The neurogenetics of remembering emotions past.

E ven if you have not waded through all seven volumes of Marcel Proust’s Remembrance of Things Past (1), you are probably familiar with its most famous scene where the narrator bites into a little cake called a madeleine, dipped in tea, and experiences a wash of vivid emotional memories. This literary moment has captured popular imagination (madeleines are now sold by Starbucks) because it so effectively captures the powerful and involuntary nature of emotional memory. Indeed, Proust’s novels developed a distinction between voluntary and involuntary memories: The former involve more of our own efforts, but it is the latter, often characterized by emotions, that form the narrative of our life stories. Regarding his own flood of emotional memories Proust asked, ‘‘Whence did it come? What did it signify? How could I seize upon and define it?’’ Almost a century later, memory researchers are asking similar questions about what happens during an emotional event and its later retrieval. What leads us to recall such an event with effortless vividness long afterward? Further, why are some of us more likely to remember emotional memories with Proustian vividness than others or more likely to relive traumatic events? Echoing Proust’s thesis that one’s emotional memories are closer to the heart than to the mind, a study in this issue of PNAS by Rasch et al. (2) suggests that individual differences in the ADRA2B gene that codes the 2B adrenoreceptor, which plays an important role in vasoconstriction and blood pressure regulation, is also related to brain activation patterns underlying heightened emotional recall.