were 2-3 times more likely to be violent criminals by age 20, and pregnant women who consumed just 1 drink per week birthed children who were 30% more aggressive than their peers. Poor nutrition during prenatal and postnatal development also leads to greater antisocial behaviors in children.
Additionally, genetics, brain structure and function, and testosterone levels have a tremendous influence on behavior. Using EEG to study the electrical activity of prisoners' brains, Dr. Raine noted that violent criminal offenders demonstrated poor-functioning prefrontal cortexes, the part of the brain associated with the regulation of behavior and emotions. The amygdala, which is responsible for emotions, is also implicated in antisocial tendencies.  For example, sociopaths have been shown to have an amygdala 18% smaller than individuals without sociopathy.
While it is extremely enticing to regard the brain as quasi-prophetic, it is necessary to consider the ethical dilemmas and misguided conclusions that can be drawn from related research. The following questions are helpful in understanding the consequences of such work: Could neuroscience research be used to fuel a eugenics movement? Is it possible to reduce antisocial tendencies in adulthood by enriching the brain in childhood? Are brain structure and function reliable predictive measures? Does brain structure lead to violent behavior, or does a violent lifestyle lead to changes in the brain? Dr. Raine explores some of these concerns and more in Radio Times with Marty Moss-Coane.
*The amygdala is critical in fear conditioning.

Wednesday, November 6, 2013

Welcome to the Mind-Meld

The way that current research is progressing, our brains may be closer than we ever thought… Ever wanted to know what someone else was thinking? We may have found the answer to connecting human minds – not only figuratively, but literally. Very literally.

Picture this: a scientific experiment, involving two rats. The first rat pressed a lever, as it was trained to, anticipating the reward it would receive for completing the task. An implant in this rat’s brain then converted its neural activity into an electrical signal and beamed the impulse to the second rat. The second rat then jumped forward to press the lever in its own cage… but this rat had never been trained to ever press a lever. The movement impulse it had to press the lever came not from its own mind, but directly from the brain of the first rat, who was in fact thousands of miles away.

What was created in 2012 by lead researcher Miguel Nicolelis was “a new central nervous system made of two brains.” After successfully connecting the brains of two rats, other labs were quick to pick up on the research and one-up Nicolelis’s experiment. A team of researchers at Harvard University engineered a brain-to-brain interface between a human and a rat in the summer of 2013 that enabled the human to control the rat’s tail movements by merely willing them to happen. Pretty crazy…

Then in August 2013 came the final leap that everyone had been waiting for. Scientists Andrea Stocco and Rajesh Rao from the University of Washington successfully created science’s first human-to-human brain-to-brain interface. One person was strapped into a transcranial magnetic stimulation (TMS) helmet, while the other was strapped into a non-invasive electroencephalogram (EEG) helmet – the two researchers became successfully mind-melded in the name of all things science.

The Experiment:
Rajesh Rao and Andrea Stocco, one strapped into each type of helmet, were placed across campus from one another while watching the same video game. Rao was wearing an EEG helmet, a non-invasive device that detects the neuronal firing activity of millions of different neurons underneath the skull. He was also in charge of the controls of the video game, but instead of actually using his hand to hit the spacebar and fire on the video game, he simply imagined moving his hand. Each time he made the conscious thought to fire, an instantaneously fast computer converted the brain signals emitted by Rao’s EEG helmet into a digital signal which was then beamed to a TMS helmet on Stocco’s head. A transcranial magnetic stimulation helmet (also non-invasive) electrically stimulates neurons in particular areas of the brain by creating a small electric current. The helmet attached to Stocco’s head converted Rao’s signals into bursts of magnetic stimulation that were delivered to the exact region of Stocco’s motor cortex that controlled his right hand. The signal would cause Stocco’s hand to involuntarily twitch, sometimes even scoring a hit in the game.

Rao stated that the experience felt very different for both of them. “For me, it was only ater the action had occurred that I had the chance to reflect upon what had happened – that it was Stocco’s hand, stimulated by my brain signal, that had caused the action. That realization was both exciting and a bit eerie.” For Stocco, all that was really felt was an involuntary muscle twitch that caused his hand to move and hit the keyboard. There was no conscious “need” to flex the muscle, he said, because the entire sequence from stimulation to movement happened within a few milliseconds. Moreover, Rao noted about Stucco, “I don’t think he can resist the movement once he’s received the stimulation, since it operates at the subconscious level.” Definitely pretty eerie…

Test Hurdles:
Even with the level of connectivity that was reached at the sub-conscious level, the process revealed that it wasn’t flawless or error-free – and this exposed some interesting discoveries about how our brains process information.

The EEG device used by Rao (which sent the outgoing brain signals) uses technology dating all the way back to 1875. Although today’s advancements in technology are obviously far greater than those of 150 years ago, they still operate on the same basic principle. Electrodes are placed across a person’s scalp that pick up frequencies oscillating within that person’s brain. Because of this, EEG signals can’t pinpoint activity to a specific 3-dimensional point in the brain, but they are handy for tracking large-scale brain impulses. TMS technology is much more recent – and much more controversial as well. It works by disrupting activity deep within the brain by using electrical signals, and some researchers have even reported seizures being triggered as a side effect of TMS. However, most researchers today agree that the risk is small, and many have succeeded in using this technology to trigger movement, increase memory, and treat depression. Rao and Stocco also both agreed to use these procedures because they were non-invasive, making this technology the clear choice. “Andrea and I got really excited about the idea, and we started brainstorming,” he said.

Leading up to the experiment, Rao had to go through quite a bit of brain training in order to successfully execute the experiment. “EEG signals are quite hard to use for controlling devices,” he explained, “because the signal is a weak, noisy, filtered version of the underlying brain activity.” Any extra movement of the eyes, face, or body—or even stray thoughts—could interfere with the signals and give false readings. Rao had to learn, through trial and error, how to control his EEG output more accurately by remaining focused. Finally, in the last session, Rao and Stocco achieved nearly 100% accuracy in the test.

What Now?

Now that scientists have created a full-blown mind-meld, what next? One of the important things to note is that the experiment was built on technology that’s rapidly becoming part of the consumer marketplace, as TMS and EEG devices are becoming more readily available. And, even though this test only transmitted movements from one mind to another, it is the hope of scientists that in the future, we could (theoretically) learn to transfer perceptions, concepts, emotions, and even thoughts. Then we would actually be talking about a REAL mind-meld, allowing people to communicate directly through their brains. As long as humans have been around, the need to communicate thoughts clearly and understanding the minds of others has been an overwhelming desire – the fact that we are this close by putting on little plastic helmets to watch what’s happening inside our brains is both exciting and a little bit scary. Where do you stand? Technologies like this might seem to have the potential to turn us all into robots – or edge us towards a future of communication, understanding, and human contact more intimate and direct than we’ve ever experienced. Where do we draw the line between human connection and complete invasiveness? The thin line is becoming a little bit eerie. Still, the effects of the mind-meld are yet to be discovered…




via Discover Magazine, The Crux