Yes, yes, it's all very embarassing, but I never got around to doing my Monday paper Survey. Sorry, folks. I've been busy getting people to commit to a book I'm editing, and I've been preparing a talk for this event. (If it so happens that you will be participating as well, please come by the Friday "aesthetics" session and say hi!) So, there…Luckily, Thomas has been posting some very nice stuff, giving us the greatest ever number of visitors this Thursday. He also wrote about the very intereting Science study indicating that bonobos and orangutangs may be able to think ahead. In the spirit of this post I thought I would do a themed Saturday Paper Survey to make up for my wrongs, focusing on work on mental time travel (MTT) – i.e., the ability to recall past events and plan ahead.
The major discussion point among researchers on MTT has been whether or not other animals than humans posses it. The best entry point to this discussion is Nicola Clayton et al.'s review paper in Nature Reviews Neuroscience that argues that food-caching birds do have some kind of MTT ability [link to paper here], and a paper in Trends in Cognitive Science by Thomas Suddendorf and Janie Busby that dismisses Clayton's arguments [link to paper]. A short debate between Clayton and colleagues and Suddendorf and Busby ensued [Clayton's letter; and Suddendorf and Busby's reply].
So what does the data say? Volume 36, issue 2 of the journal Learning and Memory is a great special issue on "cognitive time travel in people and animals". Clayton and Suddendorf both have contributed illuminating papers. There are a papers on rats, birds, and great apes, as well as some interesting papers on MTT mechanisms in humans. [Link to whole issue.]
Apart form the fascinating discussion of whether or not other animals share a MTT ability with us, much interest is naturally focused on what cognitive mechanisms actually underlie MTT. A recent study by Lesley Fellows and Martha Farah in Neuropsychologia suggests a dissociation of temporal discounting – a hotspot of current neuroeconomics research – and future time perspective. From the abstract: "The present study contrasted the effects of dorsolateral and ventromedial frontal lobe damage on two distinct aspects of future thinking in humans. Temporal discounting, the subjective devaluation of reward as a function of delay, is not affected by frontal lobe injury. In contrast, a normal future time perspective (a measure of the lenght of an individual's self-defined future) depends on the ventromedial, but not dorsolateral, frontal lobes." [Link to paper.]