E expressions had been from 4 various actors (two females, two males) with the 3 kinds of expressions for every actor. The expressions have been snapshots of dynamic facial expressions (1-sec films) and had been chosen from an current database (Simon et al., 2008). Choice of expressions was primarily based on intensity ratings acquired from authors of a previously published study (VachonPresseau et al., 2011). On all photographs, head and eye-gaze had been directed forward and the head filled the majority of the picture. See supplementary material for the photographs included within the current study.FIGURE 1 | Configuration of a common trial. Response was given making use of the dominant hand and electrical stimuli have been delivered towards the non-dominant hand.Frontiers in Psychology | www.frontiersin.orgJuly 2015 | Volume six | ArticleKhatibi et al.Observation of pain and action readinessParticipants weren’t informed regarding the presence or the type of the facial expressions. The 3 facial expression types have been presented in 3 separate blocks. Each block contained 48 trials with every with the four 
faces presented 12 instances in each block (six trials with electrocutaneous stimuli and six occasions without having). Block order was counterbalanced involving participants. After each and every block, participants were asked to rate the average intensity, unpleasantness, and painfulness of the electrocutaneous stimulation knowledgeable through the preceding block on 3 separate one hundred mm visual analog scales using the finish points labeled `0 = not intense/unpleasant/painful at all’ and `10 = really intense/unpleasant/painful.’ Breaks in between blocks had been self-paced.processor at 2.33 GHz; ATI Radeon 2400 graphics card with 256 MB of video RAM), operating Influence four.0 computer software (Spruyt et al., 2010) and connected to a 19″ CRT DELL monitor (75 Hz vertical refresh rate; refresh duration: 13.three ms/frame), an AZERTY keyboard, a mouse, as well as a constant existing stimulator (see above).ProcedureAll participants have been tested individually in a dimly lit testing area. They have been video-monitored and could communicate via an intercom together with the experimenter who was situated within a separate space. Upon arrival at the testing area, they received an information sheet describing the experimental procedure. Extra C.I. Natural Yellow 1 specifically, it was explained that the study focused around the elements involved inside the perception of pain. Participants have been informed that they would execute a uncomplicated categorization task when receiving painful electrocutaneous stimuli. Then they signed the informed consent and completed demographic inquiries and a battery of Dutch questionnaires including the PCS and the FPQ. Right after questionnaire completion, electrodes have been attached and painful electrocutaneous stimulus intensity was individually set. Then participants performed the priming task followed by the objective prime awareness check. Finally, the electrodes had been MedChemExpress Regadenoson detached and participants have been debriefed and informed regarding the purpose from the experiment.Prime Awareness CheckTo identify participants’ objective awareness of the sub-optimally presented facial expressions (i.e., the primes), a forced-choice prime awareness job was administered soon after the priming job (Van den Bussche et al., 2009). Within this process a fixation cross appeared around the screen (400 ms) and replaced by 4 consecutive masks (13.three ms each and every). Then a facial expression was presented for 27 ms and replaced by a blank screen (13.three ms) which was followed by a series of 4 masks (13.3 ms every single). Immediately after the last mask.E expressions had been from four unique actors (two females, two males) with the 3 kinds of expressions for each and every actor. The expressions were snapshots of dynamic facial expressions (1-sec films) and have been chosen from an current database (Simon et al., 2008). Selection of expressions was based on intensity ratings acquired from authors of a previously published study (VachonPresseau et al., 2011). On all photographs, head and eye-gaze were directed forward and also the head filled most of the picture. See supplementary material for the photographs incorporated in the present study.FIGURE 1 | Configuration of a typical trial. Response was provided using the dominant hand and electrical stimuli were delivered to the non-dominant hand.Frontiers in Psychology | www.frontiersin.orgJuly 2015 | Volume 6 | ArticleKhatibi et al.Observation of discomfort and action readinessParticipants were not informed regarding the presence or the type of the facial expressions. The three facial expression types had been presented in three separate blocks. Each block contained 48 trials with every on the four faces presented 12 times in each block (six trials with electrocutaneous stimuli and six instances with out). 
Block order was counterbalanced amongst participants. Just after each block, participants have been asked to rate the typical intensity, unpleasantness, and painfulness of the electrocutaneous stimulation knowledgeable during the prior block on three separate 100 mm visual analog scales using the finish points labeled `0 = not intense/unpleasant/painful at all’ and `10 = very intense/unpleasant/painful.’ Breaks amongst blocks have been self-paced.processor at two.33 GHz; ATI Radeon 2400 graphics card with 256 MB of video RAM), running Affect 4.0 application (Spruyt et al., 2010) and connected to a 19″ CRT DELL monitor (75 Hz vertical refresh price; refresh duration: 13.three ms/frame), an AZERTY keyboard, a mouse, along with a constant present stimulator (see above).ProcedureAll participants have been tested individually in a dimly lit testing area. They were video-monitored and could communicate by means of an intercom together with the experimenter who was situated inside a separate space. Upon arrival in the testing space, they received an info sheet describing the experimental procedure. Much more especially, it was explained that the study focused on the factors involved within the perception of discomfort. Participants had been informed that they would carry out a very simple categorization task while getting painful electrocutaneous stimuli. Then they signed the informed consent and completed demographic concerns as well as a battery of Dutch questionnaires like the PCS and also the FPQ. Right after questionnaire completion, electrodes have been attached and painful electrocutaneous stimulus intensity was individually set. Then participants performed the priming process followed by the objective prime awareness check. Lastly, the electrodes had been detached and participants were debriefed and informed regarding the purpose of the experiment.Prime Awareness CheckTo establish participants’ objective awareness from the sub-optimally presented facial expressions (i.e., the primes), a forced-choice prime awareness activity was administered following the priming job (Van den Bussche et al., 2009). Within this job a fixation cross appeared around the screen (400 ms) and replaced by four consecutive masks (13.three ms each and every). Then a facial expression was presented for 27 ms and replaced by a blank screen (13.3 ms) which was followed by a series of 4 masks (13.3 ms every single). Just after the last mask.