Who’s In Charge?

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The celebrated cognitive neuroscientist Michael Gazzaniga has a new book coming soon, Who’s In Charge - about the implications of neuroscientific findings for the law. To promote it, Slate printed an excerpt that asks what it means for responsibility and culpability if free will doesn’t exist.

The idea that “If determinism is true, then no one is responsible for anything” doesn’t have to be true: a person acting criminally is still the most proximal cause of the bad behavior and should be held accountable; the Big Bang isn’t to blame for his criminality. Moreover, by this reasoning, everyone who commits crimes is not responsible because their brains made them do it: if determinism is true, they also had no choice but to ‘sin’. So why should a seemingly healthy offender go to jail (where he doesn’t get rehabilitated and doesn’t learn to not repeat his offenses), while one with a brain tumor or schizophrenia should be treated medically and perhaps even reinstated into society?

These questions, I think, lead us think of determinism and free will as inappropriate for the legal system. If no one has a choice in their behavior, then clinically sick people shouldn’t be treated any differently from anyone else; if no one is responsible for their actions, then sick people aren’t somehow “less responsible” than others.
What emerges is that those who “can’t help” but to act criminally (i.e. the schizophrenics) are treated medically and released back into society when they’re healthy again (psychiatry has a whole lot of catching up to do if that is to actually happen; perhaps neuroscience can help?). So why don’t we also treat those criminals who appear healthy? If their brain made them kill, then there must be something wrong with it. What I’m driving at is that a judicial system based on retribution doesn’t make much sense. Wouldn’t we be far better off if we actually fixed criminals? Perhaps that’s wishful. Or worse, dystopian.

Automated in vivo patch clamp

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Patch clamping is an electrophysiological method used to measure cell dynamics. The setup involves attaching a pulled-glass pipette filled with conductive solution to a cell membrane and recording the currents that pass through that patch of membrane. The technique is notoriously difficult in cultured neurons or brain slices, and even more difficult in live animals (ultimately, the most appropriate system to study). Several scientists have recently developed an algorithm to automate the process, thereby reducing the skill level and time commitment required to perform patch clamp experiments in vivo.

Opto-fMRI

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Opto-fMRI

fMRI has traditionally been used for mapping the brain and correlating brain function with specific structures. The method has become a sort of laughing-stock within the electrophysiological community because of the countless studies that proclaim region A to be responsible for function B. A typical blunder can go like this: “Increased activation of the amygdala during a fear conditioning task suggests that the amygdala is the brain’s fear center.” To be fair, the method is still very useful and serious scientists don’t fall into this fallacy as much as the popular media does. Some outstanding questions are what the measured signal (blood oxygenation level; BOLD) actually means for neural activity; whether it’s possible to disambiguate excitation from inhibition; how activation in one region affects connected regions; and what the causal relationships among activated regions are. To address the last two of these, Ed Boyden and colleagues at MIT used a combination of optogenetics and fMRI (Opto-fMRI) in awake mice. The idea is that if they can change the dynamics of a defined population of cells in a localized and fast way (they infected pyramidal cells in mouse somatosensory cortex with ChR2), the network effects of that activation would be revealed by fMRI. In this way, they validate the network effects in both technologies. One limitation that’s still inherent to fMRI is the slow temporal resolution – while optogenetic stimulation changes membrane potential with millisecond-resolution, fMRI’s hemodynamic response is much slower. Perhaps other imaging methods like multiphoton imaging may be used in the future to dissect large-scale circuits in awake animals.

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Here is a nice interview with Jeff Lichtman of Harvard, who is working on a cellular-level map of synaptic connections in the brain (a connectome). The interview raises several questions, like how can we collect thousands of petabytes (millions of gigabytes) of data of the structure of the brain at the level of individual cells? Do we even need so much data? Even though connectomics won’t reveal much about neural dynamics (i.e. how neurons actually transmit or integrate information), it should be a useful tool for further work in theoretical neuroscience. Someone has to do it.

One caller in this interview asks a great question on the hard problem of consciousness: when scientists look at neuronal activity when one is thinking of a childhood pet, where in the universe is that image of the dog? All the scientists see, after all, is electrical activity…

Optogenetics to Cure Alzheimer’s?

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Preparing for SfN 2011, I have to give a shout-out to one of the coolest emerging technologies in neuroscience, optogenetics. Optogenetics, as everyone no doubt knows by now, is a method that allows researchers to control the electrical activity of neurons using light. Scientists infect certain types of neurons with an algae transmembrane channel protein that allows the flow of ions into a cell when light of preferred wavelength shines upon it. The method has been described well elsewhere (Steve Ramirez waxes poetic about it on the Mind the Gap Junction blog). Optogenetics is an amazing method for many reasons, but mainly because by allowing us to directly activate or silence neurons, it makes it possible to establish causal relationships in neural circuits: if neuron A is hyperactive, the mouse runs around in circles; if A is silenced, perhaps the mouse is unable to run in circles; therefore, activity in neuron A causes the mouse to run in circles.

This is important because traditional electrophysiological methods allow us to only record activity without manipulating it directly (stimulating electrodes are rather crude spatially), and the methods that did allow us to manipulate activity (i.e. pharmacology or stimulating electrodes) have a myriad of effects that make precise causes of behavior unclear (i.e. does TTX act only on sodium channels? Which types? etc).

