Gabriel Baud-Bovy

• PhD
• Professor (Assistant) at Vita-Salute San Raffaele University

Despite the ubiquitous interdependence between one's own decisions and others' welfare, and the controversial evidence on the behavioral effect of choosing for others, the neural bases of making decisions for another versus oneself remain unexplored. We investigated whether loss aversion (LA; the tendency to avoid losses over approaching equivalent...

How the brain determines the vigor of goal-directed movements is a fundamental question in neuroscience. Recent evidence has suggested that vigor results from a trade-off between a cost related to movement production (cost of movement) and a cost related to our brain's tendency to temporally discount the value of future reward (cost of time). Howev...

Humans possess the ability to extract highly organized perceptual structures from sequences of temporal stimuli. For instance, we can organize specific rhythmical patterns into hierarchical, or metrical, systems. Despite the evidence of a fundamental influence of the motor system in achieving this skill, few studies have attempted to investigate th...

The objective of this study was to evaluate the effects of a pretend play‐based training designed to promote the development of socio‐emotional competences. 79 children aged 5 to 6 years were evaluated before and after a pretend play‐based training. The experimental group (39 children) received this programme on emotion comprehension, negative emot...

A key feature of Anorexia Nervosa is body image disturbances, the study of which has focused mainly on visual and attitudinal aspects, did not always contain homogeneous groups of patients, and/or did not evaluate body shape concerns of the control group. In this study, we used psychophysical methods to investigate the visual, tactile and bimodal p...

A key feature of Anorexia Nervosa (AN) is a distorted perception of the body shape. Recent studies on Eating Disorders (EDs) showed that AN patients exhibit various sensory and perceptual deficits in the visual and tactile modalities. In this study, we investigated visuo-haptic integration in AN patients using Helbig and Banks (2007)’s paradigm, wh...

Two experiments were carried out to verify whether integration might be hampered when objects are grounded and force is not transmitted between two hands.

When intercepting a moving target, we typically rely on vision to determine where the target is and where it will soon be. The accuracy of visually guided interception can be represented by a model that combines the perceived position and velocity of the target to estimate when and where to hit it and guides the finger accordingly with a short dela...

Providing somatosensory feedback to amputees is a long-standing objective in prosthesis research. Recently, implantable neural interfaces have yielded promising results in this direction. There is now considerable evidence that the nervous system integrates redundant signals optimally, weighting each signal according to its reliability. One questio...

Since it has been demonstrated that spatial cognition can be affected in visually impaired children, training strategies that exploit the plasticity of the human brain should be early adopted. Here we developed and tested a new training protocol based on the reinforcement of audio-motor associations and thus supporting spatial development in visual...

In this study, we propose an optimum non-iterative algorithm for the minimum cable tension solution of two degree-of-freedom cable-driven robots. The problem is specifically defined for a cable-driven robot with one end-effector connected to four motors by four cables. A two-cable algorithm and a three-cable algorithm are presented with examples, t...

Touching objects in a virtual environment is a challenge that has yet to be addressed convincingly, in part because haptic technology and, in particular, low-cost haptic technology have strong limitations. This work aimed at assessing the impact of Chai3D texture rendering parameters on texture perception. We used Multidimensional Scaling technique...

We have adapted Sternberg’s context-recall task to investigate the neural mechanisms of encoding serial order information in working memory, in 2 male rhesus monkeys. We recorded from primary motor, premotor, and dorsolateral prefrontal cortex while the monkeys performed the task. In each cortical area, most neurons displayed marked modulation of a...

This paper presents the process and results of a set of studies within the ABBI EU project, with the general aim to co-design wearable technology (an audio bracelet) together with visually impaired children, starting at a young age. The authors discuss user preferences related to sounds and tactile materials and present the results of a focus group...

A key to robust perception is the combination and integration of multiple sources of sensory information. Previous studies have shown that the brain can integrate inputs from different sensory-modalities or within the same sense in a statistically optimal fashion. However, the mechanisms of how the brain combines haptic information from the two han...

