Toddler carrying blanket with caption Happy Towel Day!

Life, the universe and Markov blankets

Forty years ago, on 8th March 1978, the Hitchhiker’s Guide to the Galaxy was broadcast on BBC Radio for the very first time. I personally first heard it 12 years later, but since that time it has remained my favourite comedy ever. To celebrate the birthday of this remarkable show, book, film, computer game here is a section from my book. This is from a chapter on boredom, surprise and why babies are little scientists. It’s also about why scientists are big kids.

Share and enjoy!
Caspar

Security Blankets

Life is an inevitable & emergent property of any (ergodic) random dynamical system that possesses a Markov blanket. Don’t leave without it!

@FarlKriston, 12 Jan 2015, Anonymous Twitter parody of Prof Karl Friston, FRS

Professor Karl Friston is probably the most influential scientist you’ve never heard of. He works at the University College London’s world famous Functional Imaging Laboratory, affectionally known as the FIL. He has been there most of his career. Back in 1991 he invented Statistical Parametric Mapping. SPM is a statistical technique for analysing the data from brain imaging experiments. SPM is also a set of software that will do the analysis for you. The elegance of the method and the fact that Friston gave away his software for free has led to SPM being used in about 90% of all brain imaging studies. As a result, Karl Friston is the most widely cited neuroscientist alive.

Most of us would have been very happy with that but Friston’s contributions did not stop there. He worked with Chris Frith to develop a highly influential account of schizophrenia and invented something called Dynamic Causal Modelling. He is author or co-author of over a thousand scientific papers. This is a mind-boggling number. For comparison I have under 20. This is partly a consequence of his eminence but also evidence that he is a very practical researcher who stays involved in the nitty-gritty. Friends who work with him tell me he is an affable and generous colleague. Friston’s many, many awards include Fellowship of the Royal Society and something called Golden Brain Award. He is undoubtedly a worthy recipient. He is famous among brain scientists as perhaps the brainiest of them all.

Karl Friston’s most recent idea is his biggest yet. The ‘Free-Energy Principle’ tries to explain not only what brains do but possibly even life itself. But it is also making Friston infamous, as the nerdy but well-meaning mockery of @FarlKriston account shows. The trouble is that the free-energy principle is very hard to comprehend and Friston’s explanations and equations usually only make matter worse. I will do my best to translate. But if you found the last section bamboozling now might be a good time to reach for your security blanket.

Here’s a relatively tame example of Karl explaining it in his own words:

The free-energy principle says that any self-organizing system that is at equilibrium with its environment must minimize its free energy. The principle is essentially a mathematical formulation of how adaptive systems (that is, biological agents, like animals or brains) resist a natural tendency to disorder. (p.127, Friston, 2010)

This makes it sound important doesn’t it? Apparently it can explain everything from the existence of ‘Life as we know it’ (Friston, 2013) right up to Freudian theory and psychedelic drug experiences (Carhart-Harris & Friston, 2010).

The secret is nestled in our Markov blankets. As Karl helpfully explains “The term Markov blanket was introduced in the context of Bayesian networks or graphs and refers to the children of a set (the set of states that are influenced), its parents (the set of states that influence it) and the parents of its children” (Friston, 2013). Got that? In essence, Markov blankets are a supercharged version of Judea Pearl’s Bayesian networks. They provide a statistical way to represent the boundary between an organism and the world. The mathematics gets very complicated, combining Bayesian statistics, information theory and entropy to explain how life can survive in the face of the chaos of the universe. But, in some sense, the free energy principle states that life is about trying to avoid being too surprised by the future.

Knowing what might happen next sounds like a good survival strategy. For Karl Friston, life is anything that can predict its own future. From single cells to Sigmund Freud, he wraps us each in a Markov blanket and sends us out to do battle with the unknown. Describing organisms in this way has some useful features. Action, perception and learning all become mathematically well-defined properties of the system. Perception provides information to optimise future predictions, actions move us out of uncertain (dangerous) situations, and learning is about updating internal states and beliefs about the external world. This might seem a very abstract way of looking at things but it supporters see it as general framework that can be applied as easily to bees as to babies.

Critics of Friston’s theory say there is nothing easy about it. They view it as an interesting intellectual exercise but say that the Free Energy Principle and the closely related Bayesian brain hypothesis are too general to be useful in the real world. FEP is a lot more abstract that SPM. It is not easy to see how it can be used to predict how adult or baby brains will react to the world. But this style of reasoning is already being used to understand what happens in real brains.

