Con£ict monitoring engages the mediofrontal cortex during nonword processing

The current study investigated the role playedby con£ictmonitoring in a lexical-decision task involving competing word representations, using event-related potentials. We extended the multiple read-outmodel (Grainger and Jacobs,1996), a connectionistmodel of word recognition, to quantify con£ict by means of Hop¢eld Energy, which is de¢ned as the sum of the products of all orthographic word node pair activations within the arti¢cial mental lexicon of this model.With increasing con£ict levels in nonwords, a late negativity increased in amplitude (400^600ms) accompanied by activation of the anterior cingulate cortex and the medial frontal gyrus. The simulated con£ict predicted the amplitudes associated with this mediofrontal con£ict-monitoring network on an item level, and is consistent with the con£ict-monitoring theory.