Ilaria Minio-Paluello

Left hemisphere dominance in reading the sensory qualities of others’ pain?

Abstract Seeing or imagining others in pain may activate both the sensory and affective components of the neural network (pain matrix) that is activated during the personal experience of pain. Transcranial magnetic stimulation (TMS), proved adept at highlighting the sensorimotor side of empathy for pain in studies where mere observation of needles penetrating body parts of a human model brought about a clear corticospinal motor inhibition. By using TMS, we investigated whether inferring the sensory properties of the pain of a model influenced the somatomotor system of an onlooker. Moreover, we tested the possible lateralization of the motor substrates underlying this reading process. We recorded motor-evoked potentials (MEPs) to left and right motor cortex stimulation during the observation of “flesh and bone” painful stimulations of right and left hands respectively. We found a significant reduction of onlookers’ MEPs amplitudes specific to the muscle penetrated in the model. Subjective inferences about localization and intensity of the observed pain were associated with specific patterns of motor modulation with larger inhibitory effects following stimulation of the left motor cortex. Thus, results indicate that the mental simulation of the sensory qualities of others’ pain may be lateralized to the left hemisphere.

Impaired mental rotation in benign paroxysmal positional vertigo and acute vestibular neuritis

Vestibular processing is fundamental to our sense of orientation in space which is a core aspect of the representation of the self. Vestibular information is processed in a large subcortical–cortical neural network. Tasks requiring mental rotations of human bodies in space are known to activate neural regions within this network suggesting that vestibular processing is involved in the control of mental rotation. We studied whether mental rotation is impaired in patients suffering from two different forms of unilateral vestibular disorders (vestibular neuritis – VN – and Benign Paroxysmal positional Vertigo – BPPV) with respect to healthy matched controls (C). We used two mental rotation tasks in which participants were required to: (i) mentally rotate their own body in space (egocentric rotation) thus using vestibular processing to a large extent and (ii) mentally rotate human figures (allocentric rotation) thus using own body representations to a smaller degree. Reaction times and accuracy of responses showed that VN and BPPV patients were impaired in both tasks with respect to C. Significantly, the pattern of results was similar in the three groups suggesting that patients were actually performing the mental rotation without using a different strategy from the control individuals. These results show that dysfunctional vestibular inflow impairs mental rotation of both own body and human figures suggesting that unilateral acute disorders of the peripheral vestibular input massively affect the cerebral processes underlying mental rotations.

The beauty of the body

Aesthetics can be defined as our ability to perceive, feel and sense objects in the world and assign them positive or negative values along a continuum between beauty and ugliness. The psychological processes underlying the sense of what is beautiful or ugly imply perception and appraisal of objects of art, as well as emotional and interoceptive reactivity towards them. Exploration of the neural underpinnings of these processes is at the core of neuroaesthetics, a new cognitive neuroscience domain that aims to investigate the neural activity associated with feelings of pleasure or displeasure generated by either cognitive or sensuous interaction with a wide variety of objects that may thus become objects of art. We argue that the sensuous dimension of art appreciation calls into play the cerebral sensorimotor representation of one’s own and others’ bodies. Studies indicate that specific brain areas process perception of static or dynamic bodies. In the present article, we discuss two related issues (1) whether aesthetic visual appreciation of bodies is based on neural activity linked to visual body perception, beauty appreciation or both and (2) whether there exists a single cerebral locus where all possible types of aesthetic experiences ultimately converge.

Self-identification with another person's face: the time relevant role of multimodal brain areas in the enfacement illusion

The illusory subjective experience of looking at ones own face while in fact looking at another persons face can surprisingly be induced by simple synchronized visuotactile stimulation of the two faces. A recent study (Apps MA, Tajadura-Jiménez A, Sereno M, Blanke O, Tsakiris M. Cereb Cortex. First published August 20, 2013; doi:10.1093/cercor/bht199) investigated for the first time the role of visual unimodal and temporoparietal multimodal brain areas in the enfacement illusion and suggested a model in which multisensory mechanisms are crucial to construct and update self-face representation.

Fortunes and misfortunes of political leaders reflected in the eyes of their electors

Gaze-following is a pivotal social behaviour that, although largely automatic, is permeable to high-order variables like political affiliation. A few years ago we reported that the gaze of Italian right-wing voters was selectively captured by the gaze of their leader Silvio Berlusconi. This effect was particularly evident in voters who saw themselves as similar to Berlusconi. Two years later, we were able to run the present follow-up study because Berlusconi’s popularity had drastically dropped due to sex and political scandals, and he resigned from office. In a representative subsample of our original group, we investigated whether perceived similarity and gaze-following reflected Berlusconi’s loss in popularity. We were also able to test the same hypothesis in an independent group of right-wing voters when their leader, Renata Polverini, resigned as Governor of ‘Regione Lazio’ due to political scandals. Our results show that the leaders’ fall in popularity paralleled the reduction of their gaze’s attracting power, as well as the decrease in similarity perceived by their voters. The less similar right-wing voters felt to their leader, the less they followed his/her gaze. Thus, the present experimental findings suggest that gaze-following can be modulated by complex situational and dispositional factors such as leader’s popularity and voter–leader perceived similarity.

The ‘Enfacement’ illusion: A window on the plasticity of the self

Understanding how self-representation is built, maintained and updated across the lifespan is a fundamental challenge for cognitive psychology and neuroscience. Studies demonstrate that the detection of body-related multisensory congruency builds bodily and facial self-representations that are crucial to developing self-recognition. Studies showing that the bodily self is more malleable than previously believed were mainly concerned with full-bodies and non-facial body parts. Crucially, however, intriguing recent evidence indicates that simple experimental manipulations could even affect self-face representation that has long been considered a stable construct impervious to change. In this review, we discuss how Interpersonal Multisensory Stimulation (IMS) paradigms can be used to temporarily induce Enfacement, i.e., the subjective illusion of looking at oneself in the mirror when in fact looking at another persons face. We show that Enfacement is a subtle but robust phenomenon occurring in a variety of experimental conditions and assessed by multiple explicit and implicit measures. We critically discuss recent findings on i) the role of sensory extero/proprio-ceptive (visual, tactile, and motor) and interoceptive (cardiac) signals in self-face plasticity, ii) the importance of multisensory integration mechanisms for the bodily self, and iii) the neural network related to IMS-driven changes in self-other face processing, within the predictive coding theoretical framework.