My favourite experiment of this kind involved a group of ferrets who went to the cinema. In what was clearly a naked attempt to win an Ignobel Prize, Josef Fiser and Michael Weliky at the University of Rochester got ferrets to watch The Matrix on DVD. The choice was deliberate because like Neo and friends the ferrets had wires coming out the back of their heads. This allowed the scientists to watch what they were thinking. They would watch the film all day and then dream about it at night. In doing so they helped Fiser and colleagues worked out a lot more about how brains are Bayesian predictors (Fiser, Chiu, & Weliky, 2004).

Josef Fisher is the sort of scientist Hollywood might dream up. He is tall, charming, handsome and impeccably dressed. He is Hungarian but speaks English with an American accent. His work is in psychology and neuroscience but with a strong mathematical element. If they made a film about him there would be a whiteboard of equations in the background.

Using the Matrix for this research seems like a doubly prophetic choice. In grown-up ferrets, the scientists discovered patterns of neural activity which correlated significantly with the images on the screen, whilst baby ferrets were more confused. Moreover, the adults kept on thinking about the movie after it had finished. This was pretty cool but the most surprising thing was that ferrets brains were not just passively reproducing what they saw. They could dream about it and their dreams appeared to actively improve their models of the world. Like Neo in the film, they were bending their existing expectations to fit their new reality. Or in the language of Karl Friston, they were minimising their prediction errors via a Gibbs sampling over the probability space.

Still with me? Perhaps now might be a good time to mention Douglas Adams. In that wholly remarkable book the Hitchhikers Guide to the Galaxy, he relates that one the highest compliments intergalactic hitchhikers can pay to one another is to say that they are “someone who knows where their towel is.” There are, of course, many practical uses for a towel when travelling the universe but a towel’s greatest value is psychological. As the book recounts:

“any man who can hitch the length and breadth of the galaxy, rough it, slum it, struggle against terrible odds, win through, and still knows where his towel is, is clearly a man to be reckoned with” (Adams, 1979).

Babies and young children are more likely to carry a security blanket or soft toy on their adventures. Some estimates suggest that up to 70% of children have a strong attachment to a particular object. This seems to be largely a Western phenomenon, possibly a result of many more children sleeping separately from their parents than in Eastern cultures. The standard explanation was that these ‘attachment objects’ are a substitute for the original ‘object’, the mother and her breast. This does not hold up. The objects can provide security in novel situations but it seems to be an independent a child’s attachment to their mother (Donate-Bartfield & Passman, 2004).

Donald Winnicott thought attachment objects were reminder of security and love. I think this is correct. However, Karl Friston and the ferrets lets us see security blankets and velveteen rabbits in a wider context. Babies and children use these objects because we need security as we build our worlds. The ultimate aim of life is to explore enough of the world so that you can survive surprises. We will never be able to expect the unexpected but we can and we must reduce its scope and its impact. To survive we have to change our minds many times. Like the ferrets, we do this by improving in a Bayesian way, updating our beliefs to better fit our experience.

Babies are surprised every day and must continually confront uncertainty and explore the unknown. This is exhilarating and exhausting. It is not enough to add knowledge about the world, they must change their expectations, a new existential crisis every day. Mummy, teddy or a security blanket is a reassuring element of continuity and predictability. If babies know where that is, they know where they are. Perhaps this prevents the Markov blanket from unravelling?

It is hard to appreciate what a wild ride this must be for them. Adults do not change our beliefs very often. We have worked our whole lives to feel like we are right about most things. After all, in Friston’s theory that is the whole point of life; being less surprised over time. The best analogy I can suggest is to imagine your home planet gets destroyed and your best friend turns out be an alien who takes you hitchhiking across the remainder of the galaxy.

I might be biased here. Not only I am keen to meet aliens, I also still have a security blanket. I had one when I was little. I was so attached to it that my mother knitted a large elephant and sewed the tatty cotton rag onto his back. This was meant to deter me but inevitably I ended up dragging the elephant around everywhere. The original blanket disintegrated decades ago. It was replaced in my affections by a cellular blanket my mother bought home one day from hospital. The blanket wrapped a parcel containing my baby sister. No doubt I seemed alien and friendly to her. I still find cotton cellular blankets very soothing. May you do too? Around 30 percent of adults keep an old teddy or similar childhood memento. By my estimates, Charlie Brown’s friend Linus van Pelt must be into his seventies by now. I imagine he still carries his blanket some of the time.

As luck would have it just as I was finishing writing this section, Karl Friston came to my university to give a lecture. This was my chance to hear him in his own words. Would I be bamboozled? His opening was not promising, “I can give very good lectures. This is not one of them.” But he was wrong. He had us imagining ourselves as hungry owls and playing a logical guessing games. There were some of his infamous equations but he guided us through gently them. His reassuring, unhurried delivery no doubt acquired during his early training as a psychiatrist.

