Consciousness and the Secret Life of Plants

Could plants be conscious? What are the limits of consciousness and pain? 

Scientific American recently reviewed a book titled "Planta Sapiens". The title gives it all away, and the review was quite positive, with statements like: 

"Our senses can not grasp the rich communicative world of plants. We therefore lack language to describe the 'intelligence' of a root tip in conversation with the microbial life of the soil or the 'cognition' that emerges when chemical whispers ripple through a lacework of leaf cells."

This is provocative indeed! What if plants really do have a secret life and suffer pain with our every bite and swing of the scythe? What of our vaunted morals and ethics then?

I am afraid that I take a skeptical view of this kind of thing, so let's go through some of the aspects of consciousness, and ask how widespread it really is. One traditional view, from the ur-scientific types like Descartes, is that only humans have consciousness, and all other creatures, have at best a mechanism, unfeeling and mechanical, that may look like consciousness, but isn't. This, continued in a sense by B. F. Skinner in the 20th century, is a statement from ignorance. We can not fully communicate with animals, so we can not really participate in what looks like their consciousness, so let's just ignore it. This position has the added dividend of supporting our unethical treatment of animals, which was an enormous convenience, and remains the core position of capitalism generally, regarding farm animals (though its view of humans is hardly more generous).

Well, this view is totally untenable, from our experience of animals, our ability to indeed communicate with them to various degrees, to see them dreaming, not to mention from an evolutionary standpoint. Our consciousness did not arise from nothing, after all. So I think we can agree that mammals can all be included in the community of conscious fellow-beings on the planet. It is clear that the range of conscious pre-occupations can vary tremendously, but whenever we have looked at the workings of memory, attention, vision, and other components assumed to be part of or contributors to conscious awareness, they all exist in mammals, at least. 

But what about other animals like insects, jellyfish, or bacteria? Here we will need a deeper look at the principles in play. As far as we understand it, consciousness is an activity that binds various senses and models of the world into an experience. It should be distinguished from responsiveness to stimuli. A thermostat is responsive. A bacterium is responsive. That does not constitute consciousness. Bacteria are highly responsive to chemical gradients in their environment, to food sources, to the pheromones of fellow bacteria. They appear to have some amount of sensibility and will. But we can not say that they have experience in the sense of a conscious experience, even if they integrate a lot of stimuli into a holistic and sensitive approach to their environment. 

The same is true of our own cells, naturally. They also are highly responsive on an individual basis, working hard to figure out what the bloodstream is bringing them in terms of food, immune signals, pathogens, etc. Could each of our cells be conscious? I would doubt it, because their responsiveness is mechanistic, rather than being an independent as well as integrated model of their world. Simlarly, if we are under anaesthesia and a surgeon cuts off a leg, is that leg conscious? It has countless nerve cells, and sensory apparatus, but it does not represent anything about its world. It rather is built to send all these signals to a modeling system elsewhere, i.e. our brain, which is where consciousness happens, and where (conscious) pain happens as well.

So I think the bottom line is that consciousness is rather widely shared as a property of brains, thus of organisms with brains, which were devised over evolutionary time to provide the kind of integrated experience that a neural net can not supply. Jellyfish, for instance, have neural nets that feel pain, respond to food and mates, and swim exquisitely. They are highly responsive, but, I would argue, not conscious. On the other hand, insects have brains and would count as conscious, even though their level of consciousness might be very primitive. Honey bees map out their world, navigate about, select the delicacies they want from plants, and go home to a highly organized hive. They also remember experiences and learn from them.

This all makes it highly unlikely that consciousness is present in quantum phenomena, in rocks, in bacteria, or in plants. They just do not have the machinery it takes to feel something as an integrated and meaningful experience. Where exactly the line is between highly responsive and conscious is probably not sharply defined. There are brains that are exceedingly small, and neural nets that are very rich. But it is also clear that it doesn't take consciousness to experience pain or try to avoid it, (which plants, bacteria, and jellyfish all do). Where is the limit of ethical care, if our criterion shifts from consciousness to pain? Wasn't our amputated leg in pain after the operation above, and didn't we callously ignore its feelings? 

I would suggest that the limit remains that of consciousness, not that of responsiveness to pain. Pain is not problematic because of a reflex reaction. The doctor can tap our knee as often as he wants, perhaps causing pain to our tendon, but not to our consciousness. Pain is problematic because of suffering, which is a conscious construct built around memory, expectations, and models of how things "should" be. While one can easily see that a plant might have certain positive (light, air, water) and negative (herbivores, fungi) stimuli that shape its intrinsic responses to the environment, these are all reflexive, not reflective, and so do not appear (to an admittedly biased observer) to constitute suffering that rises to ethical consideration.

Computer Science Meets Neurobiology in the Hippocampus

Review of Whittington, et al. - a theoretical paper on the generalized mapping and learning capabilities of the entorhinal/hippocampal complex that separates memories from a graph-mapping grid.

These are exciting times in neurobiology, as a grand convergence is in the offing with computational artificial intelligence. AI has been gaining powers at a rapid clip, in large part due to the technological evolution of neural networks. But computational theory has also been advancing, on questions of how concepts and relations can be gleaned from data- very basic questions of interest to both data scientists and neuroscientists. On the other hand, neurobiology has benefited from technical advancements as well, if far more modestly, and from the relentless accumulation of experimental and clinical observations. Which is to say, normal science. 

One of the hottest areas of neuroscience has been the hippocampus and the closely connected entorhinal cortex, seat of at least recent memory and of navigation maps and other relational knowledge. A recent paper extends this role to a general theory of relational computation in the brain. The basic ingredients of thought are objects and relations. Computer scientists typically represent these as a graph, where the objects are nodes, and the relations are the connecting lines, or edges. Nodes can have a rich set of descriptors (or relations to property nodes that express these descriptions). A key element to get all this off the ground is the ability to chunk, (or abstract, or generalize, or factorize) observations into discrete entities, which then serve as the objects of the relational graph. The ability to say that what you are seeing, in its whirling and colorful reality, is a dog .. is a very significant opening step to conceptualization, and the manipulation of those concepts in useful ways, such as understanding past events and predicting future ones.

Gross anatomy of the hippocampus and associated entorhinal cortex, which function together in conceptual binding and memory.

A particular function of the entorhinal/hippocampal complex is spatial navigation. Reseachers have found place cells, grid cells, and boundary cells (describing when these cells fire) as clear elements of spatial consciousness, which even replay in dreams as the rats re-run their daytime activities. It is evident that these cells are part of an abstraction mechanism that dissociates particular aspects of conceptualized sensory processing from the total scene and puts them back together again in useful ways, i.e. as various maps.

