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Slow, gentle stimulation of hairy skin is generally accompanied by hedonic sensations. This phenomenon, also known as (positive) affective touch, is likely to be the basis of affiliative interactions with conspecifics by promoting inter-individual bindings. Previous studies on healthy humans have demonstrated that affective touch can remarkably impact behavior. For instance, by administering the Rubber Hand Illusion (RHI) paradigm, the embodiment of a fake hand enhances after a slow, affective touch compared to a fast, neutral touch. However, results coming from this area are not univocal. In addition, there are no clues in the existing literature on the relationship between affective touch and the space around our body. To overcome these lacks, we carried out two separate experiments where participants underwent a RHI paradigm (Experiment 1) and a Visuo-Tactile Interaction task (Experiment 2), designed to tap into body representation and peripersonal space processing, respectively. In both experiments, an affective touch (CT-optimal, 3 cm/sec) and neutral touch (CT-suboptimal, 18 cm/sec) were delivered by the experimenter on the dorsal side of participants’ hand through a “skin to skin” contact. In Experiment 1, we did not find any modulation of body representation-not at behavioral nor at a physiological level-by affective touch. In Experiment 2, no visuo-tactile spatial modulation emerged depending upon the pleasantness of the touch received. These null findings are interpreted in the light of the current scientific context where the real nature of affective touch is often misguided, and they offer the possibility to pave the way for understanding the real effects of affective touch on body/space representation.

Embodiment is the percept that something not originally belonging to the self becomes part of the body. Feeling embodiment for a prosthesis may counteract amputees’ altered image of the body and increase prosthesis acceptability. Prosthesis embodiment has been studied longitudinally in an amputee receiving feedback through intraneural and perineural multichannel electrodes implanted in her stump. Three factors—invasive (vs non-invasive) stimulation, training, and anthropomorphism—have been tested through two multisensory integration tasks: visuo-tactile integration (VTI) and crossing-hand effect in temporal order judgment (TOJ), the former more sensible to an extension of a safe margin around the body and the latter to action-oriented remapping. Results from the amputee participant were compared with the ones from healthy controls. Testing the participant with intraneural stimulation produced an extension of peripersonal space, a sign of prosthesis embodiment. One-month training extended the peripersonal space selectively on the side wearing the prostheses. More and less-anthropomorphic prostheses benefited of intraneural feedback and extended the peripersonal space. However, the worsening of TOJ performance following arm crossing was present only wearing the more trained, despite less anthropomorphic, prosthesis, suggesting that training was critical for our participant to achieve operative tool-like embodiment.

Embodiment is the percept that something not originally belonging to the self becomes part of the body. Feeling embodiment for a prosthesis may counteract amputees’ altered image of the body and increase prosthesis acceptability. Prosthesis embodiment has been studied longitudinally in an amputee receiving feedback through intraneural and perineural multichannel electrodes implanted in her stump. Three factors—invasive (vs non-invasive) stimulation, training, and anthropomorphism—have been tested through two multisensory integration tasks: visuo-tactile integration (VTI) and crossing-hand effect in temporal order judgment (TOJ), the former more sensible to an extension of a safe margin around the body and the latter to action-oriented remapping. Results from the amputee participant were compared with the ones from healthy controls. Testing the participant with intraneural stimulation produced an extension of peripersonal space, a sign of prosthesis embodiment. One-month training extended the peripersonal space selectively on the side wearing the prostheses. More and less-anthropomorphic prostheses benefited of intraneural feedback and extended the peripersonal space. However, the worsening of TOJ performance following arm crossing was present only wearing the more trained, despite less anthropomorphic, prosthesis, suggesting that training was critical for our participant to achieve operative tool-like embodiment.

