Subjects were fully informed at the outset of the experiment of the
nature of the trials about to occur. They were given three EKG
electrodes and the experimenter described their proper placement. The
subject was instructed to take a diagram with them into the bathroom
to put the electrodes on in private. Upon their return, the
experimenter assisted the subject in properly putting on the GSR (the
electrodes were attached to the distal phalanges of the index and
middle fingers of the left hand) and BVP (secured to the ring finger
of the left hand) sensor. After verifying that the signals being
received were good, the experimenter started the program that
presented a screen of consent to the subject. The screen of consent
informed the subject that if they did not want their data used in the
experiment they could retract it at any time, or abort the session if
they so desired. All subjects freely consented.
All questions regarding the experiment, the sensors, or the
instructions were answered before beginning the test. The experimenter
reminded the subject again to remain still and not vocalize for the
duration of the experiment, and to press the mouse firmly after each
slide. They were informed of the 3 second blank screen delay before
the appearance of each slide and instructed to relax and let their
signals return to their baseline during this pause. Subjects were also
reminded to allow themselves to feel the power of each emotional
response before proceeding to the next slide.
Three seconds of blank screen followed the slider question page, and preceded the next stimulus. This was required to allow the time dependent body responses, namely HR and SC, to re-stabilize between slides. Additionally, only the first ten seconds of the signals for each slide was used in the HR and SC analysis, because the signal response dampened as the subject became de-sensitized to the stimulus.
The measured sentic data for each subject was compared against the collected self-reported data. In future work it should also be compared against theoretical IAPS results for each slide stimulus and against measured and theoretical HR acceleration. Comparing, sentic data against the Lang database would provide a method to corroborate the subject's self-reported measure of valence.
The null hypothesis, that there exists no relation between sentic data and valence, can be rejected if there exists a correlation.