Event-Related Potentials during Naming“ z D. T. STUSS, E. E. LEECH, F. F. SARAZIN AND T. W. zyxwv PICTON Schools of Medicine and Psychology University zyxwv of Ottawa and Ottawa General Hospital Ottawa, Canada The ability to name an object is a basic language skill. Anomia, the inability to name an object, is a common language impairment occurring in the course of most aphasic disorders and as part of other more diffuse brain disturbances (Benson, 1979). Different types of aphasia are associated with different kinds of naming impairment (Goodglass and Baker, 1976; Grossman, 1978). Aphasic patients vary in their ability to benefit from cues (Barton, 1971), to retrieve a word from memory (Goodglass et al., 1976), or to respond to different modalities of presentation (Goodglass and Stuss, 1979). The naming task is therefore a valuable tool for understanding the functional organization of language in the brain. We evaluated the event-related potentials occurring in association with naming in a group of normal subjects. Our results could then serve as a basis for the use of event-related potentials in the investigation of language disorders. METHODS Eight right-handed male subjects (age 23-36 years) participated in the experi- ment. All subjects were right-handed according to the Edinburgh Handedness Scale (Oldfield, 1971). Trials were experimenter-initiated every 7 to 15 seconds. A zyx 10 ms 500 Hz tone occurring 500 ms after trial onset served as a warning that a visual stimulus would occur one second later. The visual stimulus was presented for 500 ms on a TV monitor by a Norpak Video-Microprocessor. Two seconds after the onset of the visual stimulus, a second 10 ms 500 Hz tone signalled the subject to make a response. The visual stimuli and the requested responses varied with the four experimental conditions. In the “naming” condition, the visual stimuli were pictures selected primarily from the Boston Naming Test (Kaplan et al., 1976). The subject was requested to respond (after the second tone) by verbally naming the object represented in the picture and giving a confidence rating for the selected name on a five point scale. A total of 79 different pictures were used, one for each trial. In the “reading” condition, the visual stimulus was a word written in capital letters and corresponding to the names of the pictures presented in the “naming” condition. The subject was asked to say the word after the second tone. In two “control” conditions, the visual stimulus was either a square or a meaningless figure. In one of these conditions the subject was requested to say “yes” after the second tone and in the other zyxwv to whistle. The order of the conditions varied across subjects, with the stipulation that the naming condition always preceded the reading condition. ‘This research was supported by the Medical Research Council of Canada, the Ontario Mental Health Foundation and the Ontario Heart Foundation. 278