As optogenetics becomes more and more refined and widespread, I can’t help to wonder what it will do for the most prevalent of neurological diseases. Will this method cure Alzheimer’s? How about Parkinson’s? Optogenetics promises to show us circuit-level interactions among neurons and perhaps even to nail down the network effects of particular diseases. But if we’re looking to find cures for diseases instead of just fixes, we ought to not forget our molecular biologists and maybe even geneticists. That’s not to say that treatments for neurological diseases are worthless! There are, after all, no cures for any brain diseases so far – so anything will be useful. With all this enthusiasm over optogenetics, we have to be honest about its capabilities and limitations.

Fertilized Eggs Are Now People

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The people of Mississippi are set to vote on an initiative to amend the state Constitution to define personhood as starting at the moment of fertilization. If fertilized eggs are people, then abortion is murder. The ballot, which has received widespread bipartisan support and is likely to pass, is rather short and rigid:

Section 33. Person defined.  As used in this Article III of the state constitution, “The term ‘person’ or ‘persons’ shall include every human being from the moment of fertilization, cloning or the functional equivalent thereof.

It’s no surprise Mississippians are against abortion; what’s interesting is that people still turn to religion to answer seemingly scientific questions like when a human should be considered a person. NPR’s Michael Martin covers the topic by interviewing religious leaders:

Now, when voters are asked to consider a weighty moral issue such as this, some turn to their faith for answers, so in a minute we’ve decided to turn to two religious leaders who are on opposite sides of this question.

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Trendy Lines for Coffee and Depression

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“Can drinking coffee help stave off depression?”, writes Anahad O’Connor for Tara Parker-Hope’s Well Blog on the New York Times. A new paper in The Archives of Internal Medicine by Alberto Ascherio’s group at Harvard School of Public Health shows a dose-dependent trend between daily caffeine consumption and relative risk of depression in women. The authors found that women who drink 4-6 cups of coffee daily have a reduced relative risk of becoming depressed compared to women who don’t drink coffee.

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Wonder and Magic

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Pretty snowflakes are nothing but some water molecules arranged in special hydrogen bond patterns. Lady Gaga’s love songs squeeze and twist your heart only because your brain may be wired to perceive such chord progressions as sad. And your significant-other means the world to you simply because some oxytocin/vassopressin molecules interact with the dopaminergic reward systems during your intimacies. The list goes on, but this is enough to illustrate the pessimism with which some frame scientific knowledge.

The explanation of a feature in terms of its underlying mechanism does not diminish its value. Just because love is not created by magic but by an awesomely complex machine (the brain) doesn’t make it any less wonderful, in the same way that knowing the ingredients and recipe of New England clam chowder doesn’t make it less delicious (I’m afraid the same can’t be said for fois gras or animelles, for different reasons of course). The danger of thinking that a mechanistic explanation of something seemingly magical is bad is that it may impede scientific progress. If our friends on Capitol Hill decide next week that it’s a waste of time to search for the neural basis or evolutionary advantage of music, we may be deprived further of knowledge about the mechanisms of language, emotions and social cohesion. Ignorance may be bliss, but it’s not what started the industrial revolution, the space race or the information age; nor will ignorance cure cancer (fruit-fly research in Paris, France might). Aside from magical parts of human nature, science promises to demystify more sinister ones like violence or racism. What happens if we discover that men have a natural rather than “merely-social” tendency to beat their wives? Does that mean science justifies wife-beating? Not a chance. But we do have to be careful with our facts, since some confuse what is with what ought to be, or worse still – what is natural with what is ought to be.

With scientific explanations of our nature, we will still have magic in our lives. But we can’t go on pretending something is true when it is not. The mystery of music may disappear when you are reading about the brain areas involved in music perception, but it won’t fail to creep up on you when you’re listening to your favorite Beethoven. The question is how to inform the public about the mechanistic nature of everything without them becoming emotionless robots.

 

 

The Hard Problem of Consciousness

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You’re lying on a sandy beach on a hot sunny afternoon, enjoying a few hours of much needed laziness. As you open your eyes and confront the vastness of the ocean in front of you, light of 600nm wavelength hits your retina, kindling an impossibly long cascade of events in your brain: a molecule called retinal changes shape, neurons fire action potentials down the optic nerve, arrive at the lateral geniculate nucleus deep in the brain causing more action potentials in primary visual cortex in the back of your head, and so on ad infinitum. At some point, the mechanical wonder of 100 billion neurons working together produces something special: your experience of the color blue. What’s special is not that you can discriminate that color from others; nor that you are aware of it and paying attention to it. It is not notable that you can tell us about it, or assign a name to it. It’s that you have a subjective, qualitative experience of the color; there is something it is like to experience the color blue. Some philosophers call these experiences qualia – meaning “what kind” – but it is not important what kind of experience you are having, just that you are having one at all. Modern science hypothesizes that subjective experience is a product of the brain, but has no explanation for it. Continue reading →

Is is not Ought

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The killing of Osama bin Laden and the ensuing controversy over the widespread jubilation in the U.S. have prompted some scientists to explain the psychological and evolutionary basis for those celebrations. Unfortunately, some of them used science to argue that since joy in this situation is natural, it is also morally good. Regardless of one’s view on the appropriateness of celebrating a killing, the fact that it is natural to do so has no relation to whether it is moral or right.

Science bases human behavior on the functions of neural networks and evolutionary adaptations, but does not excuse us from taking responsibility for those behaviors. Just as promiscuity may be a natural but not morally inacceptable temptation for males in a monogamous society, natural joy over the killing of an evil man is not necessarily good either. Our values come from philosophy, not empirical evidence. Or, as Hume wrote, what is is not necessarily what ought to be. Continue reading →