Human echolocation: Basic mechanisms and neuroplasticity

Lead Research Organisation: Durham University
Department Name: Psychology

Abstract

The human brain has many amazing perceptual abilities. One of these is the ability to echolocate. To echolocate, an organism makes a sound, and listens to the returning echoes. Echolocation is best known from bats. In people it has received comparably little research attention, even though investigations in the 1940s already established the reality of this skill.

Recent studies suggest that echolocation may be related to vision. For example, blind echolocation experts can sense their environment through echolocation in a way that seems uncannily similar to vision, and neuroimaging research has shown that blind echo experts use 'visual' brain areas to process echoes. Interestingly, and relatedly, even though echolocation is mediated through hearing, recent research suggests that there might be different processes involved. Recent echolocation research has also confirmed that young people can learn echolocation. Yet, even though there are increasing numbers of people with age related vision loss for whom echolocation might be useful, it has not been investigated how older people might learn it.

Following up on these recent developments, the proposed research will investigate how echolocation is related to vision, and 'regular' spatial hearing, and it will investigate this in young and old people. The overarching goal is to advance our understanding of information processing in the human brain. The research has the potential to improve well-being of people with vision loss.

The proposed research will make us of behavioural experiments and brain imaging techniques (magnetic resonance imaging, MRI). We will train blind and sighted, and young and old people to echolocate, and we will measure their echolocation behaviour and their brain activity and structure with MRI. Furthermore, we will measure how echolocation is related to people's 'regular' spatial hearing. We will do this by investigating if echolocation improves people's abilities to localize sound sources, and if people's echolocation accuracy is influenced by their expectations about the echolocation sounds.

The impact strategy for the proposed research is based on communicating our scientific results to academics, professionals, and the general public. We propose to do this via presentation at scientific conferences, publication of articles in scientific and professional journals, public lectures, and working with the media to publicize our research, and through the creation of a website showcasing our findings. Furthermore, even though the research is focused on human brain and behaviour, our findings are expected to benefit research in engineering (remote sensing, signal acquisition and processing, development of assistive devices for blind people). In addition, the research is expected to inform echolocation research in non-human animals, and in this way it may lead to reduction of use of animals for research.

Within the UK approx. 360,000 people are registered partially sighted / blind, and approx. 300,000 of these are older than 50 years. There is already scientific evidence that echolocation offers functional advantages to blind people, for example to detect and avoid obstacles during walking, or to navigate unfamiliar environments. Yet, within the UK (but also worldwide) echolocation is not endorsed for mobility and orientation training for blind people. The proposed research will advance scientific understanding of echolocation and add to existing scientific evidence demonstrating usefulness of echolocation for blind people. In combination with the proposed impact strategy the proposed research has the potential to increase acceptance of echolocation as part of mobility and orientation training for blind people and in this way to improve well-being of people with visual impairments.

Technical Summary

The scientific objectives of the proposed work are (1) Investigate which areas in the human brain are associated with echolocation (2) Measure how the ageing human brain learns to echolocate (3) Measure how echolocation is related to people's 'regular' spatial hearing. The proposed work will achieve these objectives using behavioural training, psychophysical testing, and magnetic resonance imaging (MRI), and by recruiting young and old sighted and blind participants.

Behavioural training will be implemented using tasks developed in past research, that require participants to determine location (azimuth, distance) and sizes of surfaces, or to approach an object placed within an enclosed area.

Psychophysical testing will measure people's echo-perception of location and size. We will also use psychophysical tests to measure participants' spatial source hearing abilities (i.e. not echolocation).

Magnetic resonance imaging will use functional MRI (fMRI) and anatomical scans (MRI). Data will be analysed using standard MRI analysis software packages (Brain Voyager, Free Surfer, SPM) and custom written analysis routines (Matlab). To minimize MR artefacts due to head movements, participants will not actively echolocate during scanning, but passively listen to echolocation recordings, an approach we developed in past research. Auditory fMRI scans will use sparse sampling, an acquisition technique commonly used for fMRI involving auditory stimulation.

