Humans have mental time in our mind, apart from physical time that is a part of system that
governs the physical world, and memory is our key cognitive ability for recognizing the
passage of time. Recent studies have suggested that the memory system of several
nonhuman animals may have an incidental nature, which is also a feature of episodic
memory. In addition, apes, which are phylogenetically close to humans, have an ability to
remember a single past event. In the case of humans, preverbal infants under the age of two …