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The temporal binding window refers to the time frame within which temporal grouping of sensory information takes place. Sense of agency is the feeling of being in control of one's actions, and their associated outcomes. While previous research has shown that temporal cues and multisensory integration play a role in sense of agency, no studies have directly assessed whether individual differences in the temporal binding window and sense of agency are associated. In all three experiments, to assess sense of agency, participants pressed a button triggering, after a varying delay, the appearance of the circle, and reported their sense of agency over the effect. To assess the temporal binding window a simultaneity judgment task (Experiment 1) and a double-flash illusion task (Experiment 2 and 3) was also performed. As expected, the temporal binding window correlated with the sense of agency window. In Experiment 3, these processes were modulated by applying occipital tACS at either 14Hz or 8Hz. We found 14Hz tACS stimulation was associated with narrower temporal biding window and sense of agency window. Our results suggest the temporal binding window and the time window of sense of agency are related. They also point towards a possible underlying neural mechanism (alpha peak frequency) for this association. [ABSTRACT FROM AUTHOR]

Tying the hands behind the back has detrimental effects on sensorimotor perceptual tasks. Here we provide evidence that beta band oscillatory activity in a resting state condition might play a crucial role in such detrimental effects. EEG activity at rest was measured from thirty young participants (mean age = 24.03) in two different body posture conditions. In one condition participants were required to keep their hands freely resting on the table. In the other condition, participants' hands were tied behind their back. Increased beta power was observed in the left inferior frontal gyrus during the tied hands condition compared to the free hands condition. A control experiment ruled out alternative explanations for observed change in beta power, including muscle tension. Our findings provide new insights on how body postural manipulations impact on perceptual tasks and brain activity. [ABSTRACT FROM AUTHOR]

Background: As social animals we share the space with other people. It is known that perceived extension of the peripersonal space (the reaching space) is affected by the implicit representation of our own and other's action potentialities. Our issue concerns whether the co-presence of a body in the scene influences our extrapersonal space (beyond reaching distance) categorization. Methodology/Principal Findings: We investigated, through 3D virtual scenes of a realistic environment, whether egocentric spatial categorization can be influenced by the presence of another human body (Exp. 1) and whether the effect is due to her action potentialities or simply to her human-like morphology (Exp. 2). Subjects were asked to judge the location ("Near" or "Far") of a target object located at different distances from their egocentric perspective. In Exp. 1, the judgment was given either in presence of a virtual avatar (Self-with-Other), or a non-corporeal object (Self-with-Object) or nothing (Self). In Exp. 2, the Self condition was replaced by a Self-with-Dummy condition, in which an inanimate body (a wooden dummy) was present. Mean Judgment Transition Thresholds (JTTs) were calculated for each subject in each experimental condition. Self-with-Other condition induced a significant extension of the space judged as “Near” as compared to both the Self-with-Object condition and the Self condition. Such extension was observed also in Exp. 2 in the Self-with-Dummy condition. Results suggest that the presence of others impacts on our perception of extrapersonal space. This effect holds also when the other is a human-like wooden dummy, suggesting that structural and morphological shapes resembling human bodies are sufficient conditions for the effect to occur. Conclusions: The observed extension of the portion of space judged as near could represent a wider portion of “accessible” space, thus an advantage in the struggle to survive in presence of other potential competing individuals. [ABSTRACT FROM AUTHOR]

The present study asks when infants are able to selectively anticipate the goals of observed actions, and how this ability relates to infants’ own abilities to produce those specific actions. Using eye-tracking technology to measure on-line anticipation, 6-, 8- and 10-month-old infants and a control group of adults were tested while observing an adult reach with a whole hand grasp, a precision grasp or a closed fist towards one of two different sized objects. The same infants were also given a comparable action production task. All infants showed proactive gaze to the whole hand grasps, with increased degrees of proactivity in the older groups. Gaze proactivity to the precision grasps, however, was present from 8 months of age. Moreover, the infants’ ability in performing precision grasping strongly predicted their ability in using the actor’s hand shape cues to differentially anticipate the goal of the observed action, even when age was partialled out. The results are discussed in terms of the specificity of action anticipation, and the fine-grained relationship between action production and action perception. [ABSTRACT FROM AUTHOR]

In social life actions are tightly linked with emotions. The integration of affective- and action-related information has to be considered as a fundamental component of appropriate social understanding. The present functional magnetic resonance imaging study aimed at investigating whether an emotion (Happiness, Anger or Neutral) dynamically expressed by an observed agent modulates brain activity underlying the perception of his grasping action. As control stimuli, participants observed the same agent either only expressing an emotion or only performing a grasping action. Our results showed that the observation of an action embedded in an emotional context (agent's facial expression), compared with the observation of the same action embedded in a neutral context, elicits higher neural response at the level of motor frontal cortices, temporal and occipital cortices, bilaterally. Particularly, the dynamic facial expression of anger modulates the re-enactment of a motor representation of the observed action. This is supported by the evidence that observing actions embedded in the context of anger, but not happiness, compared with a neutral context, elicits stronger activity in the bilateral pre-central gyrus and inferior frontal gyrus, besides the pre-supplementary motor area, a region playing a central role in motor control. Angry faces not only seem to modulate the simulation of actions, but may also trigger motor reaction. These findings suggest that emotions exert a modulatory role on action observation in different cortical areas involved in action processing. [ABSTRACT FROM AUTHOR]

To date, mutual interaction between action and perception has been investigated mainly by focusing on single individuals. However, we perceive affording objects and acts upon them in a surrounding world inhabited by other perceiving and acting bodies. Thus, the issue arises as to whether our action-oriented object perception might be modulated by the presence of another potential actor. To tackle this issue we used the spatial alignment effect paradigm and systematically examined this effect when a visually presented handled object was located close either to the perceiver or to another individual (a virtual avatar). We found that the spatial alignment effect occurred whenever the object was presented within the reaching space of a potential actor, regardless of whether it was the participant's own or the other's reaching space. These findings show that objects may afford a suitable motor act when they are ready not only to our own hand but also, and most importantly, to the other's hand. Our proposal is that this effect is likely to be due to a mapping of our own and the other's reaching space and we posit that such mapping could play a critical role in joining our own and the other's action. [ABSTRACT FROM AUTHOR]

Previous studies demonstrated the human ability to implicitly recognize their own body. When submitted to a visual matching task, participants showed the so-called self-advantage, that is, a better performance with self rather than others' body or body parts. Here, we investigated whether the body self-advantage relies upon a motor representation of one's body. Participants were submitted to a laterality judgment of self and others' hands (Experiment 1 and 3), which involves a sensory-motor mental simulation. Moreover, to investigate whether the self-advantage emerges also when an explicit self processing is required, the same participants were submitted to an explicit self-body recognition task (Experiment 2). Participants showed the self-advantage when performing the laterality judgment, but not when self-recognition was explicitly required. Thus, implicit and explicit recognition of the bodily self dissociate and only an implicit recognition of the bodily self, mapped in motor terms, allows the self-advantage to emerge. [ABSTRACT FROM AUTHOR]