*Participants* Experiments will be conducted with people who are either sighted (normal or corrected to normal vision) or blind (total blindness & ability to detect bright light), and who are either young (<35 yrs) or old (>55 yrs). Participants must have no history of neurological disease and audiometric thresholds within age specific reference norms (ISO 7029). Blind participants will be recruited regardless of age at onset of vision loss, but we will match onset of vision loss across age groups.

Planned Impact

The research will lead to new insights regarding usefulness of echolocation for young and old blind people. Of primary relevance in this context are the behavioural data, but neuroimaging data as well, because they (a) corroborate behavioural results and (b) lead to identification of brain areas involved in echolocation. This may also foster development of neural stimulation protocols to facilitate learning (e.g. Cohen Kadosh et al (2010). Current Biol 20: 2016-2020).

Primary impact of the work will be in regard to vision loss with respect to organizations, professionals, individuals, society. Furthermore, the research will have positive impact on project staff, science education and women in science.

Benefits with respect to Vision Loss
Within the UK there are about 360k people with vision loss, and about 80% of these are older than 50 years. In the UK individuals with vision loss receive assistance through organizations and professionals. For example, upon diagnosis, NHS providers refer individuals to local authority professionals and organizations (e.g. Royal National Institute for the Blind, Action for Blind People). Currently, echolocation is not widely endorsed. The proposed research will contribute to knowledge about echolocation, which will be communicated to professionals and organizations. In this way, the project will lead to wider endorsement of echolocation as part of mobility and orientation training. Furthermore, the research will increase quality of life of individuals with vision loss and their relatives mediated through organizations (see above) and directly. For example, via public engagement the research will increase knowledge about echolocation and vision loss in the general public. In this way it is expected that blind people are more likely to learn about echolocation, and to consider acquiring this skill, which would have positive impact on their mobility. Furthermore, as a result of the project sighted people will be more aware of echolocation and issues related to vision loss, which will have positive impact on how blind people (echolocating or not) are treated in society. Improvements in blind people's mobility will have positive impact on relatives who will feel more confident about the well-being of their blind child/ parent/etc. It is expected that benefits to individuals add up to socio-economic benefits. For example, consider that a blind person who echolocates uses the bus for a monthly 10 mile (20 minute) trip, instead of being driven by a relative. If we consider this at a scale of 1000 people, the use of echolocation would result in 120,000 miles/year not driven or 240,000 minutes/year that relatives could spend on other activities. We realize that these numbers are unlikely the direct consequence of our 3-year project, but the project has potential to lead up to numbers such as these.

Impact will also be achieved by informing development of assistive technology for blind people.

The PI has a good track record of public engagement, relevant connections to professionals, and collaborations, making these plans feasible.

Staff working on the project
PDRA working on the project will gain research expertise, author science papers, present on conferences, be involved in outreach. These skills will make them competitive on the job market. For the PI the project will enable her to further develop her reputation as an internationally leading expert in human echolocation, put her into excellent position to attract international funding into UK.

Science education / Women in science
Echolocation is a skill that intrigues people. Thus, it is an ideal vehicle to foster science education, because outreach events are likely to attract a good response from the general public. In my work to date I have also found that in particular female students are attracted to echolocation research. Thus, the project is likely to encourage female students to consider a career in science.
 
Description we have discovered that echolocation in people in many aspects is governed by similar principles as echolocation in bats. The other work is not yet accepted for publication or still in progress.
Exploitation Route too early to say.
Sectors Aerospace, Defence and Marine,Communities and Social Services/Policy,Education,Healthcare,Other

 
Description Professionals (VI rehab workers, VI Hab workers) request training from us and take part in training and have reported changes in their professional practice a result of taking part in our training. They integrate echolocation more as part of mobility instruction for adults and children with vision impairments. We have held various focus groups and online surveys and we are using the feedback to further develop resources. Clients have reported that they benefit from the training and experience improved well being.
First Year Of Impact 2016
Sector Communities and Social Services/Policy,Other
Impact Types Policy & public services

 
Description Improving Professional Practice of VI Rehabilitation and Habilitation Workers
Geographic Reach National 
Policy Influence Type Influenced training of practitioners or researchers
Impact We have trained VI professionals, VI rehabilitation and habilitation in echolocation both with respect to knowledge and practical skills. This has changed their professional practice, in particular it has improved services and training they offer to their clients. As a consequence clients have experienced improvements in their wellbeing.
 
