We are more than our brains
, July 31, 2018
Brains are undoubtedly somewhat computer-like – computers, after all, were invented to perform brain-like functions – but brains are also much more than bundles of wiry neurons and the electrical impulses they are famous for propagating. The function of each neuroelectrical signal is to release a little flood of chemicals that helps to stimulate or suppress brain cells, in much the way that chemicals activate or suppress functions such as glucose production by liver cells or immune responses by white blood cells. Even the brain’s electrical signals themselves are the products of chemicals called ions that move in and out of cells, causing tiny ripples that can spread independently of neurons.
Also distinct from neurons are the relatively passive brain cells called glia (Greek for glue) that are roughly equal in number to the neurons but do not conduct electrical signals in the same way. Recent experiments in mice have shown that manipulating these uncharismatic cells can produce dramatic effects on behaviour. In one experiment, a research group in Japan showed that direct stimulation of glia in a brain region called the cerebellum could cause a behavioural response analogous to changes more commonly evoked by stimulation of neurons. Another remarkable study showed that transplantation of human glial cells into mouse brains boosted the animals’ performance in learning tests, again demonstrating the importance of glia in shaping brain function. Chemicals and glue are as integral to brain function as wiring and electricity. With these moist elements factored in, the brain seems much more like an organic part of the body than the idealised prosthetic many people imagine.
Stereotypes about brain complexity also contribute to the mystique of the brain and its distinction from the body. It has become a cliché to refer to the brain as ‘the most complex thing in the known Universe’. This saying is inspired by the finding that human brains contain something on the order of 100,000,000,000 neurons, each of which makes about 10,000 connections (synapses) to other neurons. The daunting nature of such numbers provides cover for people who argue that neuroscience will never decipher consciousness, or that free will lurks somehow among the billions and billions.
But the sheer number of cells in the human brain is unlikely to explain its extraordinary capabilities. Human livers have roughly the same number of cells as brains, but certainly don’t generate the same results. Brains themselves vary in size over a considerable range – by around 50 per cent in mass and likely number of brain cells. Radical removal of half of the brain is sometimes performed as a treatment for epilepsy in children. Commenting on a cohort of more than 50 patients who underwent this procedure, a team at Johns Hopkins in Baltimore wrote that they were ‘awed by the apparent retention of memory after removal of half of the brain, either half, and by the retention of the child’s personality and sense of humour’. Clearly not every brain cell is sacred.
If one looks out into the animal kingdom, vast ranges in brain size fail to correlate with apparent cognitive power at all. Some of the most perspicacious animals are the corvids – crows, ravens, and rooks – which have brains less than 1 per cent the size of a human brain, but still perform feats of cognition comparable to chimpanzees and gorillas. Behavioural studies have shown that these birds can make and use tools, and recognise people on the street, feats that even many primates are not known to achieve. Within individual orders, animals with similar characteristics also display huge differences in brain size. Among rodents, for instance, we can find the 80-gram capybara brain with 1.6 billion neurons and the 0.3-gram pygmy mouse brain with probably fewer than 60 million neurons. Despite a greater than 100-fold difference in brain size, these species live in similar habitats, display similarly social lifestyles, and do not display obvious differences in intelligence. Although neuroscience is only beginning to parse brain function even in small animals, such reference points show that it is mistaken to mystify the brain because of its sheer number of components.
Playing up the machine-like qualities of the brain or its unbelievable complexity distances it from the rest of the biological world in terms of its composition. But a related form of brain-body distinction exaggerates how the brain stands apart in terms of its autonomy from body and environment. This flavour of dualism contributes to the cerebral mystique by enhancing the brain’s reputation as a control centre, receptive to bodily and environmental input but still in charge.
Contrary to this idea, our brains themselves are perpetually influenced by torrents of sensory input. The environment shoots many megabytes of sensory data into the brain every second, enough information to disable many computers. The brain has no firewall against this onslaught. Brain-imaging studies show that even subtle sensory stimuli influence regions of the brain, ranging from low-level sensory regions where input enters the brain to parts of the frontal lobe, the high-level brain area that is expanded in humans compared with many other primates.
