Category Archives: Theory of Mind

Cognition and Consciousness in Peter Pan

A Conversation with Rosalind Ridley

My friend and colleague, Rosalind Ridley, who has had a distinguished career with the MRC studying brain and behaviour, has just published an intriguing book about J M Barrie and Peter Pan. It turns out that Peter Pan is not just a childish story about pirates and children who can fly. Barrie was very aware of the scientific developments of his day and the original Peter Pan stories are infused with ideas about man’s place in the natural world and the mental lives of children and animals. In many places Barrie seems to have anticipated ideas in cognitive psychology that only emerged after his death.

CDF: I wonder why a respected neuroscientist came to write a book about Peter Pan?

ppkgcoverRMR: I came across an early edition of Barrie’s first Peter Pan book ‘Peter Pan in Kensington Gardens’, written in 1906. In the text I found descriptions of many aspects of cognitive psychology that have only been studied scientifically since the middle of the twentieth century. The more I read, the more I found. I was hooked.

CDF: Most people are unaware that Barrie wrote two novels about Peter Pan in addition to the pantomime. Do these give us a different view of the nature of Peter Pan and the intentions of Barrie?

Continue reading Cognition and Consciousness in Peter Pan

RMR: In ‘Peter Pan in Kensington Gardens’, Peter is about a week old while in ‘Peter and Wendy’ (1911), which is based on the pantomime, he is about six or seven years old (although he supposedly ‘still had all his baby teeth’ which indicates his immaturity). Although Peter is ‘the boy who wouldn’t grow up’ he undergoes several changes of age, out of synchrony with other people in the stories. One explanation for this is that Peter is Barrie’s memories of himself as a child, achieved through ‘mental time travel’, and that Barrie is both exploring the nature of childhood and re-living his own childhood.

CDF: What was Barrie like?

RMR: Barrie was a lonely man who had had a difficult childhood and a childless marriage that ended in divorce. He found adults difficult and sought refuge in a fantasy world outside the normal stream of consciousness of our mundane existence.

CDF: And yet, he was also one of the most successful authors of his time and knew everyone from Thomas Hardy to A. A. Milne. But he certainly had problems. I believe that Barrie suffered from insomnia, as did Lewis Carrol,  but that Barrie attempted to control this by taking heroin. He must often have experienced the strange states of consciousness that can occur at the borders of sleeping and waking. Did these experiences inspire some aspects of the Pater Pan story?

RMR: Yes, Barrie complained of terrible sleep and gave accurate descriptions of almost all the clinical parasomnias in his stories. It is more than likely that he experienced these sleep disturbances and that this taught him that what he experienced and what was happening ‘out there’ are not the same thing. When Barrie was six years old his older brother drowned. Their mother became very depressed and Barrie felt that his dead brother was more real in his mother’s mind than he was. This may have encouraged Barrie to think in terms of internal mental states rather than the outside world.

CDF: Barrie seems to have been seeking a special state of heightened consciousness, which he believed people experienced in some historical or childish Golden Age.

You call this state ‘sublime consciousness’. What is this?

RMR: Although he didn’t use these terms, Barrie clearly understood the modern distinction between primary mental representation (mainly perception) and secondary representation (mainly episodic memory, anticipation of the future, and the imagination of alternatives). His stories were based on the notion that these were different, mutually exclusive, types of consciousness and that only adult humans had what we would now call ‘secondary representation’. He longed for a pure type of primary consciousness (which is what I called sublime consciousness) which he believed was available to animals, children and only occasionally to adults. Barrie argued that animals and very young children were not burdened with the ‘sense of time’ or ‘sense of agency’ that comes with the development of secondary representation and so were free to enjoy a heightened experience of the present.

CDF: This reminds me of work showing that, if you think about being happy, you will feel less happy.

But isn’t there one animal in the stories who does have secondary representation?

