Vibrotactile Force Perception - Absolute and Differential Thresholds and External Influences

Three experiments were carried out to determine absolute and differential thresholds for vibrotactile forces and external influences in the frequency range of 5 to 1000 Hz at the tip of the index finger. Differential thresholds were obtained for reference stimuli of 0.5 N, 0.25N and near the individual threshold. Frequency, temperature, age, fingertip size, and contact force were investigated as parameters in a full-factorial design. Experiments were conducted with at least 27 subjects and a 1up-2down staircase procedure with 3IFC paradigm. We find absolute thresholds ranging from 1.7mN to 19mN with the lowest threshold at 320 Hz. Weber fractions from 18 dB to 41 dB are found near the absolute threshold. For larger references, they range from 4.9 dB to 23 dB. ANOVA finds frequency as significant medium effect for both absolute and differential thresholds. Results imply impact of age on the absolute threshold, but no effect of motor skill, temperature, fingertip size and contact force. Differential thresholds are affected by frequency only, which is attributed to saturation effects of the Pacinian channel. Fingertip size and motor skill are not able to explain effects on thresholds and the interpersonal variance. Results of this work are intended as requirement source for the design of task-specific haptic interfaces

ヒトの高周波振動知覚の類似特性に基づく触覚変調

Tohoku University昆陽雅司課