Objective We used event‐related potentials (ERPs) to test whether anorexic subjects have difficulties in filtering out irrelevant stimuli in controlled information processing tasks. Methods ERPs from 12 anorexic patients were recorded during recognition of simple and complex body images and simple and complex geometrical shapes. Results Anorexic subjects had larger P300 amplitudes for frequent stimuli during body images and simple geometrical shape recognition tasks. Longer P300 latencies were also found in simple geometrical shape recognition tasks, although task complexity had no effect on the P300 latency and amplitude. Discussion These results are explained in terms of nonspecific hyperarousal in mental anorexia and relative inability to filter out irrelevant stimuli leading to working memory saturation.