How body motion influences echolocation while walking

Luca Brayda,Alessia Tonelli,Claudio Campus

doi:10.1038/s41598-018-34074-7

Luca Brayda, Alessia Tonelli + Show 1 more

Open Access

https://doi.org/10.1038/s41598-018-34074-7

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Journal: Scientific Reports	Publication Date: Oct 24, 2018
Citations: 8	License type: open-access

Affiliation: Italian Institute of Technology

Abstract

This study investigated the influence of body motion on an echolocation task. We asked a group of blindfolded novice sighted participants to walk along a corridor, made with plastic sound-reflecting panels. By self-generating mouth clicks, the participants attempted to understand some spatial properties of the corridor, i.e. a left turn, a right turn or a dead end. They were asked to explore the corridor and stop whenever they were confident about the corridor shape. Their body motion was captured by a camera system and coded. Most participants were able to accomplish the task with the percentage of correct guesses above the chance level. We found a mutual interaction between some kinematic variables that can lead to optimal echolocation skills. These variables are head motion, accounting for spatial exploration, the motion stop-point of the person and the amount of correct guesses about the spatial structure. The results confirmed that sighted people are able to use self-generated echoes to navigate in a complex environment. The inter-individual variability and the quality of echolocation tasks seems to depend on how and how much the space is explored.

Highlights

This study investigated the influence of body motion on an echolocation task
We found that the first factor included mainly the variables Average velocity (AV), Variability of velocity (VV) and Motion duration (MD), that are variables related to the time dimension (TIME factor)
We tried to maintain the environment as much ecological as possible. i.e. performing the task in a reverberant room, without no sound-absorbing materials attenuating internal or external noises, and using different kind of sound-reflecting materials; (2) whether some behavioural variables, such as average and variability of velocity, motion duration, distance from the end wall, head movements etc. (Table 1), might be correlated with the percentage of correct responses in naïve sighted echolocators into such a real environment

Summary

Introduction

This study investigated the influence of body motion on an echolocation task. We asked a group of blindfolded novice sighted participants to walk along a corridor, made with plastic sound-reflecting panels. Kolarik et al.[9], assessed the ability of blindfolded sighted people to detect and circumvent an obstacle using mouth click sounds, compared to visual guidance They showed that auditory information was sufficient to guide participants around the obstacle without collision, but there was an increase of movement time and the number of velocity corrections (number of changes in in forward velocity along the path) compared to visual guidance. In a second study, Kolarik et al.[10], used the same task to compare the performance between blindfolded sighted, blind non-echolocators and one blind echolocator using both self-generated sounds and an electronic sensory substitution device (SSD) They found that using audition, blind non-echolocators navigated better than blindfolded sighted with fewer collisions, lower movement times, fewer velocity corrections and greater obstacle detection range. They reported that during echolocation participants tend to orient the body and head towards a specific location[18]

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