Figure 3.

Physiological responses for still picture stimuli (IAPS). Each study session of emotion recognition using IAPS stimuli lasts a total of 520 s; the 20 chosen pictures in two categories listed in Table 2 are shown as still images on the display in sequence of six seconds per image ①, and the gaps between images are each filled with a 20-s black screen ②. The x-axis shows the arrangement of the two categories of IAPS pictures according to their unique reference numbers. All participants showed unpleasant emotion when the first negative valence picture was displayed (#3053). The upper picture shows a higher heart rate deceleration during the switching of emotional valence, and the lower picture depicts a more significant skin conductance change.