Fig. 4
From: Roughness integration across fingers within compared with across the hands
Normalised roughness ratings of target square wave gratings touched using the thumb alone or the index finger and thumb together. Individual participants ratings are shown by small symbols and group means by larger bold symbols (stars for single-digit touch and squares for two-digit touch which has been averaged over distractor groove widths). Data from one-handed conditions are shown in the top panel and two-handed conditions in the bottom panel.
