Corrado Corradi-Dell'Acqua

Felt and Seen Pain Evoke the Same Local Patterns of Cortical Activity in Insular and Cingulate Cortex

The discovery of regions in the human brain (e.g., insula and cingulate cortex) that activate both under direct exposure to pain and when perceiving pain in others has been interpreted as a neural signature of empathy. However, this overlap raises the question of whether it may reflect a unique distributed population of bimodal neurons or, alternatively, the activity of intermingled but independent populations. We used fMRI on 28 female volunteers and used multivariate pattern analysis techniques to probe for more fine-grain spatial representations of seen and felt pain. Using a whole-brain approach, we found that only in the anterior insula (bilaterally) the distribution of cortical activity evoked by seeing another persons hand in pain was spatially similar to that of pain felt on ones own hand. Subsequent region of interest analyses also implicated the middle insula (right hemisphere) and the middle cingulate cortex. Furthermore, for the anterior insula, the spatial distribution of activity associated with ones pain also replicates that of the perception of negative but painless stimuli. Our data show how the neural representations of aversive events affecting oneself are also recruited when the same events affect others, and provide the stronger evidence thus far of a unique distributed cortical ensemble coding for aversive events regardless of the subject who is affected.

What Is the Position of an Arm Relative to the Body? Neural Correlates of Body Schema and Body Structural Description

Neuropsychological studies suggest that the human brain is endowed with two body representations: the body schema (BS), coding the orientation of ones body parts in space, and the body structural description (BSD), coding the location of body parts relative to a standard body. We used fMRI to disentangle the neural mechanisms underlying these putatively distinct body representations. Participants saw an arm or a pots handle (stimulus: arm, handle) rotated at different angles (angle: 30–150°). If the stimulus was an arm, subjects were instructed to imagine (1) rotating their own arm until it matched the stimulus orientation (comparing the seen arm to their own) or (2) seeing the stimulus moving toward its appropriate position on a simultaneously presented human body [comparing the arm to the one of a standard body (strategy: motor, visual imagery)]. If the stimulus was a handle, subjects were instructed to imagine (1) placing the handle on its appropriate position on a simultaneously presented pot or (2) seeing it moving toward its pots position. The analysis of the interaction stimulus × strategy revealed activation of left secondary somatosensory cortex (SII), specifically when comparing the stimulus arm to ones own. The analysis of the parameters describing the linear effect of angle revealed that neural activity of left posterior intraparietal sulcus was modulated by the stimuluss rotation, but only when relating the arm to a standard body. The results associate BS and BSD with differential neural substrates, thereby suggesting that these are independent body representations, and furthermore extend current concepts of SII function.

Where is a Nose with Respect to a Foot? The Left Posterior Parietal Cortex Processes Spatial Relationships among Body Parts

Neuropsychological studies suggest that patients with left parietal lesions may show impaired localization of parts of either their own or the examiners body, despite preserved ability to identify isolated body parts. This deficit, called autotopagnosia, may result from damage to the Body Structural Description (BSD), a representation which codes spatial relationships among body parts. We used functional magnetic resonance imaging to identify the neural mechanisms underlying the BSD. Two human body or building parts (factor: STIMULI) were shown to participants who either identified them or evaluated their distance (factor: TASK). The analysis of the interaction between STIMULI and TASK, which isolates the neural mechanism underlying BSD, revealed an activation of left posterior intraparietal sulcus (IPS) when the distance between body parts was evaluated. The results show that the left IPS processes specifically the information about spatial relationships among body parts and thereby suggest that damage to this area may underlie autotopagnosia.

she is not like i: The tie between language and action is in our imagination

Embodied theories hold that understanding what another person is doing requires the observer to map that action directly onto his or her own motor representation and simulate it internally. The human motor system may, thus, be endowed with a “mirror matching” device through which the same motor representation is activated, when the subject is either the performer or the observer of anothers action (“self-other shared representation”). It is suggested that understanding action verbs relies upon the same mechanism; this implies that motor responses to these words are automatic and independent of the subject of the verb. In the current study, participants were requested to read silently and decide on the syntactic subject of action and nonaction verbs, presented in first (1P) or third (3P) person, while TMS was applied to the left hand primary motor cortex (M1). TMS-induced motor-evoked potentials were recorded from hand muscles as a measure of cortico-spinal excitability. Motor-evoked potentials increased for 1P, but not for 3P, action verbs or 1P and 3P nonaction verbs. We provide novel demonstration that the motor simulation is triggered only when the conceptual representation of a word integrates the action with the self as the agent of that action. This questions the core principle of “mirror matching” and opens to alternative interpretations of the relationship between conceptual and sensorimotor processes.

