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5 neuroscience reality checks, from a top neuroscientist
In his new book, The Deep History of Ourselves, Joseph LeDoux explains where we come from.
- In his latest book, neuroscientist Joseph LeDoux challenges current assumptions about emotions and consciousness.
- LeDoux investigates the origins of life on this planet dating back four billion years.
- His book is a reminder that humans share the planet with a diverse array of animals and that, while unique, consciousness is not the only trait worth celebrating.
In his new book, The Deep History of Ourselves: The Four-Billion-Year Story of How We Got Our Conscious Brains, neuroscientist Joseph LeDoux assigns himself the simple tasks of explaining how consciousness developed and redefining how we create and experience emotions.
Obviously, I'm being facetious. There's nothing simple about these tasks, yet in LeDoux's capable hands the reader is led, step by step, through the past four billion years of life on this planet. Consciousness, a phenomenon responsible for your ability to read and understand these words (as well as much, much more), often feels like a given, yet that's only because human life is short and evolution is so very long.
LeDoux writes about history splendidly. In his last book, Anxious (which I write about here and here), he investigates the development of nervous systems, entertaining the prospect that anxiety and fear are not innate physiological states but rather assembled experiences that can be sorted through and overcome. Throughout the book he overturns common assumptions about behavior and cognition.
Ditto Deep History. LeDoux writes that consciousness is "often a passive observer of behavior rather than an active controller of it." This conflicts with the assumption that every decision we make is of our own volition. He also argues that emotions "are cognitively assembled states of autonoetic consciousness," products of the same processes experienced via higher-order circuitry. Emotions are not separate from thoughts; they too are created in our nervous system by the same mechanisms.
From a 30,000-foot view, this makes sense. Humans did not arrive on the planet whole-cloth. We are constructed from parts that started self-assembling billions of years ago, the consequence of billions of years of chemistry, biology, and physiology. Deep History is an engrossing investigation of the human condition through the lens of ancient evolutionary history.
No single summation could suffice to cover this book's depth and complexity, nor should it—some arguments take time to unfold. Below are five fascinating passages pulled from the brain of one of the most thoughtful neuroscientists alive.
Survival precedes behavior.
It's easy to believe there's a reason for every action, yet reason comes after the survival instinct. Humans do many things for seemingly strange (or no) reason, only later attempting to explain the cognitive process that led to the action—filling in a psychological gap rather than actually defining the event. The mind likes to insert itself in places even—and especially—when it's late to the game.
"Behavior is not, as we commonly suppose, primarily a tool of the mind. Of course, human behavior can reflect the intentions, desires, and fears of the conscious mind. But when we go deep into the history of behavior, we can't help but conclude that it is first and foremost a tool of survival, whether in single cells or more complex organisms that have conscious control over some of their actions. The connection of behavioral to mental life is, like mental life itself, an evolutionary afterthought."
Neuroscience is, relatively speaking, still new.
It is common to assign certain brain regions as responsible for the creation and/or management of functions, which is a bit misleading. As far as neuroscience has advanced the field is still in its infancy. Brain scans track blood flow; that does not mean specific functions are limited to that region. (Of course, as LeDoux's friend and mentor, Michael Gazzaniga (listen to my interview with him here) has shown in his work in split-brain patients, localization does matter in certain regards; LeDoux even co-wrote a book with him on the topic.)
"Functions are not, strictly speaking, carried out by areas, or even by neurons in areas. They come about by way of circuits that consist of ensembles of neurons in one area that are connected by nerve fibers of axons to ensembles in other areas, forming functional networks. As with other features, the wiring pattern of sensory and motor systems is evolutionarily conserved across the vertebrates."
Don't get comfortable.
We like to believe ourselves to be separate from our environment. This is a false assumption. Life has always been about the interaction of species within their environment. Humans are no different. As everyone on the planet is experiencing the consequences, to varying degrees, of climate change, Darwinian fitness matters. Those trying to coast by on previous standards might find themselves in a rough situation.
"What works in a given environmental situation is determined by natural selection, but as the environment changes, or the group moves to a new niche, new traits become important and previously useful traits become detriments."
Pain is a state of mind.
LeDoux writes that pain and pleasure are often treated as emotions, but that's not quite true. There are no specific receptors for fear, joy, or anger. By contrast, certain receptors are activated when experiencing pain or pleasure, yet even those are subjective. For example, certain painful sensations are required for one person's erotic pleasure, while in others those same sensations might be translated as traumatic. Even chronic pain, it turns out, can be overridden at times.
"If a person with chronic pain is distracted by a funny joke, he does not experience the pain while laughing. The nociceptors are still responding, but the subjective pain is not noticed."
Humans are unique. So is every species.
