Objective To use the neural signals preceding movement and motor imagery to predict which of four movements/motor imageries is about to occur, and to access this utility for brain-computer interface (BCI) applications. Methods Eight naive subjects performed or kinesthetically imagined four movements while electroencephalogram (EEG) was recorded from 29 channels over sensorimotor areas. The task was instructed with a specific stimulus (S1) and performed at a second stimulus (S2). A classifier was trained and tested offline at differentiating the EEG signals from movement/imagery preparation (the 1.5 seconds preceding movement/imagery execution). Results Accuracy of movement/imagery preparation classification varied between subjects. The system preferentially selected event related (de)synchronization (ERD/ERS) signals for classification, and high accuracies were associated with classifications that relied heavily on the ERD/ERS to discriminate movement/imagery planning. Conclusions The ERD/ERS preceding movement and motor imagery can be used to predict which of four movements/imageries is about to occur. Prediction accuracy depends on this signal’s accessibility. Significance The ERD/ERS is the most specific pre-movement/imagery signal to the movement/imagery about to be performed.

It remains controversial whether using two hands and multiple fingers provides any perceptual advantage over a single index finger. The present study examines this long-running question in the haptic-exploration literature by applying rigorous, psychophysical, and mathematical modeling techniques. We compared the performance of fourteen blindfolded sighted participants on seven tactile-map tasks using seven finger conditions. All tasks were benefited by multiple fingers, but it varied whether multiple fingers were beneficial on one hand, two hands, or both. Line-tracing tasks were performed faster when two hands were used, but not more than one finger per hand. Local and global search tasks were faster with multiple fingers, but not two hands. Distance comparison tasks were also performed faster with multiple fingers, and sometimes with two hands. Lastly, moving in a straight line was faster with multiple fingers, but was especially difficult with just two index fingers. These results provide empirical evidence that multiple hands and fingers benefit haptic perception, but the benefits are more complex than simply extending the tactile field of 'view'. This analogy between touch and vision fails to account for the autonomous movements and sensations of the fingers, which we show benefit the haptic perceptual system.

This article compares two methods of employing novice Web workers to author descriptions of science, technology, engineering, and mathematics images to make them accessible to individuals with visual and print-reading disabilities. The goal is to identify methods of creating image descriptions that are inexpensive, effective, and follow established accessibility guidelines. The first method explicitly presented the guidelines to the worker, then the worker constructed the image description in an empty text box and table. The second method queried the worker for image information and then used responses to construct a templatebased description according to established guidelines. The descriptions generated through queried image description (QID) were more likely to include information on the image category, title, caption, and units. They were also more similar to one another, based on Jaccard distances of q-grams, indicating that their word usage and structure were more standardized. Last, the workers preferred describing images using QID and found the task easier. Therefore, explicit instruction on image-description guidelines is not sufficient to produce quality image descriptions when using novice Web workers. Instead, it is better to provide information about images, then generate descriptions from responses using templates.

The most common and advocated assessment approach when a child cannot access visual materials is to use the verbal subscales of a test the psychologist already has and is familiar with. However, previous research indicates that children with visual impairments experience atypical verbal development. This raises the question of whether verbal subscale scores retain their reliability and interpretation validity when given to children with visual impairments. To answer this question, we administered a vocabulary subscale from a common intelligence test along with several nonverbal subscales to 15 early-blind adolescents (onset of ≤2 years). Reliability of only the vocabulary test scores was insufficient for high-stakes testing. This finding points to the broader issue of difficulties in assessing populations of exceptional children who experience atypical development trajectories, possibly making their assessment with common tests inappropriate. (PsycINFO Database Record

In a previous paper we documented that sighted participants complete haptic tasks faster with two hands and multiple fingers, but that these benefits are task specific. The present study investigates whether these effects are the same for participants who are blind. We compared the performance of fourteen blind participants on seven tactile-map tasks using seven finger conditions. As with sighted participants, blind participants performed all tasks faster with multiple fingers. Line-tracing tasks were faster with fingers added to an already in-use hand, and sometimes when added to the second hand. Local and global search tasks were faster with multiple fingers and two hands. Distance comparison tasks were performed faster with multiple fingers, but not two hands. Lastly, moving in a straight line was faster with multiple fingers. These results reinforce our previous finding that the haptic system performs best when it can exploit the independence of multiple fingers. Furthermore, in every instance that an effect was different between sighted and blind participants, the blind participants benefitted more from two hands or multiple fingers than the sighted participants. This indicates that the blind participants have learned, through experience or training, how to best take advantage of multiple fingers during haptic tasks.

Movement strategies were investigated in a one-handed haptic search task in which blindfolded-sighted participants used either one or five fingers to find a landmark on an unstructured tactile map. Search theory predicts that systematic strategies, such as spirals, zigzags, and parallel sweeps, should be more prevalent when the searcher's detection radius is small (one finger) and less common when the detection radius is large (five fingers). As predicted, systematic strategies were more common in one-finger than five-finger search. Participants were able to exploit the larger detection radius during five-finger searches to detect targets with any of their fingers, and in one-finger search used more systematic strategies. For the most part, participants' fingers moved together during five-finger search, expanding and moving quickly when looking for search targets/distractors, and contracting and moving slowly when examining search targets/distractors. There was no evidence of fingers being used as spatial anchors or other independent finger movements in five-finger search. While targets could be found with any fingers, examination was primarily accomplished using the index and middle fingers. Overall, these results indicate that untrained sighted participants will use optimal systematic strategies during haptic search, and this behavior is appropriately modulated by detection radius.

Introduction This study involved a systematic literature review to document the sources behind publications and citations that comprise knowledge about rates of braille usage/literacy among people with visual impairments in the United States. Methods Predefined search criteria were used to extract publications that potentially mentioned claims about braille literacy and usage rates, dating back as far as the early 20th century. Systematic analyses narrowed the set of publications to a collection of 95 articles and manuscripts that made specific statements about the prevalence of braille readership. Results The analysis revealed that even in peer-reviewed publications, many claims about braille literacy are made without citations to dependable sources. All identified citations used as the basis for braille literacy rates since the 1970s can be traced back to two primary sources: a National Library Service report from 1979 and the American Printing House for the Blind (APH) Federal Quota data (which should not be used as a source for braille literacy rates). Discussion This research explains the source of the often-cited “10%” statistic. The findings also challenge the field to question the bases for statements about braille literacy rates, including asking, “What do we mean by braille literacy?” Implications for practitioners There is no current source of data that succinctly measures braille literacy rates in the United States, and there are no data that explain whether braille literacy rates are rising or declining. Making effective, data-based decisions requires asking the right questions and being informed readers of research in the field of visual impairment.

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