Many of these stimuli seem to take direct control of us. For instance, when we view illustrations, visual features often seem to grab our eyes and steer our gaze around in spatial patterns that are largely reproducible from person to person. If we see a face, our focus darts reflexively among eyes, nose and mouth, subconsciously taking in key features. When we walk down the street, our minds are similarly manipulated by stimuli in the surroundings – the honk of a car’s horn, the flashing of a neon light, the smell of pizza – each of which guides our thoughts and actions even if we don’t realise that anything has happened.
Even further below our radar are environmental features that act on a slower timescale to influence our mood and emotions. Seasonal low light levels are famous for their correlation with depression, a phenomenon first described by the South African physician Norman Rosenthal soon after he moved from sunny Johannesburg to the grey northeastern United States in the 1970s. Colours in our surroundings also affect us. Although the idea that colours have psychic power evokes New Age mysticism, careful experiments have repeatedly linked cold colours such as blue and green to positive emotional responses, and hot red hues to negative responses. In one example, researchers showed that participants performed worse on IQ tests labelled with red marks than on tests labelled with green or grey; another study found that subjects performed better on computerised creativity tests delivered on a blue background than on a red background.
Signals from within the body influence behaviour just as powerfully as influences from the environment, again usurping the brain’s command and challenging idealised conceptions of its supremacy. [Continue reading…]
A theory of reality as more than the sum of its parts
, July 23, 2018
In his 1890 opus, The Principles of Psychology, William James invoked Romeo and Juliet to illustrate what makes conscious beings so different from the particles that make them up.
“Romeo wants Juliet as the filings want the magnet; and if no obstacles intervene he moves towards her by as straight a line as they,” James wrote. “But Romeo and Juliet, if a wall be built between them, do not remain idiotically pressing their faces against its opposite sides like the magnet and the filings. … Romeo soon finds a circuitous way, by scaling the wall or otherwise, of touching Juliet’s lips directly.”
Erik Hoel, a 29-year-old theoretical neuroscientist and writer, quoted the passage in a recent essay in which he laid out his new mathematical explanation of how consciousness and agency arise. The existence of agents — beings with intentions and goal-oriented behavior — has long seemed profoundly at odds with the reductionist assumption that all behavior arises from mechanistic interactions between particles. Agency doesn’t exist among the atoms, and so reductionism suggests agents don’t exist at all: that Romeo’s desires and psychological states are not the real causes of his actions, but merely approximate the unknowably complicated causes and effects between the atoms in his brain and surroundings.
Hoel’s theory, called “causal emergence,” roundly rejects this reductionist assumption.
“Causal emergence is a way of claiming that your agent description is really real,” said Hoel, a postdoctoral researcher at Columbia University who first proposed the idea with Larissa Albantakis and Giulio Tononi of the University of Wisconsin, Madison. “If you just say something like, ‘Oh, my atoms made me do it’ — well, that might not be true. And it might be provably not true.”
Using the mathematical language of information theory, Hoel and his collaborators claim to show that new causes — things that produce effects — can emerge at macroscopic scales. They say coarse-grained macroscopic states of a physical system (such as the psychological state of a brain) can have more causal power over the system’s future than a more detailed, fine-grained description of the system possibly could. Macroscopic states, such as desires or beliefs, “are not just shorthand for the real causes,” explained Simon DeDeo, an information theorist and cognitive scientist at Carnegie Mellon University and the Santa Fe Institute who is not involved in the work, “but it’s actually a description of the real causes, and a more fine-grained description would actually miss those causes.” [Continue reading…]
What matters
, June 13, 2018
In “The Strange Order of Things” Antonio Damasio promises to explore “one interest and one idea … why and how we emote, feel, use feelings to construct our selves; how feelings assist or undermine our best intentions; why and how our brains interact with the body to support such functions.”
