In everyday life, our behavior is often guided by environmental cues that predict rewarding or aversive outcomes. The Pavlovian-to-Instrumental Transfer (PIT) paradigm provides a framework for examining how conditioned stimuli (CS) influence instrumental actions (R) associated with specific outcomes (O). Two distinct mechanisms have been identified: specific PIT, where a cue selectively invigorates the action linked to the same outcome, and general PIT, where reward-predictive cues non-selectively enhance response vigor. Theoretical accounts propose that specific PIT depends on the reactivation of learned action representations by sensory-specific cues, yet it remains unclear whether such reactivation occurs during passive cue exposure (Pavlovian phase) and how it evolves across learning. Using fMRI (N = 31), we investigated cue-evoked neural activity during two Pavlovian learning phases, before and after instrumental learning, in a four-phase PIT paradigm. Behaviorally, participants showed robust specific and general PIT effects in the transfer phase. At the neural level, general PIT-related cues engaged occipito-temporal visual and associative regions early in learning, whereas specific PIT-related cues recruited fronto-parietal, premotor, sensorimotor and striatal regions (MFG, IPS, PMC/M1/S1, caudate, putamen) after instrumental learning. These findings indicate that Pavlovian cues dynamically engage motor and sensorimotor systems following action-outcome learning, consistent with outcome-mediated retrieval of learned action representations even in the absence of overt movement. Together, the results refine theoretical models of PIT by demonstrating learning-dependent modulation of corticostriatal circuits during passive cue processing.

Double Empathy Problem (DEP) proposes that communication breakdowns across different neurotypes arise from reciprocal mismatches, challenging the traditional pathological model of social difficulties in autism. Despite its conceptual appeal, DEP lacks formalization for empirical testing. Drawing on a constructivist view of communication, we operationalized DEP by distinguishing between global interpersonal autistic-trait differences and local dynamic interpersonal adjustment. 152 participants formed low-low, low-high, and high-high autistic-trait dyads. In a real-time conceptual coordination task, dyads developed novel signaling systems to coordinate target choices. Mixed-trait dyads exhibited reduced interpersonal adjustment, greater signaling variability, and more heterogeneous adjustment dynamics than matched-trait dyads. Interpersonal adjustment promoted communication outcomes and mediated the relationship between autistic-trait disparity and communicative outcomes. These findings suggest that autistic-trait differences may initially hinder coordination but can be attenuated through accommodate mental states towards each other. Integrating global and local processes advances theoretical precision of DEP and provides a foundation for future mechanistic investigation of neurodiverse communication and inclusive social practices.

Visual perspective taking (VPT) is a fundamental component of social cognition, allowing individuals to understand environments from diverse viewpoints. Explicit VPT involves deliberately adopting another person’s perspective, whereas implicit VPT reflects the incidental influence of others’ viewpoints when responding from one’s own. Oxytocin (OT), a neuropeptide known for its role in social bonding, has been proposed to influence self–other processing, though its effects on VPT remain unclear. In a double-blind, placebo-controlled study, seventy-nine healthy male participants (Oxytocin = 39, Placebo = 40) completed explicit and implicit VPT tasks. Participants judged object locations from an avatar’s perspective (explicit) or from their own perspective (implicit), in the presence of a human agent or an object. OT administration was associated with reduced accuracy in the explicit task under perspective conflict, reflecting increased egocentric interference. In contrast, in the implicit task, OT was associated with faster and more accurate responses in congruent trials involving a human agent. Together, these findings indicate that oxytocin-related effects on visual perspective taking vary across task demands and social context. Rather than reflecting a general enhancement or impairment of perspective-taking ability, the results provide behavioral evidence consistent with differential modulation of self-other processing.

