A word-superiority effect with print and braille characters

Letter Search by Braille Readers: Implications for Instruction

Recent research indicates that braille letters, like print letters, are detected more rapidly and accurately in words than in nonwords (nonsense collections of letters). Thus, neither the word nor the individual letters dominate perception; instead, word and letter form a mutually beneficial partnership. The authors explore the implications for teaching braille readers and suggest that practice in character recognition in word contexts will enhance reading skill.

How Blind Readers Perceive and Gather Information Written in Braille

This study examined how readers who are blind perceive and retrieve written information and investigated the strategies they used to compensate for their limitations. It found that expert braille readers are not limited to the isolated identification of individual braille characters that are later integrated, but can integrate greater quantities of written information, which indicates that braille reading is a more dynamic and integrated process than has previously been thought.

Effects of Orientation on Braille Reading by People who are Visually Impaired: The Role of Context

Research by Heller suggested that speed and accuracy of reading may be seriously compromised by the inclusion of noncanonical (tilted) braille text. The study presented here extended that research by including characters other than those used by Heller and whole words. Similar results were found for Heller's original character set ( B–J), but the effect of orientation was reduced with other letters and whole words. The authors conclude that braille readers, especially experienced ones, have more facility with noncanonical braille than would be inferred from Heller's results.

Movement Kinematics of the Braille-reading Finger

A new means of measuring the movement properties of the braille-reading finger is described and exemplified in an experiment in which experienced readers of braille encountered sentences comprised of keywords in which word and orthographic frequencies were manipulated. These new data are considered in theoretical and practical terms.

Implicit Memory in the Tactile Modality: Evidence From Braille Stem Completion in the Blind

Research on perceptual priming has previously focused exclusively on priming in the visual and auditory modalities The present study explored whether perceptual priming also extends to the tactile modality Tactile priming for Braille words was examined in a group of blind participants, using a Braille analogue of the stem-completion task The results for tactile priming paralleled previous stem-completion results in other modalities Manipulating the encoding task at study (semantic vs nonsemantic) dissociated implicit and explicit Braille stem-completion performance, and priming was unaffected by the number of study presentations (one vs three) Finally, Braille stem-completion priming was found in a cross-modal paradigm to have both a specifically tactile component and a cross-modal component These results demonstrate for the first time that verbal priming can occur in the tactile domain and that tactile priming has basic functional similarities with stem-completion priming in the visual and auditory domains

Refreshing Refreshable Braille Displays

The increased access to books afforded to blind people via e-publishing has given them long-sought independence for both recreational and educational reading. In most cases, blind readers access materials using speech output. For some content such as highly technical texts, music, and graphics, speech is not an appropriate access modality as it does not promote deep understanding. Therefore blind braille readers often prefer electronic braille displays. But, these are prohibitively expensive. The search is on, therefore, for a low-cost refreshable display that would go beyond current technologies and deliver graphical content as well as text. And many solutions have been proposed, some of which reduce costs by restricting the number of characters that can be displayed, even down to a single braille cell. In this paper, we demonstrate that restricting tactile cues during braille reading leads to poorer performance in a letter recognition task. In particular, we show that lack of sliding contact between the fingertip and the braille reading surface results in more errors and that the number of errors increases as a function of presentation speed. These findings suggest that single cell displays which do not incorporate sliding contact are likely to be less effective for braille reading.

Letter detection: A window to unitization and other cognitive processes in reading text

Experiments are reviewed that use the letter-detection task, in which subjects read text and circle target letters. Evidence is provided that the letter-detection task reveals the processing units used in reading text and is influenced as well by visual, phonetic, and a combination of semantic and syntactic factors. Specifically, it is shown that circling a target letter in a word depends on the familiarity of the word's visual configuration, the location of the word in the reader's visual field, the phonetic representation of the letter in the word, and a combination of the word's meaning and its grammatical function.

Differential cognitive and perceptual correlates of print reading versus braille reading

The relations between reading, auditory, speech, phonological and tactile spatial processing are investigated in a Dutch speaking sample of blind braille readers as compared to sighted print readers. Performance is assessed in blind and sighted children and adults. Regarding phonological ability, braille readers perform equally well compared to print readers on phonological awareness, better on verbal short-term memory and significantly worse on lexical retrieval. The groups do not differ on speech perception or auditory processing. Braille readers, however, have more sensitive fingers than print readers. Investigation of the relations between these cognitive and perceptual skills and reading performance indicates that in the group of braille readers auditory temporal processing has a longer lasting and stronger impact not only on phonological abilities, which have to satisfy the high processing demands of the strictly serial language input, but also directly on the reading ability itself. Print readers switch between grapho-phonological and lexical reading modes depending on the familiarity of the items. Furthermore, the auditory temporal processing and speech perception, which were substantially interrelated with phonological processing, had no direct associations with print reading measures.