This paper is conducted at a rather abstruse level, so there is little that I can say about it in detail. Yet it and the field it contributes to is so extremely interesting that some extra effort is warranted. By the time the hippocampus is reached, visual (and other sensory data) has already been processed to the conceptual stage. Dogs have been identified, landmarks noted, people recognized. Memories are composed of fully conceptualized, if also sensorily colored, conceptual chunks. The basic idea the authors present is that key areas of the entorhinal cortex provide general and modular mapping services that allow the entorhinal/hippocampal complex to deal with all kinds of relational information and memories, not just physical navigation. Social relations, for example, are mapped similarly.

It is important to note tangentially that conceptualization is an emergent process in the brain, not dictated by pre-existing lists of entities or god-given databases of what exists in the world and beyond. No, all this arises naturally from experience in the world, and it has been of intense interest to computer scientists to figure out how to do this efficiently and accurately, on a computer. Some recent work was cited here and is interesting for its broad implications as well. It is evident that we will in due time be faced with fully conceptualizing, learning, and thinking machines.

"Structural sparsity also brings a new perspective to an old debate in cognitive science between symbolic versus emergent approaches to knowledge representation. The symbolic tradition uses classic knowledge structures including graphs, grammars, and logic, viewing these representations as the most natural route towards the richness of thought. The competing emergent tradition views these structures as epiphenomena: they are approximate characterizations that do not play an active cognitive role. Instead, cognition emerges as the cooperant consequence of simpler processes, often operating over vector spaces and distributed representations. This debate has been particularly lively with regards to conceptual organization, the domain studied here. The structural forms model has been criticized by the emergent camp for lacking the necessary flexibility for many real domains, which often stray from pristine forms. The importance of flexibility has motivated emergent alternatives, such as a connectionist network that maps animals and relations on the input side to attributes on the output side. As this model learns, an implicit tree structure emerges in its distributed representations. But those favoring explicit structure have pointed to difficulties: it becomes hard to incorporate data with direct structural implications like 'A dolphin is not a fish although it looks like one', and latent objects in the structure support the acquisition of superordinate classes such as 'primate' or 'mammal'. Structural sparsity shows how these seemingly incompatible desiderata could be satisfied within a single approach, and how rich and flexible structure can emerge from a preference for sparsity." - from Lake et al., 2017

Getting back the the hippocampus paper, the authors develop a computer model, which they dub the Tolman-Eichenbaum machine [TEM] after key workers in the field. This model implements a three-part system modeled on the physiological situation, plus their theory of how relational processing works. Medial entorhinal cells carry generalized mapping functions (grids, borders, vectors), which can be re-used for any kind of object/concept, supplying relations as originally deduced from sensory processing or possibly other abstract thought. Lateral entorhinal cells carry specific concepts or objects as abstracted from sensory processing, such as landmarks, smells, personal identities, etc. It is then the crossing of these "what" and "where" streams that allows navigation, both in reality and in imagination. This binding is proposed to happen in the hippocampus, as firing that happens when firing from the two separate entorhinal regions happen to synchronize, stating that a part of the conceptual grid or other map and an identified object have been detected in the same place, generating a bound sensory experience, which can be made into a memory, or arise from a memory, or an imaginative event, etc. This is characteristic of "place cells", hippocampal cells that fire when the organism is at a particular place, and not at other times.

"We propose TEM’s [the computational model they call a Tolman-Eichenbaum Machine] abstract location representations (g) as medial entorhinal cells, TEM’s grounded variables (p) as hippocampal cells, and TEM’s sensory input x as lateral entorhinal cells. In other words, TEM’s sensory data (the experience of a state) comes from the ‘what stream’ via lateral entorhinal cortex, and TEM’s abstract location representations are the ‘where stream’ coming from medial entorhinal cortex. TEM’s (hippocampal) conjunctive memory links ‘what’ to ‘where’, such that when we revisit ‘where’ we remember ‘what’."

Given the abstract mapping and a network of relations between each of the components, reasoning or imagining about possible events also becomes feasible, since the system can solve for any of the missing components. If a landmark is seen, a memory can be retrieved that binds the previously known location. If a location is surmised or imagined, then a landmark can be dredged up from memory to predict how that location looks. And if an unfamiliar combination of location and landmark is detected, then either a new memory can be made, or a queasy sense of unreality or hallucination would ensue if one of the two are well-known enough to make the disagreement disorienting.

As one can tell, this allows not only the experience of place, but the imagination of other places, as the generic mapping can be traversed imaginatively, even by paths that the organism has never directly experienced, to figure out what would happen if one, for instance, took a short-cut. 

The combination of conceptual abstraction / categorization with generic mapping onto relational graph forms that can model any conceptual scale provides some of the most basic apparatus for cognitive thought. While the system discussed in this paper is mostly demonstrated for spatial navigation, based on the proverbial rat maze, it is claimed, and quite plausible, that the segregation of the mapping from the object identification and binding allows crucial generalization of cognition- the tools we, and someday AI as well, rely on to make sense of the world.

• A database of superspreader events. It suggests indoor, poorly ventilated spread of small aerosols. And being in a cold locker helps as well.
• The curious implications of pardons.
• It is going to be a long four years.
• How tires kill salmon.
• Ever think that there is more to life?

Incarnation and Reincarnation

Souls don't reincarnate. Heck, they don't even exist. But DNA does.

What a waste it is to die. All that work and knowledge, down the drain forever. But life is nothing if not profligate with its gifts. Looking at the reproductive strategies of insects, fish, pollen-spewing trees, among many others gives a distinct impression of easy come, easy go. Life is not precious, but dime-a-dozen, or less. Humanity proves it all over again with our rampant overpopulation, cheapening what we claim to hold so dear, not to mention laying the rest of the biosphere to waste.

But we do cherish our lives subjectively. We have become so besotted with our minds and intelligence that it is hard to believe, (and to some it is unimaginable), that the machinery will just cease- full stop- at some point, with not so much as a whiff of smoke. Consciousness weaves such a clever web of continuous and confident experience, carefully blocking out gaps and errors, that we are lulled into thinking that thinking is not of this world- magical if not supernatural. Believing in souls has a long and nearly universal history.

Reincarnation in the popular imagination, complete with a mashup of evolution. At least there is a twisty ribbon involved!

