Recent Research Summaries

This comparative case study, conducted in Greece, investigates the perceptions of caregivers and professionals regarding repetitive behaviour (RB) in children aged 4-13 years of age with either vision impairment (VI) or autism spectrum disorder (ASD). The study aims to identify the types of RBs observed, the explanations adults use to interpret these behaviours, and the impact RBs have on the child, caregiver, professional, and society. 

The research employed an interpretivist paradigm and a qualitative approach, using a comparative case study design based on the ecological systems theory (EST). Semi-structured interviews were conducted with 35 caregivers and professionals (17 for VI and 18 for ASD), and data was analysed using thematic analysis.

The results suggest a link between VI and ASD in terms of how RBs are socially constructed. ASD is perceived as a disability with challenging characteristics, such as RBs, which are linked to ableism, social stigmatisation, and taboo. In contrast, RBs in children with VI are seen as a consequence of sensory loss. The study also found that the bidirectionality of EST is lost, with the macrosystem driving interactions between ecological systems. The study discusses school policy and practical implications based on these findings.

For more information you can access the full PhD thesis, open access, here: https://etheses.bham.ac.uk/id/eprint/12783/1/Tavoulari2022PhD.pdf 

Summary contributed by: Aikaterini (Katrina) Tavoulari 

About a third of animal species lack vision. In many animal groups, vision never evolved. In species where vision has evolved, understanding the origin of vision sheds lights on the behavioural tasks that vision might be useful for. However, various kinds and levels of vision permit different behavioural tasks. When considering the USA's legal definition of blindness, almost half of all mammalian species would be considered blind based on their visual acuity alone. However, it should be noted that the threshold for being sighted in humans is high because humans, and closely related species, have a particularly developed visual system with much higher visual acuity than nearly all other species. On the other hand, some animals have adapted to life without vision. Such adaptive vision loss had occurred when species inhabit low light environment such as caves, underground, murky rivers, or the deep sea, or are mostly active at night. Species that, through their evolution, have lost visual ability present in ancestral species are often referred to as "blind". There are several distantly related naturally blind mammalian species which have lost visual ability to the extent that their vestigial eyelids are sealed and covered by skin and fur. These species all live underground and include true moles as well as similarly shaped species found in many parts of the world. One such example, the blind mole rats, has provided insights into the changes that occur in the brain when vision is lost. For example, the part of the cerebral cortex usually devoted to processing visual information instead processes auditory information, both in blind mole rats and in people with congenital visual impairments. Also, blind mole rats have better than expected spatial memory, providing evidence for the brain's ability to enhance non-visual abilities; Compensatory plasticity of other senses is also seen in people with congenital visual impairments. The study of blind animals provides a broader perspective on sensory functions. Comparative research on the function of vision and vision-substituting senses in animals offers new perspectives for developing assistive technology for the visually impaired. Applications need not mimic human vision, and successful approaches can be inspired by diverse evolutionary pathways. For example, sensory substitution devices translate visual information into perceivable sensory information, preserving spatial details. One such device, "The vOICe", scans images and converts greyscale pixels into audible frequencies that vary in location and amplitude. Understanding the interplay between sensory loss, environmental factors, and social behaviour could inform inclusive design strategies, healthcare, technology, and artificial intelligence.  

For more information you can access the full article, open access, here: https://doi.org/10.1016/j.neubiorev.2022.104550 

Summary contributed by: Alexandra de Sousa 

You may know echolocation from bats and marine mammals, but people can echolocate, too, for example using mouth-clicks. Everyone can learn to echolocate, and this skill can be particularly useful for people with vision impairments (VI).  

In our research we investigate human echolocation in its own right and how it may benefit people with VI. We also use echolocation as a paradigm to study brain plasticity. For example, we have found that both blind and sighted people learn to echolocate over the course of 10 weeks, and that learning echolocation led to improvements in mobility, independence and wellbeing in participants who were blind. We have also found that the brain adapts to learning echolocation. For example, those parts of the brain that typically process light in sighted people become sensitive to echoes. 

