Various enterprises and personal interests, such as Man-Machine Interaction (MMI), gesture studies, signs, language, social robotics, healthcare, innovation, music, publications, etc.

Category: Seeing Intentions

Is a Yawn a Gesture?

In an old article BBC News reported about research showing that Pet dogs can ‘catch’ human yawns. The article is available online in Biology Letters here. (Article ‘Dogs catch human yawns’ by Ramiro M Joly-Mascheroni, Atsushi Senju* and Alex J Shepherd, 2008).

The copying activity suggests that canines are capable of empathising with people, say the researchers who recorded dogs’ behaviour in lab tests.
Until now, only humans and their close primate relatives were thought to find yawning contagious.
The team – from Birkbeck College, University of London – reports its findings in Biology Letters.
Yawning, although sometimes a response to extreme stress, is more often a sign of tiredness; but the reason for why yawning is catching is not fully understood.

Human cues. There is evidence that autistic individuals are less inclined to yawn into response to another human yawning, suggesting that contagious yawning betrays an ability to empathise, explained Birbeck’s Dr Atsushi Senju. Dr Senju and his team wondered whether dogs – that are very skilled at reading human social cues – could read the human yawn signal

There are several very interesting things in these statements. Firstly, I am interested in yawning itself. It is called a social cue. What is a ‘social cue’ as opposed to an ‘intentional act of communication’, which is how I define ‘gestures’?

The article itself has this to say about dogs’ abilities:

Dogs are unusually skilled at reading human social and communicative cues. They can follow human gaze and pointing (Hare et al. 2002; Miklo´ si et al. 2003; Miklo´ si & Soproni 2006), they can show sensitivity to others’ knowledge states (e.g. indicating the location of a hidden toy more frequently to someone not involved in hiding it than to someone who did the hiding, Vira´nyi et al. 2006) and they are even able to match their own actions to observed human actions (Topa´l et al. 2006).

Goffman and Kendon both make a distinction between ‘giving information’ and ‘giving off information’. In most cases, a yawn gives off information to possible observers, but a yawner does not mean to give information, I would think (although in many cases yawners may want to indicate their tiredness or boredom). The distinction is important because giving information is typically attended to and reacted upon, whereas giving off information is not. Expectations and social etiquette are likewise.

So, how about contagious yawning? It seems to be caused by empathy or to require empathy, at least in humans and dogs. As such a co-yawn also gives off the information that this other persons is observing you and empathizes with you, for what it’s worth.

And I think that that could well be the best explanation. Contagious yawning is behaviour that serves to provide information to those present that they are aware of each other and ’empathizing’ in a very economic way. It is economic because none of those present has to overtly attend to the behaviour and react upon it with speech or gestures. A bonding mechanism mostly below the surface of our consciousness.

And possibly, contagious yawning is much like all sorts of other behaviour, such as mirroring. It is a kind of mirroring I suppose. But there are many other sorts of mirroring.

Here is an alternative interpretation and explanation of contagious yawning

Note that there is a considerable and growing literature on yawning, contagious yawning and how this relates to our psychology and biology. In humans, dogs, chimpansees, other apes and monkeys, birds, cats, etc.

A very interesting research case. Take any animal and see if it catches your yawn.

I’m off yawning at the chickens, bye…

Book Review of: Imitation and Social Learning in Robots, Humans and Animals

In 2007 an interesting book was published that I believe is also relevant to gesture researchers:

Imitation and social learning in robots, humans and animals: behavioural, social and communicative dimensions.
Chrystopher L. Nehaniv, Kerstin Dautenhahn (Eds.). Cambridge University Press, 2007 – 479 pagina’s (available online in a limited way, here)

The book is an excellent volume with many interesting chapters, some with contributions by the editors themselves but also by many other authors. Personally, I found the following chapters most interesting (of 21 chapters):

  • 1. Imitation: thoughts about theories (Bird & Heyes)
  • 2. Nine billion correspondence problems (Nehaniv)
  • 7. The question of ‘what to imitate’: inferring goals and intentions from demonstrations (Carpenter & Call)
  • 8. Learning of gestures by imitation in an humanoid robot (Calinon & Billard)
  • 10. Copying strategies by people with autistic spectrum disorder: why only imitation leads to social cognitive development (Williams)
  • 11. A Bayesian model of imitation in infants and robots (Rao et al.)
  • 12. Solving the correspondence problem in robotic imitation across ambodiments: synchrony, perception and culture in artifacts (Alissandrakis et al.)
  • 15. Bullying behaviour, empathy and imitation: an attempted synthesis (Dautenhahn et al.)
  • 16. Multiple motivations for imitation in infancy (Nielsen & Slaughter)
  • 21. Mimicry as deceptive resemblance: beyond the one-trick ponies (Norman & Tregenza)

I’ll probably update this post with more in-depth review remarks later… But at least chapter 21 has connections to earlier posts here regarding animal gestures, such as here.

Golden Oldie: Garfield & the Waving Snowman

Boy, I have been looking for this cartoon for two and a half years (off and on, that is, see here). So, a big thanks to diamond-blade for pointing out the link.

Garfield and the Waving Snowman
It was the Garfield daily comic from February 27, 2005 (source)

The reason why I like this comic so much (besides my general fascination for the gestures in Garfield, see these posts) is that it is a wonderful illustration of an idea that I would love to test experimentally. The idea is that certain movements (i.e. having certain kinematic characteristics) might automatically trigger the perception of a gesture (in the sense of a movement that is intended to communicate). This idea is not new and was, for example, described by Adam Kendon in his 2004 book ‘Gesture. Visible action as utterance’. But this idea is also present, to some extent, in the work of Gunnar Johansson (1973) and Albert Michotte.