Parallel versus sequential processing in print and braille reading

In the current study we investigated word, pseudoword and story reading in Dutch speaking braille and print readers. To examine developmental patterns, these reading skills were assessed in both children and adults. The results reveal that braille readers read less accurately and fast than print readers. While item length has no impact on word reading accuracy and speed in the group of print readers, it has a significant impact on reading accuracy and speed in the group of braille readers, particularly in the younger sample. This suggests that braille readers rely more strongly on an enduring sequential reading strategy. Comparison of the different reading tasks suggests that the advantage in accuracy and speed of reading in adult as compared to young braille readers is achieved through semantic top-down processing.

Probing the perceptual and cognitive underpinnings of braille reading. An Estonian population study

Similar to many sighted children who struggle with learning to read, a proportion of blind children have specific difficulties related to reading braille which cannot be easily explained. A lot of research has been conducted to investigate the perceptual and cognitive processes behind (impairments in) print reading. Very few studies, however, have aimed for a deeper insight into the relevant perceptual and cognitive processes involved in braille reading. In the present study we investigate the relations between reading achievement and auditory, speech, phonological and tactile processing in a population of Estonian braille reading children and youngsters and matched sighted print readers. Findings revealed that the sequential nature of braille imposes constant decoding and effective recruitment of phonological skills throughout the reading process. Sighted print readers, on the other hand, seem to switch between the use of phonological and lexical processing modes depending on the familiarity, length and structure of the word.

Adaptive changes in early and late blind: a fMRI study of Braille reading

Braille reading depends on remarkable adaptations that connect the somatosensory system to language. We hypothesized that the pattern of cortical activations in blind individuals reading Braille would reflect these adaptations. Activations in visual (occipital-temporal), frontal-language, and somatosensory cortex in blind individuals reading Braille were examined for evidence of differences relative to previously reported studies of sighted subjects reading print or receiving tactile stimulation. Nine congenitally blind and seven late-onset blind subjects were studied with fMRI as they covertly performed verb generation in response to reading Braille embossed nouns. The control task was reading the nonlexical Braille string "######". This study emphasized image analysis in individual subjects rather than pooled data. Group differences were examined by comparing magnitudes and spatial extent of activated regions first determined to be significant using the general linear model. The major adaptive change was robust activation of visual cortex despite the complete absence of vision in all subjects. This included foci in peri-calcarine, lingual, cuneus and fusiform cortex, and in the lateral and superior occipital gyri encompassing primary (V1), secondary (V2), and higher tier (VP, V4v, LO and possibly V3A) visual areas previously identified in sighted subjects. Subjects who never had vision differed from late blind subjects in showing even greater activity in occipital-temporal cortex, provisionally corresponding to V5/MT and V8. In addition, the early blind had stronger activation of occipital cortex located contralateral to the hand used for reading Braille. Responses in frontal and parietal cortex were nearly identical in both subject groups. There was no evidence of modifications in frontal cortex language areas (inferior frontal gyrus and dorsolateral prefrontal cortex). Surprisingly, there was also no evidence of an adaptive expansion of the somatosensory or primary motor cortex dedicated to the Braille reading finger(s). Lack of evidence for an expected enlargement of the somatosensory representation may have resulted from balanced tactile stimulation and gross motor demands during Braille reading of nouns and the control fields. Extensive engagement of visual cortex without vision is discussed in reference to the special demands of Braille reading. It is argued that these responses may represent critical language processing mechanisms normally present in visual cortex.