Information about our environment and bodies is complex and human sensors often provide uncertain and noisy information. Nevertheless, information coming from different senses is usually at least partially redundant and numerous studies have shown that humans’ nervous system can integrate information from multiple sources in a statistically optimal...

When several persons perform a physical task jointly, such as transporting an object together, the interaction force that each person experiences is the sum of the forces applied by all other persons on the same object. Therefore, there is a fundamental ambiguity about the origin of the force that each person experiences. This study investigated th...

Visually impaired children and adults have difficulties in engaging in positive social interactions. This study assesses social competence in sighted and visually impaired people and to propose a novel interventional strategy in visually impaired children. We designed a task that assesses the ability to initiate and sustain an interaction with the...

This paper discusses self-efficacy, curiosity, and reflectivity as cognitive and affective states that are critical to learning but are overlooked in the context of affect-aware technology for learning. This discussion sits within the opportunities offered by the weDRAW project aiming at an embodied approach to the design of technology to support e...

In this short review, we aim at providing an update about recent research on force-feedback devices in educational settings, with a particular focus on primary school teaching. This review describes haptic devices and education virtual environments before entering into the details of domain-specific applications of this technology in schools. Curre...

When watching videos, our sense of reality is continuously challenged. How much can a fundamental dimension of experience such as visual flow be modified before breaking the perception of real time? Here we found a remarkable indifference to speed manipulations applied to a popular video content, a soccer match. In a condition that mimicked real-li...

The International Workshop on Multimodal Interaction for Education aims at investigating how multimodal interactive systems, firmly grounded on psychophysical, psychological, and pedagogical bases, can be designed, developed, and exploited for enhancing teaching and learning processes in different learning environments, with a special focus on chil...

Since it has been shown that spatial development can be delayed in blind children, focused sensorimotor trainings that associate auditory and motor information might be used to prevent the risk of spatial-related developmental delays or impairments from an early age. With this aim, we proposed a new technological device based on the implicit link b...

WeDRAW aims to mediate learning of primary school mathematical concepts, such as geometry and arithmetic, through the design, development and evaluation of multisensory serious games, using a combination of sensory interactive technologies. Working closely with schools, using participatory design techniques, the WeDRAW system will be embedded into...

[This corrects the article on p. 10 in vol. 8, PMID: 28144226.].

A low-cost robotic interface was used to assess the visuo-motor performance of patients with Alzheimer’s disease (AD). Twenty AD patients and twenty age-matched controls participated in the study. The battery of tests included simple reaction times, position tracking and stabilization tasks performed with both hands. The regularity, velocity, visua...

Young children with visual impairments tend to engage less with their surroundings, limiting the benefits from activities at school. We investigated novel ways of using sound from a bracelet, such as speech or familiar noises, to tell children about nearby people, places and activities, to encourage them to engage more during play and help them mov...

INTRODUCTION: Several studies have recently investigated how Anorexia Nervosa (AN) patients process multimodal information. It has been hypothesized that AN patients might be less reliant on visual perception of bodies than healthy individuals (Longo, 2015). Case et al. 2012 have shown that processing of multimodal information might be disrupted in...

Introduction Several studies recently investigated how Anorexia Nervosa patients (ANp) process multimodal information. Longo (2015) hypothesized that ANp might be less reliant on visual perception of bodies than healthy controls (HC). Case et al. showed that processing of multimodal information might be disrupted in ANp. Literature lacks of studies...

Different sensory systems interact to generate a representation of space and to navigate. Vision plays a critical role in the representation of space development. During navigation, vision is integrated with auditory and mobility cues. In blind individuals, visual experience is not available and navigation therefore lacks this important sensory sig...

Neural responses in striatal, limbic and somatosensory brain regions track individual differences in loss aversion, i.e. the higher sensitivity to potential losses compared with equivalent gains in decision-making under risk. The engagement of structures involved in the processing of aversive stimuli and experiences raises a further question, i.e....

In this study, we investigated the integration of force and position information in a task in which participants were asked to estimate the center of a weak force field. Two hypotheses, describing how participants solved this task, were tested: (1) by only using the position(s) where the force reaches the detection threshold, and (2) by extrapolati...