We also offer training and education in echolocation for people with VI and for VI professionals.  

Click here to read more about this research 

Click here to find out more about echolocation training and education

Summary contributed by: Lore Thaler, Liam Norman & Denise Foresteire

Mainstream games are typically designed around the visual experience, with behaviors and interactions highly dependent on vision. Despite this, blind people are playing mainstream games while dealing with and overcoming inaccessible content, often together with friends and audiences.

In our work, we describe the recorded experiences (over 70 hours of YouTube videos) of multiple blind content creators playing mainstream games, with a focus on the strategies leveraged to overcome their lack of accessibility. Blind players use specific game features and mechanics to simplify or automate tasks, and act methodically on the environment to understand their in-game surroundings (e.g., by purposely bumping into walls). We describe the burden of preparation and keeping track of information not always available. We further highlight the new styles of gameplay that arise (e.g., co-pilot), as well as community efforts in creating tools to overcome gaps in accessibility.

By providing an in-depth understanding of these experiences, we call forth opportunities to shape the design of digital games toward welcoming both sighted and blind players to the medium and promoting inclusion.

To read more about this research, please go to: http://arxiv.org/abs/2301.08031 

Summary contributed by: David Gonçalves 

The complete absence of visual information from birth and extensive tactile and auditory training triggers a cascade of functional and morphological changes in the brain, enabling congenitally blind individuals to perform certain non-visual and cognitive tasks with supramodal abilities. Much evidence links these skills to cross-modal activations of areas of the cortex carrying out visual processing, but also for language, memory, and audition.

Recently, a significant body of research on the congenitally blind brain has examined specifically which morphological characteristics change following blindness and which cognitive and sensory aspects are associated with these changes. The human cortex consists of various morphological features containing folded and smooth surfaces. The folded structures are called cortical gyrification (or cortical foldings), which can be measured through a gyrification index. The cortical surface also varies in terms of its thickness. These morphological characteristics differ among individuals and have been found to change continually throughout life via sensory, cognitive, and/or aging-related factors. 

The visual cortex of congenitally blind individuals has been found to be thicker in comparison to that of sighted individuals. The increase in cortical thickness has been interpreted to reflect visual deprivation during early childhood, preventing complete synaptic pruning. Synaptic pruning is a natural process through which the brain eliminates extra synapses. This process which occurs between the first year of life until approximately early childhood, would be disrupted by visual deprivation in congenitally blind individuals. The thickening of the cortex not only reflects the deprivation of sensory information but also possibly training-induced mechanisms of brain plasticity. The cortex of congenitally blind individuals has also been found to be thinner in non-visual areas, for example, auditory and somatosensory areas which are understood to reflect training-induced plasticity. To understand the relationship between training-induced plasticity and changes derived from visual we examined various brain morphological changes and whether these morphological changes are related to one another. 

Our study examined cortical thickness and gyrification changes in 11 congenitally blind and 16 sighted individuals. We were the first to report an increase in cortical gyrification in several brain areas of congenitally blind compared to sighted controls. Importantly, we found gyrification and thickness to be inversely associated (i.e., the larger the gyrification the thinner the cortex) in brain areas involved in cross-modal processing. Previous studies have shown that increases in cortical foldings are associated with better cognitive function and a thinner cortex. These two morphological features and their relationship constitute a fingerprint of the remarkable plastic brain changes following blindness and the consequent cross-modal adaptations triggered by auditory processing, Braille reading, speech processing, and verbal memory. 

