Forward masking in the evoked responses of the guinea pig auditory cortex: effects of variation of the interaural time and phase differences |
| |
Authors: | Al'tman J A Nikitin N I Shestopalova L B |
| |
Institution: | I. P. Pavlov Institute of Physiology Russian Academy of Sciences, Nab. Makarova, 6, St. Petersburg, 199034, Russia. |
| |
Abstract: | In anaesthesized guinea pigs the evoked potentials of the auditory cortex were studied in a forward masking paradigm. In-phase and out-of-phase binaurally presented clicks with interaural time delay (ITD) were used as masker, in-phase click with ITD = 0 served as probe signal. Addition of the masking stimulus suppressed the probe-evoked response that followed the masker. The magnitude of the suppression correlated with the amount of the masker-evoked response: an increase in masker-evoked excitation caused a greater reduction in probe response magnitude. Amplitude of masker-evoked response was seen to be a monotonic or non-monotonic function of ITD. The non-monotonic response exhibited a sensitivity to the interaural phase differences when in-phase and out-of-phase maskers were presented, and showed the tendency to be periodic function of ITD in the expanded range of ITD values. Phase-sensitive responses differed in recovery time following the in-phase and out-of-phase masking stimuli. At near-threshold levels of a forward masker an enhancement of the probe-evoked response was observed. |
| |
Keywords: | |
本文献已被 PubMed 等数据库收录! |
|