Page 67 - Demo

Physiological Resonance and Interpretation of Emotional Expressions653paper. During both the PVT and the ELT, eye-tracking data was recorded (see measurements section) and a chin rest was used to ensure a stable head position. The tasks were presented using Eprime 2.0 on a Dell S2240Tb 21.5 inches touch screen (1920x1080 resolution, 60 Hz refresh rate). The background colour of all screens (fixation, stimulus, blank) was set to grey (145,145,145). All participants first completed the PVT, thus allowing us to measure the initial response to the emotional expressions without a secondary task. Each trial started with the presentation of a fixation cross for 500ms, which was followed by a 4000ms presentation of one of the above described stimuli (460x510 pixels). The stimulus presentations were separated by a 3500ms, 4000ms or 4500ms blank screen to the next trial (inter-trial interval duration varied between participants). Due to a coding error, a fearful face instead of a face with added tears was presented for one of the 8 stimulus identities and had to be excluded from data analysis (7 instead of 8 trials for this stimulus category). Apart from that, each of the remaining 102 stimuli was presented once, in a randomized order. After taking a short break, participants continued the experiment with the ELT. Each trial started with a fixation cross lasting 500ms and followed by one of the expressions for 1s. Afterwards, a question appeared next to the stimulus, asking participants to indicate which of the 5 expression categories, namely angry, happy, scared (in the following referred to as %u2018fearful%u2019), sad or neutral was displayed in the picture. In a second step, they had to rate how emotionally intense they perceived the stimulus, using a slider from neutral to very emotional (on a scale 0-100). There were not time constraints on the ratings and each expression was rated twice (208 trials; see Fig. 2b for a visualization of the tasks). The eyetracking recording was stopped and all electrodes were de-attached for the subsequent emotional dotprobe task. Upon completion of all three tasks, participant filled in the selfreport version of the Liebowitz Social Anxiety Scale (LSAS-SR; Fresco et al., 2001; Liebowitz, 1987), the Autism Spectrum Quotient (AQ; Baron-Cohen et al., 2001) and the short version of the Empathy Quotient (EQ; Baron-Cohen & Wheelwright, 2004) in the respective order. As the questionnaire scores were not included into the main analyses, descriptive statistics of these measures can be found in Table 1 in Online Resource 2. The total duration of the study was approximately 90min.