Psychology Wiki

Assessment | Biopsychology | Comparative | Cognitive | Developmental | Language | Individual differences | Personality | Philosophy | Social |
Methods | Statistics | Clinical | Educational | Industrial | Professional items | World psychology |

Cognitive Psychology: Attention · Decision making · Learning · Judgement · Memory · Motivation · Perception · Reasoning · Thinking  - Cognitive processes Cognition - Outline Index

Chronesthesia, or mental time travel, is a mental ability first hypothesized by Endel Tulving in the 80s. This refers to the ability to be aware of one's past or future. While many may describe it as uniquely human, others now argue that this ability can transcend to include non-human animals as well as birds. The mechanisms of mental time travel are not yet fully understood since there is a level of obscurity and complexity when trying to measure if or when someone underwent mental time travel or not. However, studies have been conducted to map out areas of the brain that may be responsible for mental time travel.


Chronesthesia is defined as a hypothetical ability that allows humans to be constantly aware of the past and the future.[1] Endel Tulving, one of the pioneers in this field, explained that humans adapted chronesthesia as a way to advance their survival.

Some people may go further as to say that it is a crucial ability for humans.[2] There seems to be some confusion about the definitions of episodic memory, memory for the future, and mental time travel. Episodic memory involves projecting oneself back in time and recollecting many aspects of previous experiences.[3] Mental time travel is more robust when planning for the future than for re-experiencing past events. This makes sense since it is the present and the future, and not how the past is represented, that matter. Therefore, mental time travel involves both past and future thinking, while episodic memory only deals with mentally traveling to the past.

With regards to memory for the future, this is actually a subcategory of mental time travel.

Brain regions involved[]

Scientists have mapped regions of the brain that could possibly be involved in mental time travel. While these types of studies are not numerous, they help advance understanding of this complex phenomenon.

fMRI mapping of brain regions[]

Addis D. et al. conducted an fMRI study to examine neural regions mediating construction and elaboration of past and future events.[4] The left hippocampus and posterior visuospatial regions are involved in past and future event construction, neural differentiation. The right hippocampus, right frontopolar cortex, and the left ventrolateral prefrontal cortex are involved in future event construction.

The elaboration phase, unlike the construction phase, has overlap in the cortical areas comprising the autobiographical memory retrieval network. In this study, it was also found that the left hippocampus and the right middle occipital gyrus were significantly activated during past and future event construction, while the right hippocampus was significantly deactivated during past event construction. It was only activated during the creation of future events.

Episodic future thinking involves multiple component processes: retrieval and integration of relevant information from memory, processing of subjective time, and self-referential processing.[5] D'Argembeau et al.'s study found that the ventral medial prefrontal cortex and posterior cingulate cortex are the most activated areas when imagining future events that are relevant to one's personal goals than to unrelated ones. This shows that these brain regions play a role in personal goal processing, which is a critical feature of episodic future thinking.

Brain regions involved in the 'what' and 'where' of an event[]

Cabeza R. et al. conducted a positron emission tomography (PET) scan study on a group of human test subjects to identify the brain regions involved in temporal memory, which is based on a linear progression of events. Since 'recollecting a past episode involves remembering not only what happened but also when it happened', PET scans were used to find the areas of the brain that were activated when trying to remember a certain word in a sequence.[6] The results show that temporal memory of past events involves the frontal and posterior brain regions.

Research In nonhuman Animals[]

The suggestion of mental time travel in animals has been highly controversial. Endel Tulving has argued that Episodic memory requires a specific conscious experience of past and future events which he argues is unique to humans. [7] However, given that we cannot study the conscious experience of animals, animal researchers have had to redefine episodic memory to make it amenable to study (see episodic-like memory).

It is widely known that animals can behave appropriately for future events, for example animals will eat before starving to death, run away from a predator in anticipation of injury and prepare a nest. However, these behaviors are driven by their current motivational state. We know the neural processes behind many of these motivational states, [8] however what is more contraversial is whether animals can plan for a motivational state that they will have some time in the future. The so-called "Bischof-Kohler hypothesis" states that animals cannot act on future needs and motivations that are not currently experienced because they only experience a constant present. [9] Thus, researchers have tried to design tasks which show that animals can ignore their current motivational state for a future one. 

Tests of mental time travel[]

A variety of tests for mental time travel exist, however they do not all tap the same cognitive abilties.

Anticipatory contrast studies give animals the choice of a minimal amount of food at time 1, or a greater amount of food at time 2. The ability to wait for the greater reward relies on both self-control and future anticipation. [10] Studies that aim to test planning typically aim to test if an animal can behave accordingly for a future mental state or situation. An animal feeding because of hunger would be discounted because they are satisfying their current mental state. 

