Response to editor to the comment by Bastin and Besson (2016) to our article entitled “Selective familiarity deficits in otherwise cognitively intact aging individuals with genetic risk for Alzheimer's disease”

Wewould like to thank Christine Bastin and Gabriel Besson for their thoughtful and pertinent comments regarding our recent article entitled “Selective familiarity deficits in otherwise cognitively intact aging individuals with genetic risk for Alzheimer’s disease” [1]. The authors correctly note that, for the analysis of our experiment, recollection was estimated from the proportion of correct recognition accompanied with correct source attribution, whereas familiarity was defined as the proportion of correct recognition in absence of accurate source attribution. Bastin and Besson argue that, defined as such, familiarity scores might be underestimated as both processes are known to co-occur. The authors clearly have a point here as this argument has been raised by dual-process theorists postulating that recollection and familiarity are independent processes. However, across dual-process models, the nature of the interplay and relationship between the two processes of recollection and familiarity remains a matter of debate [2]. For example, Gardiner and Parkin have suggested that recollection and familiarity might instead operate in a mutually exclusive manner [3]. In a different dual-process model proposed by Atkinson and Juola, recollection is believed to come into play only when familiarity fails to provide a clear recognition response [4]. Thus, the possibility that familiarity contributes to some extent to the recollection performance seems to be guided by theoretical considerations and conceptualizations of recollection and familiarity. Proponents of the independence assumption of recollection and familiarity have in the past introduced mathematical formulas to account for the potential co-occurrence of these two processes during the recollective experience. For example, researchers using the “Remember/Know” method sometimes divide the proportion of “Know” responses by the overall possibility of making a “Know” (K/(1 2 R)). This approach, also referred to as the Independence Remember/ Know procedure, aims to compensate for the fact that