Does Blindness Boost Working Memory? A Natural Experiment and Cross-Cultural Study

Early attentional processing and cortical remapping strategies of tactile stimuli in adults with an early and late-onset visual impairment: A cross-sectional study

Neuroplastic changes appear in people with visual impairment (VI) and they show greater tactile abilities. Improvements in performance could be associated with the development of enhanced early attentional processes based on neuroplasticity. Currently, the various early attentional and cortical remapping strategies that are utilized by people with early (EB) and late-onset blindness (LB) remain unclear. Thus, more research is required to develop effective rehabilitation programs and substitution devices. Our objective was to explore the differences in spatial tactile brain processing in adults with EB, LB and a sighted control group (CG). In this cross-sectional study 27 participants with VI were categorized into EB (n = 14) and LB (n = 13) groups. They were then compared with a CG (n = 15). A vibrotactile device and event-related potentials (ERPs) were utilized while participants performed a spatial tactile line recognition task. The P100 latency and cortical areas of maximal activity were analyzed during the task. The three groups had no statistical differences in P100 latency (p>0.05). All subjects showed significant activation in the right superior frontal areas. Only individuals with VI activated the left superior frontal regions. In EB subjects, a higher activation was found in the mid-frontal and occipital areas. A higher activation of the mid-frontal, anterior cingulate cortex and orbitofrontal zones was observed in LB participants. Compared to the CG, LB individuals showed greater activity in the left orbitofrontal zone, while EB exhibited greater activity in the right superior parietal cortex. The EB had greater activity in the left orbitofrontal region compared to the LB. People with VI may not have faster early attentional processing. EB subjects activate the occipital lobe and right superior parietal cortex during tactile stimulation because of an early lack of visual stimuli and a multimodal information processing. In individuals with LB and EB the orbitofrontal area is activated, suggesting greater emotional processing.

Blind people can actively manipulate virtual objects with a novel tactile device

Frequently in rehabilitation, visually impaired persons are passive agents of exercises with fixed environmental constraints. In fact, a printed tactile map, i.e. a particular picture with a specific spatial arrangement, can usually not be edited. Interaction with map content, instead, facilitates the learning of spatial skills because it exploits mental imagery, manipulation and strategic planning simultaneously. However, it has rarely been applied to maps, mainly because of technological limitations. This study aims to understand if visually impaired people can autonomously build objects that are completely virtual. Specifically, we investigated if a group of twelve blind persons, with a wide age range, could exploit mental imagery to interact with virtual content and actively manipulate it by means of a haptic device. The device is mouse-shaped and designed to jointly perceive, with one finger only, local tactile height and inclination cues of arbitrary scalar fields. Spatial information can be mentally constructed by integrating local tactile cues, given by the device, with global proprioceptive cues, given by hand and arm motion. The experiment consisted of a bi-manual task, in which one hand explored some basic virtual objects and the other hand acted on a keyboard to change the position of one object in real-time. The goal was to merge basic objects into more complex objects, like a puzzle. The experiment spanned different resolutions of the tactile information. We measured task accuracy, efficiency, usability and execution time. The average accuracy in solving the puzzle was 90.5%. Importantly, accuracy was linearly predicted by efficiency, measured as the number of moves needed to solve the task. Subjective parameters linked to usability and spatial resolutions did not predict accuracy; gender modulated the execution time, with men being faster than women. Overall, we show that building purely virtual tactile objects is possible in absence of vision and that the process is measurable and achievable in partial autonomy. Introducing virtual tactile graphics in rehabilitation protocols could facilitate the stimulation of mental imagery, a basic element for the ability to orient in space. The behavioural variable introduced in the current study can be calculated after each trial and therefore could be used to automatically measure and tailor protocols to specific user needs. In perspective, our experimental setup can inspire remote rehabilitation scenarios for visually impaired people.

Using tactile imagery to teach geometry to students with visual impairments in the United Arab Emirates

Learning geometry is difficult for students with visual impairments (VIs). However, tactile imagery, the process of constructing mental images of physical objects with certain shapes, may help them make sense of geometrical shapes. Thus, discussions have centred on interventions to promote the participation of students with VIs in the learning of shapes. This study explored tactile imagery connecting physical touch to memory as an approach to teaching shapes to students with VIs. Eleven students, five with VIs and six sighted students took part in this experimental design study. A tactile imagery test and intervention lessons were developed for this study. Four tactile imagery domains (tactile discrimination, tactile memory 2D, tactile memory 3D and pattern recall), each made up of 10 tests, guided the design of the tests and training lessons. The students' scores from the pre-test and post-test were subjected to mean computations, Mann-Whitney U tests and the Wilcoxon signed-rank test. The post-test results revealed that students with VIs performed better than their sighted peers. The study concludes with a discussion of the need for teacher educators to consider using tactile imagery as a way of teaching geometry to students with VIs.

