Whether ability to mentally project oneself backwards
Whether animals have the capacity to mentallytravel through time and plan for the future is a controversial and highlydebated subject. “Mental time travel” in humans is defined as the ability to mentallyproject oneself backwards or forwards in time to re-live or plan for future events(Suddendorf and Corballis, 2007). The capacity to plan for the future is stronglylinked to episodic memory, and is generally considered an ability that onlyanimals with a higher cognitive capacity are able to perform. Episodicmemory allows access to a personally experienced event, that is, the subject remembersspecific situations and the emotions associated.
In contrast, semantic memory relatesonly to the knowledge learnt from said event (Suddendorf and Corballis, 2007). Itis suggested that non-human animals simply remember the facts of an event andthe associations learnt from it. Whether non-human animals are able to recall aspecific personal event, like humans are able to, is controversial (DERE etal., 2006).
In a study by Hampton (2001), it was indicated that monkeys mayhave the ability to understand what they remember; a cognitive abilitypreviously thought to only exist in humans. The monkeys were given a choice toperform a memory test for a high value reward if correct, or to decline thememory test which provided a lower value reward. The choice to decline a memorytest depended on the ability of the subject to assess either the presence orabsence of memory itself. This study showed that, like humans, monkeys wereable to assess at least some of their own knowledge states, whereas pigeonstested in the same way appeared to lack this ability.Roberts(2002) suggested that animals do not have a subjective sense of time and theirability to anticipate rewards at certain times of day is simply by using theirinternal states which change throughout the day. These circadian rhythms allowanimals to develop time-place learning (Roberts and Feeney, 2009). However, thesuggestion that animals are “stuck in time”, does not mean that animals have absolutelyno concept of time of day or that they do not have memory, as they are able toremember commands and can anticipate feeding at the same time each day (Robertsand Feeney, 2009).
Brainimaging demonstrated frontal and temporal lobe activity both when human subjectswere asked to remember the past and when they imagined the future (Okuda etal., 2003). However, there are specific areas in the frontal pole and medialtemporal lobes that are more involved in future planning than remembering thepast (Okuda et al., 2003, Suddendorf and Corballis, 2007). This indicates thatmemory shares cognitive resources with mental time travel (Suddendorf andCorballis, 2007).Rosenbaum et al. (2005) provided an accountof a patient called “KC” who lived with amnesia. He was able to partake in mostdaily activities with the guidance of reminders from family members, andremembered how to play pool, chess, card games, and the organ.
Overall his lifemay seem like that of any other adult male, however he was unable to rememberany single event that he had experienced (Mendl and Paul, 2008). It has becomeapparent that his lack of episodic memory has had an effect on future thinking,so when asked what he will be doing later, KC was unable to provide an answer.He was unable to imagine his future or remember his past (Tulving, 2002, Mendland Paul, 2008) The Bischof-Köhlerhypothesis proposes that non-human animals have an inability to comprehendtheir future needs and instinctive behaviours, which limits their capacity formental time travel. That is, non-human animals are unable to differentiatefuture states from present ones (Bischof-Köhler, 1985). Only humans are able toflexibly anticipate future mental states and understand how to act now tosecure them (Suddendorf and Corballis, 2008).Superficially this cannot be true as thereare many species which act to secure their future needs, however thishypothesis may be useful once applied to individual situations (Suddendorf andCorballis, 2007).
As current behaviour will categorically have an effect onfuture survival, the ability to implement mental time travel and foresight inanimals should have a positive effect on survival (Suddendorf and Busby, 2005).Some recurring environmental problems such as food shortages mean that storingfood for future is a practical solution. This relies on the ability of theanimal to remember where the food is stored, however may not necessarily implythat the animal envisages the future or plans for it specifically as humans do(Suddendorf and Corballis, 2007). Togain a full understanding of mental time travel and foresight, it is importantto rule out chance, innate predispositions, and procedural and semanticprospection (Suddendorf and Corballis, 2007). Simple prospective behaviours mayappear to involve the anticipation of future events, however may not actuallyinvolve planning (Clayton et al.