Planning in primates[]

Anecdotal evidence for planning in chimpanzees was recently reported by Osvarth. [11] A male, dominant chimpanzee would collect stones from the waterbed and break off sections of concrete which would later be used for throwing at zoo visitors. All of the gathering was conducted under a calm state, always when the visitors were not present before opening time, and throwing only occured during agitated dominance displays. The stones were only stored in areas adjacent visitor areas, suggesting that this chimpanzee's planning was very specific and directed towards a future emotional state. Osvath et al. conducted a study on apes to show that they have the ability of foresight. The study consisted of testing for self-control, associative learning, and envisioning in chimpanzees, gorillas and orangutans through a series of experiments.[12] Critics questioned whether these animals truly exhibited mental time travel, or whether it was associative learning that caused them to behave as they did. The Bischof-Kohler hypothesis says that animals cannot anticipate future needs, and this study by Osvath tried to disprove the hypothesis.

The scientists showed that when the apes were presented with a food item in conjunction with a utensil that could be used to actually eat that particular food, these animals chose the utensil instead of food. They anticipated a future need for the utensil that overcame the current want for just a food reward. This is an example of mental time travel in animals. It was not a result of associative learning that they actually chose the utensil instead of the food reward since the scientists ran another experiment to account for that. Other examples, such as food caching by birds, may be examples of mental time travel in non-humans. Even survival instinct by certain animals such as elephants, in response to imminent danger, could involve mental time travel mechanisms.

Another study to show that great apes have the ability of foresight was conducted by Martin-Ordas G. et al. These scientists were able to show that 'apes remember in an integrated fashion what, where and when' a particular event had happened.[13] Two experiments were conducted in this study-the first being an investigation of the content of the memories of apes i.e. could these animals remember when and where two types of food they were shown before were now hidden. The second experiment explored the structure of the memories. It was found that the apes' memories were formed in an integrated what–where–when structure. All these findings once again show that it is not instinctive or learning predispositions that made the animals behave the way they did; rather, they have the ability to mental time travel, just like humans can.

Naqshbandi & Roberts tested for future anticipation of thirst in squirell monkeys and rats. [14] In four forced-choice pre-trials two monkeys could choose to eat 4 half dates and have their water returned to them 3 hours later, or choose to eat 1 half date and have their water returned to them 30 minutes later. After 6 trials (including the baselines trials), the monkeys reversed their preference for the larger amount of dates, which induced more thirst in the future, suggesting that the monkeys could plan for future states. However, in a second experiment, one monkey was given its water bottle back 3 hours later regardless of how many dates it ate. The researchers argued that if the monkeys based their choice of food of when they would have their water bottle back, then they would choose the larger, more satisfying portion. However, monkeys could also base their decision on the fact that eating more dates makes them more thirsty, then they would choose the smaller portion. Therefore, either option in the "control" condition would "prove" a planning hypothesis. In fact, the monkeys chose larger portions. A larger questionmark surrounds the interpretation that monkeys used planning instead of associative learning in their decision making.

Planning in Scrub-Jays[]

A western scrub-jay caching a wax worm in a ice-cube tray. This is a common storage place used in studies of corvid cognition.

Various studies have suggested that scrub-jays are capable planning for a future motivational state. Scrub-jay's episodic memory abilities have already been intensely studied, and their propensity to store food ("caching") has been manipulated in many comparative cognition experiments, including mental time travel experiments. 

Raby et al. showed that western scrub jays would preferentially store food in a place where they would later be hungry. The experiment involved teaching individual jays that would recieve breakfast (30 minutes before darkness) in one cage compartment and not in another, however these cage compartments were open during the day but not during breakfast. [15] The food given on these training days was powdered and could not be stored and therefore the birds could not learn where to store the food in the experimental condition through association learning. On the experimental task, jays were given cacheable pine nuts during the evening, and allowed to cache the food in either the compartment of the cage which would later be closed. The researchers found that birds would cache food in the compartment which birds were not fed breakfast in, suggesting that in the evening they were planning for their future state of hunger in the morning. However, animals prefer to eat in places associated with hunger generally, so as an extra control experiment, the researchers used a similar set up except every morning birds were consistently given dog kibble or peanuts in either compartment in the morning. In the evening of the experimental trial, the birds were allowed to eat and cache either item. Association learning may predict that birds would prefer to cache food in places that they normally eat the food in, whereas we know that birds prefer to eat a variety of food at a time,[16] so therefore if the birds could plan they might cache peanuts where they normally eat kibble, and visa versa. Indeed, this is what the researchers found. 