His summary of the purpose of life fits very well with the ambitions of our babies. When confronted with the big mysteries of the universe we are compelled to explain them (even if only to explain them away.) “The brain is in the game of explaining the sensory impression at hand.” This is a game of chance and we are all born with an intrinsic motivation to play it. We all keep score with the information gain measured in “Bayesian surprise” (or minimized free energy). Afterwards, I told him about this book and asked if he any insights into how this must feel for babies who play the game so much more intensely than adults? He could not much improve upon the hitchhiking analogy. And, wise man that he is, he also turned the question around. “This is why we are scientists isn’t it? To keep exploring and to try and recapture that feeling of joy?”

At the end of his famous 4 page paper Judea Pearl stated that he hoped his Bayesian networks would become “a standard point of departure for more sophisticated models of belief maintenance and inexact reasoning”. Be careful what you wish for. I do not think he could have predicted that ferrets would be watching The Matrix or that Karl Friston would drape Markov blankets over all life on Earth

“In truth it’s blankets all the way down. So cuddle close and keep that free energy minimal.”

(@FarlKriston, 8 Dec 2017)
Douglas Adams holding up a towel
Douglas Adams knew where his towel was.

For more like this, please look out for my book The Laughing Baby. It is being crowdfunded by Unbound Books. So it needs your support to make it a reality. Please pre-order your copy or tell your friends with babies

The characters Anger, Disgust, Joy, Fear and Sadness from Pixar's Inside Out

Babies and emotion

This weekend I was delighted to receive a beautiful copy of Schadenfreude by Tiffany Watt Smith. It has a close connection to my own book The Laughing Baby because Tiffany and I have compared notes as our various projects have progressed. Tiffany is an historian of emotions and the parent of young childen. She has even brought her son to our lab to take part in one of our studies…

Schadenfreude — Tiffany Watt Smith

You will have to read her book to find out if babies do expeience Schadenfreude. What’s more, Tiffany was one of the first people I interviewed when writing my book. Unfortunately, I didn’t check that sound levels so the recording is essentially inaudible. Nonetheless, her previous book was very helpful when i was trying to answer the following tricky question:

What are emotions?

(From Chapter Nine of The Laughing Baby)

“Emotions do not exist to be locked away inside individuals.”

Vasudevi Reddy and Colwyn Trevarthen, 2004

If laughter evolved as a social glue, central to this role is that it expresses emotion. The most infectious thing about a laughing baby is their absolute delight. It may seem a truism to say that ‘babies laugh because they are happy’. But this challenges us to answer the question what is happiness? While we are about it we might as well try and explain anger, sadness, worry and the rest. It should not surprise anyone that emotions are still mysterious to science. Many theories have been proposed and few have been discarded.

The race for a comprehensive theory of emotion is still wide open. Perhaps, it will always remain so, no scientific theory could catalogue all the nuances of our adult experience. In The Book of Human Emotions, Tiffany Watt Smith describes 156 different emotions. She readily admits this list is not comprehensive and the categories overlap and blur at their edges, changing over time and by culture. Tiffany’s goal as a historian of emotion to offer an argument against the tendency to reduce “the beautiful complexity of our inner lives into just a handful of cardinal emotions” (Watt Smith, 2015).

It is a tendency that has always been there. Tiffany describes the Li Chi, a book from the Confucian era that lists seven essential feelings; joy, anger, sadness, fear, love, dislike and fondness. Two and a half millennia later and little has changed. In the 2015 animated Pixar film Inside Out, the main character, a young girl called Riley, is shown with five emotions; Joy, Anger, Sadness, Fear and Disgust. Modern science usually settles on a list of about nine ‘basic emotions’; happiness, sadness, anger, fear, parental love, child attachment, sexual love, hatred, and disgust (Oatley & Johnson-Laird, 2014). These lists seem reasonable in as far as they go. But the best theories are not about listing emotions but explaining why we have emotions at all.

