A core brain network appears to be engaged in remembering the past and envisioning the future. This network overlaps with the so-called default-mode network, which shows higher activity when demands for focused attention are low. Here, the authors show that functional connectivity of the default-mode network in children and adolescents is related to the quality of past remembering and contributes to future imagination.
A strong role for the hippocampus in simulations or imagination of the future (mental time travel) has been suggested in some but not all studies. The authors did not find a relationship with the hippocampus and they suggest that the ability of patients with hippocampal lesions to imagine fictitious events may be based on processes other than those in the hippocampus. For example, future thinking in patients with hippocampal lesions may be based on world knowledge and semantic representations rather than true visualization or scene construction supported by the hippocampus. The authors suggest that more research into the role of the hippocampus in remembering and imagination, especially during development, is needed to reconcile the different views.
In summary, mental time travel appears to be modulated by the task-independent functional architecture of the default-mode network in the developing brain. Analysis also showed that local cortical arealization contributes to recall of the past and imagination of the future.
[Editor comment: Does the ability to “envision the future” predict chess playing ability in children? Imagination of the future is strongly involved in these strategic game moves.]
Østby Y, Walhovd KB, Tamnes CK, Grydeland H, Westlye LT and Fjell AM: Mental time travel and default-mode network functional connectivity in the developing brain. Proc. Natl. Acad. Sci. USA [Epub ahead of print doi: 10.1073/pnas.1210627109, October 1, 2012].