Lo spazio peripersonale (SPP) rappresenta una regione privilegiata di spazio immediatamente circostante il nostro corpo in cui stimoli visivi e tattili vengono integrati nelle aree cerebrali fronto-parietali (Hunley & Lourenco, 2018). L’ampiezza di SPP non è fissa ma può essere regolata da diversi fattori (Fogassi et al., 1996). Il presente lavoro di tesi si propone di indagare come l’integrazione visuo-tattile possa essere modulata dalla valenza intrinseca e acquisita degli stimoli visivi e da stati emotivi legati all’ansia. Negli Studi 1 e 3 è stato utilizzato il paradigma di interazione visuo-tattile (Canzoneri et al., 2012) in cui stimoli tattili venivano somministrati mentre stimoli visivi in avvicinamento a valenza intrinseca (Studio 1) e acquisita (Studio 3) si trovavano a specifiche distanze dal corpo dei partecipanti. I risultati dei due studi sono analoghi: a brevi distanze, tutti gli stimoli visivi comportano una facilitazione dell’elaborazione del tattile, a lunghe distanze dal corpo, invece, solo gli stimoli connotati da valenza modulano le interazioni visuo-tattili. Lo studio 2 è stato condotto per escludere che possibili effetti di aspettativa tattile potessero spiegare i risultati ottenuti nei due precedenti studi. Utilizzando lo stesso paradigma di interazione visuo-tattile, ora gli stimoli visivi si allontanano dal corpo anziché avvicinarsi ad esso. Contrariamente ai due studi summenzionati, si è qui riscontrato che la valenza degli stimoli non esercita nessun effetto sulla percezione spaziale, confermando dunque la validità degli Studi 1 e 3. Lo Studio 4 si propone di indagare le oscillazioni neurali sottostanti le interazioni visuo-tattili. Nello specifico, si vorrebbe replicare il risultato ottenuto da Wamain et al. (2016) il quale ha riportato un gradiente di attivazione della corteccia sensorimotoria dallo spazio peripersonale a quello extrapersonale, soltanto quando il compito richiedeva al soggetto una chiara intenzione motoria. Utili, Peripersonal Space (PPS) is a privileged region of space, immediately surrounding our body, in which visual and bodily signals are promptly integrated in fronto-parietal areas of the brain (Hunley & Lourenco, 2018). PPS amplitude is not fixed, but it can be dynamically shaped by specific experimental manipulations (Fogassi et al., 1996). In Study 1 and 3, we tried to disentangle how visuo-tactile integration in space can be shaped by intrinsic and learned valence of objects. By using a visuo-tactile interaction paradigm, participants were asked to respond to a tactile stimulus while an approaching visual one (with intrinsic and learned valence in Study 1 and 3, respectively) was located at specific distances from their body (Canzoneri et al., 2012). The results of Study 1 and 3 seem aligned to each other: positive and negative stimuli entail larger visuo-tactile interactions in space than neutral ones. Indeed, at longer distances from the body, visuo-tactile interactions are dynamically modulated by valence-connoted looming visual stimuli. At shorter distances, instead, all stimuli acquire saliency regardless of their intrinsic or acquired valence, due to their proximity to the body. Study 3 aims to exclude that the above-mentioned results might be due to tactile expectancy (Kandula et al., 2017). Indeed, the more the visual stimulus approaches the body without tactile input, the more the bodily stimulus expectancy increases (Umbach et al. 2012). By using the same visual stimuli – that now recede away from participants’ body - and spatial distances as in Study 1, it was shown that the different valence of the stimuli is not able to produce any kind of effect in space, thus stressing the validity of the findings reported in Studies 1 and 3. Study 4 investigates the neuronal oscillations related to visuo-tactile coupling in near and far space for both positive and negative visual stimuli. In particular, we would like to replicate Wamain et al. (2016) results, which st

The space around our body, the so-called peripersonal space, is where interactions with nearby objects may occur. “Defensive space” and “Reaching space”, respectively, refer to two opposite poles of interaction between our body and the external environment: Protecting the body and performing a goal-directed action. Here, we hypothesized that mechanisms underlying these two action spaces are differentially modulated by the valence of visual stimuli, as stimuli with negative valence are more likely to activate protective actions whereas stimuli with positive valence may activate approaching actions. To test whether such distinction in cognitive/evaluative processing exists between Reaching and Defensive spaces, we measured behavioral responses as well as neural activations over sensorimotor cortex using EEG while participants performed several tasks designed to tap into mechanisms underlying either Defensive (e.g., respond to touch) or Reaching space (e.g., estimate whether object is within reaching distance). During each task, pictures of objects with either positive or negative valence were presented at different distances from the participants’ body. We found that Defensive space was smaller for positively compared with negatively valenced visual stimuli. Furthermore, sensorimotor cortex activation (reflected in modulation of beta power) during tactile processing was enhanced when coupled with negatively rather than positively valenced visual stimuli regarding Defensive space. On the contrary, both the EEG and behavioral measures capturing the mechanisms underlying Reaching space did not reveal any modulation by valence. Thus, although valence encoding had differential effects on Reaching and Defensive spaces, the distance of the visual stimulus modulated behavioral measures as well as activity over sensorimotor cortex (reflected in modulations of mu power) in a similar way for both types of spaces. Our results are compatible with the idea that Reaching and Defe