, 2003). Future-orientated instinctualbehaviours include those such as nest and burrow building to raise futureoffspring in, or the gathering of food for hibernation (Suddendorf and Busby,2005). Hibernation is another species specific instinctual behaviour that willoccur even if the animal has not yet experienced winter, so does not rely onmemory of previous events (Suddendorf and Busby, 2003).
Ithas been found that past experiences have an effect on the future emotionalstate of animals through learning associations between cues and emotionalevents, and through cumulative effects which alter stress responses, baselinestress levels, or mood (Mendl and Paul, 2008). Thebest evidence for mental time travel so far involves scrub jays. The current availableevidence suggests that scrub jays possess “www memory”.
They are able toencode, store, and recall information about what, where, and when they cachedfood (Suddendorf and Busby, 2003). The ability to evaluate how long food hasbeen stored for was shown when fresh worms were chosen over nuts, whereas wormsthat had been stored long enough for them to start to decay were not chosenover nuts (Clayton and Dickinson, 1998, Clayton et al., 2003, Suddendorf andCorballis, 2010).Dally(2006) also showed that presence of other scrub jays had an effect on cachingfood. If the subject was aware of another bird watching while caching food,they were far more likely to return and change where the food has been stored.
This may indicate that these scrub jays were able to think ahead and anticipatethat another bird may steal their cached food. Rabyet al. (2007) showed that non-hungry western scrub-jays cached more food in aplace where they were more likely to experience hunger in future compared to aplace where food was readily available at all times. However, this may bedemonstrating counterbalancing food sources.Possibilitiesof future planning has been observed in other species as well as scrub-jays. Ina study by Naqshbandi and Roberts (2006) squirrel monkeys and rats who were notthirsty were provided with food that induced thirst, and then were deprived ofwater. If the subject chose the larger quantity of food, water was withheld fora longer period than if they chose the smaller amount. Gradually the animalsreversed their preference for choosing larger quantities of food (Suddendorfand Corballis, 2010).
Mulcahy (2006) found that bonobos and orangutans bothselected, transported, and saved tools that allowed them to gain food one hour,then 14 hours later, well above baseline levels. Raby and Clayton (2009) arguedthat while apes showed future-orientated behaviours, hunger is a current stateso it can be argued that this cannot count as future planning. It has been welldemonstrated that animals are able to express local expectation of futureevents such as goal directed behaviours, such as pressing on a lever for food.However, this does not confirm future planning or anticipation of futureevents, as reinforcement over a few seconds or minutes is not a clear enough demonstrationsince instrumental responses for a reward by a hungry animal is controlled bycurrent motivational state (Clayton et al.
, 2003). Infuture mental time travel the “when” is particularly important as the subjectmust be able to separate the future mental state from the current to ensure afuture need will be satisfied, independent of current state (Clayton et al.,2003). Considering the similarities between animal and human foresight abilitiesshould immediately prompt the discussion of how these abilities are notsimilar, to prevent mistaking similarity for equivalence.
For example, the welldocumented temporal capacities of scrub-jays are related to food caching,whereas the human ability to time travel is characterised by a large range andflexibility (Suddendorf and Corballis, 2008). Theliterature reviewed in this essay suggests that future planning in animals maybe more short term than in humans, however it satiates the animal’s needs. Foresightmay not be “all or nothing”, and it is possible that there is a spectrum indicatingthat different animals have different amounts of foresight for their differentrequirements (Raby and Clayton, 2009). It may be possible that some animalspecies have autobiographical knowledge including episodic memory that they areable to recall and utilise in the short term, if not the long term, withouthaving the fully developed cognitive systems of an adult human (Raby andClayton, 2009). The ability to mentally time travel does not develop in humansuntil the age of approximately four years of age (Perner, 1991), therefore itis reasonable to assume that some animals may have some ability to performmental time travel similar to that of children.
Provingthe existence of mental time travel in animals is a difficult task without havingthe ability to communicate with animals. At the current time, it is notpossible to prove either the existence or absence of this ability in animals,however future developments in research techniques may allow the capacity ofthis ability to be further understood. Mental time travel has previously beenthought of as a human-only ability, therefore if this was found in non-humananimals, it would have a large impact on how we view animal intelligence andwelfare.