Subjective ratings
In line with pupil dilation findings, we observed a main effect of Hand
type [F(1,119) = 32.062, p < 0.001,
η2 = 0.212], indicating that participants preferred
to receive a touch from a Human hand than from an Artificial hand
[t(119) = 5.662, p < 0.001]. Also,
we found a main effect of Touch type [F(1,119) =
15.087, p < 0.001, η2 = 0.113],
indicating that participants preferred to receive a Dynamic than a
Static touch [t(119) = 3.884, p <
0.001]. Finally, we also found a significant Hand type by Touch type
interaction [F(1,119) = 7.402, p = 0.044,
η2 = 0.034], which showed that participants
preferred to receive a Dynamic touch from a Human hand. Indeed, post-hoc
pairwise comparisons showed that Dynamic touch from a Human hand
condition received the highest ratings compared to all other conditions
[Dynamic_Human vs. Dynamic_Artificial: t(119) =
3.657, p < 0.001; Dynamic_Human vs. Static_Human:
t(119) = 2.343, p = 0.021; Dynamic_Human vs.
Static_Artificial: t(119) = 7.070, p <
0.001] (Figure 2e ). These results, in line with physiological
findings, indicate that participants rated as the most pleasant a
dynamic touch delivered by a human hand.