Echo amplitude selectivity of the bat is better for expected than for unexpected echo duration.

A previous study shows that most inferior collicular neurons of the bat discharge maximally to a best duration and these duration-selective neurons have better echo frequency selectivity when the duration of both echo and pulse matches the best duration. In this study, we show that these duration-selective collicular neurons also have the sharpest echo amplitude selectivity when the duration of both echo and pulse matches the best duration. These data indicate that bats can better extract multiple parameters of expected than unexpected echo within the same time window after pulse emission. These data also support the previous studies showing that bats prepare their auditory system to analyze expected returning echoes within a time window after pulse emission.