Damasio thinks that the cognitive revolution of the last 40 years, which has yielded cognitive science, cognitive neuroscience and artificial intelligence, has been, in fact, too cognitive, too rationalist, and not concerned enough with the role that affect plays in the natural history of mind and culture. Standard stories of the evolution of human culture are framed in terms of rational problem solving, creative intelligence, invention, foresight and linguistically mediated planning — the inventions of fire, shelters from the storms, agriculture, the domestication of animals, transportation systems, systems of political organization, weapons, books, libraries, medicine and computers.
Damasio rightly insists that a system with reason, intelligence and language does nothing unless it cares about something, unless things matter to it or, in the case of the emerging world of A.I., things matter to its makers. Feelings motivate reason and intelligence, then “stay on to check the results, and help negotiate the necessary adjustments.”
In an earlier book, “Looking for Spinoza,” Damasio developed the concept of conatus — drive, will, motive, urge — as the taken-for-granted force or catalyst that puts reason, creative intelligence and language to work. If there were no feelings, he adds now, there would be no art, no music, no philosophy, no science, no friendship, no love, no culture and complex life would not aim to sustain itself. “The complete absence of feeling would spell a suspension of being.” [Continue reading…]
The spiritual part of our brains — religion not required
, June 4, 2018
Scientists seek to quantify everything—even the ineffable. And so the human search for meaning recently took a physical turn as Columbia and Yale University researchers isolated the place in our brains that processes spiritual experiences.
In a new study, published in Cerebral Cortex (paywall) on May 29, neuroscientists explain how they generated “personally relevant” spiritual experiences in a diverse group of subjects and scanned their brains while these experiences were happening. The results indicate that there is a “neurobiological home” for spirituality. When we feel a sense of connection with something greater than the self—whether transcendence involves communion with God, nature, or humanity—a certain part of the brain appears to activate.
The study suggests that there is universal, cognitive basis for spirituality, as opposed to a cultural grounding for such states. This new discovery, researchers say, could help improve mental health treatment down the line.
Previous studies have examined the brain activity of Buddhist monks or Catholic nuns, say—people who are already spiritually inclined and familiar with the practice of cultivating transcendent states. But this research analyzed subjects from different backgrounds with varying degrees of religiosity, and totally different individual notions of what constitutes a spiritual experience. [Continue reading…]
Theory of predictive brain as important as evolution — an interview with Lars Muckli
, June 1, 2018
Our brains make sense of the world by predicting what we will see and then updating these predictions as the situation demands, according to Lars Muckli, professor of neuroscience at the Centre for Cognitive Neuroimaging in Glasgow, Scotland. He says that this predictive processing framework theory is as important to brain science as evolution is to biology.
Horizon magazine: You have used advanced brain imaging techniques to come up with a model of how the brain processes vision – and it says that instead of just sorting through what we see, our brains actually anticipate what we will see next. Could you tell us a bit more?
Lars Muckli: ‘We are interested to understand how the brain supports vision. A classical view had been that the brain is responding to visual information in a cascade of hierarchical visual areas with increasing complexity, but a more modern way is to realise that, actually, the brain is not meeting every situation with a clean sheet, but with lots of predictions.’
How does that work?
‘The main purpose of the brain, as we understand it today, is it is basically a prediction machine that is optimising its own predictions of the environment it is navigating through. So, vision starts with an expectation of what is around the corner. Once you turn around the corner, you are then negotiating potential inputs to your predictions – and then responding differently to surprise and to fulfilment of expectations.
‘So that’s what’s called the predictive processing framework, and it’s a proposed unifying theory of the brain. It’s basically creating an internal model of what’s going to happen next.’
Why does this happen?
‘First of all, the outside world is not in our brain so somehow we need to get something into our brain that is a useful description of what’s happening – and that’s a challenge.
‘We become painfully aware of this challenge if we try to simulate this in a computer model – how do we get information about the outside world into a computer model? The brain does that in an unsupervised way. It segments the visual input into object, background, foreground, context, people and so on, and no one ever gives the brain any kind of supervision to do so.
‘To have meaningful models of the world, you need to have something like a supervisor in your brain that says: “This is Object A. This is another object, and you need to find a name for this.” We don’t have a supervisor, but we have something – and that’s the currency of surprise. (The need) to minimise surprise is used as a supervisor.’
