Periodic Reporting for period 3 - SYNCH (A SYnaptically connected brain-silicon Neural Closed-loop Hybrid system)
Période du rapport: 2022-01-01 au 2023-06-30
The SYNCH project aimed at introducing a novel concept and technology of brain-computer interfacing to help treating neurological disorders. The core idea was to connect an artificial network of electronic neurons realized on a silicon chip to brain neurons of the rat. The connection between silicon and biological neurons is established through memristors, electrical nanodevices that emulate the function of brain synapses. Artificial neurons and brain neurons became reciprocally connected, with biological neurons providing inputs to the artificial neurons and, along the return pathway, with artificial neurons modulating the activity of brain neurons. Brain neurons were physically connected to memristors and to their electronic counterparts through a neural interface implanted in the brain, which enabled the recording and adaptive electrical stimulation of neurons at the site of implantation. As such, the system constituted a brain-computer interface, where the PC was replaced by a brain-inspired architecture able to 'speak' the spikes-based language of real neurons and where the connection strength between artificial neurons and biological neurons varied according to synaptic plasticity rules.
The technology implemented during the project constitutes the first example of implantable integrated system where artificial neurons on-chip can modulate activity of brain networks. We foresee applications of the SYNCH technology to treat brain structures focally damaged by injury – e.g. as a consequence of stroke – or as a consequence of neurodegeneration as in Parkinson’s and dementia.
The technology implemented during the project constitutes the first example of implantable integrated system where artificial neurons on-chip can modulate activity of brain networks. We foresee applications of the SYNCH technology to treat brain structures focally damaged by injury – e.g. as a consequence of stroke – or as a consequence of neurodegeneration as in Parkinson’s and dementia.
At the completion of the project, we have demonstrated the feasibility of our technological approach producing an integrated setup where artificial neurons and memritive devices can connect to brain neurons bidirectionally. We showed that an artificial network of spiking neurons can classify activity of neurons recorded by an implanted probe in the brain cortex or in deep nuclei involved in the reward circuit, distinguishing between patterns of activity induced by different sensory inputs. In this context, we could demonstrate that memristors can act as synapse-inspired computing devices capable to compress information on activity of populations of neurons in real time. On the other hand, we successfully investigated the possibility that artificial neurons influence brain activity adaptively by electrically stimulating neurons through the implanted probe according to a frequency modulation scheme. At the core of the system, a control unit was engineered that controls the signalling between brain and artificial neurons. The technology is now at a stage where it can be farther developed to treat specific neurological diseases.
As foreseen, the SYNCH technology opens new scenarios on the possible impact of AI on neurological patients. We elaborated a concise roadmap to help the European Commission and stakeholders to analyse challenges and opportunities of autonomous or semiatonomous brain implants with integrated AI.
As foreseen, the SYNCH technology opens new scenarios on the possible impact of AI on neurological patients. We elaborated a concise roadmap to help the European Commission and stakeholders to analyse challenges and opportunities of autonomous or semiatonomous brain implants with integrated AI.
The SYNCH technology is offering a new perspective for the treatment of neurological diseases. Challenges, however, must be yet overcome, and in particular miniaturisation of the system, validation of long-term endurance and biocompatibility of the implant, and, above all, a thorough understanding of the interaction between artificial neurons and brain neurons under different physiological and pathological conditions. The fundamental question we are facing now is: to what extend can we delegate to artificial neurons the possibility to influence neuronal activity in the human brain? SYNCH has certainly contributed to unveil technical bottlenecks limiting the communication between brain and implanted artificial networks, but has also demonstrated strategies enabling the two worlds to interact. This result is unique in the international scenario. In our vision, SYNCH results are the basis not only for the development of a novel class of biomedical devices, but are also contributing to trigger a necessary debate on the ethical and regulatory framework that should govern the intimate interaction between brain and AI.