Public Summary Month 5/2013

In the PsyIntEC project experiments on 70 participants have been conducted and data from ECG, eight EEG channels, EMG zygomatic, EMG corrugator and GSR sensors have been analyzed. The main purpose of the analysis was to detect any differences in psychophysiological measurements between completing the reference task with or without robots. The reference task used in the experiments is playing the Towers of Hanoi (ToH) puzzle game alone or turn taking with a human or robot.

 

The psychophysiological data was used to estimate the emotional states of each participant according to the two- dimensional valence and arousal scale. Valence, describing if the emotion is negative, positive, or neutral, and arousal, describing the physiological activation state of the body ranging from low to high.

 

Each participant data set was checked for errors. Errors were usually caused by problems like participants that did not completely understand the rules of the ToH game, or failure of one or more sensors. This caused whole or parts of the data to be invalid. The signals were cut into one segment for each game (three games per setting and participant) and one segment for the baseline period. The first minute of the baseline period was skipped to remove initial non-relaxed activation in subjects. For the rest of the baseline period, a baseline value was calculated for each sensor. The ECG data was an exception and was further processed to extract the heart rate before the baseline was calculated.

 

For each data segment the mean, minimum and maximum for each sensor were calculated and the baseline (average activation of the baseline period) was subtracted. The mean, min and max values for all eight EEG sensors were then averaged to get single values for EEG activation. After this the values were averaged over all 70 subjects. The average values over all subjects were then compared between the four different game types.

  

The two EMG sensors showed clear differences between playing alone or with another human compared to the unpredictable robot. This suggest that playing with the unpredictable robot can produce both positive and negative feelings in subjects, the differences are however not statistically significant. It is reasonable to assume that the difference is through spikes of activity, rather than slow changes. This would mean that if the EMG sensors registered more active during a setting, much of that would be lost when averaging over the whole setting due to resting periods between the spikes. A more detailed analysis on shorter time intervals is needed to see short-term changes in emotional states.

 

The EEG sensors showed increased attention and cognitive load for all collaborative tasks, but no differences were shown between collaborating with a human or robots. As for the EMG sensors, the differences in EEG activity are not statistically significant.

The heart rate activity showed small but significant differences between the game types, with a decrease in activity for playing with an unpredictable robot compared to playing without robots. This is an indication of increased arousal when playing without robots, but does not say if positive or negative emotions were produced.

 

The GSR showed a significant increase in activity when playing with a human experimenter. This is a sign of increased arousal, maybe due to fear of performing badly. It does however not say if the feelings experienced were positive or negative.