Contingent negative variation to tactile stimuli - differences in anticipatory and preparatory processes between participants with and without blindness.

People who are blind demonstrate remarkable abilities within the spared senses and compensatory enhancement of cognitive skills, underscored by substantial plastic reorganization in relevant neural areas. However, little is known about whether people with blindness form top-down models of the world on short timescales more efficiently to guide goal-oriented behavior. This electroencephalography study investigates this hypothesis at the neurophysiological level, focusing on contingent negative variation (CNV) as a marker of anticipatory and preparatory processes prior to expected events. In sum, 20 participants with blindness and 27 sighted participants completed a classic CNV task and a memory CNV task, both containing tactile stimuli to exploit the expertise of the former group. Although the reaction times in the classic CNV task did not differ between groups, participants who are blind reached higher performance rates in the memory task. This superior performance co-occurred with a distinct neurophysiological profile, relative to controls: greater late CNV amplitudes over central areas, suggesting enhanced stimulus expectancy and motor preparation prior to key events. Controls, in contrast, recruited more frontal sites, consistent with inefficient sensory-aligned control. We conclude that in more demanding cognitive contexts exploiting the spared senses, people with blindness efficiently generate task-relevant internal models to facilitate behavior.

The impact of vision loss on attitudes toward autonomous vehicles: A vision-centric analysis.

SIGNIFICANCE: Autonomous vehicles (AVs) have the promise to be an alternative transportation solution for those with vision loss. However, the impact of vision loss on the perceptions and concerns of AVs is unknown. This study therefore examined whether AVs are perceived differently by blind, visually impaired (VI), and normally sighted people. PURPOSE: This study compared the perceptions of AVs among the blind, VI, and normally sighted. METHODS: Participants' opinions on four perception measures (general opinion, trust, impact on quality of life, and intention to use AVs) and nine concerns regarding AVs were measured. The survey was administered to 51 normally sighted, 68 VI, and 65 blind participants. Analyses of covariance assessed whether the four perception measures and nine concerns varied by vision status (normal vision, VI, blind) and driving status (driver, nondriver). Univariate correlations and multiple regression analyses identified associations and predictors of AV perceptions and concerns from demographic, mood, cognition, travel behavior, and vision measures, which included visual acuity, contrast sensitivity, and visual field. RESULTS: The blind (p<0.001), VI (p<0.001), and nondrivers (p<0.001) showed a greater intention to use AVs compared with those with normal vision and drivers. Similar findings were found for the other perception measures. As visual acuity, contrast sensitivity, and visual field extent declined, positivity toward AVs increased (p<0.001). Visual field extent best predicted general opinion and trust in AVs, whereas driving measures were the best predictors of impact on quality of life and intention to use AVs. Concerns about AVs showed no differences based on vision (p=0.94) or driving (p=0.63) status. CONCLUSIONS: Individuals with vision loss expressed more acceptance of AVs despite their concerns. How positive someone is toward AVs appears to be dependent on their visual field extent and driving status.

The Influence of Blind Tennis on Subjective Inclusion Experiences-An Ableism-Critical Analysis.

In this paper, we analyze the subjective inclusion experiences of visually impaired (VI) adult tennis players from an ableism-critical perspective. The primary focus of this research is the inclusive potential of blind tennis from the perspective of VI individuals. Episodic interviews were conducted to capture subjective perspectives. A qualitative text analysis revealed that the interviewees were confronted with multiple ability assumptions by sighted people in their everyday lives. Deficit notions on the performance of VI people included sports, work, and general activities. Participation in blind tennis helped the interviewees build a "competent identity" and acquire various skills useful for their everyday lives as participation in blind tennis was a pathway for competence in sports. Further research is needed to identify exclusion experiences from the perspective of disabled people to recognize the potential of different sports in reducing barriers to participation.

Living with an artificial eye: qualitative insights into patient and family member experiences.

