MODIFICATION OF SEMANTIC MEMORY IN NORMAL SUBJECTS BY APPLICATION ACROSS THE TEMPORAL LOBES OF A WEAK (1 MICROT) MAGNETIC-FIELD STRUCTURE THAT PROMOTES LONG-TERM POTENTIATION IN HIPPOCAMPAL SLICES

Normal, right-handed human volunteers listened to a 5-min story and we re then exposed to 15 min (3 successive segments of 5 min on/5 min off ) of magnetic pulses (1 microT; 10 mG) whose temporal structure has be en shown to enhance long-term potentiation (LTP) in hippocampal slices . There were four conditions: no stimulation, bilateral stimulation (a cross both temporoparietal regions), primary stimulation of the left t emporoparietal lobes or primary stimulation of the right temporopariet al lobes. Reconstructions of the story were completed by the same subj ects within 30 min (intermediate memory) and about 10 days (long-term memory) later. The strongest effect size (25% of the variance was acco mmodated) was due to the approximately two fold increase in the number s of-accurate details for the long-term memories for subjects who had received the left hemispheric stimulation. These results suggest that contemporary technology may have the capability to access fundamental algorithms of the neuronal activity associated with declarative memory .