We are developing brain computer interfaces (BCIs) which utilize neural correlates of attentional shift, arousal, engagment and recognition as labels for exemplar based machine learning systems. Our first system, called cortically-coupled computer vision (C3Vision), uses real-time processing of the EEG, machine learning, and graph-based semi-supervised computer vision to construct an image triage system for Image Analysts. Our current work is focused on developing “opportunistic BCI” platforms where we leverage naturally evoked neural responses to events objects in real world environments.