The RT-Chair: a Novel Motion Simulator to Measure Vestibular Perception

Atten Percept Psychophys

Sandini

et al. 2022

Self Cite

Vestibular cues are crucial to sense the linear and angular acceleration of our head in three-dimensional space. Previous literature showed that vestibular information precociously combines with other sensory modalities, such as proprioceptive and visual, to facilitate spatial navigation. Recent studies suggest that auditory cues may improve self-motion perception as well. The present study investigated the ability to estimate passive rotational displacements with and without virtual acoustic landmarks to determine how vestibular and auditory information interact in processing self-motion information. We performed two experiments. In both, healthy participants sat on a Rotational-Translational Chair. They experienced yaw rotations along the earth-vertical axis and performed a self-motion discrimination task. Their goal was to estimate both clockwise and counterclockwise rotations’ amplitude, with no visual information available, reporting whether they felt to be rotated more or less than 45°. According to the condition, vestibular-only or audio-vestibular information was present. Between the two experiments, we manipulated the procedure of presentation of the auditory cues (passive vs. active production of sounds). We computed the point of subjective equality (PSE) as a measure of accuracy and the just noticeable difference (JND) as the precision of the estimations for each condition and direction of rotations. Results in both experiments show a strong overestimation bias of the rotations, regardless of the condition, the direction, and the sound generation conditions. Similar to previously found heading biases, this bias in rotation estimation may facilitate the perception of substantial deviations from the most relevant directions in daily navigation activities.

Section: Methodsmentioning

confidence: 99%

Section: Equipment and Stimulimentioning

confidence: 99%

How much I moved: Robust biases in self-rotation perception

Zanchi

Atten Percept Psychophys

Sandini

et al. 2022

Self Cite

“…Oppositely tuned cells are separated by a section of the macula with smaller otoconia called the striola. In the bottom row, movements are represented as they can be elicited in the laboratory with a motion platform as in [11,12].…”

Section: S�mulus Spacementioning

confidence: 99%

Perceptual Biases as the Side Effect of a Multisensory Adaptive System: Insights from Verticality and Self-Motion Perception

2022

Vision

Self Cite

Perceptual biases can be interpreted as adverse consequences of optimal processes which otherwise improve system performance. The review presented here focuses on the investigation of inaccuracies in multisensory perception by focusing on the perception of verticality and self-motion, where the vestibular sensory modality has a prominent role. Perception of verticality indicates how the system processes gravity. Thus, it represents an indirect measurement of vestibular perception. Head tilts can lead to biases in perceived verticality, interpreted as the influence of a vestibular prior set at the most common orientation relative to gravity (i.e., upright), useful for improving precision when upright (e.g., fall avoidance). Studies on the perception of verticality across development and in the presence of blindness show that prior acquisition is mediated by visual experience, thus unveiling the fundamental role of visuo-vestibular interconnections across development. Such multisensory interactions can be behaviorally tested with cross-modal aftereffect paradigms which test whether adaptation in one sensory modality induces biases in another, eventually revealing an interconnection between the tested sensory modalities. Such phenomena indicate the presence of multisensory neural mechanisms that constantly function to calibrate self-motion dedicated sensory modalities with each other as well as with the environment. Thus, biases in vestibular perception reveal how the brain optimally adapts to environmental requests, such as spatial navigation and steady changes in the surroundings.

“…The experimental setup included the Rotational-Translational Chair (RT-Chair; [10]) and the 3D Tune-In Toolkit tool (3DTI Toolkit; [11]).…”

Section: B Experimental Setup and Stimulimentioning

confidence: 99%

“…In this pilot study, a novel experimental procedure is presented, based on the joint use of two newly developed simulation devices. The first is a 2-Degrees-Of-Freedom motion platform, the Rotational-Translational Chair [10]; the second is an acoustic virtual reality tool, the 3D Tune-In Toolkit [11]. The combination of these tools allowed us to test how vestibular self-motion cues and auditory landmarks are combined.…”

Section: Introductionmentioning

confidence: 99%

Evaluation of a Motion Platform Combined with an Acoustic Virtual Reality Tool: a Spatial Orientation Test in Sighted and Visually Impaired People

Zanchi

2021 43rd Annual International Conference of the IEEE Engineering in Medicine &Amp; Biology Society (EMBC)

Sandini

et al. 2021

To orient and move efficiently in the environment, we need to rely on multiple external and internal cues. Previous studies reported the combined use of spatialized auditory cues and self-motion information in spatial navigation and orientation. In this study, we investigated the feasibility of a setup composed of a motion platform and an acoustic virtual reality tool with sighted and visually impaired participants. We compared the performance in a self-motion discrimination task with and without auditory cues. The results revealed good usability of the setup and increased precision with auditory cues for visually impaired people.Clinical relevance-This preliminary research presents a novel combination of a motion simulator and a simple acoustic virtual reality tool to investigate multisensory perception during passive self-motion stimulation in healthy and clinical populations.