Yet we also know it is physical- it has to be something going on in our heads, otherwise we would not be so loath to lose them. Well, lose them we do when the end comes. But it is not quite the end, since our heads and bodies are reincarnations- they come from somewhere, and that somewhere is the DNA that encodes us. DNA incarnates through biological development, into the bodies that are so sadly disposable. And then that DNA is transmitted to new carnate bodies, and re-incarnates all over again in novel combinations through the wonder of sex. It is a simple, perhaps trite, idea, but offers a solid foundation for the terms (and archetypes) that have been so abused through theological and new-age history.

• The Taliban still stands with Al Qaeda.
• Trauma and the Ring.
• Those darn astrocytes.
• Impeachable offenses? Plenty.
• Corporations are at best amoral, and routinely immoral.
• Fisheries are running thin.

The Quest For Meaning

We spend our lives searching for something that does not exist. And then realize that we have been fighting over it the whole time.

The meaning of life: 42? Or something more profound? Religions have been founded, and wars fought, over what by definition is most important to us, but on which no one seems able to agree. One advance in the philosophy of meaning was Maslow's hierarchy of values, which starts with basic sustenance, and rises through the more refined social values to self-actualization (possibly a dated concern!). If one does not have enough to eat, nothing else means much. But whether these form a true hierarchy is unclear, since many people have died for some of the more esoteric levels of this hierarchy, indicating that we are mixed-up beings, not always valuing life over some principle or ideology. It turns out that propaganda, social pressure, and decent odds, can make people kill and die for the most arcane propositions. Also, that winning means a lot to us.

Meaning is not given or objective. There is no star or cloud telling us that we mean X, while people in the other tribe mean Y. Quite the other way around. I think we can safely say at this point that we have constructed religions (as one example of indoctrinating human institutions) as complex machinery to propagate meanings that we (or at least some) have devised, using gods as fronts for desirable social hierarchies, idle speculations, melodramatic ruminations, and elevated emotions. That these machineries are passed off as objective and profound is critical to their function, elevating their impressiveness (and oppressiveness). If your meaning and values can be dictated by me, who wins? If god says you should have a beard, how can you complain, and to whom? This is the quest of propaganda generally- to instill meanings into, and thus lead, masses of people.

So we have been fighting over meaning and values all along, through our social relations. There is nothing to seek, but rather a world to win, for as far as others share one's meaning, one gains power. For example, a recent post told the story of Arthur Kornberg, eminent biochemist. One of his leadership qualities was an absolute conviction of the importance of what he was doing. If his team members were not willing to be tied to the bench at all hours and have midnight phone calls for urgent updates, their tenure was short. How much of this was willing? That is hard to say, and is one of the mysteries of personal, charismatic, leadership- the diffusion of meaning to others. Parenting is the same story, naturally, as is politics. Parents promote respect for elders and the elderly as a core societal virtue ... and no wonder! Advertising is another big example in our culture. The alchemical transformation of a natural desire- for status, sex, safety- into a value and meaning structure that renders some product essential. We are far more what we buy than what we eat.

Meaning turns out to be more of a fight than a quest. Meanings are swirling all about us, and are up for grabs. There is no grail to find, but only a social contest between those who seek to tell other people what is most valuable and important, others who promote other, maybe contrasting, values, and innocents in the middle, caught in the cross-hairs of domineering social warfare. Even Buddhism, whose doctrine revolves around the illusory nature of existence, the non-self, and the dampening of one's attachments, seems eager to propagate those very doctrines, promoting the somewhat ironic meaning of meaninglessness.

Returning to Maslow's hierarchy, many of our meanings are objectively based. We need to eat, have room to live, and have the other necessities of our current technological status. Social status is another need, biologically based. Since most of these are subject to scarcity, we are immediately thrust into competition with our fellow humans. These objective necessities can be woven into much larger ideologies of competition and tribalism. On a theatrical basis, they are portrayed in sporting events, game shows, and reality TV. But they become more grounded in the business world- that merciless competition that ends in bankruptcy and homelessness. Which is in turn only a slight step above the level that characterizes the ultimate competitive test of meaning: warfare, massacre, and murder.

We are bombarded from earliest childhood with values and messages of meaning, many of which conflict. The confusion can be difficult to deal with, leading many into the arms of simple solutions- taking meaning from those who shout the loudest, or who simplify most audaciously. It is up to us to choose, though our basis is necessarily the choices we have made already and which have been made for us earlier on in our lives. Meanings build on each other. But they also have a rational aspect. If compassion is part of our value system and self-meaning, that will not sit well with projects of tribal pride and dehumanization. It is complexity that requires careful thought, which is why morality is not just a matter of feeling, but also of reason.

The meaning of life is not hard to find, but it is hard to decide on, from the myriad choices and influences surrounding us. That is why sticking with positive influences and avoiding cesspools like Facebook / Fox news is so important. It is also why "big question" discussions are often overblown, shills for the dissemination of some particular and parochial set of meanings.  The quest is not for some elusive single meaning, but for ways to chose among the vast numbers of them we meet along the way of life.

• Imagine ... if Trump ran Hollywood.
• We are in the middle of propaganda warfare.
• More lies.
• Automatons have long been used to fake the work of gods.

Science is not the Answer

Bryan Appleyard has some complaints about the new priesthood and its corrosive effects on the old verities, in "Understanding the Present: Science and the soul of modern man".

This is a genuinely exciting book (dating from 1993) about modernity- our age where science in all its facets has not only transformed practical existence, but also our spiritual lives, de-mystifying nature and tossing religions, one after the next, onto the scrap heap. Appleyard is not happy about it, however- far from. He is tortured by it, and while he can not stomach going back to religious orthodoxy, whether of fundamentalist or mildly liberal varieties, nor can he accept the new regime, which he views, somewhat mistakenly, as scientism. That is the belief, fostered (in Appleyard's view) by the gushing popularizers like Carl Sagan, Jacob Bronowski, and Richard Dawkins, that science can not only solve all our questions of knowledge, but forms a new technocratic morality of reasonable-ness and tolerance which, if properly worshipped, could resolve our social, political, and spiritual problems as well.

The first half of the book is far better than the second. Setting up the problems of modern spirituality is far easier than solving them. In broad strokes, humanity used to be at home in heavily archetypal religious realities. While actual reality did intrude from time to time, the fables of Christianity, to take the main example in the West, were (and for some, still are) magical tales which gave us hope of a benevolent meta-reality and a pleasant afterlife. But intellectuals kept trying to make sense of them, until they "sensed" them completely out of existence. Appleyard cites Thomas Aquinas as perhaps the finest of these intellectuals in the theological tradition. His main work was to reconcile Aristotle, the pre-eminent scientist of antiquity, with Christian orthodoxy. This was taken as the height of theology, not to mention truth in general. But it planted the seed of modernization and logic- if something is logically or empirically true, it must necessarily be consonant with the Catholic religion, which is by definition true. Thence downwards through the enlightenment, Newton, the  industrial revolution, existentialism, liberal theology, to the plague of atheists we see today. The Catholic church tried to draw the line with Galileo and the heliocentric model, but that did not go well, and a few hundred years down the road, they gave up and said they were sorry.

