  Brain stimulation is a core method in neuroscience. Numerous non-invasive
brain stimulation (NIBS) techniques are currently in use in basic and clinical
research, and recent advances promise the ability to non-invasively access deep
brain structures. While encouraging, there is a surprising gap in our
understanding of precisely how NIBS perturbs neural activity throughout an
interconnected network, and how such perturbed neural activity ultimately links
to behaviour. In this review, we will consider why non-human primate (NHP)
models of NIBS are ideally situated to address this gap in knowledge, and will
consider why the oculomotor network that moves our line of sight offers a
particularly valuable platform in which to empirically test hypothesis
regarding NIBS-induced changes in brain and behaviour. NHP models of NIBS will
enable investigation of the complex, dynamic effects of brain stimulation
across multiple hierarchically interconnected brain areas, networks, and
effectors. By establishing such links between brain and behavioural output,
work in NHPs can help optimize experimental and therapeutic approaches, improve
NIBS efficacy, and reduce side-effects of NIBS.
