Attractiveness and internal consistency

A new study from the BioMotionLab just appeared in the journal Evolution and Human Behavior. We look at different features that contribute to the perception of sexual attractiveness of another person depicted as a point-light walker that consists of 15 moving dots. The representation is rich enough to convey both the individual, idiosyncratic characteristics of a person's movements and information about individual body shape.

Isolating the two, we measured the attractiveness of individual movement styles as well as individual body shapes. Then, we can recombined movement and body shape in different ways to create hybrid walkers that contain movement of one person and the shape of another person. The question is whether the attractiveness of the pieces predicts the attractiveness of the whole.

It does to some degree. But more important is the finding that attractiveness also depends on internal consistency, that is, whether movement and shape match each other or not. Hybrid walkers are rated less attractive than the original walkers which contributed to the hybrid. Our visual system is a sensitive "lie detector" which responds to even the slightest inconsistencies and perceives them negatively.

The finding has methodological implications and calls for a re-interpretation of plenty of earlier research which looked at attractiveness in a rather piece-meal way. But it also can be used to formulate advice to people who work on improving their own appearance: Be careful! What works for one person doesn't work for another one. If in doubt then just be yourself.

Here is a link to the paper.
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Popular science: How we walk makes a difference

Now that the big media response has cooled down a bit a few words about a new study from our lab and the splash it has make in the public media.

Michalak, J., Rohde, K., Troje, N. F. (2015) How we walk affects what we remember: Gait modifications through biofeedback change negative affective memory bias. Journal of Behavior Therapy and Experimental Psychiatry 46:121 – 125.

In this study, our colleague Johannes Michalak from the University of Hildesheim, Germany, his student Katharina Rohde who visited the BioMotionLab for a few months, and BML director Niko Troje demonstrated effects of walking style on the efficiency of recalling positively or negatively loaded words from memory. When the study was first published online a couple of months ago, it generated substantial interest by the public media. In addition to coverage by countless local papers, internet news sites, and science blogs, and a few TV shows, articles appeared in big newspapers like the Globe and Mail here in Canada, the Independent in the UK, the Zeit in Germany, and the Wall Street Journal in the US. It was all over the place. Queen's University likes this, our funding agencies as well, and we feel flattered.

Of course, the study is excellent and very interesting, but there are many excellent studies that do not receive media attention. Newspapers, TV channels, and web blogs pick up on a stories that sell well. Whether a story sells well or not depends on what people want to hear and whether the story can be framed in a pleasing and simple way. The relation between the soundness of a piece of research and the commercial reward associated with distributing its results is probably relatively minor.

Our study was well suited for framing it in a pleasing and simple way. “Do you feel bad? Change the way you walk and you'll be happy.” A simple message, a simple recipe.

Of course, the story that our research really tells isn't quite as simple. What we really find is: If we make you walk as if you were depressed, you remember more negative words from a list that was presented to you earlier, than if we make you walk in a more happy way. The interesting thing about this finding is that the tendency of depressed individuals to remember negative events is well known to form an essential part of the interlocking mechanism that maintains the state of the condition. The world seems to be a bad place if your biased memory amplifies bad events. That can cause depression. Depression, on the one hand, and the bias to remember negative events, on the other hand, reinforce each other and drive you deeper and deeper into depression. The fact that walking style affects the memory bias is therefore interesting. However, it doesn't necessarily mean that adopting a happy walking style makes you a happier person.

It might, though. Our study was not conducted with clinically depressed individuals but with a normal student population. The results imply that there is a reasonable chance that we can break the self-perpetuating cycle that keeps depression in place if we induce changes in walking behaviour in patients with major depressive disorder. But whether that is in fact the case, and whether it really provides an efficient intervention method to treat major depression has yet to be shown. It will require all the infrastructure necessary for a clinical trial with a larger patient population, careful consideration of all sorts of ethical issues, substantial funding, and probably new hard working graduate students to put it all together. In other words, it will require much more serious research.

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What causes the facing-the-viewer bias?

Look at the point-light walker in the BMLwalker demo. Is the walker facing you or is it facing away from you? Most observers would see the walker facing the viewer – even though the stimulus itself does not contain any information whatsoever as to what the answer to the above question is. The stimulus is completely devoid of any depth cues. A person that consists of only a few small dots with everything else being invisible would generate the very same image when seen from the front as when seen from the back.

Why then do we perceive the walker as facing us rather than facing away? There are a at least two possible answers to that question and our lab is right at the centre of the debate which one is correct. Literally! The divide between the two theories goes right through the lab. Compare Adam Heenan's recent paper in PLoS ONE to the brand new paper by Seamas Weech which appeared today in the Journal of Vision.

The conclusion: Both theories are correct to some degree. One cause for the facing-the-viewer bias, however, seems to be much more prominent than the other. Find out which it is. Here are the references:

Heenan, A., Troje, N. F. (2014) Both physical exercise and progressive muscle relaxation reduce the facing-the-viewer bias in biological motion perception. PLoS ONE.

Weech, S., McAdam, M., Kenny, S., Troje, N. F. (2014) What causes the facing-the-viewer bias in biological motion? Journal of Vision 14(12):1-15

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CSBBCS at Ryerson

Currently, two of our students are attending the annual meeting of the Canadian Society for Brain, Behaviour, and Cognitive Science at Ryerson University in Toronto. For both of them, it is their last conference while at the BioMotion Lab. Adam Heenan will be defending his PhD thesis very shortly and then move to Ottawa General Hospital and do his internship required to become a licensed clinical psychologist. Maddie Baetz-Dougan, who just received the Medal in Biology and Psychology after graduating with the highest marks of all students in her undergraduate program, will be attending Medical School here at Queen's in the fall.

Both their posters are now up on display and Adam and Maddie are happy to present them to you if you happen to be at the CSBBCS meeting. If you don't make it, here are links to the posters:

Heenan, A., Baetz-Dougan, M., Tao, C., Troje, N. F. (2014) Effects of anxiety on the perception of depth-ambiguous biological motion stimuli are mediated by inhibitory ability.

Baetz-Dougan, M., Troje, N. F. (2014) How Does Variable Response Effort Influence Risk-Sensitive Decision Making in Pigeons?

... and I should add: Adam Heenan's first paper just appeared in PLOS One

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The Alexander von Humboldt Foundation

Niko Troje received a Humboldt Research Award. According to the website of the Alexander von Humboldt Foundation “The award is granted in recognition of a researcher's entire achievements to date to academics whose fundamental discoveries, new theories, or insights have had a significant impact on their own discipline and who are expected to continue producing cutting-edge achievements in the future.”

"I am happy and grateful for this recognition. My thanks go to my ingenious colleague Karl Gegenfurtner from the Justus-Liebig University in Giessen, Germany, and all the colleagues who supported the nomination."

The Alexander von Humboldt Foundation is a German funding agency dedicated to international academic exchange. It runs a number of different programs to attract both young and established scientists to Germany – either for limited academic visits, or to stay there for good as a well funded Alexander von Humboldt Professor. The foundation also has a program that supports young German scientists to go abroad and visit former Humboldt fellows for postdoctoral research.

So, if you want to spend time at a German research institution, have a close look at the programs of the Alexander von Humboldt foundation. Likewise, if you are a German researcher who just received a PhD or equivalent degree and you are looking to conduct postdoctoral research in, say, Canada, then you should contact a Humboldt fellow like, say, myself.

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