One of the first people to realise this was Charles Darwin. In a work of visionary genius that often gets overlooked in comparison to his other incredible achievements Darwin advanced one the first ever scientific theories of emotions. His book The Expression of the Emotions in Man and Animals (Darwin, 1872a) proposed that our emotions are evolved for our survival. Of course, he would say that wouldn’t he? Like all of Darwin’s work it was supported by decades of patient accumulation of evidence. He compared the anger displays of many animals. He also included many observations of babies. Darwin kept detailed biographical diaries of several of his children and wondered what was meant by their frowns, blushes, and laughs. On a theoretical level Darwin’s account was a bit thin, all it really says is that emotions are universal, valuable and shared with animals. But it was a very radical proposal for its time

About a decade later, William James and Carl Lange each independently decided that emotions were reactions to bodily states. For example, fear might be how we interpreted our racing hearts. For James emotions are literally feelings, “we feel sorry because we cry, … not … we cry … because we are sorry” (p. 180, James 1884). By this view emotions happen after the fact and are what philosophers call ‘epiphenomena’. The theory has been remarkable popular because it suggests that if you carefully measure exactly how a person is reacting physiologically you can tell what emotion they are experiencing. The James-Lang theory feels unsatisfying to me because it relegates emotion to a passive role. But it does have two important strengths. It points out that our physiology strongly influences our mental state and that emotions depend upon interpretation of experience. Contrary to early views of the theory popularised by John Dewey, neither James nor Lang ever insisted on a single emotion for each physiological reaction. They would be quite content that a racing heart and sweaty palms could be interpreted as fear in some situations and as love in others (L. B. Feldman, 2018).

Our old friend Sigmund Freud took a very different view. For Freud, emotions were supremely mental. Our minds are seething cauldrons of desires. Emotions are the main engine that drive us forward or hold us back. Reversing James-Lange theory, Freud even thought that mental turmoil could manifest itself physically as psychosomatic illness. But Freud’s biggest contribution was the invention of the unconscious. He believed our ‘true’ emotions hide from us in our subconscious and they are shaped by momentous events in early life that echo down through our lives. Being unobservable the unconscious is unscientific. Hence my use of the word invention rather than discovery. If you read modern neuroscience papers on emotion, they usually take the trouble to explain why James & Lange were wrong, but do not even bother to mention Freud.

Jaak Panksepp, who we met tickling rats in chapter seven, believes our emotions exist to tell us what supports or detracts from our survival. He thinks we have 7 emotional systems. There are ancient systems of FEAR, RAGE, LUST and SEEKING and more modern mechanisms for CARE, PANIC and PLAY that are unique to social mammals. He capitalises the words to emphasise that he gives them very specific scientific meaning (Panksepp, 2005). Each system serving specific goal and can be mapped to equivalent brain areas in many species. Take the PANIC system which rules babies’ separation anxiety. Panksepp shows that it operates in the brain with the same neurochemistry as physical pain. The pain of separation is real pain and prompts the infant to act, usually calling out to mother in distress. The return of the mother releases opioids and oxytocin which relieve the pain. The brain circuitry goes back to the imprinting in chicks and the survival value is clear in both cases (Herman & Panksepp, 1981).

As well as his laughing rats, Panksepp has looked at sadness in chickens, what makes guinea pigs cry and mother-infant bonding in sheep. He has spent decades researching emotion in animals and is very particular that they feel things in the same way we do. He believes in an emotional consciousness common to humans and animals and cognitive consciousness that comes later with the use of language. Emotions colour our world and the conscious experience of joy or rage is essential to its function for humans and animals alike. It is an unpopular viewpoint. Plenty of scientists are dismissive of the experience of animals. They cite Morgan’s cannon and say science can only ever study animal behaviour. They criticise him because they do not believe animals have consciousness necessary to experience or interpret emotions. In Panksepp’s view, these scientists are looking down the wrong end of the telescope. It is the experience that makes the emotion and experiencing emotions was how and why consciousness evolved. We may have to describe animal emotions with human labels but FEAR came before ‘fear’ and SEEKING before ‘pleasure’. In my view the most case compelling against Panksepp’s critics is that anyone who is dismissive of animal emotions also has dismiss all the emotions of preverbal babies.

Some researchers do argue precisely this position. One forceful critic of Panksepp is Canadian researcher Lisa Barrett Feldman. A professor of psychology at Northeastern University in Boston, she argues that emotions are entirely conceptual and so animals and new born babies cannot have them. Here is what she says about babies

“Babies don’t know what telescopes are, or sea cucumbers or picnics, let alone purely mental concepts like ‘Whimsy’ or ‘Schadenfreude’. A newborn is experientially blind to a great extent.” (p. 113, L. B. Feldman, 2018)

The quote comes from her recent book How Emotions Are Made in which she describes her own theory of constructed emotion. She contrasts this with what she calls classical view of emotions shared by Darwin, Panksepp and others. As I said at the outset of this section, no one theory of emotions covers all the ground yet so it worth looking at things from the opposite perspective. To do this let us go back to Inside Out.

