Authors:
Jan Ehlers
;
Nikola Bubalo
;
Markus Loose
and
Anke Huckauf
Affiliation:
Ulm University, Germany
Keyword(s):
Affective Human-Computer Interface, Pupil Size, Biofeedback, Emotions, Voluntary Control.
Related
Ontology
Subjects/Areas/Topics:
Affective Computing
;
Applications
;
Biofeedback Technologies
;
Biomedical Engineering
;
Biomedical Instruments and Devices
;
Brain-Computer Interfaces
;
Devices
;
Human-Computer Interaction
;
Pattern Recognition
;
Physiological Computing Systems
;
Physiology-Driven Computer Interaction
;
Software Engineering
Abstract:
During the past years, increasing attention is being paid to operationalize pupil dynamics for affective
classification (Jacobs, 1996). Thereby it is generally assumed that pupil size displays a genuine impression of
user’s cognitive state but defies any voluntary control (Loewenfeld, 1993). Based on Ekman (2008) we
applied graphical feedback on pupil diameter changes to utilize mechanisms of operant conditioning to
gradually enable voluntary control over pupil size. Participants underwent a training program to exert control
by utilizing affective associations to expand pupil size and relaxation strategies to reduce it. As a result, more
than half of the participants demonstrated to be able to increase pupil sizes relative to baseline recordings.
Training effects did not show up. Furthermore, controlling influence diminishes after about ten seconds.
Intentional increase of sympathetic activity seems to be subject to habituation processes that allow central
inhibition of parasympathet
ic pathways only over a short period. Beside strategy-based factors, physiological
mechanisms like baseline pupil activity may determine inter-individual differences in exerting voluntary
control. In summary it can be noted that pupil-based communication in HCI extends affective monitoring and
may constitute an active input channel to reliably interfere by means of simple cognitive strategies.
(More)