2-solomons-sockRMR: Yes, Solomon the crow. In the picture by Arthur Rackham we see him with the sock he is using to save for his pension. Crows have always had a reputation for being clever and Nicky Clayton has published work suggesting that they can plan for the future.

CDF: And, crows’ brains contain more neurons than the brains of some monkeys of comparable size.

I remember the rather sentimental episode in the pantomime where children are told that every time they say, ‘I don’t believe in fairies’, then a fairy will die. But, in your book, you suggest that Barrie is making a comparison between the type of thing that fairies are and the type of thing that money is.

RMR: Well, yes, Barrie liked to play tricks with words and ideas. He made ethereal objects behave like solid objects; a shadow, for example, is folded up and put in a drawer. Like Lewis Carroll, Barrie saw that words and the objects they represented were separable but, whereas Carroll adopted a semantic view that ‘a word… means just what I choose it to mean’. Barrie took a more pragmatic approach in making Wendy describe a ‘kiss’ as a ‘thimble’ when she could see that Peter was using the two words the wrong way round. Barrie then goes on to distinguish between solid objects and socially constructed objects. In a rather complex scene, Peter has forgotten how to fly and is marooned on the island in the Long Water in Kensington Gardens. A boat made out of a five pound note washes up on the island, but, rather than using the boat to make his escape, Peter cuts the bank note up into smaller pieces and uses these to pay the thrushes (who have been told that these ‘coins’ are valuable) to build him a bird’s nest boat. Here Barrie recognised that money is not only a piece of paper, but is also a socially constructed object that only exists as currency so long as everyone believes in it. Similarly, fairies are socially constructed objects, who only exist if you and your friends believe in them.

CDF: We once did an imaging study where people watched bank notes being torn up. The higher the value, the more brain activity we saw.

You suggest that a major theme of the Peter Pan stories concerns the cognitive differences between animals, children and adults. After Darwin published his theory of evolution, people had to reconsider these differences, since he had shown that we are all animals.

RMR: Peter Pan is described as a ‘betwixt-and-between’,
part child, part bird (he can fly) and part instinctive, slightly dangerous creature, like the god Pan. This allowed Barrie to compare the mental world of adults, children and animals and to consider the extent to which human behaviour is instinctive rather than rational and enculturated. These are very post-Darwinian themes and Barrie clearly believed that children start life with animal instincts and develop additional, specifically human cognitive skills as they mature. This reflects the view put forward by the nineteenth century embryologist, Ernst Haeckel, that ‘ontogeny recapitulates phylogeny. It would not have occurred to anyone before Darwin to compare the behaviour, especially the moral behaviour, of humans and animals because humans were made in the image of God and animals were just dumb beasts. Barrie also refers to paths in Kensington Gardens that have been made by men and adjacent ‘vagrant paths that have made themselves’ suggesting that he understood that evolution could apply to anything that was based on bottom-up processes, not just plants and animals.

CDF: One of the more exciting research programmes to emerge toward the end of the 20th century was about theory of mind or mentalising. This is the ability that enables us to realise that other people may have different beliefs from us and that it is those beliefs, rather than reality, that will determine their behaviour. Children don’t seem to acquire a full version of this ability until they are about 6 or 7 years old.

RMR: Although Barrie does not specifically name the nature of Peter’s cognitive limitations, his various descriptions of Peter’s behaviour certainly indicate failures of mentalising. Peter cannot remember events of the past and cannot understand what ‘afraid’ means because it is about the future. Peter also appears not to have a fully developed theory of mind and the social cognition that develops from it. He has great difficulty dealing with the beliefs and desires of others.

“What are your exact feelings for me?”
“Those of a devoted son, Wendy.”
“I thought so,” She said, and went and sat by herself at the extreme end of the room.
“You are so queer,” he said, frankly puzzled, “and Tiger Lily is just the same. There is something she wants to be to me, but she says it is not my mother.”
“No, indeed it is not,” Wendy replied with frightful emphasis.

