Linguistic Specificity of the Left Temporal Cortex : Intraoperative Brain Mapping Data

The present study sought to test the hypothesis that the production of speech and the comprehension of speech in the left temporal lobe can be anatomically disassociated. Moreover, it is aimed to show that the standard intraoperative object naming task is not sufficient to test all the functionally essential areas in the left temporal lobe. In the introductory part of the article we described the existing information about the left temporal lobe and the awake surgery procedure. In the course of the study, we collected and analyzed the data from intraoperative brain mapping of 25 patients with brain lesions – gliomas or pharmacoresistant epilepsy, who underwent awake craniotomy. All the patient went through intraoperative language mapping with the use of direct electrical stimulation. In order to map language production and comprehension modalities, in addition to the classical object naming task we used an additional task, the phonological judgment task. The results showed substantial dissociation between mapping of two tasks. According to these findings, we can conclude that the object naming task alone is not suitable for adequate brain mapping of the left temporal cortex. The same dissociation may be regarded as an argument in favor of the anatomical dissociation of the production and comprehension of speech in the left temporal cortex