PURPOSE: Artificial eye users (AEUs) can experience a negative impact on psychological and emotional wellbeing, including reduced social functioning, which may be a consequence of living with one eye removed, and/or of having a prosthetic eye. This may have wider consequences for their families. We aimed to explore what it means to live with a prosthetic eye, for both AEUs and their families-and how any quality of life (QoL) issues impact on their day-to-day functioning. METHODS: A subset of AEUs and their family members taking part in a feasibility randomised controlled trial comparing hand-painted to digitally printed artificial eyes were invited for semi-structured interviews. Transcripts were analysed using reflexive thematic analysis. Qualitative results related to trial participation are covered elsewhere. Here, we focus on QoL and day-to-day functioning. RESULTS: Twelve AEUs (eight males) and five spouses (one male) who had worn artificial eyes for 2-65 years took part, and four themes were identified. (1) Impact on day-to-day life: AEUs and their spouses have to adapt to (partial) sight loss, reduced levels of confidence, and social withdrawal. (2) Impact on psychological and emotional wellbeing: distress among AEUs and their spouses can be severe and prolonged, highlight unmet support needs. (3) Challenges with treatment experiences: AEUs experienced negative impact of fragmentation of care and long waiting times. (4) Worries about the future: AEUs mentioned fragility of remaining sight, and concerns around potential need for further treatment. CONCLUSION: Patients and their family members experience negative impact of being an AEU on their everyday lives and quality of life. There is a potential role for psychosocial support services in supporting AEUs and their families even long after eye loss.

Network QoS Impact on Spatial Perception through Sensory Substitution in Navigation Systems for Blind and Visually Impaired People.

A navigation system for individuals suffering from blindness or visual impairment provides information useful to reach a destination. Although there are different approaches, traditional designs are evolving into distributed systems with low-cost, front-end devices. These devices act as a medium between the user and the environment, encoding the information gathered on the surroundings according to theories on human perceptual and cognitive processes. Ultimately, they are rooted in sensorimotor coupling. The present work searches for temporal constraints due to such human-machine interfaces, which in turn constitute a key design factor for networked solutions. To that end, three tests were conveyed to a group of 25 participants under different delay conditions between motor actions and triggered stimuli. The results show a trade-off between spatial information acquisition and delay degradation, and a learning curve even under impaired sensorimotor coupling.

Design of a "Cobot Tactile Display" for Accessing Virtual Diagrams by Blind and Visually Impaired Users.

Access to graphical information plays a very significant role in today's world. Access to this information can be particularly limiting for individuals who are blind or visually impaired (BVIs). In this work, we present the design of a low-cost, mobile tactile display that also provides robotic assistance/guidance using haptic virtual fixtures in a shared control paradigm to aid in tactile diagram exploration. This work is part of a larger project intended to improve the ability of BVI users to explore tactile graphics on refreshable displays (particularly exploration time and cognitive load) through the use of robotic assistance/guidance. The particular focus of this paper is to share information related to the design and development of an affordable and compact device that may serve as a solution towards this overall goal. The proposed system uses a small omni-wheeled robot base to allow for smooth and unlimited movements in the 2D plane. Sufficient position and orientation accuracy is obtained by using a low-cost dead reckoning approach that combines data from an optical mouse sensor and inertial measurement unit. A low-cost force-sensing system and an admittance control model are used to allow shared control between the Cobot and the user, with the addition of guidance/virtual fixtures to aid in diagram exploration. Preliminary semi-structured interviews, with four blind or visually impaired participants who were allowed to use the Cobot, found that the system was easy to use and potentially useful for exploring virtual diagrams tactually.

Enhanced Odorant Localization Abilities in Congenitally Blind but not in Late-Blind Individuals.