This study examined the role of language and executive functions (EFs) as potential mediators of the relation between family socioeconomic status (SES) and Theory of Mind (ToM) in preschool and school-aged children. A total of 375 children aged 3 to 7 years completed assessments of ToM (false beliefs task), language abilities (vocabulary, syntax, and novel word learning), and EFs (inhibition and cognitive flexibility). Family SES was measured based on parental education and occupational status. Structural equation modeling revealed that language mediated the SES-ToM association, whereas EFs did not significantly contribute to this relation when language abilities were considered. When accounting for potential ceiling effects of the language task, we found no evidence that age moderated the mediation effect of language on the association between SES and ToM. These findings underscore the pivotal role of language abilities in shaping social-cognitive development and highlight the importance of designing targeted interventions that use language-based materials to support ToM, particularly for children from low-SES backgrounds.

Communication difficulties are often attributed to social cognitive deficits in autistic individuals, yet the Double Empathy Problem (DEP) proposes that breakdowns arise from reciprocal interpersonal mismatch. Despite its growing influence, DEP has lacked a formal operationalization enabling direct empirical evaluation. Here we develop a framework grounded in a constructivist account of communication that distinguishes global autistic-trait differences within dyads from local, moment-to-moment adjustment of mental states during interaction. We test this framework in 152 participants forming dyads varying in autistic-trait similarity (low-low, low-high, high-high) who completed a real-time conceptual coordination task requiring the emergence of novel signaling systems. Mixed-trait dyads exhibited reduced interpersonal adjustment, increased signaling variability, and more heterogeneous coordination dynamics compared with matched-trait dyads. Interpersonal adjustment positively predicted joint correctness, subjective experience of the interaction, and willingness for future interaction, and statistically accounted for the association between trait differences and coordination outcomes. These findings operationalize the Double Empathy Problem and suggest that continuous accommodation of mental states during interaction is a mechanism through which individual differences shape communication outcomes. More broadly, the framework provides an empirical approach for studying communicative accommodation across a wide range of social and cultural contexts characterized by substantial interpersonal differences.

The 'Reading the Mind in the Eyes Test' (RMET) is one of the most used tests of theory of mind. Its principle is to match an emotion word to the corresponding face image. The performance at this test has been associated with multiple psychological variables, including personality, loneliness and empathy. Recently, however, the validity of the RMET has been questioned. An alternative version of the test has been tested using eye-tracking in addition to manual responses and was hypothesized to be more sensitive. Here, we put this hypothesis to the test by attempting to reproduce already-assessed correlational results between the performance at the classical RMET and the self-reported personality, loneliness and empathy, now using eye-gaze as an RMET performance index. Despite a marked eye-gaze bias towards the face image corresponding to the target word, the eye-gaze pattern correlated with none of the self-reported psychological variables. This result highlights the interest in using eye-tracking for theory of mind tests, while questioning the robustness of the association between psychological variables and RMET performance, and the validity of the RMET itself.

Reward-predictive cues can affect decision-making by enhancing instrumental responses toward the same (specific transfer) or similar (general transfer) rewards. The main theories on cue-guided decision-making consider specific transfer as driven by the activation of previously learned instrumental actions induced by cues sharing the sensory-specific properties of the reward they are associated with. However, to date, such theoretical assumption has never been directly investigated at the neural level. We hypothesize that such reactivation occurs within the premotor system and could be mapped by lateralized beta (12-30 Hz) desynchronization, a widely used marker of action selection and decision-making policy. To test this hypothesis, 42 participants (22 females) performed a pavlovian-to-instrumental transfer paradigm, while electroencephalographic activity was recorded. We anticipated increased beta desynchronization during the transfer phase when cues promoting specific transfer were presented, compared with cues predicting general transfer and neutral cues. The evidence collected confirmed our hypothesis, thus providing the first neural evidence in favor of the theorized reactivation of instrumental actions and corroborating the presence of two dissociable neural pathways underpinning specific and general transfer.