"Science was the lethally dispassionate search for truth in the world whatever its meaning might be; religion was the passionate search for meaning whatever the truth might be."

All religious pretensions to scientific truth have been exploded, and the only choices left, as Appleyard sees it, are regression into fundamentalism, continuation to the endpoint of modernist anomie where humans are morally worthless or even negative destroyers of pristine nature, an acceptance of science itself as humanity's triumphalist project, which through its powers and gifts can give us all meaning, ... or something else. Appleyard spends much of the second half of the book on the fourth option, discussing quantum weirdness, chaos theory, computational incompleteness theories, and related fields which put the lie to the determinist dreams of nineteenth century science. Science does not know everything, and can not know everything, thus there is some gap for us as humans to be free of its insidious, deadening influence- a humanist space.

There are many things wrong with Appleyard's take on all this, some of which are contained in his own arguments and writing. Science has long held to the fact/value distinction, as he discusses at length. Even such a solidly scientistic enterprise as Star Trek recognizes regularly that Spock can neither supply all our values, nor even on his own terms operates without idiosyncratic values and meaning. The world of Star Trek is morally progressive and rational, but its motivations and meaning come from our human impulses, not from an algorithm. Exploration, skimpy uniforms, and great fight scenes are who we are.

"The key to the struggle, it cannot be said too often, is the way in which science forces us to separate out values from our knowledge of the world. Thanks to Newton we can not discover goodness in the mechanics of the heavens, thanks to Darwin we cannot find it in the phenomenon of life and thanks to Freud we cannot find it in ourselves. The struggle is to find a new basis for goodness, purpose, and meaning."

But then Appleyard frequently decries the new scientistic regime as having destroyed morals in general.

"... all moral issues in a liberal society are intrinsically unresolvable and all such issues will progressively  tend to be decided on the basis of a scientific version of the world and of values. In other words they will cease to be moral issues, they will become problems to be solved. The very idea of morality will be marginalized and, finally, destroyed."

This makes no sense, as he himself concludes by the end of the book. It seems to be a matter of looking for morals and meaning in all the wrong places. After a long excursion through the death of scientific determinism, he consoles us that science doesn't, and can't know everything. Thus we can go about our lives with our own values, desires, and dreams without paying much mind to any moral teachings from the scientific priesthood, which didn't exist anyhow. Whew! Determinism is a complete red herring here. Science studies all of reality, whether complicated or simple. If broad swathes can be subsumed into the master equation of gravity, that is wonderful- empowering on practical and psychological levels. But sometimes the result of all this study is a large database of genes and their properties, whose complicated interactions preclude easy prediction or codification (harkening back to the cataloguing of Aristotle and Linnaeus). Or sometimes it is a prediction system for weather which, despite our best efforts, can only see a limited distance into the future, due to inherent limitations to any model of a chaotic reality. That is OK too. Such pursuits are not "not science", and nor does such ignorance furnish us with free will- that comes from adaptability. The results of our studies of reality do not imply much about our meaning and values in any case, even as they defang the oddly materialistic superstitions and totems of yore. Our powers of understanding may be amazing, and fetishized by the educational system and science popularizers, but are not the foundation of our moral humanity.

Scientific studies of ourselves have, however, been enlightening, uncovering the unconscious, Darwinian designs, ancient urges, and a great diversity of ways of being. They have also clarified the damage we are doing to our environment via the wonders of modern life. This has informed our self-image and hopefully our values, but hardly determined them. Humility is the overall lesson, as it has been from all the better religious traditions. Appleyard decries relativism, the liberal tendency towards excessive humility- suspicion of one's own culture, and excessive regard for those of others. But isn't that merely a slight overshoot / correction from the madness of colonialism, slavery, genocide, rampant technology, greed, and war that has been the Western history over the last couple of centuries? Isn't it a spiritually healthy step back? In any case, it is an example of human values at work, perhaps more influenced by our prosperous condition than by any dictates from science.

Appleyard's fundamental complaint is against the new priesthood that has taken over management of the wonders of creation, but has at the same time failed to address our human needs for solace and meaning. Indeed, some of its high theologians delight in telling us that the universe, and ourselves, are utterly meaningless. Appleyard constantly weaves god into the discussion, while taking no exlicit pro-god position. He can not bring himself to bite that bullet, but rather is content to complain about being thrown out of Eden for the sin of too much knowledge. Well, it was always a cheap trick to read our fate in the stars or in goat entrails, and to read our meaning in ancient wonder-tales. These methods were merely externalizing values that came from within. The patriarchial systems of theology express most clearly the interests and desires of the men who run them. So we are, in the modern dispensation, merely reduced to a state of honesty about stating what we want, without the false veils of magic, authority, and supposed moral objectivity. And that change seems, at least to me, beneficial for our moral situation, overall.

• Can morality be reasonable? Which animals are worth helping?
• Typical enviro screed about saving space for nature...
• Forest loss continues apace.
• Roubini forcasts disaster, as usual. With details.
• We saved the wrong people in the last financial crisis.
• Financial sleaze.
• Who cares about truth anymore?
• Our common economic statistics are not cutting it.
• Japan is doing very well, thank you.

Shape-Shifting: The New Phrenology

Anatomical and connectivity patterns in brains correlate with behavior patterns.

Remember phrenology? This was the reading of people's traits and destinies in the shape of their skulls. While the motivation made sense, the brain being the seat of our traits and character, along with consciousness and all other mental functions, the science didn't. It turns out that the brain is far more plastic within its vault than we ever see from the outside - a skull that hardens during early childhood, long before the rest of brain and mental development is complete.

Brain visualization methods have long battled with variability. To do studies using many subjects to find some area of the brain that is "activated" during some task, the brains of those subjects need to be correlated, even though they may be shaped differently. The major landmarks of human brains are quite uniform, but on smaller scales they are not, making comparisons difficult.