Although often considered a nondominant sense for spatial perception, chemosensory perception can be used to localize the source of an event and potentially help us navigate through our environment. Would blind people who lack the dominant spatial sense-vision-develop enhanced spatial chemosensation or suffer from the lack of visual calibration on spatial chemosensory perception? To investigate this question, we tested odorant localization abilities across nostrils in blind people compared to sighted controls and if the time of vision loss onset modulates those abilities. We observed that congenitally blind individuals (10 subjects) outperformed sighted (20 subjects) and late-blind subjects (10 subjects) in a birhinal localization task using mixed olfactory-trigeminal stimuli. This advantage in congenitally blind people was selective to olfactory localization but not observed for odorant detection or identification. We, therefore, showed that congenital blindness but not blindness acquired late in life is linked to enhanced localization of chemosensory stimuli across nostrils, most probably of the trigeminal component. In addition to previous studies highlighting enhanced localization abilities in auditory and tactile modalities, our current results extend such enhanced abilities to chemosensory localization.

Light therapy for seasonal affective disorder in visual impairment and blindness - a pilot study.

OBJECTIVE: Seasonal and non-seasonal depression are prevalent conditions in visual impairment (VI). We assessed the effects and side effects of light therapy in persons with severe VI/blindness who experienced recurrent depressive symptoms in winter corresponding to seasonal affective disorder (SAD) or subsyndromal SAD (sSAD). RESULTS: We included 18 persons (11 with severe VI, 3 with light perception and 4 with no light perception) who met screening criteria for sSAD/SAD in a single-arm, assessor-blinded trial of 6 weeks light therapy. In the 12 persons who completed the 6 weeks of treatment, the post-treatment depression score was reduced (p < 0.001), and subjective wellbeing (p = 0.01) and sleep quality were improved (p = 0.03). In 6/12 participants (50%), the post-treatment depression score was below the cut-off set for remission. In four participants with VI, side effects (glare or transiently altered visual function) led to dropout or exclusion. CONCLUSION: Light therapy was associated with a reduction in depressive symptoms in persons with severe VI/blindness. Eye safety remains a concern in persons with residual sight.

Children five-to-nine years old can use path integration to build a cognitive map without vision.

Although spatial navigation competence improves greatly from birth to adulthood, different spatial memory capacities emerge at different ages. Here, we characterized the capacity of 5-9-year-old children to use path integration to build egocentric and allocentric spatial representations to navigate in their environment, and compared their performance with that of young adults. First, blindfolded participants were tested on their ability to return to a starting point after being led on straight and two-legged paths. This egocentric homing task comprising angular and linear displacements allowed us to evaluate path integration capacities in absence of external landmarks. Second, we evaluated whether participants could use path integration, in absence of visual information, to create an allocentric spatial representation to navigate along novel paths between objects, and thus demonstrate the ability to build a cognitive map of their environment. Ninety percent of the 5-9-year-old children could use path integration to create an egocentric representation of their journey to return to a starting point, but they were overall less precise than adults. Sixty-four percent of 5-9-year-old children were capable of using path integration to build a cognitive map enabling them to take shortcuts, and task performance was not dependent on age. Imprecisions in novel paths made by the children who built a cognitive map could be explained by poorer integration of the experienced turns during the learning phase, as well as greater individual variability. In sum, these findings demonstrate that 5-9-year-old children can use path integration to build a cognitive map in absence of visual information.

Distinctive Interaction Between Cognitive Networks and the Visual Cortex in Early Blind Individuals.

In early blind individuals, brain activation by a variety of nonperceptual cognitive tasks extends to the visual cortex, while in the sighted it is restricted to supramodal association areas. We hypothesized that such activation results from the integration of different sectors of the visual cortex into typical task-dependent networks. We tested this hypothesis with fMRI in blind and sighted subjects using tasks assessing speech comprehension, incidental long-term memory and both verbal and nonverbal executive control, in addition to collecting resting-state data. All tasks activated the visual cortex in blind relative to sighted subjects, which enabled its segmentation according to task sensitivity. We then assessed the unique brain-scale functional connectivity of the segmented areas during resting state. Language-related seeds were preferentially connected to frontal and temporal language areas; the seed derived from the executive task was connected to the right dorsal frontoparietal executive network; and the memory-related seed was uniquely connected to mesial frontoparietal areas involved in episodic memory retrieval. Thus, using a broad set of language, executive, and memory tasks in the same subjects, combined with resting state connectivity, we demonstrate the selective integration of different patches of the visual cortex into brain-scale networks with distinct localization, lateralization, and functional roles.

