Category-specific naming and recognition deficits in temporal lobe epilepsy surgical patients.
OBJECTIVE
Based upon Damasio's "convergence zone" model of semantic memory, we predicted that epilepsy surgical patients with anterior temporal lobe (TL) seizure onset would exhibit a pattern of category-specific naming and recognition deficits not observed in patients with seizures arising elsewhere.


METHODS
We assessed epilepsy patients with unilateral seizure onset of anterior TL or other origin (n=22), pre- or post-operatively, using a set of category-specific items and a conventional measure of visual naming (Boston Naming Test: BNT).


RESULTS
Category-specific naming deficits were exhibited by patients with dominant anterior TL seizure onset/resection for famous faces and animals, while category-specific recognition deficits for these same categories were exhibited by patients with nondominant anterior TL onset/resection. Patients with other seizure onset did not exhibit category-specific deficits. Naming and recognition deficits were frequently not detected by the BNT, which samples only a limited range of stimuli.


CONCLUSIONS
Consistent with the "convergence zone" framework, results suggest that the nondominant anterior TL plays a major role in binding sensory information into conceptual percepts for certain stimuli, while dominant TL regions function to provide a link to verbal labels for these percepts. Although observed category-specific deficits were striking, they were often missed by the BNT, suggesting that they are more prevalent than recognized in both pre- and post-surgical epilepsy patients. Systematic investigation of these deficits could lead to more refined models of semantic memory, aid in the localization of seizures, and contribute to modifications in surgical technique and patient selection in epilepsy surgery to improve neurocognitive outcome.
Drane
Daniel L
DL
Department of Neurology, University of Washington, Seattle, WA, United States; UW Regional Epilepsy Center, Harborview Medical Center, Seattle, WA, United States. ddrane@emory.edu
Ojemann
George A
GA
Aylward
Elizabeth
E
Ojemann
Jeffrey G
JG
Johnson
L Clark
LC
Silbergeld
Daniel L
DL
Miller
John W
JW
Tranel
Daniel
D
D000328:Adult; D003072:Cognition Disorders / Q000209:etiology* / Q000523:psychology*; D004569:Electroencephalography; D004833:Epilepsy, Temporal Lobe / Q000000981:diagnostic imaging / Q000523:psychology* / Q000601:surgery*; D005260:Female; D006801:Humans; D008297:Male; D008568:Memory / Q000502:physiology; D008606:Mental Processes / Q000502:physiology*; D008960:Models, Psychological; D009483:Neuropsychological Tests; D019635:Neurosurgical Procedures; D010775:Photic Stimulation; D049268:Positron-Emission Tomography; D011183:Postoperative Complications / Q000523:psychology*; D011597:Psychomotor Performance / Q000502:physiology; D021641:Recognition, Psychology / Q000502:physiology*; D015899:Tomography, Emission-Computed, Single-Photon