Emotion slider

Beside some rather unsuccessful attempts at psychophysiological measurement, the best part of the last two years have been occupied by a series of experiments with a device (the “emotion slider”) I developed together with Pieter Desmet (one of my PhD advisors and also the person responsible for the sketches in the paper), Rob Luxen (who never stopped improving the electronics) and Hannah Ottens (who actually built the thing).

I presented a first article about it at the Design Research Society conference in Sheffield last year and I never uploaded it to my website, but I recently noticed that it is now available online. The paper is titled Designing a research tool and describes the development of the device from a design angle.

Since then, I have also written a more classical experimental psychology-type of paper, which I finally presented at ACII last week. Apparently it's not online yet but you can always contact me for more info. In the meantime, you can also download the slides from my presentation.

In a few words the conclusion of all this is that there is evidence of compatibility effects between movements on the slider and affective state (for example how good or bad you feel or how you evaluate a picture). Participants in the experiment were quicker to push to evaluate positive pictures than negative pictures and also quicker to pull to evaluate negative pictures than positive pictures. This difference in response time shows the one set of movements is more intuitive or easier than the other one.

However, unlike what some earlier reports suggested, this effect is very sensitive to the context (how the slider is positioned, what the instructions are, if there is some form of feedback, etc.) With "neutral" instructions (in my case I asked the participants to « push » and « pull » without any other precision) and a slider positioned between the screen and the user, the more natural mapping seems to be pushing for « positive » and pulling for « negative ».

Using the « wrong » movements also seems to have a small but noticeable effect on the number of errors people make but the evidence is not very strong.