Helping the Blind to Get through COVID-19: Social Distancing Assistant Using Real-Time Semantic Segmentation on RGB-D Video.

The current COVID-19 pandemic is having a major impact on our daily lives. Social distancing is one of the measures that has been implemented with the aim of slowing the spread of the disease, but it is difficult for blind people to comply with this. In this paper, we present a system that helps blind people to maintain physical distance to other persons using a combination of RGB and depth cameras. We use a real-time semantic segmentation algorithm on the RGB camera to detect where persons are and use the depth camera to assess the distance to them; then, we provide audio feedback through bone-conducting headphones if a person is closer than 1.5 m. Our system warns the user only if persons are nearby but does not react to non-person objects such as walls, trees or doors; thus, it is not intrusive, and it is possible to use it in combination with other assistive devices. We have tested our prototype system on one blind and four blindfolded persons, and found that the system is precise, easy to use, and amounts to low cognitive load.

[Autism spectrum symptoms in children with congenital blindness]. / Autismus-Spektrum-Symptome bei Kindern mit Geburtsblindheit.

Autism spectrum symptoms in children with congenital blindness Abstract. Objective: Previous studies reported increased rates of autistic symptoms in children with impaired visual abilities (IV). However, the application of existing screening questionnaires for autism spectrum disorders (ASD) proved problematic, as intact visual abilities are typically required. The current study examines the general applicability of three autism-screening questionnaires in children with congenital blindness. Methods: Autistic symptoms were assessed in 15 children with congenital blindness, 15 children with ASD (without IV), and 20 typically developing controls (aged from 8 to 14 years), using the Social Communication Questionnaire, the Marburg Rating Scale for Asperger's Syndrome, and the Social Responsiveness Scale. Results: Items assessing motor, mimic/gesture-related, or joint attention deficits were identified as highly prevalent in children with congenital blindness. These children scored, in general, higher on ASD-screening questionnaires than typically developing controls but lower than sighted children with ASD. Depending on the screening questionnaire used, between 23 % and 67 % of the sample with congenital blindness reached clinical cutoff scores for ASD. SRS total score was negatively correlated to cognitive empathy and verbal IQ in those children. Conclusions: Mothers of children with congenital blindness reported increased autistic symptoms in ASD-screening questionnaires. ASD and IV might share a broad range of symptoms. Future development and validation of screening instruments specifically adapted to the needs of persons with impaired visual abilities seem necessary.

As if by Magic: An Abrupt Change in Motion Direction Induces Change Blindness.

Magicians claim that an abrupt change in the direction of movement can attract attention, allowing them to hide their method for a trick in plain sight. In three experiments involving 43 total subjects, we tested this claim by examining whether a sudden directional change can induce change blindness. Subjects were asked to detect an instantaneous orientation change of a single item in an array of Gabor patches; this change occurred as the entire array moved across the display. Subjects consistently spotted the change if it occurred while the array moved along a straight path but missed it when it occurred as the array changed direction. This method of inducing change blindness leaves the object in full view during the change; requires no additional distractions, visual occlusion, or global transients; and worked in every subject tested here. This phenomenon joins a body of magic-inspired work that yields insights into perception and attention.

Loneliness among adults with visual impairment: prevalence, associated factors, and relationship to life satisfaction.

