How can we rigorously measure human emotions while, at the same time, avoid the limitations of the laboratory settings?

A group of researchers from Pompeu Fabra University of Barcelona led by ICREA professor Paul Verschure, director of the laboratory of SPECS , in collaboration with University of Pisa (Italy),  propose a new approach based on the eXperience Induction Machine (XIM),  an immersive mixed-reality space located at the SPECS lab, which combines virtual reality (VR) with wearable recording technology to infer psychophysiological signatures of emotions.

"Traditionally, most of the psychophysiological studies on emotions have been conducted in strictly controlled environments that present a bottleneck: the artificial conditions in which experiments are conducted may not induce genuine emotions which normally occur under everyday situations" explain Alberto Betella and Riccardo Zucca doctoral researchers at SPECS and main authors of the study.

Improvements in hardware miniaturization and portability has recently witnessed an increasing interest in the real world environment. However, measures of affective states in the natural world still present a number of limitations in terms of reliability.

The laboratory and the natural world should be seen as alternatives that are not fundamentally opposed and XIM answers exactly to this challenge. "XIM allows to conduct research on emotion in humans in ecologically valid conditions through the use of life-like VR scenarios and custom-tailored unobtrusive technology which is suitable for the acquisition of psychophysiological signals in a more natural context, while, at the same time, ensuring a high degree of control  over the experimental protocol", explains Prof. Paul Verschure, led of SPECS.

To validate this novel approach, two different studies were conducted

In the first study, the researchers were able to successfully discriminate and predict the emotional content of visual stimuli projected in the XIM from the recorded cardiac and the electrodermal activity of freely moving participants.

 

In the second study, the well-known classical conditioning paradigm was reproduced using virtual reality (VR) and physiological sensors. In the CC paradigm, subjects learn to predict the occurrence of an aversive event (unconditioned stimulus or US) from contextual cues (conditioned stimulus or CS), which, after several presentations of the CS-US pairings, results in the expression of an anticipatory conditioned response.

Similar studies that have investigated conditioning using VR and measuring psychophysiological signals, constrained participants to sit on a chair and to use devices such as joysticks to move in the virtual space, while keeping the hand where the EDR electrodes were mounted still for the entire duration of the experimental session in order to minimize signal artifacts.

The new experimental design presented in this new research, instead, allows the participants to freely interact in the VR scenario.

These results provide evidence on how to tackle the well-known challenge of interpreting emotion-eliciting events from physiological signatures in the presence of movements and gestures, thus advancing beyond standard laboratory settings.

This research has been conducted within the framework of the CEEDs European Project (FP7-ICT-2009-5) whose aim is the development of novel, integrated technologies to support human experience, analysis and understanding of very large datasets by measuring the user's unconscious states.

More information:

Vídeo: "Smart Thanks to Science: Stimulating the Subconscious - Futuris"

 

Reference:

Citation: Betella A*, Zucca R*, Cetnarski R, Greco A, Lanatà A, Mazzei D, Tognetti A, Arsiwalla XD, Omedas P, De Rossi D and Verschure PFMJ (2014) Inference of human affective states from psychophysiological measurements extracted under ecologically valid conditions [ http://journal.frontiersin.org/journal/10.3389/fnins.2014.00286/full ]. Front. Neurosci. 8:286. doi: 10.3389/fnins.2014.00286.