To read more about this research, please go to: https://www.frontiersin.org/articles/10.3389/fnins.2022.970878/full 

Summary contributed by: Isabel Arend

Both in the classroom and within the academic community, evolution instruction relies heavily on visual information. Under this status quo, people with visual impairments are denied access to knowledge and to participation in scientific communities. Evolution case studies usually assume an understanding of how the shape, size, and colour of organisms and their environment can vary. Such is the case of the evolution of beak shape in Darwin’s finches to adapt to different foods; or the evolution of adaptive camouflage coloration of moths in industrial areas. Thus, it might seem that evolution and natural selection can only be perceived visually.  However, evolution concepts can be ideal for tactile learning, because much of the descriptions of morphological and environmental variation can easily be felt from real specimens or translated into 3D haptic images. 

evALLution is a project to make evolution touchable. We developed a multisensory tree-of-life for people with blindness. We propose three main inclusive steps to teach evolution: (1) make biodiversity accessible through touch, (2) provide haptic evolutionary and/or ecological context for biodiversity and (3) discuss the evolutionary processes underlying biodiversity patterns. 

We assembled a multisensory tree-of-life in a 125m2 room. The branching pattern was drawn on the floor with carpet, to allow participants to feel the branches’ texture and follow species’ evolutionary paths. The branches were arranged to represent time and species relatedness based on shared genetic and morphologic characteristics. As species evolve and adapt to different conditions and environments, branching occurs. For example, all birds have feathers and other shared characteristics so they were put on a branch that was separate from fish;  But, both groups share a common ancestor in the past, which was represented as the point on the carpet where those two branches diverged. If we follow a given organism’s evolutionary path (its branch) back in time, we will find that it connects to all others by a common ancestor. At the root of the tree rests the common ancestor of all life, a single-celled organism. Starting at the entrance door, and following the carpet branching pattern from the root of the tree, a participant would first find the bifurcation to the bacteria branch, then plants, fungi, and so on. At the tip of each branch, there was a table containing specimens representative of that specific group of organisms, such as taxidermy birds, mollusk and turtle shells, a snakeskin, aromatic plants, and ancestral human fossil replicas. By touching these, participants could feel the textures and shapes found in nature. While touching, listening, smelling, and tasting biodiversity, participants were taught about the evolutionary histories of the specimens, and  quizzed on basic evolution knowledge. 

We learned three things form this project:  (1) there is a lack of access to evolutionary biology education for people with visual impairment despite high interest in the matter, (2) evolution case studies are easily translated into activities that include people with blindness, (3) touch and haptic models provide a powerful vehicle for inclusive education both for people with and without visual impairment. 

Two participants with blindness shared that they had wanted to become biologists but did not because “it was too visual”.  People with visual impairment have much to add to scientific knowledge because they experience the world and interact with data differently and are not biased by visual patterns. Scientific education, be it in classrooms, museums or outreach programs, should be multisensory, inclusive and promote equity and social justice for us to build a diverse and richer scientific community. We hope that with increasing inclusiveness everyone will be able to follow their passion for biodiversity and evolution.  Please get in touch for discussions and collaborations: telma_laurentino@berkeley.edu 

Find a video of the multisensory tree-of-life with text description at:  https://www.youtube.com/watch?v=4o3JLsXH12w

To read more about this research, please go to: https://evolution-outreach.biomedcentral.com/articles/10.1186/s12052-021-00143-1 

Summary contributed by: Telma Laurentino

When searching for a romantic partner, men and women often differ in what qualities they consider important. For example, there is now a large amount of research showing that men typically prefer women that look attractive, while women tend to prefer wealthy men with high social status. These findings have been consistently replicated across several decades and many different cultures. But where do these sex-differences between men and women come from, and are they influenced by the experiences we make?

In order to explore how sex differences in partner preferences develop, and whether they depend on direct accessibility, such as visual experience (for example when judging physical attractiveness), we asked 94 sighted and blind men and women to tell us what they consider important in a potential partner. Using an online questionnaire, participants judged how important they considered each of 30 individual traits (such as healthy skin, a well-proportioned figure, intelligence, career-orientation, reliability, emotional maturity etc.). These 30 traits represented three overall concepts: 1. physical attractiveness, 2. high social status and ability to provide resources, and 3. a pleasant personality and similar values. We calculated average importance scores for these three concepts for each participant individually, and then compared importance scores between women and men. We did this for both sighted and blind participants, and tested whether blind men and women differ in the same way that sighted men and women differ.