Another study on western scrub jays from the same lab suggests that western scrub-jays can plan for future motivations. Correria et al. also exploited jay's preference for eating multiple food types. [17] In stage 1, birds were given either pine seeds or kibbles for 3 hours, and immediately afterwards (stage 2) a preference test was given were birds were allowed to eat and cache both food items for 10 minutes in cage compartments which opened only for this session and closed afterwards. Then, 30 minutes later (stage 3), jays received a second 3-hour-long feeding session: in the "different" group, the jays ate a different food in stage 3 to stage 1, and in the "same" group, the jays ate only the same food from stage 1.  In the final stage (4), birds were allowed to collect the caches they made in stage 2. 4 trials like this were conducted for every jay. At stage 2 the birds would prefer to eat the different food, and based on their current motivational state, they might also want to cache this same food for later. However, the birds in the "different" group, if they had foresight, could predict that at stage 4 they would want to eat the food that they currently do not prefer, and cache that instead. Indeed, this is the pattern shown in the experiments, suggesting that mental time travel is used.  

Developmental Perspective []

Tests of Mental Time Travel in Children[]

Theorists still debate over the exact nature of mental time travel and which tasks should be used to measure it. Russell et al. divide tests of mental time travel into three broad categories. [18]

  1. Asking children questions about what they would or would not do tomorrow. Busby & Suddendorf found that for both types of questions 3, 4 and 5  year olds could progressively score better on this task, with 11-31%, 60-69% and 63-87% of children scoring correctly (95% confidence intervals of percentages given). [19]
  2. Asking children to respond appropriately for a future motivational state which conflicts with their present state. Russell includes delay-of-gratification tasks as part of this type. This task places demands on executive function aswell as future-thinking and planning. 
  3. Asking children to select items for future use. Development on these tasks also occur in the preschool period, Atance & Meltzoff, who both orignally designed the test, found that correct responses in 3,4 & 5 year olds increased from 61% to 92%. [20]

Atance & Jackson examined how individual differences across a variety of "mental time travel" tasks covary- if we suspected that it was a unitary concept then children's performances on these tasks should be correlated with each other. [21] Although zero-order correlations between tasks were moderate, when controlling for age and vocabulary, most tasks did not correlate with each other. However, Atance and Jackson included planning tasks' (such as the tower-of-hanoi task) or "prospective memory" tasks which do not necessarily invovle thinking about a future event. It's likely that these two types of task rely on different cognitive processes. In summary, vague terms such as "future thinking" or "planning" might need to be dissemintated and the underlying processes behind them need to be further analysed. 

When does Mental Time Travel Develop?[]

Of course, in order to answer this question one needs a good idea of how to measure the construct. However, as Atance & Jackson showed (see above), we currently do not understand how tasks of future thinking are related, and therefore it is impossible to measure the construct easily. One can contrast this to intelligence or personality research where we know the extent to which questions/tasks correlate with their constructs (intelligence or personality) and how subcomponents inter-relate (i.e. neuroticism, extraversion, etc.). 

The ages of 3-5 are the most intensely studied in developmental studies, and over this period increases in task performance are often seen (see above), however its likely that many children below the age of 3 can also perform well in episodic memory tasks. Children as young as two years old talk about the future, however some have argued that they rely on "scripts" of routine activities like going to bed rather than having a true representation about a future event. [22] 

Issues and Future Research[]

The two biggest questions in the field right now are whether mental time travel is unique to humans or not, and what the mechanisms of this phenomenon are.[23] Suddendorf and Corballis say that while mental time travel is uniquely human, it does not mean that animals cannot exhibit future-oriented behavior.[24] In contrast, it is that there are several characteristics that distinguish one from the other. For example, future-orientation can be based on instincts, and imagination may be involved. However, mental time travel does not involve these things. Rather, it is a mental state that cannot be directly observed. It involves flexibility in situations to adapt to individual goals, and therefore must be unique to humans. But, as Toomela describes in his study, since mental time travel is a complex episodic psychological phenomenon that is personal and subjective, evidence of it in animals can only be indirect. It may also be beneficial to look at research in the field of psychology to further understand this state.

The future of this field lies in understanding what the specific behavioral markers for mental time travel are, and being able to exactly identify which regions in the brain cortex correspond to mental time travel specifically. As was mentioned in the Clayton N.S. et al. study, research needs to be done to figure out whether episodic memory and future planning are linked. Also, if birds exhibit signs of episodic memory and future planning, how is it possible to link that to humans, since the mammalian cortex is different from that of a bird? It has been suggested to use more mammalian models in order to understand chronesthesia better, as well as to map out more regions in the cortex that are specifically devoted to mental time travel.