The space around our body, the so-called peripersonal space, is where interactions with nearby objects may occur. "Defensive space" and "Reaching space", respectively, refer to two opposite poles of interaction between our body and the external environment: protecting the body and performing a goal-directed action. Here, we hypothesized that mechanisms underlying these two action spaces are differentially modulated by the valence of visual stimuli, as stimuli with negative valence are more likely to activate protective actions whereas stimuli with positive valence may activate approaching actions. To test whether such distinction in cognitive/evaluative processing exists between Reaching and Defensive spaces, we measured behavioral responses as well as neural activations over sensorimotor cortex using EEG while participants performed several tasks designed to tap into mechanisms underlying either Defensive (e.g., respond to touch) or Reaching space (e.g., estimate whether object is within reaching distance). During each task, pictures of objects with either positive or negative valence were presented at different distances from the participants' body. We found that Defensive space was smaller for positively compared with negatively valenced visual stimuli. Furthermore, sensorimotor cortex activation (reflected in modulation of beta power) during tactile processing was enhanced when coupled with negatively rather than positively valenced visual stimuli regarding Defensive space. On the contrary, both the EEG and behavioral measures capturing the mechanisms underlying Reaching space did not reveal any modulation by valence. Thus, although valence encoding had differential effects on Reaching and Defensive spaces, the distance of the visual stimulus modulated behavioral measures as well as activity over sensorimotor cortex (reflected in modulations of mu power) in a similar way for both types of spaces. Our results are compatible with the idea that Reaching and Defe

The space around our body, the so-called peripersonal space, is where interactions with nearby objects may occur. "Defensive space" and "Reaching space", respectively, refer to two opposite poles of interaction between our body and the external environment: protecting the body and performing a goal-directed action. Here, we hypothesized that mechanisms underlying these two action spaces are differentially modulated by the valence of visual stimuli, as stimuli with negative valence are more likely to activate protective actions whereas stimuli with positive valence may activate approaching actions. To test whether such distinction in cognitive/evaluative processing exists between Reaching and Defensive spaces, we measured behavioral responses as well as neural activations over sensorimotor cortex using EEG while participants performed several tasks designed to tap into mechanisms underlying either Defensive (e.g., respond to touch) or Reaching space (e.g., estimate whether object is within reaching distance). During each task, pictures of objects with either positive or negative valence were presented at different distances from the participants' body. We found that Defensive space was smaller for positively compared with negatively valenced visual stimuli. Furthermore, sensorimotor cortex activation (reflected in modulation of beta power) during tactile processing was enhanced when coupled with negatively rather than positively valenced visual stimuli regarding Defensive space. On the contrary, both the EEG and behavioral measures capturing the mechanisms underlying Reaching space did not reveal any modulation by valence. Thus, although valence encoding had differential effects on Reaching and Defensive spaces, the distance of the visual stimulus modulated behavioral measures as well as activity over sensorimotor cortex (reflected in modulations of mu power) in a similar way for both types of spaces. Our results are compatible with the idea that Reaching and Defe

The peripersonal space (PPS) is the space surrounding our body, represented in a multisensory fashion by integrating stimuli of different modalities. Recently, it has been demonstrated that PPS is emotionally connoted, being sensitive to the different affective valence of the stimuli located inside it. However, how visuo-tactile interactions can be spatially shaped by intrinsic or acquired valence of stimuli is not clear. To investigate this, we conducted three experiments in which participants performed a visuo-tactile interaction task, while the intrinsic valence (Exp. 1 and 2) or the learned valence (Exp. 3) of visual stimuli was manipulated. Participants were asked to respond as fast as possible to a tactile stimulus that was delivered while a visual stimulus was approaching (Exp.1 and 3) or receding (Exp.2) from the hand. Touch was synchronized with different distances of the visual stimulus from the hand. We found that both the expectancy of stimulus and the distance of the visual one from the hand impact RTs to tactile targets. Crucially, we found that spatial modulation was also influenced by stimulus valence, but only for the approaching and not the receding stimuli. At far distances, neutral stimuli yielded overall slower RTs than intrinsically positive or negative stimuli (Experiment 1), while no modulation was exerted by the level of conditioning (Experiment 3). At near distances, response to touches accompanied by looming neutral stimuli became as fast as that occurring with positive and negative ones. Stimulus valence did not interact with the expectancy of a tactile stimulus (Experiment 2). Overall, these findings support the vision that visuo-tactile interactions can be dynamically modulated by the valence of looming visual stimuli when these are located at longer distances from the body. When closer to it, all stimuli acquire saliency, regardless of their intrinsic or acquired valence, due to their proximity, and then relevance, to the body. Overall

We propose a type-based analysis to infer the session protocols of channels in an ML-like concurrent functional language. Combining and extending well-known techniques, we develop a type-checking system that separates the underlying ML type system from the typing of sessions. Without using linearity, our system guarantees communication safety and partial lock freedom. It also supports provably complete session inference for finite sessions with no programmer annotations. We exhibit the usefulness of our system with interesting examples, including one which is not typable in substructural type systems.

Consensus is an often occurring problem in concurrent and distributed programming. We present a programming language with simple semantics and build-in support for consensus in the form of communicating transactions. We motivate the need for such a construct with a characteristic example of generalized consensus which can be naturally encoded in our language. We then focus on the challenges in achieving an implementation that can efficiently run such programs. We setup an architecture to evaluate different implementation alternatives and use it to experimentally evaluate runtime heuristics. This is the basis for a research project on realistic programming language support for consensus., Comment: 15 pages, 5 figures, symposium: TFP 2013