Psychedelic medicine may become available sooner than you expect
, May 17, 2018
Just how soon might psychedelic-assisted psychotherapy be available aboveground, to the many people who stand to benefit from it? Before the F.D.A. approves a new medicine, the drug must survive testing for safety and efficacy in a three-stage sequence of trials, each of them involving a larger sample and more rigorous methods. When researchers recently brought to the F.D.A. the results of Phase 2 clinical trials of cancer patients who were given psilocybin and MDMA, they were stunned by the positive response of the regulators. Regulators told them they could move forward to Phase 3 with MDMA, the last step before F.D.A. approval. The F.D.A. is still considering when psilocybin trials can move into Phase 3. The agency wouldn’t comment on drugs in the approval process, but a researcher who attended one of these meetings told me the regulators seemed untroubled by the illicit status of the drugs in question or by the unique challenges of controlling studies of psychedelics. These meetings took place before a Trump-appointed F.D.A. commissioner was sworn in; it remains to be seen how the Justice Department under Jeff Sessions would respond to F.D.A. approval of psychedelics. The researchers felt heartened by the F.D.A.’s response. The message the scientists took away from the meeting was that they should raise their sights and not limit themselves to treating cancer patients, but rather test the drugs on the much larger population of patients suffering from major depression.
Thus encouraged, the Multidisciplinary Association for Psychedelic Studies (MAPS), a nonprofit that has been working for federal approval of psychedelics since 1986, will begin Phase 3 trials of MDMA-assisted psychotherapy this summer for the treatment of post-traumatic stress disorder, involving more than 200 volunteers at 16 sites in the United States, Canada and Israel. Later this year, pending F.D.A. approval, two Phase 3 trials of psilocybin — one for the treatment of major depression and the other for “psychospiritual distress” in cancer patients — are expected to get underway at Hopkins, N.Y.U. and a half-dozen other sites around the country.
Phase 3 trials, which typically involve hundreds of subjects at dozens of sites, can cost tens of millions of dollars — a cost ordinarily borne by the big pharmaceutical companies that stand to profit from approval. But Big Pharma has not demonstrated significant interest in psychedelics, and it’s not hard to see why: Psychedelic therapy is a rather square peg to fit into the round hole of psychopharmacology as we now know it. Patents on the molecules in question — LSD, psilocybin and MDMA — have long since expired (psilocybin comes from a common mushroom); the drugs, if approved, don’t need to be taken more than a few times; and as the C.I.I.S. program recognizes, psychedelic-assisted psychotherapy is a novel hybrid of pharmacology and talk therapy, making it uncharted territory for a pharmaceutical industry organized around the selling of pills.
But the obstacle of funding Phase 3 trials appears to have been recently surmounted. The Psychedelic Science Funders Collaborative (P.S.F.C.), a new Bay Area-based consortium of philanthropists including the hippie-soap entrepreneur David Bronner, the author and tech investor Timothy Ferriss and other donors both in and out of the tech community, has helped raise more than $63 million in charitable contributions, an amount that could be sufficient to complete the trials. The two main beneficiaries of these funds will be MAPS and Usona Institute, a nonprofit medical-research organization that is sponsoring forthcoming psilocybin trials. Rebekah Mercer, the Trump funder behind Cambridge Analytica and Breitbart, is also a donor to MAPS.
There is at least one corporation betting that psychedelic therapy will soon become a business. Founded in London by George Goldsmith, a health care industry consultant, and Ekaterina Malievskaia, a physician, Compass Pathways aims to become the world’s first psychedelic pharmaceutical company. (The couple, who are married, were inspired to expand access to psilocybin after Malievskaia’s college-age son was successfully treated by an underground guide with the drug for a debilitating case of depression.) Compass aims to be much more than a drug company, however. The company is developing a complete treatment package — consisting of a training program for therapists; protocols for orchestrating the entire experience; and the medicine itself — that it hopes to sell to health care institutions and national health services, first in Europe and then in the United States.