Classical conditioning states that the systematic co-occurrence of a neutral stimulus with an unconditioned stimulus can cause the neutral stimulus to, over time, evoke the same response as the unconditioned stimulus. On a neural level, Hebbian learning suggests that this type of learning occurs through changes in synaptic plasticity when two neurons are simultaneously active, resulting in increased connectivity between them. Inspired by associative learning theories, we here investigated whether the mere co-activation of visual stimuli and stimulation of the primary motor cortex using TMS would result in stimulus-response associations that can impact future behavior. During a learning phase, we repeatedly paired the presentation of a specific color (but not other colors) with a TMS pulse over the motor cortex. Next, participants performed a two-alternative forced-choice task where they had to categorize simple shapes and we studied whether the shapes' task-irrelevant color (and its potentially associated involuntary motor activity) affected the required motor response. Participants showed more errors on incongruent trials for stimuli that were previously paired with high intensity TMS pulses, but only when tested on the same day. Using a drift diffusion model for conflict tasks, we further demonstrate that this interference occurred early, and gradually increased as a function of associated TMS intensity. Taken together, our findings show that the human brain can learn stimulus-response associations using externally induced motor cortex stimulation. Although we were inspired by the Hebbian learning literature, future studies should investigate whether Hebbian or other learning processes were also what brought about this effect.

In this paper, we propose that interpersonal bodily interactions represent a fertile ground in which the bodily and psychological self is developed, gradually allowing for forms of more abstract and disembodied interactions. We start by focusing on how early infant–caregiver bodily interactions play a crucial role in shaping the boundaries of the self but also in learning to predict others’ behavior. We then explore the social function of the sense of touch in the entire life span, highlighting its role in promoting physical and psychological well-being by supporting positive interpersonal exchanges. We go on by introducing the concept of implicit theory of mind, as the early ability to interpret others’ intentions, possibly grounded in infant-caregiver bodily exchanges (embodied practices). In the following part, we consider so-called higher level forms of social interaction: intellectual exchanges among individuals. In this regard, we defend the view that, beside the apparent private dimension of “thinking abstractly”, using abstract concepts is intrinsically a social process, as it entails the re-enactment of the internalized dialogue through which we acquired the concepts in the first place. Finally, we describe how the hypothesis of “dialectical attunement” may explain the development of abstract thinking: to effectively transform the world according to their survival needs, individuals co-construct structured concepts of it; by doing so, humans fundamentally transform not merely the world they are being in, but their being in the world.

Classical conditioning states that the systematic co-occurrence of a neutral stimulus with an unconditioned stimulus can cause the neutral stimulus to, over time, evoke the same response as the unconditioned stimulus. On a neural level, Hebbian learning suggests that this type of learning occurs through changes in synaptic plasticity when two neurons are simultaneously active, resulting in increased connectivity between them. Inspired by learning theories, we here investigated whether the mere co-activation of visual stimuli and stimulation of the primary motor cortex using transcranial magnetic stimulation (TMS) would result in stimulus-response associations that can impact future behaviour. During a learning phase, we repeatedly paired the presentation of a specific colour (but not other colours) with a TMS pulse over the motor cortex. Next, participants performed a two-alternative forced choice task where they had to categorize simple shapes and we studied whether the shapes’ task-irrelevant colour (and its potentially associated involuntary motor activity) affected the required motor response. Participants showed more errors on incongruent trials for stimuli that were previously paired with high intensity TMS pulses, but only when tested on the same day. Using a drift diffusion model for conflict tasks, we further demonstrate that this interference occurred early, and gradually increased as a function of associated TMS intensity. Taken together, our findings show that the human brain can learn stimulus-response associations using externally induced motor cortex stimulation.

In this review, we propose that interpersonal bodily interactions represent a fertile ground in which the bodily and psychological self is developed, gradually allowing for forms of more abstract and disembodied interactions. We start by focusing on how early infant-caregiver bodily interactions, mediated by the sense of touch, play a crucial role in shaping the boundaries of the self but also in learning to predict others’ behavior. We then explore the social function of the sense of touch in the entire life span, highlighting its role in promoting physical and psychological wellbeing by supporting positive interpersonal exchanges. We go on by introducing the concept of implicit theory of mind, as the very early ability to interpret others’ intentions, possibly grounded in infant-caregiver bodily exchanges (embodied practices). In the second section, we embrace a more collective perspective about the role of sociality in human development, by describing the hypothesis of “dialectical attunement”, reconsidering the self beyond the individual, where it really emerges, unfolds, and manifests itself — in social relationships. We finally consider the most evolved forms of social relationship: intellectual exchanges among individuals. In this regard, we defend the view that, beside the apparent private dimension of “thinking abstractly”, using abstract concepts is an intrinsically social process, as it entails the re-enactment of the internalized dialogue through which we acquired the concepts in the first place.