This paper reports results from two workshops organized with children with visual impairments ranging from blindness to low vision. The aim of the workshops was to suggest gestures for the interaction with a small wearable audio-bracelet. Results show a preference for mechanical buttons and touch-based gestures on the device (mainly tapping and sli...

This paper presents the process and results of a set of studies within the ABBI EU project, with the general aim to co-design wearable technology (an audio bracelet) together with visually impaired children, starting at a young age. The authors discuss user preferences related to sounds and tactile materials and present the results of a focus group...

Considering that cortical plasticity is maximal in the child, why are the majority of technological devices available for visually impaired users meant for adults and not for children? Moreover, despite high technological advancements in recent years, why is there still no full user acceptance of existing sensory substitution devices? The goal of t...

It has been suggested that tactile perception becomes less acute during movement to optimize motor control and to prevent an overload of afferent information generated during action. This empirical phenomenon, known as “tactile gating effect,” has been associated with mechanisms of sensory feedback prediction. However, less attention has been given...

The system comprises at least one module (11; 111) comprising, in turn: - a sensor apparatus (12), for being worn by a user and designed to detect data representing the arrangement assumed within the space by the part of the user's body on which said sensor apparatus (12) is worn by the user, - a signaling apparatus (14), for providing a signal tha...

The present paper reports on a games workshop within the ABBI EU project involving children with visual impairments as co-creators. The created games show that it is possible to create fun, rich and social co- located games with wearable technology employing very simple interactivity. Having a device that makes a sound when you move allows for th...

This study was designed to assess the effectiveness of the Audio Bracelet for Blind Interaction (ABBI) system for improving mobility and spatial cognition in visually impaired children. The bracelet is worn on the wrist and the key feature is to provide an audio feedback about body movements to help visually impaired children to build a sense of sp...

This work presents a novel haptic device to study human grasp, which integrates different technological solutions thus enabling, for the first time, to achieve: (i) a complete grasp characterization in terms of contact forces and moments; (ii) an estimation of contact point location for varying-orientation contact surfaces; (iii) a compensation of...

The ABBI (Audio Bracelet for Blind Interaction) device is designed for visually impaired and blind children to wear on the wrist and produce sound based on the movement of the arm through space. The primary function is to inform a child (or adult) about his/her own movements to aid spatial cognition rehabilitation. However , the device could also b...

Early onset of blindness adversely affects psychomotor, emotional and social development [1], that mostly depend on spatial cognition. Some studies suggest that the lack of vision could potentially explain this delayed or weakened development since vision is the most accurate and robust sense to encode spatial information [2,3,4]. We recently found...

ABBI, the audio bracelet for blind interaction, aims to rehabilitate spatial cognition, mobility and social interaction in children and adults with visual deficits through natural audio-motor and tactile-motor interactions. ABBI is a new tool that provides spatial information on where and how the body is moving, providing significant information re...

Low-cost gaming technologies offer promising devices for the rehabilitation of stroke patients at home. While several attempts have been made to use low-cost motion tracking devices (Kinect) or balance boards (Wii Board), the potential of low-cost haptic devices has yet to be explored in this context. The objective of this study was to investigate...

Softness perception offers a good opportunity to study how position and force information are integrated during exploratory movements. This chapter presents a model of how this integration might happen when identifying the central position of a very weak elastic force field rendered with a haptic device. In this task, the force near the central pos...

Background: The emergence of commercial haptic devices offers new research opportunities to enhance our understanding of the human sensory-motor system. Yet, commercial device capabilities have limitations which need to be addressed. This paper describes the customization of a commercial force feedback device for displaying forces with a precision...

Introduction Studies of cross-modal plasticity in blind people typically show that blind subjects perform as well as, or even better than, sighted controls when tested for various auditory or tactile discrimination tasks. Differently, we report that visually impaired adults and children are impaired in those auditory and proprioceptive tasks that r...

