NEURAL ORGANIZATION OF MATERIAL-SPECIFIC MEMORY FUNCTIONS IN TEMPORAL-LOBE EPILEPSY PATIENTS AS ASSESSED BY THE INTRACAROTID AMOBARBITAL TEST

Lateralization of material-specific memory processing was evaluated in 105 epilepsy patients undergoing the intracarotid amobarbital test (IAT) prior to temporal lobectomy (TL). Left hemisphere (LH) language dominant patients demonstrated LH specialization for long-term verbal recognition memory and right hemisphere specialization for visuospatial recognition memory. The pattern of hemispheric memory specialization was similar for LH language dominant patients with brain injuries before 2 years of age and those without history of early brain injury, suggesting that the apparent sparing of memory post-TL in early brain injury patients reflects reorganization of memory functions within the epileptic hemisphere. Non-LH-language dominant patients showed no lateral specialization for either verbal or visuospatial memory processing, suggesting that in these individuals reorganization of memory functions between hemispheres accompanies the lateral shift in language representation.