Many people believe Homo sapiens represent the apex of the animal world. Some even believe we have a divine mandate to lord over other species. In reality, we are a quick blip in the long history of species. LeDoux points out factors that truly make humans unique—language, autonoesis, complex emotions. He also warns against the dangers of anthropocentrism and anthropomorphism. Fitness means adapting to the environment. Over the course of the last century we've arguably accomplished the opposite.
"Differences, while important in defining a species, do not endow some with greater value than others in the vast scheme of life. We may prefer the kind of life we lead, but in the end there is no scale, other than survivability, that can measure whether ours is a better or worse kind of life, biologically speaking, than that of apes, monkeys, cats, rats, birds, snakes, frogs, fish, bugs, jellyfish, sponges, choanoflagellates, fungi, plants, archaea, or bacteria. If species longevity is the measure, we will never do better than ancient unicellular organisms."
How would the ability to genetically customize children change society? Sci-fi author Eugene Clark explores the future on our horizon in Volume I of the "Genetic Pressure" series.
- A new sci-fi book series called "Genetic Pressure" explores the scientific and moral implications of a world with a burgeoning designer baby industry.
- It's currently illegal to implant genetically edited human embryos in most nations, but designer babies may someday become widespread.
- While gene-editing technology could help humans eliminate genetic diseases, some in the scientific community fear it may also usher in a new era of eugenics.
Tribalism and discrimination<p>One question the "Genetic Pressure" series explores: What would tribalism and discrimination look like in a world with designer babies? As designer babies grow up, they could be noticeably different from other people, potentially being smarter, more attractive and healthier. This could breed resentment between the groups—as it does in the series.</p><p>"[Designer babies] slowly find that 'everyone else,' and even their own parents, becomes less and less tolerable," author Eugene Clark told Big Think. "Meanwhile, everyone else slowly feels threatened by the designer babies."</p><p>For example, one character in the series who was born a designer baby faces discrimination and harassment from "normal people"—they call her "soulless" and say she was "made in a factory," a "consumer product." </p><p>Would such divisions emerge in the real world? The answer may depend on who's able to afford designer baby services. If it's only the ultra-wealthy, then it's easy to imagine how being a designer baby could be seen by society as a kind of hyper-privilege, which designer babies would have to reckon with. </p><p>Even if people from all socioeconomic backgrounds can someday afford designer babies, people born designer babies may struggle with tough existential questions: Can they ever take full credit for things they achieve, or were they born with an unfair advantage? To what extent should they spend their lives helping the less fortunate? </p>
Sexuality dilemmas<p>Sexuality presents another set of thorny questions. If a designer baby industry someday allows people to optimize humans for attractiveness, designer babies could grow up to find themselves surrounded by ultra-attractive people. That may not sound like a big problem.</p><p>But consider that, if designer babies someday become the standard way to have children, there'd necessarily be a years-long gap in which only some people are having designer babies. Meanwhile, the rest of society would be having children the old-fashioned way. So, in terms of attractiveness, society could see increasingly apparent disparities in physical appearances between the two groups. "Normal people" could begin to seem increasingly ugly.</p><p>But ultra-attractive people who were born designer babies could face problems, too. One could be the loss of body image. </p><p>When designer babies grow up in the "Genetic Pressure" series, men look like all the other men, and women look like all the other women. This homogeneity of physical appearance occurs because parents of designer babies start following trends, all choosing similar traits for their children: tall, athletic build, olive skin, etc. </p><p>Sure, facial traits remain relatively unique, but everyone's more or less equally attractive. And this causes strange changes to sexual preferences.</p><p>"In a society of sexual equals, they start looking for other differentiators," he said, noting that violet-colored eyes become a rare trait that genetically engineered humans find especially attractive in the series.</p><p>But what about sexual relationships between genetically engineered humans and "normal" people? In the "Genetic Pressure" series, many "normal" people want to have kids with (or at least have sex with) genetically engineered humans. But a minority of engineered humans oppose breeding with "normal" people, and this leads to an ideology that considers engineered humans to be racially supreme. </p>