Neuropsychological perspectives on the mechanisms of imitation

Cognitive neuroscientists have contributed to the understanding of imitation according to their expertise. Neuropsychologists first established over a century ago that lesions to the left hemisphere of right-handed individuals lead to a dramatic reduction of their ability to imitate gestures. In contrast, after frontal lobe damage, patients may experience severe difficulties in inhibiting their imitative tendency. These findings suggested that our tendency to imitate is mostly sustained by the left hemisphere and that we normally manage successfully to keep it under control. Neuropsychologists went on investigating other aspects of gesture imitation. These include the existence of putative mechanisms involved in imitating different types of gestures (e.g. meaningful and meaningless or transitive and intransitive), the strategic control over these mechanisms and whether there are differences in imitation depending on the action goal or the body part used. Based on neuropsychological findings, some cognitive models of gesture imitation have been forwarded, the most influential of which will be reviewed here. In particular, reference will be made to the dual route model and to accounts that associate the imitative deficit to putative degraded body representations.

Thalamic-insular dysconnectivity in schizophrenia: Evidence from structural equation modeling

Structural and functional studies have shown that schizophrenia is often associated with frontolimbic abnormalities in the prefrontal and mediotemporal regions. It is still unclear, however, if such dysfunctional interaction extends as well to relay regions such as the thalamus and the anterior insula. Here, we measured gray matter volumes of five right‐hemisphere regions in 68 patients with schizophrenia and 77 matched healthy subjects. The regions were amygdala, thalamus, and entorhinal cortex (identified as anomalous by prior studies on the same population) and dorsolateral prefrontal cortex and anterior insula (isolated by voxel‐based morphometry analysis). We used structural equation modeling and found altered path coefficients connecting the thalamus to the anterior insula, the amygdala to the DLPFC, and the entorhinal cortex to the DLPFC. In particular, patients exhibited a stronger thalamus‐insular connection than healthy controls. Instead, controls showed positive entorhinal‐DLPFC and negative amygdalar‐DLPFC connections, both of which were absent in the clinical population. Our data provide evidence that schizophrenia is characterized by an impaired right‐hemisphere network, in which intrahemispheric communication involving relay structures may play a major role in sustaining the pathophysiology of the disease. Hum Brain Mapp, 2012.

Neural responses to emotional expression information in high- and low-spatial frequency in autism: evidence for a cortical dysfunction

Despite an overall consensus that Autism Spectrum Disorder (ASD) entails atypical processing of human faces and emotional expressions, the role of neural structures involved in early facial processing remains unresolved. An influential model for the neurotypical brain suggests that face processing in the fusiform gyrus and the amygdala is based on both high-spatial frequency (HSF) information carried by a parvocellular pathway, and low-spatial frequency (LSF) information separately conveyed by a magnocellular pathway. Here, we tested the fusiform gyrus and amygdala sensitivity to emotional face information conveyed by these distinct pathways in ASD individuals (and matched Controls). During functional Magnetical Resonance Imaging (fMRI), participants reported the apparent gender of hybrid face stimuli, made by merging two different faces (one in LSF and the other in HSF), out of which one displayed an emotional expression (fearful or happy) and the other was neutral. Controls exhibited increased fusiform activity to hybrid faces with an emotional expression (relative to hybrids composed only with neutral faces), regardless of whether this was conveyed by LSFs or HSFs in hybrid stimuli. ASD individuals showed intact fusiform response to LSF, but not HSF, expressions. Furthermore, the amygdala (and the ventral occipital cortex) was more sensitive to HSF than LSF expressions in Controls, but exhibited an opposite preference in ASD. Our data suggest spared LSF face processing in ASD, while cortical analysis of HSF expression cues appears affected. These findings converge with recent accounts suggesting that ASD might be characterized by a difficulty in integrating multiple local information and cause global processing troubles unexplained by losses in low spatial frequency inputs.

