PERSISTING VERSUS SUSTAINED NEURAL ACTIVITY - EFFECTS ON TRANSIENT N100M RESPONSE

PREVIOUS evidence from animal and human studies suggests that neural a ctivity, both during a continuous tone and persisting after the offset of a first tone, can prolong the latency and enhance the amplitude of a transient response to a second tone. Our results showed that the la tency of N100m to a second tone presented to the opposite ear was prol onged equally in both conditions. Unexpectedly, the effects on respons e strength strongly depended on stimulus laterality: the ipsilateral b ut not the contralateral N100m to the second tone was enhanced by the simultaneous presence of the first when compared with the effect of th e preceding tone. This suggests that sustained neural activity during a continuous tone can release inhibition normally induced by ipsilater al stimulation.