There are constantly statements about what abilities humans have that are unique. One of these is mental time travel. Decades ago Tulving put forward the notion of episodic memory and at the same time stated his opinion that it was unique to humans and that animals do not have episodic memory or a conscious experience of remembering. Suddendorf and Corballis put forward the notion of mental time travel: “the human ability to travel mentally in time constitutes a discontinuity between ourselves and other animals”. Lately Corballis has changed his mind: “Mental time travel has neurophysiology underpinnings that go far back in evolution, and may not be as some (including myself) have claimed, unique to humans.” Other animals may experience remembering specific events and may experience the planning of future events. In fact, I would find it difficult to explain their behavior if they did not have these abilities.
Imaging the old grandmother elephant leading her family to the bones of dead relatives, where they can touch and look at bones of specific dead loved ones. We know elephants are conscious even self-conscious, have theory of mind, have long memories, know and can navigate huge territories and know individual elephants that are not part of their group. I find it very difficult to imagine that when they touch the bones they have come to visit, they are not experiencing vivid memories of their dead relatives.
Time travel has been indicated in rats, pigeons, jays and dolphins but without convincing all critics. Now another study is even more convincing. (Gema Martin-Ordas, Dorthe Berntsen, Josep Call; Memory for Distant Past Events in Chimpanzees and Orangutans; Current Biology, Volume 23, Issue 15, p1438–1441, 2013) Here is the abstract:
Determining the memory systems that support nonhuman animals’ capacity to remember distant past events is currently the focus an intense research effort and a lively debate. Comparative psychology has largely adopted Tulving’s framework by focusing on whether animals remember what-where-when something happened (i.e., episodic-like memory). However, apes have also been reported to recall other episodic components after single-trial exposures. Using a new experimental paradigm we show that chimpanzees and orangutans recalled a tool-finding event that happened four times 3 years earlier (experiment 1) and a tool-finding unique event that happened once 2 weeks earlier (experiment 2). Subjects were able to distinguish these events from other tool-finding events, which indicates binding of relevant temporal-spatial components. Like in human involuntary autobiographical memory, a cued, associative retrieval process triggered apes’ memories: when presented with a particular setup, subjects instantaneously remembered not only where to search for the tools (experiment 1), but also the location of the tool seen only once (experiment 2). The complex nature of the events retrieved, the unexpected and fast retrieval, the long retention intervals involved, and the detection of binding strongly suggest that chimpanzees and orangutans’ memories for past events mirror some of the features of human autobiographical memory.
It seems unscientific to assume the answer before asking the question. Why was it assumed that animals did not feel? Then why assume that they did not think? Then, anyway they were not conscious, right? And now that they cannot consciously remember personal events? There was tool using, then tool making, and then serial tool use, all disproved. The only thing that has come close is that animals have no language ability. Even that may be over turned by whales. This drive to find human uniqueness and the stubbornness in defending it, is unbecoming to science. It is not creationism – but somehow it has a tiny bit of the same odour. Science should be looking at why animals (including humans) have a episodic memory, how it helps them think, plan, react and not whether it has some mystical ‘autonoetic’ insight to its conscious experience in humans but not other animals.