See also[]


  1. Murray, B. (2003). What makes mental time travel possible? Monitor Staff, 34(9), 62.
  2. Quoidbach, J., Hansenne, M., & Mottet, C. (2008). Personality and mental time travel: A differential approach to autonoetic consciousness. [Article]. Consciousness and Cognition, 17(4), 1082-1092.
  3. Schacter DL, Wang PL, Tulving E, Freedman M. Functional retrograde amnesia: a quantitative case study (1982). Neuropsychologia, 20(5), 523-32.
  4. Addis, D. R., Wong, A. T., & Schacter, D. L. (2007). Remembering the past and imagining the future: Common and distinct neural substrates during event construction and elaboration. [Article]. Neuropsychologia, 45(7), 1363-1377.
  5. D'Argembeau, A., Stawarczyk, D., Majerus, S., Collette, F., Van der Linden, M., Feyers, D., et al. (2010). The Neural Basis of Personal Goal Processing When Envisioning Future Events. [Article]. Journal of Cognitive Neuroscience, 22(8), 1701-1713.
  6. Cabeza R., Mangels J., Nyberg L., Habib R., Houle S., McIntosh A.R., et al. (1997). Brain Regions Differentially Involved in Remembering What and When: a PET Study. [Article]. Neuron, 19, 863–870.
  7. Tulving, E. (2002) Episodic Memory: From Mind to Brain. Annual Reviews of Psychology, 53, 1-25.
  8. i.e. Panksepp, J. & Biven, L. (2012) The Archaeology of Mind: Neuroevolutionary Origins of Human Emotions. W.W. Norton.
  9. Feenet, M.C. & Roberts, W.A. (2012) Comparative Mental Time Travel: Is There a Cognitive Divide between Humans and Animals in Episodic Memory and Planning? IN: Vonk, J. & Shackelford, T.K. (eds.) The Oxford Handbook of Evolutionary Psychology.
  10. Naqshbandi, M. & Roberts, W.A. (2006) Anticipation of Future Events in Squirrel Monkeys (Saimiri sciureusI) and Rats (Rattus norvegicus): Tests of the Bischof-Kohler Hypothesis. Journal of Comparative Psychology, '120, 4, 345-357.
  11. Osvarth, M. (2009) Spontaneous planning for future stone throwing by a male chimpanzee. Current Biology, 19, 5, R190.
  12. Osvath, M. (2010). Great ape foresight is looking great. [Editorial Material]. Animal Cognition, 13(5), 777-781.
  13. Martin-Ordas, G., Haun, D., Colmenares, F., & Call, J. (2010). Keeping track of time: evidence for episodic-like memory in great apes. [Article]. Anim Cogn, 13, 331–340.
  14. Naqshbandi, M. & Roberts, W.A. (2006) Anticipation of Future Events in Squirrel Monkeys (Saimiri sciureusI) and Rats (Rattus norvegicus): Tests of the Bischof-Kohler Hypothesis. Journal of Comparative Psychology, '120, 4, 345-357.
  15. Raby, C.R. (2007) Planning for the future by western scrub-jays. Nature, 445, 22, 919-921. 
  16. e.g. Clayton, N.S. & Dickinson, A. (1999) Motivational control of food-caching behavior in the scrub jay, Aphelocoma coerulescens. Animal Behavior,' 57, 435-444.
  17. Correria, S.P.C., Dickinson, A. & Clayton, N. (2007) Western Scrub-Jays Anticipate Future Needs Independently of Their Current Motivational State. Current Biology, '17, 856-861.
  18. Russell, J., Alexis, D. & Clayton, N. (2010) Episodic Future Thinking in 3- to 5-year old children: The ability to think of what will be needed from a different point of view. Cognition, 114, 56-71.
  19. Busby, J., & Suddendorf, T. (2005). Recalling yesterday and predicting tomorrow. Cognitive Development, 20, 362–372
  20. Atance, C. M., & Meltzoff, A. N. (2005). My future self: Young children’s ability to anticipate and explain future states. Cognitive Development, 20, 341–361
  21. Atance, C.M. & Jackson, L.K. (2009) The development and coherence of future-orientated behaviors during the preschool years. Journal of Experimental Child Psychology, 102, 379-391.
  22. See Summary on Atlance, C.M. (2008) Future Thinking in Young Children. Current Directions in Psychological Science, 17, 295.
  23. Toomela, A. (2010). Biological Roots of Foresight and Mental Time Travel. [Article]. Integrative Psychological and Behavioral Science, 44(2), 97-125.
  24. Suddendorf T., Corballis M.C. (2007) The evolution of foresight: What is mental time travel, and is it unique to humans? [Article]. Behav brain Sci., 30(3), 299-313.