Create Your Future: Remembering the Past to Imagine the Future

For more than a century, memory research has focused on the past. Psychologists have analysed the cognitive processes that allow people to retain past experiences, and neuroscientists have identified the brain structures, such as the hippocampus, that support this ability. A function of memory that has been largely overlooked until recently is its role in allowing individuals to imagine possible future events. Indeed, brain regions that have traditionally been associated with memory appear to be used when people imagine future experiences.

Tulving published a paper more than 20 years ago claiming that the capacity for mental time travel is uniquely human. As a result of this claim, much research focused on whether non-human animals are capable of mental time travel, using ingenious demonstrations to question the claim for human uniqueness. Debates about mental time travel in non-human animals might actually never be settled completely given the main stumbling block is that animals can’t actually talk….[please don’t Email me to say that your pet can talk – our Jack Russell definitely could – but science sometimes does lag behind :=) ]

Several recent neuroimaging studies have shown evidence of shared activity between the past & future areas in the brain. These were performed whilst a PET (positron emission tomography) scan was being carried out and volunteers were describing past and future events. These regions included the prefrontal cortex and parts of the medial temporal lobe.

In an MRI (fMRI) study, participants were instructed to remember specific past events, imagine specific future events or imagine specific events that involved a familiar individual (specifically, Bill Clinton) in response to event cues. Again, there was striking overlap in the activity associated with past and future events in prefrontal and medial temporal regions. These regions were not activated to the same extent when imagining events that involved Bill Clinton, which demonstrates the existence of a neural signature that is specific to the events in one's personal past or future. I wonder if they tried future experiments involving cigars….

So for those of you who are actively creating your day and envisioning your future, you now know that science has found out what your brain is doing. Not that I hope would have stopped you if it hadn’t !

See you again next month!


References:
Daniel L. Schacter, Donna Rose Addis & Randy L. Buckner, Nature Reviews Neuroscience 8, 657-661 (2007)

Tulving, E. Elements of Episodic Memory. (Clarendon Press, Oxford England, 1983).

Tulving, E. Memory and consciousness. Canadian Psychology. 26, 1–12 (1985).

Tulving, E. in The Missing Link in Cognition (eds Terrace, H. S. & Metcalfe, J.) 3–56 (Oxford Univ. Press, New York, 2005).

Clayton, N. S., Bussey, T. J. & Dickinson, A. Can animals recall the past and plan for the future? Nature Rev. Neurosci. 4, 685–691 (2003).

Suddendorf, T. & Corballis, M. C. Mental time travel and the evolution of the human mind. Genet. Soc. Gen. Psychol. Monogr. 123, 133–167 (1997).

Suddendorf, T. & Corballis, M. C. The evolution of foresight: what is mental time travel, and is it unique to human? Behav. Brain Sci. (about to be published).

Clayton, N. S. & Dickinson, A. Episodic-like memory during cache recovery by scrub jays. Nature 395, 272–274 (1998).

Okuda, J., et al. Thinking of the future and the past: the roles of the frontal pole and the medial temporal lobes. NeuroImage 19, 1369–1380 (2003).

Szpunar, K. K., Watson, J. M. & McDermott, K. B. Neural substrates of envisioning the future. Proc. Natl Acad. Sci. USA 104, 642–647 (2007)