The dorso-posterior parietal cortex (DPPC) is a major node of the grasp/manipulation control network. It is assumed to act as an optimal forward estimator that continuously integrates efferent outflows and afferent inflows to modulate the ongoing motor command. In agreement with this view, a recent per-operative study, in humans, identified functional sites within DPPC that: (i) instantly disrupt hand movements when electrically stimulated; (ii) receive short-latency somatosensory afferences from intrinsic hand muscles. Based on these results, it was speculated that DPPC is part of a rapid grasp control loop that receives direct inputs from the hand-territory of the primary somatosensory cortex (S1) and sends direct projections to the hand-territory of the primary motor cortex (M1). However, evidence supporting this hypothesis is weak and partial. To date, projections from DPPC to M1 grasp zone have been identified in monkeys and have been postulated to exist in humans based on clinical and transcranial magnetic studies. This work uses diffusion-MRI tractography in two samples of right- (n = 50) and left-handed (n = 25) subjects randomly selected from the Human Connectome Project. It aims to determine whether direct connections exist between DPPC and the hand control sectors of the primary sensorimotor regions. The parietal region of interest, related to hand control (hereafter designated DPPChand), was defined permissively as the 95% confidence area of the parietal sites that were found to disrupt hand movements in the previously evoked per-operative study. In both hemispheres, irrespective of handedness, we found dense ipsilateral connections between a restricted part of DPPChand and focal sectors within the pre and postcentral gyrus. These sectors, corresponding to the hand territories of M1 and S1, targeted the same parietal zone (spatial overlap > 92%). As a sensitivity control, we searched for potential connections between the angular gyrus (AG) and the pre and postcentral regions. No robust pathways were found. Streamline densities identified using AG as the starting seed represented less than 5 % of the streamline densities identified from DPPChand. Together, these results support the existence of a direct sensory-parietal-motor loop suited for fast manual control and more generally, for any task requiring rapid integration of distal sensorimotor signals.

Early studies on long-term functional recovery after motor and premotor lesions showed better outcomes in younger monkeys than in older monkeys. This finding led to the widespread belief that brain injuries cause less impairment in children than adults. However, this view has limitations and a large body of evidence now indicates that cerebral damages can be more harmful when inflicted at young age, during critical periods of neural development. To date, this issue has been mainly investigated in the context of focal and diffuse cortical lesions. Much less is known about the potential influence of early cerebellar damages. Several studies exist in survivor of posterior fossa tumours. However, in these studies, critical confounders were not always considered and contradictory conclusions were provided. We studied the impact or early cerebellar damage on long-term functional recovery in three groups of 15 posterior fossa survivors, comparable with respect to their tumour characteristics (type, size and location) but operated at different ages: young (<= 7 years), middle (>7 and <= 13 years) and older (>13 years). Daily (health-related quality of life scale, performance status scale), motor (International Cooperative Ataxia Rating Scale, Pegboard Purdue Test) and cognitive (full-scale intelligence quotient) functioning were assessed. A general linear model controlling for age at surgery, radiotherapy, preservation of deep cerebellar nuclei, tumour volume and delay between surgery and assessment was used to investigate significant variations in outcome measures. Early age at surgery, lesion of deep cerebellar nuclei and postoperative radiotherapy had a significant, independent negative influence on long-term recovery. Tumour volume and delay between surgery and assessment had no statistically detectable impact. The negative influence of early age at surgery was significant in all domains: daily functioning (health-related quality of life scale, performance status scale), motor functioning (International Cooperative Ataxia Rating Scale, Pegboard Purdue Test) and cognitive functioning (full-scale intelligence quotient). These results support the existence of an early critical period of development during which the cerebellar 'learning machine' is of critical importance. Although the extent to which the early deficits here observed can be reversed needs now to be established, our data plead for the implementation of prompt and intense rehabilitation interventions in children operated before 7 years of age.

