Complex sentence: Another example is if people see an incomplete sketch that they are unable to identify and they are shown more of the sketch until they recognize the picture, later they will identify the sketch at an earlier stage than was possible for them the first time.
Split into simpler sentences: Another example is when people see an incomplete sketch that they are unable to identify: they are shown more of the sketch until they recognize the picture. Later they will identify the sketch at an earlier stage than was possible for them the first time.