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It has been widely assumed that internal forward models use efference copies to create predictions about the sensory consequences of our own actions. While these predictions have frequently been associated with a reduced blood oxygen level dependent (BOLD) response in sensory cortices, the timing and duration of the hemodynamic response for the processing of video feedback of self-generated (active) versus externally generated (passive) movements is poorly understood. In the present study, we tested the hypothesis that predictive mechanisms for self-generated actions lead to early and shorter neural processing compared with externally generated movements. We investigated active and passive movements using a custom-made fMRI-compatible movement device. Visual video feedback of the active and passive movements was presented in real time or with variable delays. Participants had to judge whether the feedback was delayed. Timing and duration of BOLD impulse response was calculated using a first (temporal derivative [TD]) and second-order (dispersion derivative [DD]) Taylor approximation. Our reanalysis confirmed our previous finding of reduced BOLD response for active compared to passive movements. Moreover, we found positive effects of the TD and DD in the supplementary motor area, cerebellum, visual cortices, and subcortical structures, indicating earlier and shorter hemodynamic responses for active compared to passive movements. Furthermore, earlier activation in the putamen for active compared to passive conditions was associated with reduced delay detection performance. These findings indicate that efference copy-based predictive mechanisms enable earlier processing of action feedback, which might have reduced the ability to detect short delays between action and feedback.

Body orientation of gesture entails social‐communicative intention, and may thus influence how gestures are perceived and comprehended together with auditory speech during face‐to‐face communication. To date, despite the emergence of neuroscientific literature on the role of body orientation on hand action perception, limited studies have directly investigated the role of body orientation in the interaction between gesture and language. To address this research question, we carried out an electroencephalography (EEG) experiment presenting to participants (n = 21) videos of frontal and lateral communicative hand gestures of 5 s (e.g., raising a hand), followed by visually presented sentences that are either congruent or incongruent with the gesture (e.g., “the mountain is high/low…”). Participants underwent a semantic probe task, judging whether a target word is related or unrelated to the gesture‐sentence event. EEG results suggest that, during the perception phase of handgestures, while both frontal and lateral gestures elicited a power decrease in both the alpha (8–12 Hz) and the beta (16–24 Hz) bands, lateral versus frontal gestures elicited reduced power decrease in the beta band, source‐located to the medial prefrontal cortex. For sentence comprehension, at the critical word whose meaning is congruent/incongruent with the gesture prime, frontal gestures elicited an N400 effect for gesture‐sentence incongruency. More importantly, this incongruency effect was significantly reduced for lateral gestures. These findings suggest that body orientation plays an important role in gesture perception, and that its inferred social‐communicative intention may influence gesture‐language interaction at semantic level., We collected EEG when participants process visual sentences primed by frontal and lateral gestures. Lateral gestures elicited reduced beta band power decrease during perception. Additionally, in the visual sentences, the N400 effect, as derived from semantic incongruency between the critical word and the gesture prime, was reduced for lateral gestures.

The feeling of being addressed is the first step in a complex processing stream enabling successful social communication. Social impairments are a relevant characteristic of patients with major depressive disorder (MDD). Here, we investigated a mechanism which—if impaired—might contribute to withdrawal or isolation in MDD, namely, the neural processing of social cues such as body orientation and gesture. During funtional magnetic resonance imaging (fMRI) data acquisition, 33 patients with MDD and 43 healthy control subjects watched video clips of a speaking actor: one version with a gesture accompanying the speech and one without gesture. Videos were filmed simultaneously from two different viewpoints: one with the actor facing the viewer head‐on (frontal) and one side‐view (lateral). After every clip, the participants were instructed to evaluate whether they felt addressed or not. Despite overall comparable addressment ratings and a large overlap in activation patterns in MDD and healthy subjects for gesture processing, the anterior cingulate cortex, bilateral superior/middle frontal cortex, and right angular gyrus were more strongly activated in patients than in healthy subjects for the frontal conditions. Our analyses revealed that patients showed specifically higher activation than healthy subjects for the frontal condition without gesture in regions including the posterior cingulate cortex, left prefrontal cortex, and the left hippocampus. We conclude that MDD patients can recognize and interpret social cues such as gesture or body orientation; however, they seem to require more neural resources. This additional effort might affect successful communication and contribute to social isolation in MDD.

Identifying someone else's noncooperative intentions can prevent exploitation in social interactions. Hence, the inference of another person's mental state might be most pronounced in order to improve social decision‐making. Here, we tested the hypothesis that brain regions associated with Theory of Mind (ToM), particularly the right temporo–parietal junction (rTPJ), show higher neural responses when interacting with a selfish person and that the rTPJ‐activity as well as cooperative tendencies will change over time. We used functional magnetic resonance imaging (fMRI) and a modified prisoner's dilemma game in which 20 participants interacted with three fictive playing partners who behaved according to stable strategies either competitively, cooperatively or randomly during seven interaction blocks. The rTPJ and the posterior–medial prefrontal cortex showed higher activity during the interaction with a competitive compared with a cooperative playing partner. Only the rTPJ showed a high response during an early interaction phase, which preceded participants increase in defective decisions. Enhanced functional connectivity between the rTPJ and the left hippocampus suggests that social cognition and learning processes co‐occur when behavioral adaptation seems beneficial.