Description Conacyt PhD Studentship
Amount £128,000 (GBP)
Organisation National Council on Science and Technology (CONACYT) 
Sector Public
Country Mexico
Start 09/2016 
End 09/2020
 
Description ESRC Impact Acceleration Award
Amount £25,000 (GBP)
Organisation Economic and Social Research Council 
Sector Public
Country United Kingdom
Start 01/2018 
End 12/2018
 
Description Using Echolocation To Study The Development Of Cue Combination
Amount £40,000 (GBP)
Organisation Economic and Social Research Council 
Sector Public
Country United Kingdom
Start 05/2016 
End 05/2019
 
Description CPD Lecture (Durham, UK) 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Professional Practitioners
Results and Impact 15 rehab workers and service commissions from local council attended my lecture on echolocation. This sparked questions and discussions afterwards, and increased awareness of echolocation as mobility technique for the blind. The rehab workers highlight this to their clients, who also got in touch with us. The council expressed in interest in continuing receiving information about our research.
Year(s) Of Engagement Activity 2016
 
Description Cafe Scientifique (Stockton, UK) 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Public/other audiences
Results and Impact 80 people attended a café scientifique lecture about our research. There was a very lively discussion and many questions afterwards. People expressed interest in the research, many reported to not have known about echolocation before and how useful it could be for people who are blind. Many people also reported to have interest in receiving more information about our research. We collected evidence for impact (people completed questionnaires).
Year(s) Of Engagement Activity 2017
URL http://www.cafesci-stockton.org.uk/
 
Description Echolocation Workshops for Rehab Workers 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Professional Practitioners
Results and Impact Echolocation training workshops for Rehab workers as well as for people with vision impairments.
Year(s) Of Engagement Activity 2014,2016,2017,2018
 
Description Invited Lecture (Rehabilitation Worker National Seminar, UK) 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Professional Practitioners
Results and Impact ~200 UK Rehab workers attended my lecture 'Echolocation in People - Definitions and Applications'. I had been invited to give this lecture as part of the Rehabilitation Worker National Seminar, UK; Birmingham City University, UK, July, 2016.There was discussion and questions afterwards. Many people had not known about echolocation as mobility tool for blind people before. People were enthusiastic to consider echolocation and to recommend it to potential service users as part of their professional practice. My materials have been placed on the webpage, for members of the rehab workers network, UK.
Year(s) Of Engagement Activity 2016
URL https://rehabilitationworkers.wildapricot.org/event-2233256
 
Description Sensing Nature - Echolocation Lecture (Suffolk, UK) 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Public/other audiences
Results and Impact ~50 people of the general public, people with vision impairments, family members and rehab workers came to a lecture. I had been invited for this by Waveney & Blyth Arts Council. The name of the event was "Sensing Nature - Echolocation Lecture & Workshop". 6 November, 2016 . There were questions and discussions afterwards. Many people had not known about echolocation before, or its potential for blind people. I received a request to write an article for the bat conservation trust magazine.
Year(s) Of Engagement Activity 2016
URL https://www.waveneyandblytharts.com/
 
Description Sensing Nature - Echolocation Workshop (Suffolk, UK) 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Patients, carers and/or patient groups
Results and Impact ~20 people with vision impairments, family members and rehab workers participated in the workshop (1-day event). I had been invited for this by Waveney & Blyth Arts Council. The name of the event was "Sensing Nature - Echolocation Lecture & Workshop". 5 November, 2016 During the workshop people engaged with exercises. Afterwards all of them stated to have learned to echolocate and find their way in simple scenarios. we collected evidence for impact via an online survey. Impressions were discussed.
Year(s) Of Engagement Activity 2016
URL https://www.waveneyandblytharts.com/
 