BACKGROUND: Little is known about whether and to what extent loneliness impacts the lives of people with visual impairment (VI). Thus, the aim of this study was to examine the prevalence of and factors associated with loneliness in adults with VI, and to examine its association with life satisfaction. METHODS: This cross-sectional interview study included a probability sample of 736 adults (≥18 years old) with VI who were members of the Norwegian Association of the Blind and Partially Sighted. The interviews took place from January to May 2017, collecting information about sociodemographics, VI characteristics, adverse life events, loneliness (Three Item Loneliness Scale), and life satisfaction (Cantril's Ladder of Life Satisfaction). The prevalence of loneliness was compared to data obtained from the general Norwegian population (N = 14,884; mean age 46.4 years; 50.7% females). RESULTS: The prevalence of moderate and severe loneliness in the VI population was 28.7% (95% CI: 25.4, 32.1) and 19.7% (95% CI: 16.9, 22.8), respectively. The rates were consistently higher across age groups compared to the general population. Loneliness was associated with younger age, blindness, having other impairments, unemployment, and a history of bullying or abuse. In addition, higher scores on loneliness were associated with lower levels of life satisfaction (fully adjusted ß = - 0.48, 95% CI: - 0.55, - 0.41). CONCLUSIONS: Loneliness is common in adults with VI. Strategies capable of reducing loneliness could improve life satisfaction among people who are blind or visually impaired.

Modern contraceptive methods knowledge and practice among blind and deaf women in Ethiopia. A cross-sectional survey.

BACKGROUND: Evidences from various parts of the world reveal that women with disabilities are facing widespread barriers in accessing public services. Service providers and program managers do not grasp the relevance of their work and interventions in addressing the sexual and reproductive health needs of women with disabilities. The present study therefore aimed to assess family planning knowledge and practice among women with sensory disabilities. METHODS: A mixed method approach using quantitative and qualitative methods was employed to collect the data. The study included 326 blind and deaf women using respondent driven sampling technique and 29 purposely selected key informants. We carried out the study from August 2016-April 2017. The quantitative data were analyzed using SPSS and the qualitative analysis was done using Open code software version 4.02 and triangulated with the quantitative findings. RESULTS: The findings showed that nearly two third of the respondents of were sexually active. The majority (97.2%) of study respondents had heard about FP methods, however the level of comprehensive knowledge on modern contraceptive methods was 32.5%. The prevalence of unwanted pregnancy was 67.0% and abortion was 44%. Almost half of sexually active respondents ever used modern contraceptive methods, yet the contraceptive prevalence at the time of survey was 31.1%. Implants were the most commonly used (51%) contraceptive method among current users. CONCLUSIONS: The use of modern contraceptive methods among women with sensory disabilities was low. Thus, the government and concerned organizations need to address the attitudinal, social, and physical barriers women with sensory disabilities are facing while seeking, accessing to and using family planning services.

How the Blind Hear Colour.

Crossmodal correspondences between seemingly independent sensory modalities are often observed in normal participants. For instance, colours commonly map consistently onto pure tones. In this study, we investigated colour-tone mapping in both normal trichromats and in people with congenital blindness. Participants were asked to match tones of differing pitch to named colours. In both cases, the tones selected varied consistently with the colour. The blind responses were similar to those of the trichromats, except in the case of red and green; the blind did not differentiate these colours, whereas the trichromats associated red with a higher tone and green with a lower tone. Otherwise, the results are consistent with a well-established association between pitch and lightness, with lighter colours associated with higher tones, and darker colours with lower tones. Because the blind never had any sensory experience of colour, their matching of colour to pitch is most likely based on semantic understanding.

The implicit learning of metrical and non-metrical rhythms in blind and sighted adults.