Saccades cause compression of visual space around the saccadic target, and also a compression of time, both phenomena thought to be related to the problem of maintaining saccadic stability (Morrone et al., 2005; Burr and Morrone, 2011). Interestingly, similar phenomena occur at the time of hand movements, when tactile stimuli are systematically mis...

The performance of a haptic device generally varies across its workspace. This work measures the force rendering accuracy and maximum force output rendering capabilities of two commercial devices – the Falcon and Omega devices – in six directions at 46 and 49 set locations, respectively, in the mechanical workspace. The results are compared to seve...

We recently showed that congenitally blind adults have severely impaired thresholds in an auditory spatial bisection task, pointing to the importance of vision in constructing auditory spatial maps (Gori et al.2014). To test if also children show a spatial impaired performance, we compared blind and sighted children (6-16 years) on different aspec...

This paper describes an haptic system designed to vary the stiffness of three contact points in an independent and controllable fashion, by suitably regulating the inner pressure of three pneumatic tactile displays. At the same time, the contact forces exerted by the user are measured by six degree-of-freedom force sensors placed under each finger....

Many human activities are performed in groups and require that the individuals in the group coordinate their actions. For example, carrying bulky objects, dancing, handshaking, musicians playing together in an orchestra are examples of joint actions. A crucial aspect of joint action is that it requires that the partners share information and commun...

Video-games are effective and motivating tools in the rehabilitation of patients. This study presents a video-game based platform controlled by a haptic device for the rehabilitation of Neglect patients. Haptic structure, game engine, game design criteria and example games are presented in detail.

The aim of this work was to create an apparatus that will allow for the study of sensorimotor control development in children, specifically the interaction with a simple kinematically constrained object. A one-degree-of-freedom rotational joystick was built, sensorized with an encoder and force/torque sensor, and outfitted with a custom damper. The...

The link between time perception and action has attracted special interest in recent years and it is progressively disclosing a multifaceted nature. A large set of temporal effects variously associated to the execution of actions has been documented (Haggard et al., 2002, Hagura et al., 2012, Tomassini et al., 2012 and Yarrow et al., 2001), suggest...

Computer games are a promising tool to support intensive rehabilitation. However, at present, they do not incorporate the supervision provided by a real therapist and do not allow a safe and effective use at patient’s home. We show here how specifically tailored computational intelligence based techniques allow extending exergames with functionalit...

Decision making under risk entails the anticipation of prospective outcomes, typically leading to the greater sensitivity to losses than gains known as loss aversion. Previous studies on the neural bases of choice-outcome anticipation and loss aversion provided inconsistent results, showing either bidirectional mesolimbic responses of activation fo...

Saccades cause compression of visual space towards the saccadic target, and also a compression of time, both phenomena thought to be related to the problem of maintaining saccadic stability. Interestingly, similar phenomena occur around the time of hand movements, when brief tactile stimuli are systematically mislocalized in the direction of the mo...

The human hand has so many degrees of freedom that it may seem impossible to control. A potential solution to this problem is "synergy control" which combines dimensionality reduction with great flexibility. With applicability to a wide range of tasks, this has become a very popular concept. In this review, we describe the evolution of the modern c...

Rehabilitation for stroke patients with postural instability or balance disorders can be enhanced using game-based rehabilitative strategies. Our work explored the potential of commercially available haptic devices for a home rehabilitation system. One group of participants used a low-cost device (Falcon) while another group used a high-end device...

Computer games are a promising tool to support rehabilitation at home. It is widely recognized that rehabilitation games should (i) be nicely integrated in general-purpose rehabilitation stations, (ii) adhere to the constraints posed by the clinical protocols, (iii) involve movements that are functional to reach the rehabilitation goal, and (iv) ad...

This research examines the haptic perception of orientations in the frontal plane in order to identify the nature of their representation. Blindfolded participants inserted the tip of the index finger into a thimble mounted on the extremity of a haptic interface and manually explored the orientation of a "virtual rod". After a short delay, particip...

Series elastic actuators (SEAs) are frequently used for force control in haptic interaction, because they decouple actuator inertia from the end effector by a compliant element. This element is usually a metal spring or beam, where the static force-deformation relationship offers a cheap force sensor. For high-precision force control, however, the...

