視覚ノイズが触2点閾に及ぼす効果についての報告

Abstract

Stochastic resonance refers to the phenomenon in which a specific level of weak noise improves detection of sub-threshold signals. In this study we examined whether tactile two-point discrimination threshold is improved by addition of visual noise using random dots, with five different intensities. In 3 healthy adult participants, the two-point threshold measured at the 3rd pad of the index finger of the non-dominant hand. The two-point threshold was improved significantly by addition of weak noise near its detection threshold as compared to a control without noise. On the other hand, a more intense or a less intense noise had no such effect. Thus, the two-point threshold showed U-shaped curve against the noise intensity. Similar results were observed in both the mean and individual scores. The sample number was small, but nevertheless statistically significant difference between the weak noise and control was obtained. These results suggest that the visual noise can improve the two-point threshold via the cross-modal stochastic resonance.