Reversed negative priming following frontal lobe lesions.

The present study investigated whether lesions to the prefrontal cortex would lead to impaired inhibitory control in selective attention. Patients with uni- and bilateral frontal lobe damage and age-matched control participants were compared in an identity negative priming task involving letter naming. Whereas all control groups revealed robust negative priming and distractor interference, the majority of patients showed positive instead of negative priming and not all of them were more susceptible to interference. These results suggest that frontal lobe lesions disrupt distractor inhibition and cannot be explained in terms of a retrieval deficit. However, the level of interference may not only be determined by inhibition but also by excitation of the target stimulus.