Cortical stimulation elicits regional distinctions in auditory and visual naming

We used electrical stimulation mapping to compare performance on auditory and visual naming tasks in inferotemporal, lateral temporal, frontal, and parietal cortex in 8 temporal lobe epilepsy (TLE) patients with subdural electrodes placed for preoperative language localization. Performance on auditory responsive naming (ARN) and visual confrontation naming (VCN) was best during stimulation of parietal cortex and was equally impaired during stimulation of inferotemporal and frontal cortex. In contrast, ARN performance was significantly poorer than VCN performance during stimulation of anterior and posterior lateral temporal cortex. In most patients, stimulation of inferotemporal cortex at relatively low stimulus intensities (less than or equal to 5 mA) during either ARN or VCN elicited reproducible errors in which patients could describe, gesture, spell, or draw, but not name, in response to auditory or visual cues. Inferotemporal and frontal cortex appear to be multimodality language regions distinct from lateral temporal cortex.