Modular Acquisition and Stimulation System for Timestamp-Driven Neuroscience Experiments

Dedicated systems are fundamental for neuroscience experimental protocols that require timing determinism and synchronous stimuli generation. We developed a data acquisition and stimuli generator system for neuroscience research, optimized for recording timestamps from up to 6 spiking neurons and entirely specified in a high-level Hardware Description Language (HDL). Despite the logic complexity penalty of synthesizing from such a language, it was possible to implement our design in a low-cost small reconfigurable device. Under a modular framework, we explored two different memory arbitration schemes for our system, evaluating both their logic element usage and resilience to input activity bursts. One of them was designed with a decoupled and latency insensitive approach, allowing for easier code reuse, while the other adopted a centralized scheme, constructed specifically for our application. The usage of a high-level HDL allowed straightforward and stepwise code modifications to transform one architecture into the other. The achieved modularity is very useful for rapidly prototyping novel electronic instrumentation systems tailored to scientific research.Comment: Preprint submitted to ARC 2015. Extended: 16 pages, 10 figures. The final publication is available at link.springer.co

Playing at the edge of criticality: Expanded whole-brain repertoire of connectome-harmonics

In order for us to survive, our behaviour has to be perched somewhere between stability and flexibility, or between exploitation and exploration of available resources. This requires the underlying spatiotemporal brain dynamics to be delicately balanced between order and disorder, drawing upon a large repertoire of available brain states. Beyond survival, in order to thrive the brain has to be sufficiently flexible to be able to seek novel trajectories and expand the dynamical repertoire. Here we propose that a key ingredient could be play, the active exploration of novelty beyond exploiting existing potentially scarce resources. Using a novel analysis method called ‘connectome harmonics’ we not only demonstrate that brain activity resides close to criticality—at the delicate balance between order (stability) and disorder (flexibility)—but this whole-brain criticality is also intrinsically linked to oscillatory brain dynamics. We show that compared to wakefulness, other conscious states are related to different connectome-harmonic repertoires and differ in their proximity to criticality, where the critical regime may enhance the ability to flexibly seek new brain states. In particular, we propose that these brain dynamics may underlie the creative process found in play and improvisation, and as such may shed new light on discovering how the brain optimizes the balance between exploitation and exploration needed for behavioural flexibility