ERP component analysis for rapid image searching in finer categories

Event-related potentials (ERP)-based image triage (or search) in the context of Rapid Serial Visual Presentation (RSVP) exploits difference in the human brain response to target and distracted stimuli in the form of an image. So far, most paradigms focus on image triage (or search) among rough object categories. In this paper, we explored the possibility and effectiveness of target detection among finer categories like different animals. We analyzed on the difference of ERP components in two image search tasks, a simple-recognition task in which all images of a target are the same and a discriminative-recognition task in which all images are randomly different but belong to the same target category (the same kind of animal). We observed that the P3 amplitude reduced and the P3 latency delayed on the discriminative-recognition condition due to the increased difficulty of identifying different images belonging to the same category. But the average area under ROC curve reached 0.82 which indicated that rapid target detection among finer categories by single-trial ERP were feasible with trivial contribution of N1 and stable contribution of N2 and P3.