A neuro-processing adjunct is a Borg device implanted just behind the humanoid ear, intended to increase the synaptic efficiency of Borg drones. One effect of such a device is the heightening of the visual cortex. (VOY: "Dark Frontier")

Upon her brief return to the Borg Collective in 2375, former drone Seven of Nine was forcibly fitted with a neuro-processing adjunct as she regenerated. (VOY: "Dark Frontier").