Previous behavioral studies using stimulus-response compatibility tasks have shown that people are faster to carry out instructed approach/avoidance responses to positive/negative stimuli. This result has been taken as evidence that positive/negative stimulus valence directly activates a tendency to approach/avoid, which in turn, facilitates execution of instructed approach/avoidance behavior. In these studies, however, it cannot be excluded that the results reflect a purely semantic link between stimulus valence and instructed responses. According to this alternative interpretation, positive/negative stimuli do not elicit an approach/avoidance tendency, but instead they interact with the positive/negative valence of the instructed responses, and in this way, produce the observed compatibility effect. To circumvent this possible disadvantage of compatibility tasks, we used a novel method for the measurement of early action tendencies: TMS induced MEPs. In two experiments, participants were first trained to abduct the index finger to approach and the thumb to avoid. Then, they observed a series of positive and negative stimuli. Each stimulus was followed by a TMS pulse (at 400 ms post-stimulus onset) and MEPs were measured continuously on the muscles of both fingers. These observation trials were randomly intermixed with response trials, in which neutral stimuli were presented and participants were instructed to approach/avoid the stimuli. In Experiment 1, participants received clear visual feedback on the outcome of their response in the response trials. In Experiment 2, we omitted this feedback to test whether it was necessary for the effect to occur. The results indicated higher MEPs for the approach/avoidance finger after positive/negative stimuli in Experiment 1 but not in Experiment 2. Analyses on the data aggregated over both experiments suggest that the visual feedback was necessary for stimulus valence to elicit action tendencies. Taken together, the results are in line with the results of behavioral studies with compatibility tasks, suggesting that stimulus valence directly elicits specific action tendencies already at 400 ms but they indicate that clear visual feedback is necessary for this effect to occur.

The present review includes transcranial magnetic and transcranial electric stimulation studies on time perception and shows that the neural processing of time requires the activity of wide range-distributed brain networks. Moreover, a critical discussion regarding non-invasive brain stimulation in the study of time processing is included to give the reader insights into the study of temporal processing in neuroscience. The cerebellum and auditory cortex seem most crucial when participants are required to estimate the passage of sub-seconds intervals and this conclusion holds independently of the modality used to mark the temporal intervals. Conversely, the primary visual area and MT/V5 seem to process primarily visual stimuli. The areas included in the prefrontal cortex are mostly implicated in the processing of supra-second time intervals and when time is processed in conjunction with other cognitive functions. Although previous fMRI studies showed activation in the supplementary motor area during sub-second timing tasks, TMS studies failed to confirm these observations. We conclude that the contribution of these strongly interconnected structures in the processing of temporal information is not fixed; their contribution depends not only on the duration of the time interval to be assessed by the brain but also on the cognitive set involved in the chosen task and on the stimulus modality used for marking time. Critical observations regarding the specificity of each method of stimulation as well as limitations and criticisms of the studies that used brain stimulation techniques will be also discussed.

Individuals high in psychopathic traits are known for manipulating others, while having at the same time a lack of empathy. An open question is whether the lack of empathy leads them to represent other persons’ beliefs and actions less strongly or whether their manipulative character leads them to represent other persons’ beliefs and actions more strongly. Confirming past research, three experiments show a negative correlation between psychopathic traits and self-reported empathy. In addition, the results from an implicit Theory of Mind task (Experiment 1) demonstrate that the higher individuals score on psychopathic traits, the more they represent other persons’ beliefs. Additionally, results from an imitation task (Experiment 1) as well as from a Joint Simon task (Experiment 2) demonstrate that high psychopathic traits are predictive for a stronger representation of other persons’ actions. However, a higher-powered study (Experiment 3) could not replicate the finding that psychopathic traits correlate with implicit Theory of Mind and Joint Simon effects. Theoretical implications and limitations of the experiments are discussed.