memory span
noun [ C ] psychology specialized uk/ˈmem.ər.i ˌspæn/ us/ˈmem.ɚ.i ˌspæn/
记忆广度（一个人在见到系列事物一次之后能记住的数量，或更广义地说，一个人能记住某事物的时间长度）
the number of things someone can remember after being shown a set of objects once, or more generally, the length of time someone can remember something