Fig. 5

Sensitivity (\(d^{\prime }\)) and response bias (c) for identity recognition (Question 1). Note. Error bars indicate standard errors. Each data point shows the sensitivity (\(d^{\prime }\); panel a) or response bias (c; panel b) of a single participant indicating whether they saw a face in the study phase, separately for familiar and unfamiliar faces and faces that wore a mask (blue dots) or not (gray dots) in the study phase. a Main effects of familiarity and masks on recognition sensitivity for faces. Higher values of \(d^{\prime }\) indicate better performance. A value of zero indicates ‘guessing.’ b Main effects of familiarity and masks on recognition bias for faces. Values greater than zero indicate a conservative bias (tendency to answer ‘no’) and values lower than zero indicate a liberal bias (tendency to answer ‘yes’)