Is it possible to reliably generate déjà vu in participants? Is it possible to get participants to reliably report déjà vu? These very similar questions are not necessarily as closely linked as we might think.
A paper I wrote with Radka Jersakova (@RadkaJersakova) and Chris Moulin (@chrsmln), recently published in PLOS ONE, reports a series of experiments in which we tried to stop people reporting déjà vu. Why? Because even in simple memory experiments that shouldn’t generate the sensation, upwards of 50% of participants will agree to having experienced déjà vu when asked about it. On the one hand, it’s a pretty strange set of experiments in which we are chasing non-significant results. On the other, it’s really important for the field of subjective experience research. If we can’t reliably assess the absence of an experience, how can we trust reports of its presence (OR if your null hypothesis isn’t a true null, don’t bother with an alternative hypothesis)?