The thresholds were determined using five ascending and descending series of electrical stimuli with successive intensity changes of 0.02 mA. During the experiment, painful stimuli were presented at twofold pain threshold (mean, M, 0.33 ± 0.09 mA) and nonpainful stimuli at 1.5-fold sensation threshold (M = 0.12 ± 0.04 mA). Visual stimuli comprised 36 naturalistic clips depicting the volar view of a left hand, the index finger of which was either pricked by a needle or touched by a Q-tip. Similar to previous experiments

(e.g. Avenanti et al., 2005; Azevedo et al., 2012; Höfle et al., 2012), both items were attached to a syringe BKM120 datasheet (Fig. 1A). In accordance with our previous study (Höfle et al., 2012), an additional clip of a hand alone was presented. Hand-alone trials were not included in the further analyses because they substantially differed from the needle and Q-tip clip trials, prohibiting the interpretation of effects, particularly with

respect to PDR and EEG. For the same reason, we had refrained from comparing PDRs to the hand-alone clips with PDR to needle or Q-tip clips in our previous study (Höfle et al., 2012). The presentation of each needle and Q-tip clip started with the first frame of the clip, which was presented for 0.8 s. The following 60 frames were presented at a rate of 60 Hz and the last frame of the clip was sustained on the screen for 1.2 s. Participants were seated in front Selleck Cisplatin of an infrared eye-tracking system (iView X, SensoMotoric Instruments, Teltow, Germany) with their heads secured. Visual stimuli were spatiotemporally aligned with the intracutaneous electrical stimuli. Specifically, the participant’s left hand was placed on a board mounted below a flat screen,

so that the position of the hand matched the position of the incorporated hand (i.e. a hand that was perceived as one’s own) on the screen (the setup has been illustrated elsewhere; Fig. 1A in Höfle et al., 2012). Participants were instructed to imagine that the hand on the screen would be their own. Each experimental trial started with the presentation of a clip (Fig. 1A). Simultaneously with the last frame find more depicting the needle that pricked or the Q-tip that touched the index finger of the incorporated hand, participants received a painful or nonpainful electrical stimulus at the index finger of their own hand. Throughout all clips, participants fixated a gray-shaded circle located above the left index finger. Together with the onset of the video clip, the circle filled from surrounding to center and was filled up when the electrical stimulus was presented 1 s after the clip onset. The filling circle was presented to ensure that the same temporal information about the occurrence of the electrical stimulus was provided in all clips. During each trial, pupil size was monitored from the left eye at a sampling rate of 500 Hz.