Its initial therapeutic target is treatment-resistant depression (patients who have failed to respond to at least two previous treatments); after an advisory process with the European Medicines Agency (the E.U.’s drug-regulating body), it has decided to conduct trials in eight to 10 sites across Europe. It is also in discussions with the F.D.A. to organize trials here. According to Goldsmith, Compass has already raised $13 million from investors in the United States and Europe, many of them from the tech community (Peter Thiel is an investor) but also institutional investors in the health care sector.
Phase 3 trials will take at least three years, but access to psychedelic therapy could come sooner than that. Under “expanded access” or “compassionate use” programs, patients who stand to benefit from therapies still deemed experimental can gain access to them before trials are complete. In the case of MDMA, this could happen as soon as 2020. [Continue reading…]
Why we need to figure out a theory of consciousness
, May 13, 2018
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By Adam Barrett, University of Sussex
Understanding the biology behind consciousness (or self-awareness) is considered by some to be the final frontier of science. And over the last decade, a fledgling community of “consciousness scientists” have gathered some interesting information about the differences between conscious and unconscious brain activity.
But there remains disagreement about whether or not we have a theory that actually explains what is special about the brain activity which produces our miraculous inner worlds.
Recently, “Integrated Information Theory” has been gaining attention – and the backing of some eminent neuroscientists. It says that absolutely every physical object has some (even if extremely low) level of consciousness. Some backers of the theory claim to have a mathematical formula that can measure the consciousness of anything – even your iPhone.
These big claims are controversial and are (unfortunately) undermining the great potential for progress that could come from following some of the ideas behind the theory.
Integrated Information Theory starts from two basic observations about the nature of our conscious experiences as humans. First, that each experience we have is just one of a vast number of possible experiences we could have. Second, that multiple different components (colours, textures, foreground, background) are all experienced together, simultaneously.
Given these two observations, the theory says that brain activity associated with consciousness must therefore be ever-changing, consist of lots of different patterns, and involve a great deal of communication between different brain regions.
This is a really solid starting point for a theory, and to some extent, we have been able to test it. In one experiment, for example, researchers looked at brain responses to a short pulse of “transcranial magnetic stimulation”, in which a magnetic coil is placed on top of the scalp, and a very brief pulse of magnetic field emitted.
The response was recorded from electrodes at locations all over the rest of the scalp. When fully awake, the response to the little burst of magnetic field would spread far and wide, in complex patterns of ripples.
But when participants were in deep sleep, or under general anaesthesia, the response did not spread very far from the magnet, and the shapes of the ripples were much more simple. These results support the theory. They demonstrate that when we’re conscious, each region of the brain is doing something different, but are all managing to communicate.
So far so good. But it would be great to go further than this. Hence the attempt to find a formula that can give us a precise “level of consciousness” from detailed data. It is here that the serious controversy begins.
The theory claims that the ultimate formula will somehow quantify the information something contains. In this context, “information” means how much you can find out about the past and future of the object in question by looking in detail at the present.
For example, you record voltages from a bunch of neurons in the brain, and see how well you can use one result to predict earlier and later results. If you can make good predictions from using the readings from all neurons, but only poor predictions if you use just some neurons, then you score high.
The spirit molecule
, April 25, 2018
Identified in 300 BCE by the Greek physician Herophilos as the brain’s only unpaired organ, the pineal gland has long been a source of mystery and speculation. Galen, another Greek physician and philosopher, discussed its role as a valve regulating the flow of ‘psychic pneuma’. This view informed René Descartes, who in the 17th century situated the soul (for him, the mind) precisely in this tiny mid-brain structure, which he imagined to be something of a thought valve; he called it ‘the seat of the soul’.
It wasn’t until the latter half of the 20th century that scientists recognised the pineal as an endocrine organ – an important hub at night for converting the neurotransmitter serotonin, essential for higher cognitive processes, into the hormone melatonin, which plays a crucial role in activating sleep cycles. Finally, in the late 1980s, the neurochemist James Callaway proposed that pineal melatonin is converted into DMT (along with pinoline and 5-MeO-DMT) just before the onset of REM (rapid eye-movement) sleep, when we dream. Were such endogenous, psychoactive molecules literally fuelling our dreams?
