Brief: This lecture covers basic concepts of mental time travel – both in humans and non-humans.
Mental Time Travel
Episodic memory is the ability to remember events. This is different from semantic memory which is memory of facts. For a long period it has been assuming that memory is there to provide an accurate record of the past. Indeed, accuracy has been the dependent variable in most, if not all, memory research. However, the research shows that episodic memory is not very good at keeping a faithful record. It is characterized by errors and biases, and retrieval is a reconstructive process. It seems that we remember the general gist, or ‘outline’ of an event the actively reconstruct it during recall. From an evolutionary perspective, natural selection can only work on what memory contributes to fitness, not on how accurately it reflects the past per se. If memory is not accurate but still has adaptive function it may be selected for, yet if it is not accurate and without adaptive function, it almost certainly will cease to be a trait.
Some argue that MTT into the past is to provide a better understand of the present, allowing integration of information from different learning events. Yet other argue (Suddendorf) that episodic memory may be there to enable simulation of potential future events. He argue the episodic memory may only be an adaptive design features of a foresight system – this argument could explain why there are characteristic errors in recall. Our foresight system needs to be flexible for seeing into the future, knowing this we see the same ‘flexible’ errors in recollection.
Into the future:
Being able to ‘predict the future’ offers many benefits. It offers opportunities to increase future survival and reproduction chances by allowing us to prepare for anticipated future events and contingencies. In this sense we plans and shape the future (both individually and collectively – as societies, governments, etc).
When engaging in remembering an event (what did you have for breakfast yesterday) and answering a future question (what will you have for breakfast tomorrow) there are similar areas of brain activation. The medial temporal and prefrontal lobes are activated.
We observe similar impairment in amnesic patients – who have problems with imagining the future as they do with remembering the past. We find the development in childhood occurs at the same time – around age 3 or 4 in children the ability to recall events from yesterday and predict tomorrow co-emerge.
MTT in human society
Many of the actions we engage in daily are based on remote future goals. Give that our action is driven by future need anticipation; an alien observer of human behaviour would have trouble making sense of many people’s actions without knowledge of their past or future plans. We even see crazy things (biological paradoxes) such as celibacy and hunger-strikes where one actively decides to engage in a biological dead-end behaviour in order to achieve some kind of future goal.
Episodic-like Memory in animals
Scrub jays recover food caches according to what was stored, where and when. In short, a scrub jay won’t look for a cached worm after a certain period of time has passed because it ‘knows’ that it will have decomposed, instead it will try to retrieve a peanut that stays good longer. (Experimental conditions here). There is much similar www research (what where when research).
Given that fact that memory is a personal event and the new definition is based on autonoetic (self-knowing) consciousness (that is self, subjective time and recollective experience) we have trouble readily demonstrating this in the absence of language. Suddendorf proposes that an alternative approach is to study foresight; MTT future should be evident in flexible future-directed behaviour.
Animal forethought is limited by their current need/drive state. Imaging future needs Is uniquely human – “A full-bellied lion is no threat to a zebra, whereas a full-bellied human may well be?.
D’Amato’s monkeys were fed only once a day. After they had had their fill and had food left over they soon began a food fight and their food was scattered all around (including outside their cage). Later, when they were hungry, they had no food as they had thrown it away.
Current theory is hotly debated, and not yet falsified.
There evidence for instinctual future-directed behaviour is not yet relevant (there is no novel application; simply an animal running a program possibly cued by environmental factors). And there is no evidence yet of flexibly anticipating future needs (as in monkeys no keeping and refining of tools after use).