Objective: Disruption of fascicular tracts that connect Wernicke's to Broca's areas is the classic mechanism of conduction aphasia. Later work has emphasised cortical mechanisms.
Methods: To determine the distribution of language on dominant cortex, electrical cortical stimulation was performed using implanted subdural electrodes during brain mapping before epilepsy surgery.
Results: A transient, isolated deficit in repetition was elicited with stimulation of the posterior portion of the dominant superior temporal gyrus.
Conclusion: This finding suggests that cortical dysfunction, not just white matter disruption, can induce conduction aphasia.