Forming temporal expectancies plays a crucial role in our survival as it allows us to identify the occurrence of temporal deviants that might signal potential dangers. The dynamic attending theory suggests that temporal expectancies are formed more readily for rhythms that imply a beat (i.e., metrical rhythms) compared to those that do not (i.e., nonmetrical rhythms). Moreover, metrical frameworks can be used to detect temporal deviants. Although several studies have demonstrated that congenital or early blindness correlates with modality-specific neural changes that reflect compensatory mechanisms, few have examined whether blind individuals show a learning advantage for auditory rhythms and whether learning can occur unintentionally and without awareness, that is, implicitly. We compared blind to sighted controls in their ability to implicitly learn metrical and nonmetrical auditory rhythms. We reasoned that the loss of sight in blindness might lead to improved sensitivity to rhythms and predicted that the blind learn rhythms more readily than the sighted. We further hypothesized that metrical rhythms are learned more readily than nonmetrical rhythms. Results partially confirmed our predictions; the blind group learned nonmetrical rhythms more readily than the sighted group but the blind group learned metrical rhythms less readily than the sighted group. Only the sighted group learned metrical rhythms more readily than nonmetrical rhythms. The blind group demonstrated awareness of the nonmetrical rhythms while learning was implicit for all other conditions. Findings suggest that improved deviant-sensitivity might have provided the blind group a learning advantage for nonmetrical rhythms. Future research could explore the plastic changes that affect deviance-detection and stimulus-specific adaptation in blindness.

Oral health status among visually impaired schoolchildren in Northeast China.

BACKGROUND: Visual impairment is an important disability affecting a substantial proportion of people globally. The aim of this study was to assess the oral health status of visually impaired schoolchildren in northeast China, and to investigate the influencing factors. METHODS: The study was performed in 2015, according to the criteria and methods used in the Third National Oral Health Epidemiological Survey in China. One hundred and three visually impaired schoolchildren from the only special school for the blind in northeast China were included in the study. Oral examinations were performed to assess the caries of deciduous and permanent teeth, periodontal disease, malocclusion. A questionnaire-based survey was conducted to investigate oral health-related behaviors, knowledge and attitude about oral care. RESULTS: The overall prevalence of caries was 78.64%, and mean number of caries was 2.43 ± 2.75. The prevalence of caries in deciduous and permanent teeth was 65.22 and 71.84%, respectively. The rates of gingival bleeding and dental calculus were 44.66 and 67.96%, respectively. Malocclusion was observed in 49.51% of the children with visual impairment. The prevalence of caries was significantly higher in girls than boys (P < 0.05). The logistic regression analysis identified the knowledge level of parents and the toothache experience as risk factors for oral health, while the daily use of fluoride toothpaste could reduce the caries incidence. CONCLUSIONS: This group of visually impaired schoolchildren exhibited a high prevalence of dental caries, poor periodontal health, and severe malocclusion. Oral health status is relatively poor among visually impaired schoolchildren in northeast China. Factors that significantly affected the prevalence of dental caries included education level of the mother, experience of toothache, and use of fluoride toothpaste.

Neuroticism and depression: a moderated mediation model of secure peer attachment and blindness.

Background: Prior studies have shown strong pairwise relationships between neuroticism, peer attachment, and depression but very little was found on the questions of how neuroticism is associated with depression through secure peer attachment, and what role individual difference played in these relations (i.e., the moderating mechanism of being visually impaired or not). Objective: The present study investigated the relationship between neuroticism and depression with secure peer attachment as the mediator and being visually impaired or not as the moderator among visually impaired and sighted adolescents. Methods: The sample consisted of 67 visually impaired adolescents from a special education school, and 160 sighted adolescents from an elementary school and a middle school in Guangzhou, China. All of the adolescents completed a battery of questionnaires that measured secure peer attachment, neuroticism, and depression. Results: The results suggested that neuroticism and depression were negatively associated with secure peer attachment. Moreover, it was found that secure peer attachment partially mediated the relationship between neuroticism and depression and that this link was stronger in visually impaired adolescents than in sighted adolescents. Conclusions: The findings highlighted the importance of secure peer attachment for visually impaired adolescents, and results were interpreted in terms of implications for future studies.

On Blindness and Blind Spots.

This story is a reflection on the evolving relationship of a family physician with a patient suffering from a severe conversion disorder, expressed inter alia through "blindness." The narrative follows our journey as I attempt to unravel the meaning of the symptoms as a metaphoric expression of her agony. Eventually, I conclude that clinicians at times also may have a "blind spot" that prevents us from entirely grasping patients' complex inner struggles.