Sounds of moving objects change perceptions of body size

sound
Credit: CC0 Public Domain

Sound and object motion can be used to change perceptions about body size, according to a new study by an international team involving UCL researchers.

The study, published today in PLOS ONE, found that introducing a mismatch between the predicted and actual outcome of an action, such as dropping a ball, can make people feel taller.

When an is dropped, the brain accurately predicts when it will hit the floor by considering the from which it fell. Artificially lengthening the time it takes to hear the impact of the object on the ground leads people to update their perceived body height, making them feel taller.

How humans perceive their is highly flexible, even beyond the ages when we stop growing. Most previous studies into this used sensory feedback on or about one's body but this study shows that even objects around us are used to compute our body size.

The findings could have implications for studies already using for rehabilitation for people with poor proprioception—the sense of the position of parts of the body in relation to other parts—including for those who have Parkinson's Disease or have suffered a stroke.

"These results reveal the surprising importance that sound and movement have on body representation. We don't just feel and see our bodies, we also hear ourselves whenever we interact with solid objects," explained lead researcher Dr. Ana Tajadura-Jiménez (UCL Interaction Centre and Universidad Carlos III de Madrid).

"This could be a really promising avenue for treating clinical conditions where people suffer from chronic pain or other conditions linked to distorted mental body representations such as anorexia nervosa."

"As these mechanisms are understood, they inform the design of sound-based technology to support novel therapies for such conditions," added co-author Professor Nadia Berthouze (UCL Interaction Centre and UCL Psychology & Language Sciences).

For the study, blind-folded participants dropped a ball from head height. The actual sound of the ball dropping and hitting the floor was masked and a simulated sound was played at longer and shorter intervals using four simulations—actual height, or from half, two or three times this height.

Participants were then asked to take a step backwards to an already memorised point and visually estimate their body size. "Results show that as the perceived time it took the ball to hit the floor increased, so too did the participants' perception of their body height and leg length", explained co-author Prof Ophelia Deroy (LMU).

Co-author Dr. Norimichi Kitagawa (NTT) added: "This is not only valuable for clinical applications but could also inform the development of technologies for motion controlled games where players take on a larger character on screen."


Explore further

Hearing a sound can alter perception of finger size

More information: Audio-tactile cues from an object's fall change estimates of one's body height, PLOS ONE (2018). journals.plos.org/plosone/arti … journal.pone.0199354
Journal information: PLoS ONE

Citation: Sounds of moving objects change perceptions of body size (2018, June 27) retrieved 24 June 2019 from https://medicalxpress.com/news/2018-06-perceptions-body-size.html
This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.
69 shares

Feedback to editors

User comments

Jun 28, 2018
This may be a bit of over-interpretation. Being further from the rebound surface can have many causes, such as the surface being in a dip or hole or the the person standing on a object.

Thus 'tallness' may be a misinterpretation of the simple calculation that estimates the distance between the ball's launch site and rebound which under normal circumstances one would be able to identify the reason for the extra length, sudden extra tallness being toward the bottom of the list of possibilities.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more