An exploratory study to improve reading and comprehending mathematical expressions in braille

Braille readers read and comprehend mathematical expressions while moving their fingertips over braille characters. The aim of this exploratory study was to investigate the effect of an intervention that teaches braille readers who use a braille display to use finger movements with a focus on the expression’s mathematical structure. The finger movements involved movements where the two index fingers are about one or two braille cells apart and movements where the index fingers explore different parts of the expression. We investigated to what extent the intervention supports an interplay between finger movements and the expression’s mathematical structure to make the process of calculating the value of an expression easier and to make braille readers more aware of the expression’s structure. Three braille readers, respectively in Grades 7, 8, and 11, received the intervention consisting of five individual lessons. During the pre-, post-, and retention test, the braille readers’ finger movements were video recorded, as well as the time needed to read and process the mathematical tasks. Four expressions were selected for further analysis. The results show that during the posttest, each braille reader required at least 29% less time to read and process the expressions. The retention test results were even better. Scanpaths indicated that braille readers picked up features of mathematical structures more easily after the intervention. Based on our findings, we recommend that braille readers receive lessons in tactile reading strategies that support the reading and processing of mathematical expressions and equations.

Anisotropic distortion in the perceived orientation of stimuli on the arm

Mechanoreceptors on the skin are heterogeneously distributed, and the sampling of neural signals in the brain can vary depending on the part of the body. Therefore, it can be challenging for the brain to consistently represent stimuli applied to different body sites. Here, we report an example of a regional perceptual distortion of the tactile space. We used a piezoelectric braille display to examine shape perception on the volar surface of the arm and to compare it to that on the palm. We found that the orientation of perceived stimuli on the arm was distorted in certain areas. In particular, an inwardly-inclined line shape was perceived as being more inwardly-inclined than it actually was. On the other hand, an outwardly-inclined line was perceived accurately. When the same stimuli were applied to the palm, this anisotropic bias was not observed. We also found that changing the posture of the arm changed the angle at which this anisotropic distortion occurred, suggesting the influence of the skin frame of reference on this illusion. This study showed a clear example of how the representation of even simple stimuli is complexly distinct when the stimuli are applied to different body sites.

Multifunctional And Low Cost Braille Display

Braille Display is a device which helps the visually impaired to read a text file in Braille format and as well receive an audio output of the text file. It gives an option to the user whether to receive output in terms of braille or audio. Braille is a tactile writing language of raised dots using which blinds and visually impaired people read and write through touch. The pattern of raised dots can be read with the fingers by blinds. The number and arrangement of these dots forms alphabets, numbers and special characters. The braille output in Braille display is observed in Braille text popper device which is made up of a plate having holes. Solenoids are placed under each hole to raise or lower the braille pin which will emerge through perforations on the top plate to form a Braille dot. The perforations serve as guides for the pins and form six dots which is equivalent to one Braille cell. Raspberry Pi Microcontroller is used to convert the text file into Braille format and thus controls the corresponding solenoid present below each of the holes to either pop up or down the hole by sending signal values to solenoids. Thus the solenoids align themselves based on the input character from the text file . The blinds can feel the sense of touch of the Braille pins that are popped up and they recognize the character accordingly. This way, blinds can recognize character by character. At every iteration, three characters from text file comes out in braille in Braille text popper device. The next button would display next three characters and previous button would display previous three characters. If the user prefers to hear audio, then it would give audio output of the text file through ear phones. Thus, the device facilitates the user either to read the text in braille or to hear the text as audio making it multifunctional.

Difference in Somatosensory Event-Related Potentials in the Blind Subjects Leads to Better Performance in Tactile P300 BCI

In this study, we created 8-command P300 tactile brain-computer interface, running on minimally modified consumer Braille display, and tested it on 10 blind subjects and 10 sighted controls with two stimuli types, differing in size. Larger stimuli provide better BCI performance both in blind and sighted participants than smaller stimuli. With large stimuli, median target selection accuracy in the blind group was 95%, which is 27% more than sighted controls (p < 0.05), suggesting that blind subjects are not only able to use tactile brain-computer interface but also can achieve superior results in comparison with sighted subjects. The difference in event-related potentials between groups is located in frontocentral sites around 300 ms post-stimulus and corresponds with early cognitive event-related potential components. Blind subjects have higher amplitude and shorter latency of ERPs. This effect was consistent across stimuli types. This is the first study to evaluate differences in event-related potentials between blind and sighted subjects in a BCI-specific task.

Exploring the influence of reading medium on braille learning outcomes: A case series of six working-age and older adults

Tactile sensitivity is known to decline with age. Braille provides a vital method of reading and writing for working-age and older adults with acquired visual impairment. The proliferation of low-cost braille displays raises new possibilities for adult braille learners, with dots of greater height than standard paper braille, potentially benefitting older adults with reduced tactile sensitivity. This study explored the influence of reading medium (paper vs braille display) on the accuracy and speed of six working-age and older adult braille learners and examined differences when transitioning from one reading medium to another. Findings indicate that (1) learning letters on a braille display resulted in better speed and accuracy (time: M = 44.2, SD = 37.3, accuracy: M = 83%, SD = 24.8%) than on paper (time: M = 54.3, SD = 40.4, accuracy: M = 80.6%, SD = 28.1%); (2) transitioning from one medium to another generally resulted in the same or better performance (reading times decreased by 11.2% and accuracy improved by 2.4%); and (3) the advantage of the braille display appears to be greatest when reading letters in combination (reading times decreased by 26.8% and accuracy improved by 6.5% for letter-pairs vs a 1.9% reduction in speed and a 2% improvement in accuracy for single letters). The benefit of the braille display condition was most pronounced for participants with reduced tactile sensitivity. Although preliminary, these findings suggest that the use of braille displays in early braille instruction may decrease frustration for those with reduced tactile sensitivity and should not adversely affect the ability for learners to transition to standard paper braille, assuming that both formats are introduced and reinforced throughout training.