A neuro-processing adjunct was a Borg device implanted just behind the humanoid ear, intended to increase the synaptic efficiency of Borg drones. One effect of such a device was 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").