Fig. 2From: Surgical face masks impair human face matching performance for familiar and unfamiliar facesa Sensitivity (d′) and b response bias (criterion c) on the GFMT and the SFFMT (plotted separately for familiar and unfamiliar faces). Positive criterion c values indicate a conservative response bias (inclined to say ‘mismatch’), while negative values indicate a liberal bias. All error bars show the standard error of the mean (SEM)Back to article page