Here Peter is clearly described as not knowing what it is that Tiger Lily wants to be to him, rather than not knowing how he should respond to her amorous advances. Later Peter gives a puzzled, nervous laugh and skips off merrily when he thinks that Wendy has been shot dead.

CDF: Well, it’s certainly amazing that Barrie was so much ahead of his time in presenting these various ideas, which we associate with contemporary cognitive psychology, but is this enough? What does your foray into the humanities contribute to contemporary neuropsychology?


RMR: Barrie was a close observer of human and animal behaviour as well as being extremely well read. I suspect that many of his astute observations were entirely his own but the implications of scientific discovery was a very pressing issue amongst the intelligentsia of the time and Barrie knew a great deal about science. For example, his story of the fairy duke who does not know that he is in love charmingly demonstrates the James/Lange theory of emotion, which was proposed at the end of the nineteenth century. At first I was surprised by the cognitive approach he adopted but I now realise that much early psychology, especially that proposed by William James (whom Barrie had met), was very cognitive in approach. But it was then overshadowed by the subsequent schools of Psychoanalysis and Behaviourism. We should pay much more attention to the psychological insights of the nineteenth and early twentieth century.

                                                                                                                                                                                            

Barrie’s literature makes science accessible, but Barrie also argued that a good grounding in science and the scientific approach could contribute to literature when he said ‘science is the surest means of teaching you how to know what you mean’.

Photograph of the paths in Kensington Gardens courtesy of Harry Baker
A version of this conversation previously appeared in The Psychologist, January 2017

Putting language into the social brain

cartoon@langBlogChris and I are visitors at the Interacting Minds Centre at Aarhus University during August and September 2014.  This is a great opportunity to meet people who excel at providing stimulating conversation on “What makes us social”.  Admittedly I am more of a talker than a listener, and I assume that talking is completely, utterly, super-important in interactions. So why do social neuroscientists not pay more attention to language? Continue reading Putting language into the social brain

Kristian Tylen is the person I turned to with my burning question: What is the role of language? When we consider social interactions this almost always involves language. Is language actually the primary driver of our social interactions, or is it the other way round?

KT:  Language is multimodal. It probably started with gestures and this presupposed social interaction of a kind. There are different theories about the evolution of language and there is actually no real consensus.

UF: That’s what I felt when I recently read Stephen Levinson’s review  of two new books on the evolution of language, one by Derek Bickerton and one by Michael Tomasello.

KT: These represent interestingly different theories and there are others too. There is the view that language should be seen as completely separate from social communication, and that it grows from its own cognitive mechanisms. I sort of doubt this. I think language is primarily for the use of communication and it evolved as a tool to improve communication.

UF: Without specifically referring to Chomsky, what do you think about an innate predisposition for language in humans?

KT: It depends on what you mean by innate. My preference is to think that language both evolves from and is shaped by our interactions with the surrounding physical and social environment.  And so it is out there rather than inside us. This is demonstrated by the way that language structures are motivated. Take the way we talk about pitch  In English and Danish: We talk about low and high pitch mapping onto low and high spatial notation. Other languages for instance use thick and thin or big and small. These relations all map onto universal experience. Low tones come from big creatures and high tones from small creatures. And it turns out that it is very difficult to learn the opposite relations.

UF: But things out there need to act on the brain, no?  I don’t disagree with you that the world outside the mind is a starting point, but the experience of the outside shaped the inside, over millenia.  As a consequence, I guess there are some pre-shaped circuits in the brain, which might become obsolete, if  the environment changed radically.  So this is why I would put the outside in second place, and the inside first.

KT: So what do you mean by innate?

UF: I use the word for neural circuits that have a long evolutionary history. I don’t use innate to mean present at birth, and I don’t use it to mean that learning is not required. But I believe the circuits are preprogrammed for certain types of learning to be facilitated. That is why I like to talk of start-up kits rather than innate circuits. Start-up kits lead to effortless fast learning. No start-up kits require effortful slow learning.