Our results showed, as expected, that sighted men consider physical attractiveness more important than sighted women. Sighted women, on the other hand, considered social status and resources more important. So far, this was not surprising– but how does the absence of vision influence this preference? Interestingly, compared to all other groups, blind men cared the least about physical attractiveness. Blind women, on the other hand, found physical attractiveness in a partner as important as did sighted women. Also, blind and sighted women judged the importance of social status and resources as equally important. The desire for a partner with a likeable personality and equal values was eqully high across all participants, independently of their sightedness and sex. We further found that a person’s relationship status influenced partner preferences: those that were single or divorced rated many traits as more important compared to those who were currently married or in a relationship. Lastly, participants who reported that their partner’s appearance influenced how they themselves were perceived by others, were more concerned about their partner’s physical appearance and status. In terms of the senses that were used to assess a potential partner’s traits, blind people placed less importance on vision, but more importance on hearing. A good odour was generally rated as more important than other cues in all groups.

Our findings suggest that a partner’s physical attractiveness might bear an indirect advantage to women by increasing their desirability, while sighted men assess physical attractiveness as a direct indicator for a woman’s fertility and health. Furthermore, they show that personal sensory experience can influence what we consider important in a partner.

The study has been published and is openly accessible via the following link: https://link.springer.com/article/10.1007/s10508-020-01901-w

Summary contributed by: Meike Scheller

Vibrotactile displays can be used for an alternative method to communicate information for active interfaces and sensory substitutional devices. Each tactile pixel, or taxel, is vibrated individually using a single solenoid coil actuator. This electromagnetically attracts and repels a steel washer attached under each taxel to vibrate it. 

The size, weight and limited special resolution of vibrotactile displays restricts their real world uses. Hence, developments at the University of Bath (Dr. A. Mohammadi, M Abdelkhalek and S Sadrafshari) have been carried out to overcome this limitation by increasing the number of taxels controlled by each actuator. Designing pads with different resonant frequencies by changing their mass spring resonance, and applying multiple frequencies to resonate each pad individually, allows multiple taxels to be individually vibrated using a single solenoid. This reduces the overall size, weight and cost while increasing special resolution with the same power consumption.

To read more about this research, please go to: https://www.sciencedirect.com/science/article/pii/S0924424719315973

Summary contributed by: Elisa-Jayne Barber

This study intended to investigate how blind people perceive 3D tactile objects, how they characterize them, and whether the perception and aesthetic (pleasantness) appreciation of 3D tactile objects can be affected by the level of visual experience. To this end, we conducted two fMRI (functional Magnetic Resonance Imaging) experiments in congenitally blind, late-onset blind and blindfolded sighted participants using 3D tactile stimuli. Our behavioral data demonstrated that both blind and blindfolded-sighted participants assessed curved 3D tactile objects as significantly more pleasing than sharp 3D tactile objects, and symmetric 3D tactile objects as significantly more pleasing than asymmetric 3D tactile objects. However, as compared to the sighted, blind people showed significantly better skills in tactile discrimination as demonstrated by both accuracy and speed of discrimination. Our functional MRI data showed that there was a large overlap and characteristic differences in the aesthetic appreciation brain networks and perceptual judgment brain networks in the blind as compared to the sighted. Both populations commonly recruited the somatosensory and motor areas of the brain, but with stronger activations in the blind as compared to the sighted. Secondly, sighted people recruited more frontal regions whereas blind people, in particular, congenitally blind people, paradoxically recruited more ‘visual’ areas of the brain. These differences were more pronounced between the sighted and the congenitally blind rather than between the sighted and the late-onset blind, indicating the key influence of the onset time of visual deprivation. We conclude that these differences were caused by cortical functional reorganization resulting from compensatory neuroplasticity in the blind. 

To read more about this research, please go to: https://doi.org/10.2352/ISSN.2470-1173.2018.14.HVEI-532

Summary contributed by: A.K.M. Rezaul Karim