Deductive Reasoning and Working Memory Skills in Individuals with Blindness

Deductive reasoning and working memory are integral parts of executive functioning and are important skills for blind people in everyday life. Despite the importance of these skills, the influence of visual experience on reasoning and working memory skills, as well as on the relationship between these, is unknown. In this study, fifteen participants with congenital blindness (CB), fifteen with late blindness (LB), fifteen sighted blindfolded controls (SbfC), and fifteen sighted participants performed two tasks of deductive reasoning and two of working memory. We found that while the CB and LB participants did not differ in their deductive reasoning abilities, the CB group performed worse than the sighted controls, and the LB group performed better than the SbfC group. Those with CB outperformed all the other groups in both of the working memory tests. Working memory is associated with deductive reasoning in all three visually impaired groups, but not in the sighted group. These findings suggest that deductive reasoning is not a uniform skill, and that it is associated with visual impairment onset, the level of reasoning difficulty, and the degree of working memory load.

Seeing Beyond Anatomy: Quality of Life with Geographic Atrophy

Quality of life (QoL) is a complex idea without a clear consensus definition. Generally speaking, QoL refers to several subjective measures of wellbeing that vary by individual and circumstance. QoL can decline noticeably as a disease progresses. This is particularly true for geographic atrophy (GA), an advanced form of age-related macular degeneration. GA leads to vision loss for which there is no currently approved pharmacological treatment. There is a lack of qualitative, patient-driven research on QoL in GA. There is also limited information available to both patients and physicians about GA, existing support groups and available assistive technologies. To address this, we have collated the experiences of a person with GA and those of her partner and carer with the current literature on QoL in GA. We have also outlined some of the wide range of developing technologies available to help people with GA carry out daily tasks and hobbies. It is clear that support, whether through informal or structured care, is vital to the wellbeing of people with GA. Despite this, the general public are often unaware of care work, which may result in this integral role being undervalued and under acknowledged. Furthermore, it is apparent that the general public have fundamental misunderstandings around what vision loss entails and are unaware that blindness is a vast spectrum. This feeds into the seemingly paradoxical mix of isolation and dependence on others that often results from GA and vision loss. Through this qualitative examination of a patient's experiences, we hope to inform and educate both patients and physicians about GA as well as precipitate discussion around the frameworks that should be in place to support both newly diagnosed and long-term patients with GA and other retinal diseases. Seeing beyond anatomy: quality of life with geographic atrophy (WMV 29479 kb).

Impact of Prajñā yoga on cognition in adolescents with congenital and adventitious visual impairment

CONTEXT

Numerous scientific studies have investigated the impact of yoga on cognition in children and adults. However, fewer studies have assessed the impact of yogic practices on cognition in children and adolescents with visual impairment. Despite their keen intellectual abilities and advanced linguistic skills, teens with visual impairment often experience difficulties with cognitive control and behavioral regulation. Memory plays an important role in cognition. Besides storing information, memory is also used for recall, defined as the retrieval of information the brain has recently been exposed to, and recognition, defined as the ability to recognize or retrieve the information previously encountered and stored in the brain.

OBJECTIVE

The objective of the study was to observe the effectiveness of Prajñā Yoga on enhancing the cognition and verbal memory in adolescents with visual impairment. Degree of visual impairment and age of onset of visual impairment were considered while analyzing the study data.

DESIGN

An open-trial, single arm, pre-post study design was adopted. 273 adolescents with visual impairment were assessed across India using the Rey Auditory Verbal Learning Test (RAVLT), at baseline (before the intervention), immediately after the intervention, and at 40 days after the intervention. RAVLT measures recall and recognition through verbal memory.

INTERVENTION

Prajñā Yoga (PY) or the Art of Living Intuition Program is a unique intervention, based on ancient techniques of Pranayama, Super Brain Yoga, and Meditation, taught to children & adolescents between the ages 5 and 17.

RESULTS

The mean scores for Recognition (p=0.011) and Immediate recall (p=0.011) improved significantly after PY for the entire study population, regardless of the degree of visual impairment, gender and age of onset. A significant improvement in mean scores for Delayed Recall was seen after 40 days of daily practice (p = 0.007).