Regulating designer babies<p>On a policy level, there are many open questions about how governments might legislate a world with designer babies. But it's not totally new territory, considering the West's dark history of eugenics experiments.</p><p>In the 20th century, the U.S. conducted multiple eugenics programs, including immigration restrictions based on genetic inferiority and forced sterilizations. In 1927, for example, the Supreme Court ruled that forcibly sterilizing the mentally handicapped didn't violate the Constitution. Supreme Court Justice Oliver Wendall Holmes wrote, "… three generations of imbeciles are enough." </p><p>After the Holocaust, eugenics programs became increasingly taboo and regulated in the U.S. (though some states continued forced sterilizations <a href="https://www.uvm.edu/~lkaelber/eugenics/" target="_blank">into the 1970s</a>). In recent years, some policymakers and scientists have expressed concerns about how gene-editing technologies could reanimate the eugenics nightmares of the 20th century. </p><p>Currently, the U.S. doesn't explicitly ban human germline genetic editing on the federal level, but a combination of laws effectively render it <a href="https://academic.oup.com/jlb/advance-article/doi/10.1093/jlb/lsaa006/5841599#204481018" target="_blank" rel="noopener noreferrer">illegal to implant a genetically modified embryo</a>. Part of the reason is that scientists still aren't sure of the unintended consequences of new gene-editing technologies. </p><p>But there are also concerns that these technologies could usher in a new era of eugenics. After all, the function of a designer baby industry, like the one in the "Genetic Pressure" series, wouldn't necessarily be limited to eliminating genetic diseases; it could also work to increase the occurrence of "desirable" traits. </p><p>If the industry did that, it'd effectively signal that the <em>opposites of those traits are undesirable. </em>As the International Bioethics Committee <a href="https://academic.oup.com/jlb/advance-article/doi/10.1093/jlb/lsaa006/5841599#204481018" target="_blank" rel="noopener noreferrer">wrote</a>, this would "jeopardize the inherent and therefore equal dignity of all human beings and renew eugenics, disguised as the fulfillment of the wish for a better, improved life."</p><p><em>"Genetic Pressure Volume I: Baby Steps"</em><em> by Eugene Clark is <a href="http://bigth.ink/38VhJn3" target="_blank">available now.</a></em></p>
A leading British space scientist thinks there is life under the ice sheets of Europa.
- A British scientist named Professor Monica Grady recently came out in support of extraterrestrial life on Europa.
- Europa, the sixth largest moon in the solar system, may have favorable conditions for life under its miles of ice.
- The moon is one of Jupiter's 79.
Neil deGrasse Tyson wants to go ice fishing on Europa<div class="rm-shortcode" data-media_id="GLGsRX7e" data-player_id="FvQKszTI" data-rm-shortcode-id="f4790eb8f0515e036b24c4195299df28"> <div id="botr_GLGsRX7e_FvQKszTI_div" class="jwplayer-media" data-jwplayer-video-src="https://content.jwplatform.com/players/GLGsRX7e-FvQKszTI.js"> <img src="https://cdn.jwplayer.com/thumbs/GLGsRX7e-1920.jpg" class="jwplayer-media-preview" /> </div> <script src="https://content.jwplatform.com/players/GLGsRX7e-FvQKszTI.js"></script> </div>
Water Vapor Above Europa’s Surface Deteced for First Time<span style="display:block;position:relative;padding-top:56.25%;" class="rm-shortcode" data-rm-shortcode-id="9c4abc8473e1b89170cc8941beeb1f2d"><iframe type="lazy-iframe" data-runner-src="https://www.youtube.com/embed/WQ-E1lnSOzc?rel=0" width="100%" height="auto" frameborder="0" scrolling="no" style="position:absolute;top:0;left:0;width:100%;height:100%;"></iframe></span>
Scientists discover burrows of giant predator worms that lived on the seafloor 20 million years ago.
- Scientists in Taiwan find the lair of giant predator worms that inhabited the seafloor 20 million years ago.
- The worm is possibly related to the modern bobbit worm (Eunice aphroditois).
- The creatures can reach several meters in length and famously ambush their pray.
A three-dimensional model of the feeding behavior of Bobbit worms and the proposed formation of Pennichnus formosae.
Credit: Scientific Reports
Beware the Bobbit Worm!<span style="display:block;position:relative;padding-top:56.25%;" class="rm-shortcode" data-rm-shortcode-id="1f9918e77851242c91382369581d3aac"><iframe type="lazy-iframe" data-runner-src="https://www.youtube.com/embed/_As1pHhyDHY?rel=0" width="100%" height="auto" frameborder="0" scrolling="no" style="position:absolute;top:0;left:0;width:100%;height:100%;"></iframe></span>
Answering the question of who you are is not an easy task. Let's unpack what culture, philosophy, and neuroscience have to say.
- Who am I? It's a question that humans have grappled with since the dawn of time, and most of us are no closer to an answer.
- Trying to pin down what makes you you depends on which school of thought you prescribe to. Some argue that the self is an illusion, while others believe that finding one's "true self" is about sincerity and authenticity.
- In this video, author Gish Jen, Harvard professor Michael Puett, psychotherapist Mark Epstein, and neuroscientist Sam Harris discuss three layers of the self, looking through the lens of culture, philosophy, and neuroscience.