Fear Spreading Across Senses: Visual Emotional Events Alter Cortical Responses to Touch, Audition, and Vision

Abstract Attention and perception are potentiated for emotionally significant stimuli, promoting efficient reactivity and survival. But does such enhancement extend to stimuli simultaneously presented across different sensory modalities? We used functional magnetic resonance imaging in humans to examine the effects of visual emotional signals on concomitant sensory inputs in auditory, somatosensory, and visual modalities. First, we identified sensory areas responsive to task‐irrelevant tones, touches, or flickers, presented bilaterally while participants attended to either a neutral or a fearful face. Then, we measured whether these responses were modulated by the emotional content of the face. Sensory responses in primary cortices were enhanced for auditory and tactile stimuli when these appeared with fearful faces, compared with neutral, but striate cortex responses to the visual stimuli were reduced in the left hemisphere, plausibly as a consequence of sensory competition. Finally, conjunction and functional connectivity analyses identified 2 distinct networks presumably responsible for these emotional modulatory processes, involving cingulate, insular, and orbitofrontal cortices for the increased sensory responses, and ventrolateral prefrontal cortex for the decreased sensory responses. These results suggest that emotion tunes the excitability of sensory systems across multiple modalities simultaneously, allowing the individual to adaptively process incoming inputs in a potentially threatening environment.

Editorial: What Determines Social Behavior? Investigating the Role of Emotions, Self-Centered Motives, and Social Norms

In the last decade, a growing research effort in behavioral sciences, especially psychology and neuroscience, has been invested in the study of the cognitive, biological, and evolutionary foundations of social behavior. Differently from the case of sociology, which studies social behavior also at the group level in terms of organizations and structures, psychology and neuroscience often define “social” as a feature of the individual brain that allows an efficient interaction with conspecifics, and thus constitutes a possible evolutionary advantage (Matusall). In this view, an extremely wide range of mental and neural processes can be classified as “social,” from the coding of relevant sensory stimuli about conspecifics (facial expressions, gestures, vocalizations, etc.), to the selection and planning of behavioral responses in complex interpersonal settings (economic transactions, negotiations, etc.). Despite such heterogeneity, there is a converging interest in the scientific community toward the identification of neural and psychological mechanisms that underlie all the many facets of social behavior, and their comparison across species and cultures. This Research Topic was initiated by researchers from the Swiss National Center of Competence in Research “Affective Sciences—Emotions in Individual Behaviour and Social Processes,” a multidisciplinary institution devoted to the study of affect-related processes across various disciplines (from psychology and neuroscience through to history, philosophy, art, and economy). In keeping with this spirit, this Research Topic comprehends 38 contributions from an interdisciplinary community each addressing specific psychological and neural phenomena that can be defined as “social.” In particular, we collected both theoretical and empirical contributions, concerning animals, human individuals (neurotypical adults and children, but also individuals with neurological, psychiatric and developmental disorders) as well as human groups, engaged in either laboratory-controlled settings or real-life situations. Although the theoretical models and the applied research techniques (psychophysical, physiological, neuroimaging, genetic) are very diverse, they converge with a global framework suggesting that the determinants of social behavior can be described across two independent dimensions: (1) a personal-to-environmental dimension, and (2) a transient-to-stable dimension. These contributions thus represent an important cornerstone for building an interdisciplinary and comprehensive model of how individuals deal with the complexity of their social environment.

Beyond unpleasantness. Social exclusion affects the experience of pain, but not of equally-unpleasant disgust

Seminal theories posit that social and physical suffering underlie partly-common representational code. It is unclear, however, if this shared information reflects a modality-specific component of pain, or alternatively a supramodal code for properties common to many aversive experiences (unpleasantness, salience, etc.). To address this issue, we engaged participants in a gaming experience in which they were excluded or included by virtual players. After each game session, participants were subjected to comparably-unpleasant painful or disgusting stimuli. Subjective reports and cardiac responses revealed a reduced sensitivity to pain following exclusion relative to inclusion, an effect which was more pronounced in those participants who declared to feel more affected by the gaming manipulation. Such modulation was not observed for disgust. These findings indicate that the relationship between social and physical suffering does not generalize to disgust, thus suggesting a shared representational code at the level of modality-specific components of pain.