But what if that variability is functional, and reflective of our capabilities and personalities? That is the subject of a recent paper, which used a style of MRI called resting state fMRI, which compares brains when they are not doing anything in particular, to see how different areas fire in relation to each other. We have what is called a "default network", which hums along even when we are consciously not doing anything. As any meditator knows, emptying the mind is virtually impossible.. there is always something going on, and these stray activities, not to mention the vast amount of unconscious processing, is the target of this rfMRI. And not just the activity per se, but the correlations between activity in different locations, which, when suitably processed, can tell us about the actual locations of functional modules of brain anatomy, and the strength of their connection.

An illustration/map of the author's data, showing variable and behavior-correlating regions by color. For example, the yellow region bottom left/right, rear of the brain, is in the parietal-occipital sulcus, associated with visually-guided behavior and planning. 

The authors devised measures of variation of region size, and correlated them with behavioral measures. Some of these were remarkably strong, indicating that small increases in a particular brain areas can have strong association with phenotypes like susceptibility to addiction and other vices, intelligence, and self-discipline. The authors focus on the technical implications of their work, which shows that inter-individual variation in functional brain structure is substantial, and makes merging/averaging for many kinds of brain studies more perilous than previously realized. It also implies that previous conclusions about variations in "coupling strength" between regions might be better interpreted as a signal of mass action caused by physically larger regions devoted to a given function.

Functions correlated with anatomical variation in the brain.

It is not surprising that, as we understand the brain better, its evident variations in effect will start to be reflected in corresponding variations in its structure and function. But it is rather disturbing as well, as this work implies that, someday down the road, brain scans may be able to tell others significant secrets about our personal lives and prospects. A "pre-crime" kind of scenario, indeed. It is, of course, one more reason to definitively separate health care from employment. It is also part of a general trend making of our lives, inside and out, an open book.

"Our results indicate that spatial variation in the topography of functional regions across individuals is strongly associated with behaviour. ... Furthermore, recent work has shown that resting state spatial maps can be used to predict task activation maps from individual subjects very accurately, and that interdigitated and highly variable subnetworks can be identified within individuals."

• TED talk on Russian information warfare.
•  ... which becomes our contemporary intelligence test.
• Arming teachers? Right.
• Why not mix a little political corruption with your business corruption?
• Supreme court says it is OK.
• Want a free AR15?
• Some people are naturally more important than other people.
• When reasonable people become socialists....
• Where do tax cuts go? Into stock buybacks.
• Our new feudal reality.

"Taken together, this evidence casts doubt on the idea that more rapid technological progress alone has been the primary driver of rising inequality over recent decades, and tends to lend support to more institutional and structural explanations."

Encounter With Aristotle

Leading Western cultures encountered Aristotle at critical times. What was the result?

This is a continuation of last week's appreciation of Norman Cantor's "The Civilization of the Middle Ages", which devotes a great deal of space to the renaissance of the twelfth century. This was when most of the extant writings of Aristotle- an enormous corpus- reached Europe, from various sources, including translations from Arabic and then later, translations from the original Greek, which had remained on file in Christian Byzantium.

I can not claim any expertise on Aristotle whatsoever; it is a mountain I have yet to climb. But his central position in both ancient and later philosophy is clear. This episode of recovery and rediscovery by Western Europeans after their long intellectual darkness is particularly interesting and momentous in many ways, not just to philosophy.

Aristotle.

Aristotle was the proto-scientist, to Plato's idealist. Christian thought had developed as a fusion of Judaism and Platonism. Ideals such as god, categories, spheres, were to Plato not only real, but the only real things at all, with particular, empirical manifestations being of far less interest, merely the deficient instantiations of ideals and inferences which an intensely abstract intellectual would find the only compelling things. Imagine that you had just discovered gravity. The examples of it in everyday life are interesting, but the universal idea of it is vastly more powerful and conceptually deep.

On the other hand, Aristotle, while not dismissing Platonic idealism, matched it with a regard for empirical complexity and existence. His biology is a good example, where actual observations and even dissection support a classification scheme without a lot of idealistic baggage. Aristotle believed in god, but in a sort of deistic version- the prime mover. Nor did he think we have immortal souls, but that all life forms have souls in various gradations that are just our vital motive forces, and which, at best, reunite with a universal soul at death, but in most instances die with the body. One can portray Aristotle as a stage in humanity's maturation, from childish magical thinking, where all concepts have to revolve around the self, to an ability to deal with reality forthrightly, with fewer mythical crutches, and more humility.

His huge and advanced corpus was clearly far beyond what the local philosophers and scientists of the Muslim, Jewish, or Western European worlds had achieved. Naturally, it challenged them in fundamantal ways. The greatest intellects of each tradition grappled with Aristotle and wrote commentaries: Averroes, Maimonides, and Thomas Aquinas. Cantor writes:

"In both Moslem and Jewish thought, the attempts of great thinkers to deal with the relationship of revelation and the new Aristotelian science thus ended in defeat and disaster at the beginning of the thirteenth century. Islam turned away from science because it was considered heretical by religious leaders who were able to obtain the assistance of fanatical princes to destroy rational speculation. The general decline of vigor in Islamic civilization undoubtedly also played a part in the termination of the great scientific and philosophical movement in the Arabic world. Judaism at the same time turned its back on science and secular thought, partly again because of the hostility of orthodox leaders and partly because of the ghettoization of European Jewry which began in the twelfth century."

The result here was that, for all the heroic efforts of Averroes and Maimonides (and their followers and colleagues) to blaze a compatibalist path that shoehorned the two systems together, the larger community was not having it. Any shoehorning of elements of the faith, especially of the Koran, was unacceptable. One can surmise that the social functions of the respective faiths were recognized as such, and as more important than free searches for truth that were clearly sowing the seeds of heresy if not total obliteration of the faith.

Saint Thomas Aquinas.

On the other hand, the European scholastics such as Aquinas, in their innocence, had such faith in the truth of their faith that they did not even consider that another truth, whatever its source, could threaten it. Heresy was untrue, but true things necessarily had to be consistent with the Gospel and church. So Aquinas adopted Artitotelianism in large part, and insisted on compatibalist solutions- on the soul, on natural morality, on sensory empiricism. This took quite a bit of interpretive effort, but was rewarded by everlasting fame and sainthood- quite a different result than in the other religious traditions. Aquinas is still a bedrock of Catholic theology.