Prelimary ideas about experiments:

  • Generate a randomized display of motion (within some likely parameter space) and let people all watch that same fragment, then check if they see a gesture at the same time.
  • Condition: Manipulate it in such a way that it is easier or harder to imagine seeing a hand.
  • Condition: Create conditions where subjects feel it is likely or unlikely they will be insulted (perception of intention to communicate appears linked to sensitivity to insults, see my thesis or Bucci et al. 2008).

Gesturing Monkeys and Sexual Harassment

Thanks to Alexis Heloir, a fellow PhD working on gestures, for sending me this story: Wild Vervet Monkeys Wreak Havoc in Kenya (or check the BBC which is the source).

The most interesting part of this nice story (which tells of a group of vervets monkeys stealing food from a village and threatening specifically the women) is the following quote:

“The monkeys grab their breasts, and gesture at us while pointing at their private parts. We are afraid that they will sexually harass us,” said Mrs Njeri.

Well, that is an interesting statement by Mrs Njeri. In the picture below you can see vervet monkeys:

Vervet Monkeys (source)

It must be said, these monkeys are not very big and the idea of ‘sexual harassment’ seems to me at first glance to be a tale of imagination gone wild. What are they going to do? Pinch a ladies bottom? Squeeze a boob? Certainly that is as far as they can go? Or is it? Perhaps I am thinking in the wrong direction.

Perhaps sexual harassment is more like psychological warfare? Indeed, wikipedia states on sexual harassment that it can include many types of behavior and has a variety of purposes, most of which appear to be psychological rather than directly involving sexual intercourse. Dominance and humiliation can be important parts of it.

From wikipedia we also learn that Vervets seem to “possess what has been called the “rudiments of language”. Vervet Monkey alarm calls vary greatly depending on the different types of threats to the community. There are distinct calls to warn of invading leopards, snakes, and eagles.”

Now, there is an excellent web page on The Phallic Threat: Giant Penises and Similar Threat Devices. From it, I gather that the idea of a phallic threat is not unheard of, but instead common in both men and monkeys. Specifically on Primata (with a good overview of the Vervet’s signals) it is stated that Vervets have the folllowing use of the penile display.

penile display: This is when an adult male vervet monkey will present his erect penis and scrotum so that a neighboring group will see them (Estes, 1991). This display is used to demarcate territory (Estes, 1991). red-white-and-blue display: This display is used to communicate dominance by one male over another within a group (Estes, 1991). The male walks back and forth with his penis and scrotum in full view for the receiver to see; the sender will encircle the receiver (Estes, 1991). Occasionally the sender will stand on his hind legs and present his penis and scrotum to the receiver (Estes, 1991).

Moreover, the pigmentation of the Vervet Monkey’s scrotum is a vivid blue that pales when the animal falls in social rank. In other words, Vervets may perhaps refer to their dominance over someone else by referring to the color of their genitals.

So now we may have (1) an ability to communicate a variety of messages, (2) a phallic threat with (3) a reference to dominance. Suddenly it is not so difficult to imagine that it is real. Or at least as real as sexual harassment gets. If the monkeys mean to express their dominance, mark their territory or humiliate the women and the women feel dominated or humiliated then that is a successful (if you will pardon the expression) case of sexual harassment.

Unfortunately we cannot be sure of anything from such a distance. The whole story could just be exaggerated. It could even be an excuse for the villagers to start physically harassing the monkeys.

Elsewhere: Atheism Central on this story A YouTube playlist on monkeys and their penal displays The Colobus Trust website, has more info on pest behavior by vervet monkeys

Double Movement Detection

As a young researcher I see opportunities for grand research proposals everywhere. And so it was when my friend Edwin told me about the rugby drama he had experienced in an Irish pub in the final day of the recent Six Nations.

Ireland beat Italy with a monsterscore, and they were about to win the tournament. But the French scored in overtime to beat Scotland, just edging themselves in front of the Irish and claiming Six Nations victory in 2007.

That in itself is tragedy enough for Irish fans to start some serious forgetting/drinking. But it gets better: The final French try was an almost impossible call. The ball was buried in a pile of players, and even the video ref (who was Irish!) could not make the call. It was granted nevertheless.

Now to the point: in extra time at Ireland-Italy an Italian player scored a try that was contestable. The Irish in their pub were convinced that it was a case of double movement (or even triple movement). This requires some explanation.

BBC Sport: “Often when a player has been tackled close to the try line, they will often attempt to make another movement to ground the ball for the try. However, if they have been tackled, the referee will not award the try because it is seen as a double movement [if] the ball and the player have been grounded before the second movement for the try. However, if the player is in the process of being tackled and the ball has not been grounded before the try line, then they can make a second movement for the score.

A nice case of a visual perception task. The referee has to see that a player makes two separate movements and not one big one. A simple task? I dare to disagree. What exactly makes us see a movement boundary? Do we all agree on it, or did the Irish see double movement (around 4:30 in the movie) and the Italians only one?

Rubin and Richards (1985) did some nice work on Boundaries of Visual Motion that I think definitely applies. But there has not been much work on actually implementing their ideas into algorithms that I know of.

Could we build a computer to automatically segment movement? Can a robot referee call double movement? I am thinking of the automated line judgements in tennis. It would not be the first time people relied on machines rather than their own perception. When we think of time measurements for racing machines are possibly trusted even better than men. In this case I think more research is necessary.

If you agree and have R&D money to spend, give me a call at +31 15 2783908. I’ll be looking for a nice chunk of basic research work on visual perception somewhere next year I presume. Full Game Report at Irish Rugby:

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