Forward models can predict sensory consequences of self‐action, which is reflected by less neural processing for actively than passively generated sensory inputs (BOLD suppression effect). However, it remains open whether forward models take the identity of a moving body part into account when predicting the sensory consequences of an action. In the current study, fMRI was used to investigate the neural correlates of active and passive hand movements during which participants saw either an on‐line display of their own hand or someone else's hand moving in accordance with their movement. Participants had to detect delays (0–417 ms) between their movement and the displays. Analyses revealed reduced activation in sensory areas and higher delay detection thresholds for active versus passive movements. Furthermore, there was increased activation in the hippocampus, the amygdala, and the middle temporal gyrus when someone else's hand was seen. Most importantly, in posterior parietal (angular gyrus and precuneus), frontal (middle, superior, and medial frontal gyrus), and temporal (middle temporal gyrus) regions, suppression for actively versus passively generated feedback was stronger when participants were viewing their own compared to someone else's hand. Our results suggest that forward models can take hand identity into account when predicting sensory action consequences.

During face-to-face communication, body orientation and coverbal gestures influence how information is conveyed. The neural pathways underpinning the comprehension of such nonverbal social cues in everyday interaction are to some part still unknown. During fMRI data acquisition, 37 participants were presented with video clips showing an actor speaking short sentences. The actor produced speech-associated iconic gestures (IC) or no gestures (NG) while he was visible either from an egocentric (ego) or from an allocentric (allo) position. Participants were asked to indicate via button press whether they felt addressed or not. We found a significant interaction of body orientation and gesture in addressment evaluations, indicating that participants evaluated IC-ego conditions as most addressing. The anterior cingulate cortex (ACC) and left fusiform gyrus were stronger activated for egocentric versus allocentric actor position in gesture context. Activation increase in the ACC for IC-ego>IC-allo further correlated positively with increased addressment ratings in the egocentric gesture condition. Gesture-related activation increase in the supplementary motor area, left inferior frontal gyrus and right insula correlated positively with gesture-related increase of addressment evaluations in the egocentric context. Results indicate that gesture use and body-orientation contribute to the feeling of being addressed and together influence neural processing in brain regions involved in motor simulation, empathy and mentalizing.

Gestures are an important component of interpersonal communication. Especially, complex multimodal communication is assumed to be disrupted in patients with schizophrenia. In healthy subjects, differential neural integration processes for gestures in the context of concrete [iconic (IC) gestures] and abstract sentence contents [metaphoric (MP) gestures] had been demonstrated. With this study we wanted to investigate neural integration processes for both gesture types in patients with schizophrenia. During functional magnetic resonance imaging‐data acquisition, 16 patients with schizophrenia (P) and a healthy control group (C) were shown videos of an actor performing IC and MP gestures and associated sentences. An isolated gesture (G) and isolated sentence condition (S) were included to separate unimodal from bimodal effects at the neural level. During IC conditions (IC > G ∩ IC > S) we found increased activity in the left posterior middle temporal gyrus (pMTG) in both groups. Whereas in the control group the left pMTG and the inferior frontal gyrus (IFG) were activated for the MP conditions (MP > G ∩ MP > S), no significant activation was found for the identical contrast in patients. The interaction of group (P/C) and gesture condition (MP/IC) revealed activation in the bilateral hippocampus, the left middle/superior temporal and IFG. Activation of the pMTG for the IC condition in both groups indicates intact neural integration of IC gestures in schizophrenia. However, failure to activate the left pMTG and IFG for MP co‐verbal gestures suggests a disturbed integration of gestures embedded in an abstract sentence context. This study provides new insight into the neural integration of co‐verbal gestures in patients with schizophrenia. Hum Brain Mapp, 2013. © 2012 Wiley Periodicals, Inc.

Gestures are an important part of interpersonal communication, for example by illustrating physical properties of speech contents (e.g., “the ball is round”). The meaning of these so‐called iconic gestures is strongly intertwined with speech. We investigated the neural correlates of the semantic integration for verbal and gestural information. Participants watched short videos of five speech and gesture conditions performed by an actor, including variation of language (familiar German vs. unfamiliar Russian), variation of gesture (iconic vs. unrelated), as well as isolated familiar language, while brain activation was measured using functional magnetic resonance imaging. For familiar speech with either of both gesture types contrasted to Russian speech‐gesture pairs, activation increases were observed at the left temporo‐occipital junction. Apart from this shared location, speech with iconic gestures exclusively engaged left occipital areas, whereas speech with unrelated gestures activated bilateral parietal and posterior temporal regions. Our results demonstrate that the processing of speech with speech‐related versus speech‐unrelated gestures occurs in two distinct but partly overlapping networks. The distinct processing streams (visual versus linguistic/spatial) are interpreted in terms of “auxiliary systems” allowing the integration of speech and gesture in the left temporo‐occipital region. Hum Brain Mapp, 2009. © 2009 Wiley‐Liss, Inc.

During face‐to‐face communication, body orientation and coverbal gestures influence how information is conveyed. The neural pathways underpinning the comprehension of such nonverbal social cues in everyday interaction are to some part still unknown. During fMRI data acquisition, 37 participants were presented with video clips showing an actor speaking short sentences. The actor produced speech‐associated iconic gestures (IC) or no gestures (NG) while he was visible either from an egocentric (ego) or from an allocentric (allo) position. Participants were asked to indicate via button press whether they felt addressed or not. We found a significant interaction of body orientation and gesture in addressment evaluations, indicating that participants evaluated IC‐ego conditions as most addressing. The anterior cingulate cortex (ACC) and left fusiform gyrus were stronger activated for egocentric versus allocentric actor position in gesture context. Activation increase in the ACC for IC‐ego>IC‐allo further correlated positively with increased addressment ratings in the egocentric gesture condition. Gesture‐related activation increase in the supplementary motor area, left inferior frontal gyrus and right insula correlated positively with gesture‐related increase of addressment evaluations in the egocentric context. Results indicate that gesture use and body‐orientation contribute to the feeling of being addressed and together influence neural processing in brain regions involved in motor simulation, empathy and mentalizing. Hum Brain Mapp 36:1925–1936, 2015. © 2015 Wiley Periodicals, Inc.