Description TV, Radio and podcastst about our research, echolocation and about issues related to blindness 
Form Of Engagement Activity A broadcast e.g. TV/radio/film/podcast (other than news/press)
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Media (as a channel to the public)
Results and Impact we have engaged with media leading to various broadcasts >>>>> Radio/Podcasts: "Seeing with Sound" (National Public Radio), with support from the Alfred P. Sloan Foundation, published on PRX July 15, 2013 • "No End in Sight" (30 Minutes West), featured at the Oregon Museum of Science and Industry, March 26, 2014 • "How to become Batman" (part of the Invisibilia series; National Public Radio), published January 23, 2015 • "Batman" (This American Life), published January 9, 2015 • "What is it like to be a bat?" (Nature Podcast), January 12, 2015 • Feature on echolocation (BBC Tees; Mike Parr/Lisa McCormick), May 20, 2015 • "The Listeners" (BBC4), published 29 & 30 Dec, 2015 • "Spectrum" (Deutsche Welle), published March 2016 • "Quirks & Quarks" (Canadian Broadcasting Company, CBC), 23 September 2017 • "Can we see with our ears?" (1.program Radio Slovenija), 15th February 2018 • World Update (38mins in) (BBC World Service), 28 Feb 2018 • Human Echolocators Use Tricks Similar to Bats (Scientific American), 6 March 2018.

TV: "Superhuman" (ABC Australian TV), April 2016. • "Catalyst Science" (ABC Australian TV), 12 April 2016. • "Decouverte - Echolocation" (ICI Tele, Canadian TV), 14 January 2018.
Year(s) Of Engagement Activity 2013,2014,2015,2016,2017
 
Description engagament with media about our research, echolocation and issues related to vision impairment 
Form Of Engagement Activity A press release, press conference or response to a media enquiry/interview
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Media (as a channel to the public)
Results and Impact engagement with media leading to multiple articles etc. we list a selection of the coverage we received and contributed to >>>> "The brain on sonar - how blind people find their way around with echoes" (Discover Magazine), May 25, 2011 • "Hirnforschung: Wie sich Blinde per Echoortung orientieren" (Der Spiegel), May 26, 2011 • "Klickblitze im Dunkeln" (Spektrum der Wissenschaft), December 5, 2011 • "Human brain's 'bat sight' found" (BBC), May 26, 2011 • "Human echolocation: Using tongue-clicks to navigate the world" (BBC World News), 12 September 2012 • "Humans Can Learn to Echolocate" (Life Science), August 27, 2013 • Bat-Inspired Tech Could Help Blind People See with Sound (PBS, Nova), October 23, 2013 • "Ultrasonic helmet lets anyone see like a bat" (Popular Science), February 9, 2015 • "Human bat uses echoes and sounds to see the world" (New Scientist), May 9, 2015 • "Echolocation" (AsK - Kid's Science Magazine), September, 2016 • "Learning Echolocation" (Scientific American "Mind Matters" Guest Blog), April, 2017 • "How Blind People use Echolocation" (Science Magazine), 1 September 2017 • "What it takes to be an expert echolocator" (Wired), 31 August 2017 • "This is how some people are able to echolocate like bats" (New Scientist), 31 August 2017 • "Mouth clicks used in human echolocation captured in unprecedented detail" (Science Daily), 31 August 2017 • "'Seeing with sound': study explores how the blind use echolocation (CTV News), 31 August 2017 • "Human echolocators 'see' with sound. Here's what that actually looks like." (PBS News), 8 September 2017 • made it to top on Reddit 31.5k votes; 1000 comments • "Mouth Clicks Used in Human Echolocation Captured in Unprecedented Detail" (EurekAlert), 31 August 2017 • "Echolocation: helping the blind see with sound" (The Mathworks Blog), 18 October, 2017 • "Blind people able to use array of bat-like clicks as 'sonar' to sense their surroundings" (The Independent), 28 February 2018 • "Just Like Bats, Humans Are Able to Echolocate" (Seeker), 28 February 2018 • "How humans echolocate 'like bats" (BBC News), 28 February 2018 • "Echolocation could help blind people learn to navigate like bats" (The Guardian), 28 February 2018.
Year(s) Of Engagement Activity 2011,2012,2013,2014,2015