CNITs require a paradigm shift for experimental neuroscience which has traditionally focussed on off-line analysis of behavioural correlates and/or responses to open-loop interventions. Incorporating closed-loop methods into laboratory experiments is technically challenging and requires multidisciplinary cooperation but enables causal investigations into how multi-scale dynamics and feedback shapes brain circuits and behaviour. This in turn will reveal new insights into how the brain behaves ‘in the loop’ to inform future clinical applications of neural interface technologies. This WS will focus on the development of physiological, behavioural or imaging paradigms that use CNITs in vitro and in vivo in animal systems or humans. Topics will explore the new scientific principles that emerge at the intersection of biology and technology, including investigations of neural plasticity, functional reorganisation, learning and coadaptivity between brains and algorithms.