Left: Under automatic experimental conditions, in the absence of any behavioral response requirement to trials of interest, schizophrenia patients with positive thought disorder showed a larger attenuation of the N400 to indirectly related (versus unrelated) target words (underlined in the examples) than healthy controls.
Right: When participants performed an explicit relatedness judgment task, the same patients, unlike controls, showed no attenuation of the N400 to indirectly related (versus unrelated) target words (underlined in the examples).
The plots indicate one central parietal electrode site (Pz) where the N400 effect is maximal.