Age-Related Impact in Illusory Torque Cues Induced by Asymmetric Vibrations

Illusory pulling sensations in the translational or rotational direction are induced by asymmetric vibrations applied to the fingertips. Although previous studies have discussed the involvement of mechanoreceptors associated with skin deformation and spatial processing in the parietal association cortex in the generation of illusory cues, the precise mechanism underlying this phenomenon remains unclear. In this study, we aimed to indirectly estimate the contribution of mechanoreceptors to the perception of illusory pulling torque cues by examining the relationship between vibration thresholds and the properties of these illusions, leveraging the known decline in cutaneous sensation sensitivity associated with aging (N = 40). Our results revealed an age-related increase in vibration thresholds, which is consistent with previous research. While male participants showed consistent sensitivity to illusory pulling cues across age groups, female participants exhibited a decline in sensitivity with age. Moreover, we observed only weak or no correlations between the vibration thresholds and the sensitivity of the illusory pulling cue. Although we were unable to identify any findings that explain the contribution of mechanoreceptors, we discovered a gender difference in the sensitivity to induced illusions among older individuals. These findings offer valuable insights for elucidating the mechanism underlying the illusion.