Anticipating the sensorimotor consequences of an action for both self and other is fundamental for action coordination when individuals socially interact. Somatosensation constitutes an elementary component of social cognition and sensorimotor prediction, but its functions in active social behavior remain unclear. We hypothesized that the somatosensory system contributes to social haptic behavior as evidenced by specific anticipatory activation patterns when touching an animate target (human hand) compared with an inanimate target (fake hand). fMRI scanning was performed during a paradigm that allowed us to isolate the anticipatory representations of active interpersonal touch while controlling for nonsocial sensorimotor processes and possible confounds because of interpersonal relationships or socioemotional valence. Active interpersonal touch was studied both as skin-to-skin contact and as object-mediated touch. The results showed weaker deactivation in primary somatosensory cortex and medial pFC and stronger activation in cerebellum for the animate target, compared with the inanimate target, when intending to touch it with one's own hand. Differently, in anticipation of touching the human hand with an object, anterior inferior parietal lobule and lateral occipital-temporal cortex showed stronger activity. When actually touching a human hand with one's own hand, activation was stronger in medial pFC but weaker in primary somatosensory cortex. The findings provide new insight on the contribution of simulation and sensory prediction mechanisms to active social behavior. They also suggest that literally getting in touch with someone and touching someone by using an object might be approached by an agent as functionally distinct conditions.

We investigated the functional properties of a previously described cingulo-opercular network (CON) putatively involved in cognitive control. Analyses of common fMRI task-evoked activity during perceptual and episodic memory search tasks that differently recruited the dorsal attention (DAN) and default mode network (DMN) established the generality of this network. Regions within the CON (anterior insula/frontal operculum and anterior cingulate/presupplementary cortex) displayed sustained signals during extended periods in which participants searched for behaviorally relevant information in a dynamically changing environment or from episodic memory in the absence of sensory stimulation. The CON was activated during all phases of both tasks, which involved trial initiation, target detection, decision, and response, indicating its consistent involvement in a broad range of cognitive processes. Functional connectivity analyses showed that the CON flexibly linked with the DAN or DMN regions during perceptual or memory search, respectively. Aside from the CON, only a limited number of regions, including the lateral pFC, showed evidence of domain-general sustained activity, although in some cases the common activations may have reflected the functional-anatomical variability of domain-specific regions rather than a true domain generality. These additional regions also showed task-dependent functional connectivity with the DMN and DAN, suggesting that this feature is not a specific marker of cognitive control. Finally, multivariate clustering analyses separated the CON from other frontoparietal regions previously associated with cognitive control, indicating a unique fingerprint. We conclude that the CON's functional properties and interactions with other brain regions support a broad role in cognition, consistent with its characterization as a task control network.

The default mode network is active during restful wakefulness and suppressed during goal-driven behavior. We hypothesize that inhibitory interference with spontaneous ongoing, that is, not task-driven, activity in the angular gyrus (AG), one of the core regions of the default mode network, will enhance the dominant idling EEG alpha rhythms observed in the resting state. Fifteen right-handed healthy adult volunteers underwent to this study. Compared with sham stimulation, magnetic stimulation (1 Hz for 1 min) over both left and right AG, but not over FEF or intraparietal sulcus, core regions of the dorsal attention network, enhanced the dominant alpha power density (8–10 Hz) in occipitoparietal cortex. Furthermore, right AG-rTMS enhanced intrahemispheric alpha coherence (8–10 Hz). These results suggest that AG plays a causal role in the modulation of dominant low-frequency alpha rhythms in the resting-state condition.

TMS interference over right intraparietal sulcus (IPS) causally disrupts behaviorally and EEG rhythmic correlates of endogenous spatial orienting before visual target presentation [Capotosto, P., Babiloni, C., Romani, G. L., & Corbetta, M. Differential contribution of right and left parietal cortex to the control of spatial attention: A simultaneous EEG-rTMS study. Cerebral Cortex, 22 , 446–454, 2012; Capotosto, P., Babiloni, C., Romani, G. L., & Corbetta, M. Fronto-parietal cortex controls spatial attention through modulation of anticipatory alpha rhythms. Journal of Neuroscience, 29, 5863–5872, 2009]. Here we combine data from our previous studies to examine whether right parietal TMS during spatial orienting also impairs stimulus-driven reorienting or the ability to efficiently process unattended stimuli, that is, stimuli outside the current focus of attention. Healthy volunteers ( n = 24) performed a Posner spatial cueing task while their EEG activity was being monitored. Repetitive TMS (rTMS) was applied for 150 msec simultaneously to the presentation of a central arrow directing spatial attention to the location of an upcoming visual target. Right IPS-rTMS impaired target detection, especially for stimuli presented at unattended locations; it also caused a modulation of the amplitude of parieto-occipital positive ERPs peaking at about 480 msec (P3) post-target. The P3 significantly decreased for unattended targets and significantly increased for attended targets after right IPS-rTMS as compared with sham stimulation. Similar effects were obtained for left IPS stimulation albeit in a smaller group of volunteers. We conclude that disruption of anticipatory processes in right IPS has prolonged effects that persist during target processing. The P3 decrement may reflect interference with postdecision processes that are part of stimulus-driven reorienting. Right IPS is a node of functional interaction between endogenous spatial orienting and stimulus-driven reorienting processes in human vision.

