Automatic and controlled verbal-information processing in patients with frontal lobe lesions

The selectivity of frontal lobe lesion effects in the domains of verbal-information processing has not been well established. The authors hypothesized that capacitylimited controlled processing would be more impaired than automatic processing in frontal lobe patients (FLPs). Fifteen FLPs were compared with 2 matched control groups: 14 posterior-lesion patients and 15 normal controls. Both behavioral and event-related brain potential (ERP) measures were collected. Results suggest that both automatic and controlled processing were affected by frontal lobe lesions. ERP results indicated that the main difficulty for the FLPs was in the perceptual stage of information processing. This rather unexpected result may be explained by a basic difficulty of FLPs in attending to a new stimulus in order to process it.