Tal manipulation. Each participant completed a single trial where the followingwww.frontiersin.orgJuly 2012 | Volume 3 | Post 244 |Asai et al.Heaviness contagionFIGURE five | Time course from the height on the hand (fingertips) in every single group in Experiment I B.body parts were recorded: shoulder, elbow, wrist, and tip on the middle finger.Benefits and discussionThe time courses with the hand positions with the participants indicated that the heavy-ball group tended to raise their ideal hand more than their shoulders steadily even though observing a model’s hand holding a ball; however, right after 60 s, when the image was changed to a picture of a hand devoid of a ball, the 
hand began to decrease. This indicates that the hand raising was primarily based on their shoulder as a fulcrum point, because they may well feel heaviness around the back on the hand as if it have been the model’s hand. Conversely, participants in the light-ball group lowered their hands steadily (Figure five; Figure A1 in Appendix). We carried out a two-way ANOVA (two groups ?two visual stimuli) to examine the movement velocity from the hand (i.e., fingertips; Figure six). These analyses demonstrated a important major effect of group [F (1.six) = 6.00, p < 0.05], and a significant main effect of visual stimuli [F (1.6) = 18.49, p < 0.01], but nonsignificant interaction [F (1.6) = 0.67, p > 0.50]. It’s clear that the trend to raise the appropriate hand was observed throughout the presentation with the image of a 
model’s hand holding a ball, when participants simultaneously held a visually identical heavy ball in their left hand, suggesting replication of Experiment 1A inside a withinparticipants manner. Conversely, soon after 60 s, participants in both groups lowered their hands steadily, possibly mainly because of expected muscle fatigue. The present experiment aimed to observe arm movement up to the limit of fatigue; nonetheless, there may very well be confounding in between muscle fatigue and hand-lowering, though the rising hands started lowering soon after just 60 s in the beginning of the experiment (see Figure 5). We addressed this limitation inside the following experiments. Experiment 1B reconfirmed the “heaviness contagion” general; observation from the model’s hand holding a heavy ball was related to raising of your hand. This might be driven predictively (merely the prediction of heaviness raises the hand of a participant) and mandatorily (which is why participants have to compensateFIGURE 6 | Movement velocity in every single group in Experiment lB.for their illusory heaviness: they did not ignore it). However, a further question has to be addressed: which mechanism would lead to this phenomenon? By far the most probable mechanism is direct matching, where we straight map the observed sensation of other agents onto our personal sensorimotor GSK1278863 biological activity representation (Iacoboni et al., 1999). Recent studies have suggested that the direct matching technique, which contains motor simulation, bodily resonance, and automatic imitation, could possess a biological bias (Press et al., 2005; Tsai and Brass, 2007; Watanabe, 2008; Liepelt and Brass, 2010; Liepelt et al., 2010), indicating that we do not simulate non-human agents. Experiment 2A, with some alterations in experimental procedure, was performed to address this challenge. In the current experiment, we presented”with ball”first, followed by”without ball,”and the durations from the two visual stimuli have been various (60 s for “with ball” and 30 s for “without ball”) in an effort to confirm that the raising on the hand would continue for a longer time (so long as “with ball.Tal manipulation. Each participant completed a single trial exactly where the followingwww.frontiersin.orgJuly 2012 | Volume 3 | Article 244 |Asai et al.Heaviness contagionFIGURE 5 | Time course of the height from the hand (fingertips) in each group in Experiment I B.physique parts have been recorded: shoulder, elbow, wrist, and tip on the middle finger.Outcomes and discussionThe time courses of the hand positions in the participants indicated that the heavy-ball group tended to raise their correct hand over their shoulders steadily even though observing a model’s hand holding a ball; nevertheless, following 60 s, when the image was changed to a image of a hand without PubMed ID:http://www.ncbi.nlm.nih.gov/pubmed/19910816 the need of a ball, the hand began to reduced. This indicates that the hand raising was primarily based on their shoulder as a fulcrum point, since they could feel heaviness around the back from the hand as if it had been the model’s hand. Conversely, participants in the light-ball group lowered their hands gradually (Figure 5; Figure A1 in Appendix). We performed a two-way ANOVA (two groups ?two visual stimuli) to examine the movement velocity in the hand (i.e., fingertips; Figure six). These analyses demonstrated a substantial key impact of group [F (1.six) = six.00, p < 0.05], and a significant main effect of visual stimuli [F (1.6) = 18.49, p < 0.01], but nonsignificant interaction [F (1.6) = 0.67, p > 0.50]. It’s clear that the trend to raise the proper hand was observed through the presentation with the image of a model’s hand holding a ball, when participants simultaneously held a visually identical heavy ball in their left hand, suggesting replication of Experiment 1A within a withinparticipants manner. Conversely, right after 60 s, participants in both groups lowered their hands steadily, possibly due to the fact of anticipated muscle fatigue. The present experiment aimed to observe arm movement up to the limit of fatigue; however, there may very well be confounding among muscle fatigue and hand-lowering, although the rising hands started lowering soon after just 60 s from the beginning from the experiment (see Figure five). We addressed this limitation within the following experiments. Experiment 1B reconfirmed the “heaviness contagion” overall; observation in the model’s hand holding a heavy ball was related to raising on the hand. This might be driven predictively (merely the prediction of heaviness raises the hand of a participant) and mandatorily (that may be why participants need to compensateFIGURE six | Movement velocity in each and every group in Experiment lB.for their illusory heaviness: they didn’t ignore it). Nonetheless, a additional query should be addressed: which mechanism would lead to this phenomenon? By far the most probable mechanism is direct matching, exactly where we straight map the observed sensation of other agents onto our own sensorimotor representation (Iacoboni et al., 1999). Recent research have recommended that the direct matching system, which contains motor simulation, bodily resonance, and automatic imitation, might have a biological bias (Press et al., 2005; Tsai and Brass, 2007; Watanabe, 2008; Liepelt and Brass, 2010; Liepelt et al., 2010), indicating that we do not simulate non-human agents. Experiment 2A, with some modifications in experimental process, was performed to address this concern. Within the existing experiment, we presented”with ball”first, followed by”without ball,”and the durations with the two visual stimuli were diverse (60 s for “with ball” and 30 s for “without ball”) in order to confirm that the raising of the hand would continue for a longer time (as long as “with ball.