This preliminary study investigated behaviorally the performance of a sample of young twins in a set of classical visuomotor tasks. The assessment was carried out using a small haptic interface used to produce force and record the hand trajectory during the execution of tasks requiring rapid and precise movements. The aim of the study was to evalua...

Robot-assisted rehabilitation is often found to help in recovery, but its use is often experimental or limited to clinical trials. This paradox is partly explained by the difficulty in bridging the gap between the score on a robot-assisted exercise and the control processes that mediate the measured performance. Building upon recent computational m...

When we manipulate an object, grip force is adjusted in anticipation of the mechanical consequences of hand motion (i.e., load force) to prevent the object from slipping. This predictive behavior is assumed to rely on an internal representation of the object dynamic properties, which would be elaborated via visual information before the object is g...

This study measured the minimum amount of force necessary to identify its direction. The force was produced by a robot and transmitted to a small spherical handle held between the thumb and index finger. We also examined whether this threshold changed during movement. We found that the force threshold was lower when it was possible to move the arm...

In haptically enabled virtual reality, most existing devices render kinesthetic feedback via one 3DoF single-contact-point, thus they cannot stimulate tactily teh fingertip skin. This lack of information prevents the perception of contact surface orientation in absence of vision and of free exploratory movements. In this work we experimentally inve...

We measured the minimum transient change of length of a bimanually hand-held bar that could be detected. A bimanual haptic interface was used to haptically render the bar in a static condition and two dynamic conditions involving discrete movements. The detection thresholds were much lower in the static ( 10 mm). This finding suggests that our prop...

In this paper, we propose a method to estimate the parameters of a double hinge model of the trapeziometacarpal joint (TMC) by MRI-based motion analysis. The model includes two non-orthogonal and non-intersecting rotation axes accounting for flexion-extension (F-E) and adduction-abduction (A-A). We evaluated the quality of the estimated model param...

The flash-lag effect (FLE) consists in perceiving a briefly presented stationary stimulus to lag behind an aligned moving stimulus. This study investigates the effects of actively controlling the moving stimulus. By means of a robotic arm, observers continuously moved a dot along a circular trajectory, and a flash was displayed closely at unpredict...

While robot-assisted rehabilitation is often found to help recovery, their use often remain limited to clinical trials. Amongst the reasons that may explain their under-use is the difficulty to bridge the gap between the score on a robot-assisted exercise and the control processes that mediate the measured performance. This paper illustrates the po...

We present a visuo-haptic display and a set of tasks aimed at evaluating upper-limb sensory-motor functions. The visual and force feedbacks were manipulated to assess the functioning of different feedforward and feedback elements of movement control. We report the results of healthy adults who performed these tasks with both hands over two differen...

While exploratory movements are an integral part of the act of perceiving in the haptic modality, little is known about the processes that perform the mental synthesis necessary to gain a unified representation of the object. To address this issue, we investigated the accuracy and precision with which participants could identify the central positio...

This article analyzes a realistic kinematic model of the trapezio-metacarpal (TM) joint in the human thumb that involves two non-orthogonal and non-intersecting rotation axes. The estimation of the model parameters, i.e. the position and orientation of the two axes with respect to an anatomical coordinate system, was carried out by processing the m...

This review examines the isotropy of the perception of spatial orientations in the haptic system. It shows the existence of an oblique effect (i.e., a better perception of vertical and horizontal orientations than oblique orientations) in a spatial plane intrinsic to the haptic system, determined by the gravitational cues and the cognitive resource...

Saccades may not always wait for the completion of the perceptual analysis. By taking advantage of a motion-induced illusion of position and of the spontaneous scatter of saccade latency, we showed that in normal observers, regular saccades (latency, approximately 200 ms) were accurately directed to the target, whereas at higher latencies, saccades...

Transcranial magnetic stimulation (TMS) is a tool of choice to study the functionality of the corticospinal pathway. In this study, we used single-pulse TMS at different intensities and during different levels of grasping force, to stimulate the hand area of the left primary motor cortex (M1). We measured, the TMS-evoked forces, or motor evoked for...