In the film Inside Out, each of the basic emotions is personified as a character inside Riley’s mind. Joy appears first when Riley is a new born baby seeing her blurry parents for the first time. Her job it seems is to press buttons the cause Riley to respond and collect the memories associated with her actions. She is shortly joined by Sadness and the others and each interpret situations and responds according to their nature. Joy delights, Anger gets mad, Fear worries, Disgust dislikes things and Sadness is sad. If we forgive the artistic licence of little people inside your head pressing buttons it is a wonderful depiction of the classical view of emotions. This is to be expected, the main scientific advisor on the film was Paul Ekman who is one of main theorists behind the idea that emotions are universal biological drives (Keltner & Ekman, 2015).

The outer plot revolves around an eleven year old Riley having to adapt as her family move from Minnesota to a new home and new school San Francisco. The inner plot revolves around Joy trying to understand the purpose of Sadness. It is a good film so I won’t spoil it for you but it is not giving too much away to say that the Emotions learn to work as a team and Riley learns that other people struggle with their emotions too. At various points we see into her parents’ heads, their own teams of five emotional essences at their controls. It is a story Barrett claims that would be recognisable to Aristotle, Plato and even the Buddha, but she argues it is built on a myth. Barrett does not believe there are universal emotions. Your emotions are not fixed by evolution but constructed as part of your culture. They do not bubble up from a set of brain areas but are constructed by your highly sophisticated human brain building abstract categories to help classify and your inner and outer lives.

Lisa Feldman Barrett’s theory has no problem with there being hundreds of subtle emotions like those listed in Tiffany Watt-Smith’s Handbook. In fact, Barrett is the editor of her own Handbook of Emotions, an academic volume running to over 900 pages. There can be countless, complex emotions because our highly social lives and big brains create that complexity. But then Ekman and Panksepp do not have any problem with the existence of complex emotions like embarrassment, ennui or exasperation. Where her theory differs is that she does not think happiness, anger or sadness are any more natural or biological than technostress or Torschlusspanik.

But that does not mean that in Barrett’s version of the film there would be 156+ characters all clamouring for attention in Riley’s head. That would be a terrible movie and it would be committing the error of Essentialism. Just because we can classify a set of behaviours as ‘anger’, does not make anger is a real thing. According to Barrett, Plato, Darwin and Panksepp all commit this error. Plato we can forgive. Essences and Platonic Ideals were kind of his ‘thing’. Barrett gives Darwin a particularly hard time and she has a point. His theory evolution removed the need for essentialism from biological classification. But his book on emotions went the other way. Barrett notes that at Darwin says “Even insects express, anger, jealously and love” (p.350, Darwin, 1872).

Why is this an error? Let us take a closer look at Anger. In several chapters of How Emotions Are Made Barrett deconstructs anger to show it is not a single, simple thing. First, she takes aim at Ekman’s famous work supposedly showing that expressions of emotion are universal. But her research shows that neither facial expressions or physiological signals are highly ambiguous. You can be angry without giving any outward sign of it and seems like anger might not be. Second, there is ambiguity in language. ‘Anger’ might mean annoyance, irritation, rage or fury. But some languages Utka Eskimos have no concept of “Anger” while Mandarin has five or more different “Angers”. Some languages would not even recognise our Western notion of emotion. Finally, in Chapter 12 Barrett asks, “Is a Growling Dog Angry”? As you might guess her answer is that “there is no clear evidence that any non-human animals have the sort of emotion concepts that humans do.” (p. 270). Even dogs, who we have been breeding for their loyalty and understanding of us for millennia. The best we can say is that dogs have raw feelings but this is a long way from emotion. Insects, not even that.

It is in how they approach the emotions of babies where gulf between these theories comes into focus. Barrett, for whom emotions are conceptual, spends a lot of time discussing infant pattern recognition abilities and how they learn words and concepts, the mental prerequisites for her cognitive concept of emotions. Panksepp, for whom emotions are feelings, does more to evoke our empathy but usually cannot help reducing things down to biology and brain areas (Panksepp, 2001). It is notable that neither camp engages directly with the experience of the babies themselves. Yet, I think this is precisely where we will find a better sense of what human emotions are and how they build on our animal affect.

Emotion is about more than just classifying feelings, it is about the feelings themselves. A baby may not know that their sadness is “Sadness” or their happiness is “Joy”. But any parent can see that there is something very real contained in their experiences. I am sure that Barrett and Panksepp would both acknowledge this but there does not seem to be much space in their theories for the subjective sense of emotion, its ‘phenomenology’ if you wanted to be fancy. I do not believe a comprehensive theory of emotions exists yet, but such a theory would not be complete if it did not encompass the primal emotional experience of infants.

For more like this, please look out for my book The Laughing Baby. It is being crowdfunded by Unbound Books. Please pre-order your copy or tell your friends with babies.