Such questions tantalised [the psychiatrist Rick] Strassman, prompting him to pursue the phantom of the ‘psychedelic pineal gland’. He speculated that the pineal might excrete large quantities of DMT during extremely stressful life episodes, notably in the events of birth and death. He speculated that the gland’s central position in the brain, within the epithalamus, could allow for DMT secretion directly into the cerebrospinal fluid, impacting visual and auditory pathways. Absorbing the tenets of Tibetan Buddhism, he wondered whether, when we die (or indeed, have near-death experiences), the life force could be leaving the body through the pineal gland. Was DMT like the floodwaters carrying the soul into the liminal phase (or bardo) between life and life, as depicted in The Tibetan Book of the Dead? He proposed that, functioning like a spirit antenna, ‘pineal DMT release at forty-nine days after conception marks the entrance of the spirit into the fetus’. The impact of these speculations were felt in popular esoteric (spiritualist) circles and within Strassman’s Zen Buddhist community in Northern California, where he was ordained as a lay member until he was censured and subsequently exited in the late 1990s. [Continue reading…]
A revolution in our sense of self
, April 2, 2018
At the climax of Anna Karenina, the heroine throws herself under a train as it moves out of a station on the edge of Moscow. But did she really want to die? Had the ennui of Russian aristocratic life and the fear of losing her lover, Vronsky, become so intolerable that death seemed the only escape? Or was her final act mere capriciousness, a theatrical gesture of despair, not seriously imagined even moments before the opportunity arose?
We ask such questions, but can they possibly have answers? If Tolstoy says that Anna has dark hair, then Anna has dark hair. But if Tolstoy doesn’t tell us why Anna jumped to her death, then Anna’s motives are surely a void. We can attempt to fill this void with our own interpretations and debate their plausibility. But there is no hidden truth about what Anna really wanted, because, of course, Anna is a fictional character.
Suppose instead that Anna were a historical figure and Tolstoy’s masterpiece a journalistic reconstruction. Now Anna’s motivation becomes a matter of history, rather than a literary interpretation. Yet our method of inquiry remains the same: the very same text would now be viewed as providing (perhaps unreliable) clues about the mental state of a real person, not a fictional character. Historians, rather than literary scholars, might debate competing interpretations.
Now imagine that we could ask Anna herself. Suppose the great train slammed on its brakes just in time. Anna, apparently mortally injured, is conveyed in anonymity to a Moscow hospital and, against the odds, pulls through. We catch up with Anna convalescing in a Swiss sanatorium. But, as likely as not, Anna will be as unsure as anyone else about her true motivations. After all, she too has to engage in a process of interpretation as she attempts to account for her behaviour. To be sure, she may have “data” unavailable to an outsider – she may, for example, remember the despairing words “Vronsky has left me forever” running through her mind as she approached the edge of the platform. However, any such advantage may be more than outweighed by the distorting lens of self-perception. In truth, autobiography always deserves a measure of scepticism.
There are two opposing conclusions that one might draw from this vignette. One is that our minds have dark and unfathomable “hidden depths”. From this viewpoint, we cannot expect people to look reliably within themselves and compile a complete and true account of their beliefs and motives. Psychologists, psychiatrists and neuroscientists have long debated how best to plumb the deep waters of human motivation. Word associations, the interpretation of dreams, hours of intensive psychotherapy, behavioural experiments, physiological recordings and brain imaging have been popular options.
I believe, though, that our reflections should lead us to a different conclusion: that the interpretation of real people is no different from the interpretation of fictional characters. If Tolstoy’s novel had been reportage, and Anna a living, breathing member of the 19th-century Russian aristocracy, then, of course, there would be a truth about whether Anna was born on a Tuesday. But, I argue, there would still be no truths about the real Anna’s motives. No amount of therapy, dream analysis, word association, experiment or brain scanning can recover a person’s “true motives”, not because they are difficult to find, but because there is nothing to find. [Continue reading…]