"It was his Aristotelian epistemology that allowed Aquinas to work his way to his conclusion. His whole system rests on the principle that knowledge comes not from the illuminating participation of the mind in pure and divine ideas, as was held by Augustinian Platonism, but that it is primarily built up out of sensory experience. As an Aristotelian he could not accept that Platonic theory of forms; to him it was not scientific, and any Christian philosophy that was based on a false epistemology would fail, as the twelfth-century realists had failed, in the face of nominalist attack. ... He admitted that  there are certain ultimate areas of the Christian faith to which reason cannot penetrate: it is impossible to prove the miracle of the Incarnation or the Trinity. But it is possible to prove rationally the existence and many of the attributes of God. Aquinas presented five proofs for the existence of God, all of which were based on the Aristotelian argument for the existence of a first cause. ... He proceeded to argue, with a validity that was doubted by many, that from this premise could be derived the Christian attributes of God as perfect, omniscient, omnipotent, and free.... Similarly, he proceeded from Aristotelian causality by way of logical argument to prove creation ex nihilo, and similarly from Aristotelian psychology to the human soul, and from Aristotelian ethics to Christian virtue."

Yet acceptance of the innovations of Aristotle, of natural theology and rational ethics, etc., obviously also sowed the seeds of theological destruction, since if god is read in his or her works- the book of nature- the more carefully you read, the less you may find, if that god does not actually exist there, and faith was the key ingredient all along. First the Protestants insisted in reading the books of nature and scripture for themselves, and then scientists discarded scripture entirely. Now here we are in the post-Newtonian and post-Darwinian epoch, shorn of any (natural) rationale for god other than Aristotle's wan prime mover, though even that remains only as an unknown possibility rather than a necessity.

Lastly, what of the status of Aristotle in the culture where his writings were originally preserved- Eastern Rome, or Byzantium? Obviously, despite their wealth and institutional stability, they had no more of a scientific or philosophical revolution in the first millenium than the Western Europeans had. They were just as, and perhaps more, besotted with Christian theology, in characteristically "byzantine" disputes over iconography in particular, such that free thought seems to have been in very short supply. There was evidently just enough attention paid to the classics to keep them in print, but little more.

The endless and exceedingly complex ruminations about the nature of the soul through all this time were especially remarkable and saddening in their vacuity. They expressed little more than a profound ignorance of biology, which is understandable, as we still are some ways from understanding how it all works. The vegetable, animal, and rational souls of the Aristotelian system were reasonable stabs at classifying the levels of consciousness / biological being. Nor did they, in Aristotle's hands, appear to be immortal, with all due respect to Aquinas's efforts, but at best universal as "forms" by way of Plato's idealism / realism about such things, not individually. Death, is, after all, such an obvious and final fact of life. The centrality of the afterlife- the promises on which the whole Christian corpus and attraction is based- led to the very unfortunate dominance of intuition and magical thinking over simple reasoning, which haunts us to this day.

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Audio Perception and Oscillation

Brains are reality modeling machines, which isolate surprising events for our protection and delectation. Does music have to be perpetually surprising, to be heard?

Imagine the most boring thing imaginable. Is it sensory deprivation? More likely it will something more active, like a droning lecturer, a chattering relative, or driving in jammed traffic. Meditation can actually be very exciting, (just think of Proust!), and sensory deprivation generates fascinating thought patterns and ideas. LSD and similar drugs heighten such internal experiences to the point that they can become life-altering. Which indicates an interesting thing about the nature of attention- that it is a precious resource that feels abused not when it is let loose, but when it is confined to some task we are not interested in, and particularly, that we are learning nothing from.

Music exists, obviously, not to bore us but to engage us on many levels, from the physical to the meditative and profound. Yet it is fundamentally based on the beat, which would seem a potentially boring structure. Beats alone can be music, hypnotically engaging, but typically the real business of music is to weave around the beat fascinating patterns whose charm lies in a tension between surprise and musical sense, such as orderly key shifts and coherent melody.

Why is all this attractive? Our brains are always looking ahead, forecasting what comes next. Their first rule is ... be prepared! Perception is a blend of getting new data from the environment and fitting it into models of what should be there. This has the virtues of providing understanding, since only by mapping to structured models of reality are new data understandable. Secondly, it reduces the amount of data processing, since only changes need to be attended to. And thirdly, it focuses effort on changing or potentially changing data, which are naturally what we need to be paying attention to anyhow ... the stuff about the world that is not boring.

"Predictive coding is a popular account of perception, in which internal representations generate predictions about upcoming sensory input, characterized by their mean and precision (inverse variance). Sensory information is processed hierarchically, with backward connections conveying predictions, and forward connections conveying violations of these predictions, namely prediction errors." 

"It is thus hypothesised that superficial cell populations calculate prediction errors, manifest as gamma-band oscillations (>30 Hz), and pass these to higher brain areas, while deep cell populations [of cortical columns] encode predictions, which manifest as beta band oscillations (12–30 Hz) and pass these to lower brain areas." 

"In the present study, we sought to dissociate and expose the neural signatures of four key variables in predictive coding and other generative accounts of perception, namely surprise, prediction error, prediction change and prediction precision. Here, prediction error refers to absolute deviation of a sensory event from the mean of the prior prediction (which does not take into account the precision of the prediction). We hypothesised that surprise (over and above prediction error) would correlate with gamma oscillations, and prediction change with beta oscillations."

A recent paper (and review) looked at how the brain perceives sound, particularly how it computes the novelty of a sound relative to an internal prediction. Prediction in the brain is known to resemble a Bayesian process where new information is constantly added to adjust an evolving model.

The researchers circumvented the problems of low-resolution fMRI imaging by using volunteers undergoing brain surgery for epilepsy, who allowed these researchers to study separate parts of their brains- the auditiory cortex- for purposes completely unrelated to their medical needs. They also allowed the researchers to only record from the surfaces of their brains, but to stick electrodes into their auditory cortexes to sample the cortical layers at various depths. It is well-known that the large sheet of the cortex does significantly different things in its different layers.

Frequencies of tones (dots) given to experimental subjects, over time.

The three subjects were played a series of tones at different frequencies, and had to do nothing in return- no task at all. The experiment was merely to record the brain's own responses at different positions and levels of the auditory cortex, paying attention to the various frequencies of oscillating electrical activity. The point of the study was to compare the data coming out with statistical models that they generated separately from the same stimuli- ideal models of Bayesian inference for what one would expect to hear next, given the sequence so far.

Electrode positions within the auditory areas of the subject's brains.

Unfortunately, their stimulus was not quite musical, but followed a rather dull algorithm: "For each successive segment, there is a 7/8 chance that that segment’s f [frequency] value will be randomly drawn from the present population, and a 1/8 chance that the present population will be replaced, with new μ [mean frequency] and σ [standard deviation of the frequency] values drawn from uniform distributions."

