Before revision:  However, we still lack a systematic understanding of the neural mechanisms of how animals perceive, maintain, and use time intervals ranging from hundreds of milliseconds to multi-seconds in working memory , the combination of time information with spatial information processing and decision making , and the reasons for the strong neuronal temporal signal even when animals performing tasks in which time information is not required  .
After revision:  However, we still lack a systematic understanding of the neural mechanisms of how animals perceive, maintain, and use time intervals ranging from hundreds of milliseconds to multi-seconds in working memory , the combination of time information with spatial information processing and decision making , and the reasons for the strong neuronal temporal signal even when animals performing tasks in which time information is not required ? A systematic understanding of the underlying neural mechanisms is still lacking .