KT: For me, it’s important to remember that the driver of evolutionary history is the environment, and this rather puts anything innate in second place. I am not very comfortable with putting too much stress on the inside of humans. Communication happens because we share the same experiences and systems on the outside and can create symbols that are mutually understood almost irrespective of our individual insides.

UF: Here is my naïve sketch of a likely scenario for the evolution of language in human beings, as opposed to other species. I want to speculate on what might be an innate start-up kit, still requiring learning, and what might not be innate and can only be gained by learning.

Chris, who meanwhile did the sensible thing of googling ‘evolution of language’, weighed in with a devastating remark:  You might be interested to know that the Linguistic Society of Paris in 1866 banned any debate on the topic as unsuitable for study because of the lack of empirical evidence.

UF: Too bad. I will still tell my story. I have only just made it up!  And what you are saying means that It cannot be worse than any other current proposals. They’re all speculation.

In the beginning was not the word. In the beginning there were two things: a start-up kit for spontaneous vocalisations, and another for spontaneous mentalising. These innate mechanisms are visible in precisely located and well connected neural circuits in the brain. They evolved separately, growing from already existing capacities in our remote ancestors.

KT: What were these pre-existing capacities?

UF: I speculate that even very remote ancestors had vocalisations, and they had the experience of agency. They must have had this to distinguish prey and predator and behave accordingly.

My story requires a third thing, and it demands a sufficiently complex brain. This is combining language and mentalising. This is not trivial. I imagine it needed many generations of our ancestors inventing words and telling each other what they mean, influencing each others minds along the way. Now for the magic bit: Language and mentalising put together enhanced each of their effects. This third thing is perhaps primarily responsible for the rise of human culture.

CDF: Mike Tomasello made a similar but different proposal. He believes that the ability to cooperate is a uniquely human driver of language and of culture.

UF: But what underlies the ability to cooperate in the way humans do? I would guess it depends on mentalising. I find it hard to conceptualise cooperation, or joint attention for that matter, as a more primary mechanism than mentalising. Cooperation and joint attention are not so much cognitive mechanisms as behaviours. No doubt cooperation is an important driver of culture, but so is probably competition. We cooperate within groups but compete with other groups.

KT: Why not? It’s a ‘just so story’ as always happens when people talk about evolution.

CDF: I think the Linguistic Society of Paris had the right idea.

Our conversation ended, but here are some details  that I would have given to bolster up my argument – if I had had the chance.

1. Spontaneous vocalisation. These have a useful instrumental purpose, like the warning cries that initiate flight from predators, or the high pitched cries that bind mothers and babies. This is a mechanism present in many mammal brains and presumably present in human ancestors as well. However, as Stephen Levinson reminds us in his review, the vocal apparatus of human beings is immensely complex and is under voluntary control, which may not be the case in many other animals. Speech is a complex motor action and well localized in the brain. Voice actions and hand gestures have similar requirements in terms of motor programmes and syntax. The FOXP2 gene has been associated with such actions and their relevance to speech and motor disorders has been documented.

2. Spontaneous mentalising. I find it very interesting that Martin & Santos have shown that the monkey brain can represent another’s viewpoint, but not another’s belief. Only the latter counts as mentalising, and Agnes Kovacs and her colleagues observed this in 7 months old babies. There are many other advantages, such as friendship, and also some disadvantages, such as deception. Apparently, there are forms of friendship and deception present in monkeys, but typically as rare examples. It is easy to see how language can scale up both advantages and disadvantages.

3. The third thing – two together. I am speculating that one of the two mechanisms on its own would probably bring you up to the level of a three-year old child. Not bad, but not enough to get on with the business of creating lasting and cumulative culture. Culture, as we all know depends on learning from others.  The specifically human form of learning from others which involves teaching is likely to be dependent on mentalising, but it would be a poor vehicle for learning without language.  Humans use language not just to make others do something, but also to express their mental states and to appeal to another’s mental state. Humans have done very well by learning from each other through the use of language. After many thousands of years humans got to a point where language was turned into literacy, and then science and technology started to take off.

