CATEGORY-SPECIFIC NAMING DEFICIT AFTER EPILEPSY SURGERY IN THE LEFT TEMPORAL LOBE: FACT OR FICTION?

Objective. Object naming for specific semantic categories was assessed in a sample of 24 patients with left temporal lobe epilepsy. Testing occurred during preoperative clinical diagnostics and 6 months after surgery. Background. Category-specific deficits constitute a naming disorder for living or nonliving objects or subsets of these categories (e.g. animals, fruits, tools) with relatively spared naming for other object domains. Theoretically, these deficits can provide insight into the storage of conceptual information in distinct brain regions. Method. For the purpose of this study a test battery of 160 clipart illustrations was used. Object naming was registered for different sets of living and nonliving categories. Results. Two patients with preoperative intact naming performance showed a specific naming deficit for living categories (food, animals) after surgery in the left temporal lobe. Conclusions. Category-specific naming deficits comprise a potential negative side effect after surgery in the speech-dominant left temporal lobe. Based on the requirements for object identification it is hypothesized that the left temporal lobe represents a visual feature store sensitive for the identification of living objects.