Previous studies suggested that the observation of other individuals' somatosensory experiences also activates brain circuits processing one's own somatosensory experiences. However, it is unclear whether cortical regions involved with the elementary stages of touch processing are also involved in the automatic coding of the affective consequences of observed touch and to which extent they show overlapping activation for somatosensory experiences of self and others. In order to investigate these issues, in the present fMRI study, healthy participants either experienced touch or watched videos depicting other individuals' inanimate and animate/social touch experiences. Essentially, a distinction can be made between exteroceptive and interoceptive components of touch processing, involved with physical stimulus characteristics and internal feeling states, respectively. Consistent with this distinction, a specific negative modulation was found in the posterior insula by the mere visual perception of other individuals' social or affective cutaneous experiences, compared to neutral inanimate touch. On the other hand, activation in secondary somatosensory and posterior superior temporal regions, strongest for the most intense stimuli, seemed more dependent on the observed physical stimulus characteristics. In contrast to the detected vicarious activation in somatosensory regions, opposite activation patterns for the experience (positive modulation) and observation (negative modulation) of touch suggest that the posterior insula does not reflect a shared representation of self and others' experiences. Embedded in a distributed network of brain regions underpinning a sense of the bodily self, the posterior insula rather appears to differentiate between self and other conditions when affective experiences are implicated.

The perception of tactile stimuli on the face is modulated if subjects concurrently observe a face being touched; this effect, termed visual remapping of touch (VRT), is maximum for observing one's own face. In the present fMRI study, we investigated the neural basis of the VRT effect. Participants in the scanner received tactile stimuli, near the perceptual threshold, on their right, left, or both cheeks. Concurrently, they watched movies depicting their own face, another person's face, or a ball that could be touched or only approached by human fingers. Participants were requested to distinguish between unilateral and bilateral tactile stimulation. Behaviorally, perception of tactile stimuli was modulated by viewing a tactile stimulation, with a stronger effect when viewing one's own face being touched. In terms of brain activity, viewing touch was related with an enhanced activity in the ventral intraparietal area. The specific effect of viewing touch on oneself was instead related with a reduced activity in both the ventral premotor cortex and the somatosensory cortex. The present findings suggest that VRT is supported by a network of fronto-parietal areas. The ventral intraparietal area might remap visual information about touch onto tactile processing. Ventral premotor cortex might specifically modulate multisensory interaction when sensory information is related to one's own body. Then this activity might back project to the somatosensory cortices, thus affecting tactile perception.

Previous studies have shown a shared neural circuitry in the somatosensory cortices for the experience of one's own body being touched and the sight of intentional touch. Using functional magnetic resonance imaging (fMRI), the present study aimed to elucidate whether the activation of a visuotactile mirroring mechanism during touch observation applies to the sight of any touch, that is, whether it is independent of the intentionality of observed touching agent. During fMRI scanning, healthy participants viewed video clips depicting a touch that was intentional or accidental, and occurring between animate or inanimate objects. Analyses showed equal overlapping activation for all the touch observation conditions and the experience of one's own body being touched in the bilateral secondary somatosensory cortex (SII), left inferior parietal lobule (IPL)/supramarginal gyrus, bilateral temporal-occipital junction, and left precentral gyrus. A significant difference between the sight of an intentional touch, compared to an accidental touch, was found in the left primary somatosensory cortex (SI/Brodmann's area [BA] 2). Interestingly, activation in SI/BA 2 significantly correlated with the degree of intentionality of the observed touch stimuli as rated by participants. Our findings show that activation of a visuotactile mirroring mechanism for touch observation might underpin an abstract notion of touch, whereas activation in SI might reflect a human tendency to “resonate” more with a present or assumed intentional touching agent.