Of course there are alternative views

The great Smurf Experiment

I am at the gorgeously magnificent Széchenyi baths with Ágnes Kovács, one of the senior researchers of the CDC group at the CEU. I have long admired Ági’s work and one experiment conducted with Ernő Téglás and Ansgar Endress, has completely changed how we think about the development of Theory of Mind. 

We are sitting at the edge of the pool marked 36ºC. Silky water is all around us and we can comfortably settle at the edge.

UF: Agi, how did you come to embark on your amazing experiment that showed that 7-months old infants can track another person’s false belief? Most researchers up until then were convinced that Theory of Mind was testable only from age four onwards. Continue reading The great Smurf Experiment

agnes melinda kovacs

AK: It started in a conversation I had on a train in Trieste. I did my PhD there in Jacques Mehler’s lab, on bilingualism and its effects on cognitive development. Amongst the effects I considered were Theory of Mind (ToM) and Executive functions (EF).

It turned out that these two factors had been confounded in the well known Sally-Anne task that was typically used to test ToM. I wanted a pure test of ToM. It occurred to me that I actually wanted a ToM test for babies, and that it simply had be a non-verbal version of the Sally-Ann task.

UF: Wow that was ambitious! So how did you get this idea and go about designing such a test?

AK: I didn’t know it was ambitious, – I only knew that there was a risk  of not finding anything. So I only pursued the project on the side. Jacques Mehler very kindly allowed me to do this – even though he himself was very skeptical about it. In his lab I had learned that by merely observing babies’ looking behavior you can get an idea about what they expect. So it should be possible to look for evidence of whether or not they have an implicit form of ToM.

UF: If babies have expectations, does this mean that they have mental representations –  images perhaps of what might be there in the outside world? And sometimes this image agrees with what is out there, and sometimes it doesn’t?

AK: You could say that. We knew already from earlier studies that infants can represent the continued presence of an object even when the object was hidden behind a screen. When the screen was lifted, the infants still expected the object to be there.

UF: So, they did a double take when the object wasn’t there.

AK:  These and other findings suggested that young infants can also represent another agent’s goal, and this made me think that it might be possible to study not just infants’  representation of objects, whether they are present or absent….but beyond this, whether infants represent not just their own beliefs about objects, but the belief of another person.

UF: Why did you test 7months olds?

AK: I thought even 6 months olds might do this, since even at this age they understand goals.  But at the time, the babies coming to the lab to be tested were 7 months old.

To go on exploring the baths we are moving to a slightly warmer and larger pool, surrounded by Roman style marble columns.

UF: You designed the famous Smurf task. Can you briefly describe what your aim was with this task?

AK: We wanted to we find out whether human beings would spontaneously track another agent’s belief about a location of an object – even when the agent and his beliefs are completely irrelevant for the task. So, basically, we transformed an object detection task into an implicit ToM task.

UF: The other agent was a Smurf! The thrilling question was whether observers, adults or babies, were influenced by the Smurf’s belief. So when he had a false belief, namely that an object was still there when it had actually been removed, then the observer might be systematically affected by this. But how did you measure the effect on the observer?

With adults we used a simple visual detection paradigm. They have to detect the presence of a ball and press a button as quickly as possible when it was present. We knew already that our expectations and knowledge modulate behavior. For instance, imagine a person arriving to a crowded airport and spotting her best friend. She will be much faster in noticing her friend if she knew in advance that the friend was waiting for her, as opposed to the situation when she did not know that the friend was coming.

In our baseline task participants watch short video and have to detect the presence of a ball behind a screen when the screen falls. We find that they are faster in detecting the ball when they have previously seen the ball rolling behind the screen, and expect it to be there, as compared to the situation when they have seen the ball rolling out of the scene, and thus don’t expect to find the ball.