This paper describes methods and experimental studies concerned with quantitative reconstruction of finger movements in real-time, by means of multi-camera system and 24 surface markers. The approach utilizes a kinematic model of the articulated hand which consists in a hierarchical chain of rigid body segments characterized by 22 functional degree...

In real object manipulation, the deformation of the fingerpads along the contact surfaces provides local information about the geometry of the object the subject is manipulating, even in absence of vision and any exploratory movement. In virtual reality with haptic feedback this kind of stimulation is not available because the haptic devices curren...

This research studied the haptic perception of orientations in space rather than in a plane. It aimed at identifying the nature of the system of coordinate used to represent an orientation in space, when two parameters are necessary to code an orientation. Blindfolded participants inserted the tip of the index finger in a thimble mounted at the ext...

In this chapter, we present a study of the human grasp conducted with a mathematical formalism that has been developed in robotics during the last two decades. The main objective of this study is to assess the extent to which the structure of the hand is adapted to its grasping function by identify the conditions under which a model minimizing ener...

Transcranial magnetic stimulation (TMS) is a tool of choice to study the functionality of the corticospinal pathway in the intact human. In this study, we used TMS to stimulate the hand area of the primary motor cortex (Ml) and measured TMS-evoked forces in a multi-fingered grasp. This short report aims at presenting the experimental setup and some...

We investigated the accuracy with which, in the absence of vision, one can reach again a 2D target location that had been previously identified by a guided movement. A robotic arm guided the participant's hand to a target (locating motion) and away from it (homing motion). Then, the participant pointed freely toward the remembered target position....

The ambiguity of the notion of centre for most shapes raises the question of whether children perceive the centre of a shape in the same place as adults. To answer this question, we asked five- year old children and adults to mark the centre of a triangle with a pen. The responses of children and adults were strikingly similar. First, the two group...

The aim of this investigation was to determine the factors that influence the variability in the load force during a precision grip. Subjects grasped an object with three coarse contact surfaces using a tripod grasp of the thumb, index and middle fingers. The orientations of the contact surfaces and their locations relative to the object's center o...

To investigate the organization of multi-fingered grasping, we asked subjects to grasp an object using three digits: the thumb, the index finger, and the middle or ring finger. The object had three coarse flat contact surfaces, whose locations and orientations were varied systematically. Subjects were asked to grasp and lift the object and then to...

This study aimed at understanding how visual information is used to locate the center of mass. The center of mass is an important physical property of objects that must be taken into account when grasping and/or manipulating them. Participants were instructed to identify the point of equilibrium of compact, bidimensional, massless shapes displayed...

This study aimed at understanding how visual information is used to locate the center of mass. The center of mass is an important physical property of objects that must be taken into account when grasping and/or manipulating them. Participants were instructed to identify the point of equilibrium of compact, bidimensional, massless shapes displayed...

An experiment investigated in human adults the sensorimotor transformation involved in pointing to a spatial target identified previously by kinesthetic cues. In the "locating phase," a computer-controlled mechanical arm guided the left [condition LR (left-right)] or right [condition RR (right-right)] finger of the blindfolded participant to one of...

Two experiments pursued previous studies (P. Viviani & P. Mounoud, 1990; P. Viviani & N. Stucchi, 1989) on motor-perceptual interactions. The right arm of blindfolded participants was moved passively along elliptic trajectories. Kinematics was either coherent or at variance with the relation (two-thirds power law) observed in active movements. In E...

The deformation of the fingerpads along the contact surfaces in a real grasp provides local information about the shape of the object, which is crucial for the stability of the grasp. Several experiments were performed to investigate whether it was possible to transmit information about the shape of a virtual object grasped via a single-contact hap...

We present a method to compute the interaction force during an imposed movement. First, we show how to incorporate a kinematic constraint into the equation of motion of a simple but realistic model of the arm. Second, we apply this method to predict the interaction force during an imposed movement of the arm. The results of these simulations are co...