Touch and Hearing Mediate Osseoperception

Abstract

Osseoperception is the sensation arising from the mechanical stimulation of a bone-anchored prosthesis. Here we show that not only touch, but also hearing is involved in this phenomenon. Using mechanical vibrations ranging from 0.1 to 6 kHz, we performed four psychophysical measures (perception threshold, sensation discrimination, frequency discrimination and reaction time) on 12 upper and lower limb amputees and found that subjects: consistently reported perceiving a sound when the stimulus was delivered at frequencies equal to or above 400 Hz; were able to discriminate frequency differences between stimuli delivered at high stimulation frequencies (~1500 Hz); improved their reaction time for bimodal stimuli (i.e. when both vibration and sound were perceived). Our results demonstrate that osseoperception is a multisensory perception, which can explain the improved environment perception of bone-anchored prosthesis users. This phenomenon might be exploited in novel prosthetic devices to enhance their control, thus ultimately improving the amputees’ quality of life.

Separability of neural responses to standardised mechanical stimulation of limbs

“…Although poking the foot with a needle would result in a reduced touch and proprioceptive contribution to the nociceptive neural recordings, the needle would become blunt with repetitive application and may not provide a reproducible stimulus intensity. Another interesting sensation to study would be the detection of different vibratatory stimuli, although some of this information may already be conveyed to the patient as sound through osseoperception 40 . Nevertheless, the Arduino system would be easy to adapt to apply other stimulus types or intensities depending on the desired purpose of a experiment.…”

Tactile Feedback in Closed-Loop Control of Myoelectric Hand Grasping: Conveying Information of Multiple Sensors Simultaneously via a Single Feedback Channel

“…It does, however, restrict the locations that this technique can be applied to on the upper limb, as there are relatively fewer bony landmarks on the upper limb than skin surface. A psychophysical evaluation in Mayer et al (2019) demonstrates comparable results in non-invasive vibrotactile feedback on the bone to the invasive (osseointegrated) study in Clemente et al (2017). It is highlighted that personalization is required for the perception threshold in order to be used as an interface.…”

“…For each combination, a standard two-interval forced-choice (2IFC) threshold procedure is used. For the 2IFC, the reference stimulus f ref is selected out of the three predetermined frequencies and the target stimulus f t was varied in a stochastic approximation staircase (SAS) manner, where the variation is based on the report of the subjects of the perceived stimulus (Clemente et al, 2017). Therefore,…”

“…Investigations in the prosthetic literature have so far focused on conveying each independent sensor information to the human user through a single transducer. The feedback is either continuous (Chaubey et al, 2014) or event driven (Clemente et al, 2017) and multiple transducers have been deployed via high density electrotactile arrays (Franceschi et al, 2017). The number of feedback transducers that can be deployed on the human is limited due to the physiology and the available space.…”

“…The limitation of the available stimulation points is even more compelling when using bone conduction for vibrotactile sensation. For osseointegrated implants there is only one rigid abutment point (Clemente et al, 2017;Li and Brånemark, 2017) and for non-invasive bone conduction there are 2-3 usable bony landmarks near the elbow (Mayer et al, 2019). In all these experiments, each sensory information is still conveyed by one dedicated feedback channel.…”