In our critical condition we vary the belief of the Smurf and this is how we did it: if the Smurf walks out of the scene before the ball rolls away, he would “think” that the ball is still behind the screen.

UF: Ingenious! So you expect participants not only to be faster in detecting the presence of the ball when they themselves believed the ball to be behind the screen, but also when the Smurf believed this.

Baby watching Smurf

AK: And this was the result. It suggested that just watching animations could lead participants to automatically compute the Smurf’s (false) beliefs, even though the Smurf’s belief was entirely irrelevant to the task they had to perform.

 

UF:  What was the task in the case of the infants?

AK:  Here we measured looking time. In exactly the same situation as the adults, they looked longer when the Smurf had a false belief.

UF: These findings must have just clicked into place for you. It must have been thrilling to see your ‘high risk’ study work out.

We visit the steam room and are surrounded by thick mist. My glasses completely become clouded and I can only see through a fog. After a refreshing shower we brave the outside. There is an open air hot pool at Szechenyi baths. An amazing sight greeted as: steam rising against a purple evening sky, lights glinting and water pouring from the spouts of statues at the edges of the pool. We braved a short walk through the cold air and then gratefully slipped into the delightful warmth of the water. 

AK: Well, arriving to the final design took many hours of discussions with Erno and Ansgar to make sure we control for various factors to rule out other interpretations. Another difficulty was that we wanted to use the same movies with adults and young infants, thus movies had to be simple (1 location, 1 object, 1 agent).

UF: Can you tell me something about your collaborators, Erno Teglas and Ansgar Endress?

AK: It was Ansgar I had the conversation with in the train when it all started. He suggested that we test the paradigm first with adults.  Here we used Reaction Times, not eye gaze. This was a really good idea. Ernö was indispensable. First he was my boyfriend, and we previously had had long discussions on how to study ToM in infants; second he was doing a PhD where he had gained the necessary experience with studying looking behaviour in infants.

UF:  Can you briefly summarise the results?

The results were just as I had expected. With the adults and then also with the babies, when we used eye gaze as a response. We have found that adults and infants spontaneously tracked an agent’s belief about a location of an object, even when the agent and his beliefs were completely irrelevant for their task.

UF: I believe it took some time before you published the paper?

AK: I had to finish my PhD first. We did present the results at a conference and it was known what we were trying to do – and there were many skeptics.  So we did not rush to get into print. We wanted to do every thing properly and be sure about our results…

The nice thing was that Jacques Mehler encouraged us to submit the paper to Science, and just as the three of us, only students, without him as a senior author. This is actually quite rare, and it had the additional benefit, that on the strength of this publication I could apply for a European grant.

After more showers, and a short stay in a sauna, Agi and I get ready to leave. But first, we share a refreshingly cold Stella Artois overlooking the outdoor pool. The evening visitors are now arriving.

UF: Thank you for telling me the story behind the Smurf experiment. I vaguely remember when I saw this study, when it was published in Science in 2010 it made me jump for joy. It was not only because I liked the results – it was the beautiful design that made it possible to compare children less than 1 year old with adults. Getting the same results for both groups really put a big question mark about what we call ‘development’ of Theory of Mind. New questions had to be asked. For example: Is the ability to attribute mental states part of our brain’s hard ware?

AK: Well, this is a highly interesting question! Together with my students and collaborators we are currently performing studies addressing this question as well.

Smurf

Post-script 30th April 2014:

“Why on earth was it a Smurf?”   Because they are cute, of course,  but here is Agnes:

“The practical reason was that we had the software to animate a Smurf, making him roll the ball, turn around, move along, and so on. Also we knew from other experiments that babies really love animated shapes.  They don’t need to watch real people doing things to pay attention; simple shapes with faces and self initiated movements are just as good, if not better. Deep down there was perhaps also another reason: For our generation, and certainly for Ernö, Ansgar and myself,  Smurfs are incredibly bound up with happy childhood memories.”