SSCN 2013 Abstracts

Full Papers
Paper Nr: 1

An Experimental Platform Aimed at Long Lasting Electrophysiological Multichannel Recordings of Neuronal Cultures


G. Regalia, E. Biffi, A. Lucchini, M. Capriata, S. Achilli, A. Menegon, G. Ferrigno, L. Colombo and A. Pedrocchi

Abstract: The elucidation of physio-pathological mechanisms expressed by a neuronal network over extended time scales (i.e., from hours to weeks) is the goal of many neurophysiological and neuropharmacological in vitro studies. In this context, a challenging technological requirement is the establishment of an experimental setup able to collect long-term neuronal signals. In this work we report the development of a compact environmental chamber designed to perform prolonged recordings of the bioelectrical activity exhibited by neuronal networks grown on MicroElectrode Arrays (MEAs). To reproduce an environment suitable for cells growth (temperature, pH and humidity) the chamber was coupled with a temperature control system and an air humidifying module. Validation tests demonstrated that the environment inside the portable chamber is comparable to standard cell incubators environment. To collect neuronal extracellular signals, custom multichannel pre-processing boards have been developed and integrated with the chamber. With this equipment, we were able to reliably record spontaneous neuronal electrical activity from hippocampal cultures grown inside the chamber for several hours, which is not possible with the standard MEA recording setup due to environmental fluctuations. This system can collect multichannel data from neuronal cultures over long periods, providing an effective solution for long-term studies of neural activity.

Short Papers
Paper Nr: 2

Carryover Effect after Functional Electrical Stimulation Treatment - Pilot Study for a Quantitative Approach


Marta Gandolla, Alessandra Pedrocchi, Simona Ferrante , Eleonora Guanziroli, Nick S. Ward and Franco Molteni

Abstract: Functional Electrical Stimulation (FES) has been reported to be an effective treatment for neurological patients, e.g. post-stroke patients. Besides beneficial effects at muscles themselves, a re-learning process named carryover effect has been observed in some patients. This work aims at defining a quantitative method to assess the carryover effect in a group of patients, starting from a set of outcome measures that are specific to the considered treatment. Fifteen post-stroke chronic subjects have been recruited for 20 half an hour sessions of FES-based treatment for Foot Drop correction during ambulation. Gait velocity, a spatial asymmetry index, a temporal asymmetry index, endurance velocity and tibialis anterior activation index during gait have been selected as outcome measures. After the analysis performed with the proposed method based on principal component analysis, 50% of patients presented the carryover effect. The proposed approach is a quantitative method that can be applied to any set of outcome measures of interest. The results could inform further studies aimed at identifying the carryover effect mechanism of action.

Paper Nr: 3

Brain-inspired Sensorimotor Robotic Platform - Learning in Cerebellum-driven Movement Tasks through a Cerebellar Realistic Model


Claudia Casellato, Jesus A. Garrido, Cristina Franchin, Giancarlo Ferrigno, Egidio D'Angelo and Alessandra Pedrocchi

Abstract: Biologically inspired neural mechanisms, coupling internal models and adaptive modules, can be an effective way of constructing a control system that exhibits a human-like behaviour. A brain-inspired controller has been developed, embedding a cerebellum-like adaptive module based on neurophysiological plasticity mechanisms. It has been tested as controller of an ad-hoc developed neurorobot, integrating a 3 degrees of freedom serial robotic arm with a motion tracking system. The learning skills have been tried out, designing a vestibular-ocular reflex (VOR) protocol. One robot joint was used to get the desired head turn, while another joint displacement corresponded to the eye motion, which was controlled by the cerebellar model output, used as joint torque. Along task repetitions, the cerebellum was able to produce an anticipatory eye displacement, which accurately compensated the head turn in order to keep on fixing the environmental object. Multiple tests have been implemented, pairing different head turn with object motion. The gaze error and the cerebellum output were quantified. The VOR was accurately tuned thanks to the cerebellum plasticity. The next steps will include the activation of multiple plasticity sites evaluating the real platform behaviour in different sensorimotor tasks.

Paper Nr: 4

Effect of Stimulus Size and Shape on Steady-State Visually Evoked Potentials for Brain-Computer Interface Optimization


Wenjie Zheng, Francois-Benoit Vialatte, Parvaneh Adibpour, Chen Chen, Antoine Gaume and Gérard Dreyfus

Abstract: Steady-state visually evoked potentials (SSVEP) can be elicited by a large variety of stimuli. To the best of our knowledge, the size and shape effect of stimuli has never been investigated in the literature. We study the relationship between the visual parameters (size and shape) of the stimulation and the resulting brain response. A tentative physiological interpretation is proposed and the potential of the effect in a Brain-Computer Interface is outlined.