Correlations were calculated out between the observed and predicted signals, giving data like the following:

Prediction error and surprise are closely correlated, but the experimenters claim that surprise is a better correlated to the gamma band brain waves observed (B).

The difference between observation and prediction, and between surprise and prediction error. Surprise apparently takes into account the spread of the data, i.e. if uncertainty has changed as well as the mean predicted value.

What they found was that, as others have observed, the highest frequency oscillations in the brain correlate with novelty- surprise about how perceptions are lining up with expectations. The experimenter's surprise (S) measurement and prediction error (Xi) are very closely related, so they both correlate with each other and with the gamma wave signal. The surprise measure is slightly better correlated, however.

On the other hand, they observed that beta oscillations (~20 Hz) were correlated with changes in the predicted values. They hypothesized that beta oscillations are directed downward in the processing system, to shape and update the predictions being used at the prior levels.

Lastly, they find that the ~10 Hz alpha oscillations (and related bands) correlate with the uncertainty or precision of the predicted values. And theta oscillations at ~6 Hz were entrained to the sound stimulus itself, hitting when the next sound was expected, rather than encoding a derived form of the stimulus.

It is all a bit neat, and the conclusions are dredged out of very small signals, as far as is shown. But the idea that key variables of cognition and data processing are separated into different oscillatory bands in the auditory cortex is very attractive, has quite a bit of precedent, and is certainly an hypothesis that can and should be pursued by others in greater depth. The computational apparatus of the brain is very slowly coming clear.

"These are exciting times for researchers working on neural oscillations because a framework that describes their specific contributions to perception is finally emerging. In short, the idea is that comparatively slow neural oscillations, known as “alpha” and “beta” oscillations, encode the predictions made by the nervous system. Therefore, alpha and beta oscillations do not communicate sensory information per se; rather, they modulate the sensory information that is relayed to the brain. Faster “gamma” oscillations, on the other hand, are thought to convey the degree of surprise triggered by a given sound."

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Where do Thoughts Come Together?

Brain anatomy and the binding problem- some scanning attempts to localize concept integration.

Our minds can range incredibly widely, from shopping to integrated circuits, from sewing to theology. More specifically, our knowledge and memory spans vast scales and topics, as a typical video of micro to macro universe scales shows. How can we handle all this? How and where is it stored, and how it is put together again?

In philosophy this is, part, called the binding problem, which asks how features of perception and conception are put together into the larger concept of, say, a rose. Neuroscience has taken a low-key path of labelling our thought and memory patterns as "schemas", which are sort of cartoons of thought, shaping what new things we can fit into our minds and learn, which may be encoded into memories as engrams. Schemas are the structures which can be added together for larger conceptions, or drilled into and ramified to create new distinctions and greater detail. Operationally, schemas allow someone to learn something quickly instead of slowly, largely circumventing the hippocampus as a way-station for memory consolidation / storage. This is all reviewed in a fine paper from 2012.

A recent paper tried to locate where schema-tized thought gets recombined in the brain, and came up with the angular gyrus, which is a structure in the side of the brain, on the temporal-parietal border, known to function in memory, attention, and cognition. How successful they actually were in showing this is another story. They asked human volunteers to learn a very simple task- a sort of brain teaser pattern recognition task, which could give one of two results, depending on which mode or rule was applied. If one rule set was applied, the shapes seen would give one answer, and if the other was applied, another result. A day later, the subjects where shoved in a fMRI machine and tested for their recall of these rules, looking for where in their brains the activity of applying alternate frameworks or schemas to the problem happened. There were many tasks involved here:

• viewing the screen
• understanding the screen text that specifies which rule to apply (spatial or non-spatial)
• interpreting the colors and locations of the imaged circles
• deciding how to decode the problem
• responding to the task by pressing a button with either index finger
• providing an extra response judging the subject's own confidence, with another screen text and button press
• having one's head in a scanner, with corresponding anxiety, boredom, discomfort, etc.

While these tasks were separated in time, it is still alot to disentangle from the whole-brain scanning which finds subtle differences of brain activity in different regions. Overall, they reported seeing activations in many brain areas. But when taking the difference between runs with different rules only, and on the second day when the subjects presumably had their schemas all set up and were tested on their recall and performance, one region stood out, the angular gyrus.

By way of introduction, they mention:
"The medial prefrontal cortex (MPFC) and hippocampus (HC), together with the parahippocampal cortex (PHC), posterior cingulate cortex (PCC), and angular gyrus (AG) have been identified as regions forming a network that is important for successful (episodic) memory retrieval."

Turning to their own results:
"To sum up, while the MPFC mainly showed increased neocortical coupling during spatial schema retrieval, the PCC was connected to an extensive network of regions during retrieval of both schema conditions. This network consistently involved MTL [medial temporal lobe], MPFC, PCC, and left AG and constitutes a set of brain regions that was previously reported to underlie successful memory retrieval."

At this point they tried to isolate the schema-specific parts of the process, making use of the ambiguous nature of their orginal testing, which had the same shapes/colors mean different things depending on the rules the subjects were taught. Thus their recall, while identical or at least very similar in the visual system, would be different wherever the rules were being applied to retrieve different learned memories. Their question was.. where do the visual processing and the rule application activations converge?

Significant difference clusters for various data comparisons. Green shows the locations of visual feature interpretation, deduced from the experimental runs where shapes were shown without further rule-based tasks. These maps were the same between the two days of experiments. Red shows the activation specific to interpreting the various rules by which the experimenters prompted subjects to interpret the same shape patterns in different ways. This activity only appeared on day two, consistent with the schema consolidation hypothesis. Blue shows the activity seen when a slightly altered set of shapes were presented on day two, with the request to interpret them by the same rules already learned. This activation is consistent with the pre-set schema being used to rapidly learn and interpret this new but similar information. The angular gyrus is where all these phenomena converge, suggesting a role in integrating them.

Answer: the angular gyrus. On the first (learning) day as well as the second (recall) day, the visual processing touched here, but the memory processing stream only activated this region on the second day, suggesting that this might be a place that specifically binds prior memories with current perceptions to yield higher-level understanding or cognition.

The angular gyrus is one of the more interesting places in the brain, associated with memory, attention, and out of body experiences. Some suggest, for instance, that it is the site where metaphors are recognized, and where concept integration takes place.

Wiki page:
"The fact that the angular gyrus is proportionately much larger in hominids than other primates, and its strategic location at the crossroads of areas specialized for processing touch, hearing and vision, leads Ramachandran to believe that it is critical both to conceptual metaphors and to cross-modal abstractions more generally. However, recent research challenges this theory."

