Investigating the microstructure of human visual fields and generating low-vision applications

Lead Research Organisation: University of Aberdeen
Department Name: Psychology

Abstract

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Publications

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Description There is a disconnect in vision science between studies on early and late bottlenecks of visual perception. Studies on early bottlenecks often focus on visual acuity or contrast sensitivity, measuring the minimal amount of contrast required to perform simple tasks such as detection of a stimulus or discrimination of its basic features such as orientation. However, there are additional, later-stage bottlenecks stemming from interference or facilitation of perception due to proximal objects in the scene, known as visual crowding or grouping. Later bottlenecks are normally examined in experiments that use stimuli at relatively high levels of contrasts. To bring early and late bottlenecks into a common framework, we systematically examined detection, discrimination or integration of visual elements in the presence of neighbouring elements under conditions of low contrast. This allowed us to build a more comprehensive picture of the connection between early and late bottlenecks in vision. Previous studies reported correlations across participants between tasks that tapped into early or late processing but could not definitively argue as to the source of these connections. Our results indicate that contrast-processing units may lie at the core of the shared idiosyncrasies between early and late bottlenecks reported in many previous studies, despite the fundamental differences in the extent of their spatial windows - where detection operates in smallest-sized receptive fields, crowding operates in medium-sized integration fields, whilst grouping operates in the largest-sized association fields.
Exploitation Route Our results indicate that contrast-processing units may lie at the core of the shared idiosyncrasies between early and late bottlenecks reported in many previous studies. Future research will be able to extend this work by examining these contrast processing units in more detail, using adaptive optics techniques to examine their retinal constraints. This could lead to a better understanding of visual processing in healthy ageing and potentially generate useful low-vision applications.
Sectors Digital/Communication/Information Technologies (including Software),Healthcare

 
Title Dataset from a large-scale experiment on low and mid-level vision 
Description Data from an age-diverse sample of 40 participants, with luminance contrast sensitivities and performance on masking, crowding and grouping tasks utilising a common stimulus framework. 
Type Of Material Database/Collection of data 
Year Produced 2022 
Provided To Others? Yes  
Impact The dataset will enable modelling of the contrast bottlenecks shared between low and mid-level vision by others, furthering progress into our understanding of these important stages of visual processing. 
URL https://osf.io/qd2bp/
 
Title Dataset from two experiments on visual crowding with low contrast stimuli (Lee, Reuther, Chakravarthi & Martinovic, 2021) 
Description This is the dataset that forms the basis of our pre-print "Emergence of crowding: The role of contrast and orientation salience". The dataset consists of two experiments. The first experiment evaluates crowding using S-cone islating and low-contrast luminance isolating stimuli with 8 experienced participants. The second experiment has a larger sample of 24 participants and examines crowding with low-contrast luminance isolating stimuli. The pre-print describes in detail the methods and results obtained from the experiment, and a 'readme' file in the data repository denotes the structure of the data. 
Type Of Material Database/Collection of data 
Year Produced 2021 
Provided To Others? Yes  
Impact The dataset allows for re-analysis of our findings or for meta-analytic work that intends to compile multiple datasets and perform additional tests that go beyond what is reported in our pre-print. 
URL https://osf.io/5a8ec/
 
Description "Speed, brightness and noise" - digital talk at the Aberdeen Art Gallery 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Public/other audiences
Results and Impact "Speed, brightness and noise" discusses the inherently noisy nature of perception, and uses several demonstrations to show how this noisyness affects how we see and what we see. The talk connects these concepts to the work of Marcel Duchamp and was intended to resonate with conceptual artworks that were meant to be exhibited in the gallery in April 2020. Due to the Covid-19 lockdown, the talk was recorded and made available digitally, rather than being given in the gallery setting. 120 people have viewed the talk on Youtube and i received positive feedback from members of the public who commented that it had sparked an interest in vision science related topics.
Year(s) Of Engagement Activity 2020
URL https://www.youtube.com/watch?v=ahdvgApqiwM
 
Description Dundee Science Festival 2021 - Visual Illusions 
Form Of Engagement Activity Engagement focused website, blog or social media channel
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Public/other audiences
Results and Impact I generated online content on visual perception for the Dundee Science Festival, held in November 2021, including interactive demos that allowed participants to explore visual illusions in a scientific way, manipulating key parameters of the image to see how they influence what is seen. The activity enabled the audience to have a hands-on engagement with science from the safety of their own homes in a period when this would not have been possible in person due to the existing covid-19 regulations.
Year(s) Of Engagement Activity 2021
URL https://www.dundeesciencefestival.org/2021-11-12-visual-illusions-the-university-of-edinburgh
 
Description Participant panel research visit day - demonstrations of perceptual phenomena and discussions of potential impact 
Form Of Engagement Activity Participation in an open day or visit at my research institution
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Public/other audiences
Results and Impact Around 60 members of the older adult participant panel of the School of Psychology, University of Aberdeen, attended an annual 2-hour public engagement lunchtime event. Researchers discuss the outcomes of studies that involved panel volunteers or present various engaging and thought-provoking psychology-related demonstrations. While my current PhD student Ms Rozman (BBSRC Eastbio) and my postdoc Dr Reuther (BBSRC) discussed their own research with panel members and demonstrated various visual phenomena which we have prepared for such events (e.g. the Beuchet chair, the hollow face illusion, etc.), I discussed the EPSRC project on visual displays with interested panel members and handed out questionnaires for those who wanted to take part in the qualitative part of the project. Panel members were enthused about their views being given consideration by our project and I handed out more than 30 questionnaires and had conversations with more than 50 older adults. Due to the school holidays, quite a few of them brought their grandchildren to the event, who were enthralled by some of the visual demonstrations, in particular the opportunity to take family photos with the Beuchet chair illusion. This should engender enthusiasm about visual science in both the youngest and the older generation.
Year(s) Of Engagement Activity 2020
 
Description Visual Ageing Workshop 2021 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Postgraduate students
Results and Impact I organised a half-day workshop on visual ageing, bringing together researchers from different disciplines (psychology, architecture, user experience, display engineering) with an interest in this topic. The workshop began with talks from experts in the field (Prof Leonards, University of Bristol, Dr Allen, University of Nottingham, Dr Akhavan, Faurecia IRYSTec, Prof Platt, Harvard Extension School) which was followed by a general discussion and a networking session. Amongst the 30 attendees, the majority were postgraduates and postdoctoral researchers, mainly from the UK but also including some international participants. The attendees reported that the event benefited both their own research and their future work due to the increased awareness of interdisciplinarity, with some forming potential collaborative links with researchers from other disciplines during the event.
Year(s) Of Engagement Activity 2021
URL https://2021visualageing.wordpress.com/