In sum, I view the current work as somewhat sketchy. It is rather difficult to credit their extremely simple experimental protocol with isolating memory schemas specifically, or that the one-day delay created exactly the schema they thought they were looking at by brain scanning. Nevertheless, the field is in a stab-in-the-dark phase, trying to pick apart the incredibly intertwined and dynamic network of the brain, so each attempt, however flawed, is interesting and welcome.

• Incidental citation on the posterior cingular cortex, which is also heavily involved here:

"One of the most striking physiological features of the PCC is its high rate of metabolism. In the human, cerebral blood flow and metabolic rate are ∼40% greater than average within the PCC and adjacent precuneus." 

"Therefore, the dorsal PCC is involved in detecting and responding to environmental events that may require a change in behaviour and that are not part of the current cognitive set. We envisage that dynamic interactions between the subdivisions of the PCC and other intrinsic connectivity networks are important for regulating the balance between internal and external attentional focus."

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Raising Consciousness

New methods to detect and characterize consciousness in the brain. AKA, going beyond Granger causality to understand brain dynamics.

Neuroscience and the study of consciousness has to date peeked at the living human brain via MRI, and analyzed it by correlation, trying to join slight activity signatures to various mental tasks and subjective experiences. There has been a great deal of speculation about what the neural correlates of consciousness are, complete with fanciful mathematical theories (phi, critique of phi, gamma waves, etc.) But none has been convincing, though there has been a general coalescence around some ideas- that consciousness involves fleeting coalitions among many brain areas coordinated to some degree by anatomical connection and rhythmic oscillation in the gamma band.

Getting beyond that, to a more detailed theory of consciousness, will take not only better techniques of looking at the brain, with higher time and space resolution, but also better analytical methods & theories to make sense of the vast amount of activity we see and data we already gather.

As David Eagleman illustrated in his excellent PBS show on the brain, there is a storm of activity taking place all the time, associated, as usual, with the words "billions" and "trillions". Somehow, it gets the job done, but figuring all this out from the outside requires another order of analysis. A recent paper describes new mathematical methods that appear very promising, for determining causality within a complex network like the brain.

"A dilemma is that overly realistic and detailed simulations often require a number of unknown parameters and can obscure physiological principles. It is, therefore, not straightforward to instantiate an appropriate reductive model that capture dynamical complexity and diversity across multiple brain areas. "

The problem, for a complex dynamic system, is that correlation methods alone are extremely crude. Imagine probing a computer's internal circuits with a correlation meter, and expecting to figure out its logic and mechanisms- it would be impossible. The system is non-linear, which means that a signal here can lead to negative signals there, or to vastly amplified signals, or altered patterns of waves, etc., so that simple correlations among points of activity have very limited analytical power. Then there is feedback and other network behavior that can obscure the directionality of causation.

The next step of analysis has been Granger causality, which is an extension of correlation analysis to a time series. Compare two time series of events, and if changes in one series routinely predict changes in the other, (i.e. correlate with a time lag), that supports a hypothesis of causality from one series to the other. But this method relies on the two variables being independent, and also struggles with non-linear effects, as other correlation methods do.

The new method, called convergent cross-correlation mapping (CCM) or cross-embedding, arrives from a recent ecology paper that asked what causes the unusual cycles of anchovies and sardines, each of which go through boom and bust cycles which seem anti-correlated with each other. Do they compete with each other's food sources? Is there a predator cycle that determines their abundance? The authors conclude that each population is driven by sea surface temperature, independently of the other. The causality went precisely from temperature to each species' abundance, not from either species to the other. The new method uses correlation, but through some higher-level math that better accommodates non-linear systems with feedback characteristics.

This paper showed a nice example of the method, analyzing the predator-prey relationship of the classic protists, Didinium and Paramecium. The dynamic cyclicity is very clear (in A), but what causes what? The Granger method could call it either way, depending on how you set the lag time. The cross-embedding method (rho, on the Y-axis of B) finds a higher amount of information provided by the Paramecium graph against the Didinium graph, suggesting that the predator exerts stronger top-down control of Paramecium than the reverse. In other words, the subject variable (Paramecium in this case) is more dependent on, and thus directly informative about, the driving variable (Didinium) than the reverse. A feature of this method is that it provides stronger results (suggesting true causality) the longer the time series, whence the "convergent" in its name.

A Didinium eating a Paramecium.

Population dynamic between the predator Didinium and its prey, Paramecium. 

Getting back to humans, (or thereabouts), another recent paper used this method to look at neural correlates of consciousness in macaque monkeys. They used electrodes applied directly to the exposed brain surface, getting much higher signal and resolution than when they only applied to the scalp. The monkeys were either anesthetized or conscious and behaving in various ways to test visual and other forms of perception / consciousness. The question was whether, over large distances in the whole brain, correlates of consciousness can be detected. (They also have prior work, using Granger methods.)

Electrode map and anatomical codes, top. At bottom, an example of one electrode pair and its analysis shows directionality of signaling, from #118 (red, visual cortex) to #41, (green, motor and somatosensory cortex).

The answer is that they can get significant signals from awake and behaving brains that are not only different from anestheized brains, but also reflective of an expected hierarchy of directionality and complexity, for instance that the visual system is causal towards signals in the frontal cortex during visual perception, and that the frontal areas overall have significantly higher complexity than the primary sensory processing areas at the rear of the brain.

Complexity and directionality measures among major brain areas in macaque brains under different conditions, using cross-embedding analysis. Consciousness is easily detectable, among other significant characteristics.

"Based on this method, we simultaneously characterized the large-scale cortical interaction and the dynamical complexities embedded in individual area activities. It revealed that the awake brain has a hierarchical structure of the dynamical complexity, where the frontoparietal areas had more complex dynamics than visual areas. Intriguingly, this hierarchy was linked to the directed cross-area interaction from visual to frontoparietal areas. To our best knowledge, this is the first study reporting clear cortical hierarchy in terms of dynamical complexity, as well as its relationship to the global cortical interaction. Moreover, we found that this hierarchy was universal across different behavioral/sensory conditions and disappeared after the loss-of-consciousness induced by either of two different anesthetization methods. These results indicate that this hierarchical structure is correlated with the level of consciousness rather than its specific contents reflecting perception or action."

This work is not unique in finding distinctions between conscious and unconscious states, but the improved data analysis is a significant step forward in teasing out reliable correlates of consciousness as observed from (sort-of) outside. Of course it is still a long, long way from telling what the content of that conscious state is, let alone sharing it in any rich way. And, being based on naked brain EEG, it is not clinically useful either.

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