Spatial representations of words and nonwords

The first two experiments investigated whether the representations of words, besides being unitary, are also spatial in nature. Subjects were required to search for target letters in either five-letter words or five-letter nonwords. They were instructed to press the right-side key for one target and the left-side key for the other target. The center item of the letter string was always at fixation. Targets appeared one at a time, located at the second (left side) or the fourth (right side) position within the letter string. The results showed that: a) responses to targets within words were faster than responses to targets within nonwords (the word-superiority effect); b) responses to compatible stimulus-response pairings were faster than responses to incompatible stimulus-response pairings (the spatial compatibility, or, more precisely, the Simon effect); and c) in Experiment 2, left-side targets were responded to faster than right-side targets within nonwords (the left-right scanning effect). It was concluded that representations of both words and nonwords are spatial in nature. Experiment 3 was aimed at testing whether the spatial layout of the representations of words is always along the left-right horizontal dimension, regardless of the topographic transformation of the stimulus. The same words and nonwords used in the previous experiments were shown vertically and the subjects were required to make left-right discriminative responses to upper and lower target letters. The results showed the word-superiority effect but no spatial compatibility effects. It was concluded that the representation of a vertically presented word is vertically arranged.

On time differences in searching for letters in words and nonwords: do they emerge during the initial encoding or the subsequent scan?

Krueger (1970a, 1970b, 1982) has demonstrated that subjects can search for target letters within words faster than they can complete an equivalent search through nonwords, and he further demonstrated that the effect did not arise during the comparison stage. The present study involved three experiments in which the usual word advantage disappeared either when subjects knew where within a display the target item would appear (i.e., it was always the first letter), or when all the component letters were encoded into memory before the task began (i.e., a memory-search task). These data, in conjunction with Krueger's, where interpreted as localizing at least one (and possibly the only) source of the word-nonword difference in this task to the events that occur during the item-to-item transitions subjects make when scanning the letter arrays. That is, these transitions are faster for words than nonwords, and it was suggested that the time difference may emerge because although all the letters from within a word appear to be available in memory before the scan begins, this seems not to be true for consonant arrays. Given that this is the case, part of the word-nonword difference may be attributable to subsequent encoding events that would be needed for the consonant arrays as the scan moves from letter to letter.

Detection of intraword and interword letter repetition: a test of the word unitization hypothesis

Do words, as familiar units or gestalts, tend to swallow up and conceal their letter components (Pillsbury, 1897)? Letters typically are detected faster and more accurately in words than in nonwords (i.e., scrambled collections of letters), and in more frequent words than in less frequent words. However, a word advantage at encoding, where the representation of the string is formed, might compensate for, and thus mask, a word disadvantage at decoding and comparison, where the component letters of the representation are accessed and compared with the target letter. To better reveal any such word disadvantage, a task was used in this study that increased the amount of letter processing. Subjects judged whether a letter was repeated within a six-letter word or a nonword (Experiment 1; intraword letter repetition) or was repeated between two adjacent unrelated six-letter words or nonwords (Experiment 2; interword letter repetition). Contrary to Pillsbury's word unitization hypothesis, both types of letter repetition (intraword and interword) were detected faster and just as accurately with words as with nonwords. In Experiment 2, however, interword letter repetition was detected less accurately on common words (but not on rare words or third-order pseudowords) than on the corresponding nonwords. Thus, although the familiar word does not deny access to its own component letters, it does make their comparison with letters from other words more difficult.

Perceptual and task factors in fluent braille

Hypotheses that fluent braille depends (i) on coding letters by global outline shape for all task and speed levels, or (ii) on lateral dot-gap density scanning in fast reading for meaning were tested with three groups of fluent braillists who differed in reading speeds. In experiment 1, 90 degrees-rotated (near to far) texts under vertical and horizontal finger orientation were used. Hypothesis (i) was not supported. Finger orientation interacted significantly with Speed and Task. Vertical finger orientation, which disrupts lateral scanning, slowed reading for comprehension more than for letter search, and differentially more for faster readers. Horizontal finger orientation, which instead disrupts the familiar finger-body relation, did not have differential effects. The findings support hypothesis (ii). In experiment 2, normal texts and texts containing a degraded dot in some letters were used. These are felt in searching for individual letter patterns, but would disrupt lateral scanning of expected dot-gap density patterns in reading for meaning. The results supported the predictions from hypothesis (ii), that degraded texts slow reading for meaning significantly more than for letter search, and more in the case of faster readers than for the slowest group. Findings were not consistent with hypothesis (i), which predicts that text degradation affects tasks equally, and affects the slowest rather than the fastest readers. The results suggest that perceptual coding in reading differs with task demands and speed.

Aphasic dyslexia of Braille in a congenitally blind man

Due to an ischemic attack a congenitally blind man became aphasic. He had a severe Wernicke's aphasia and aphasic dyslexia of Braille. The patient had been a very expert Braille reader before his illness. Two texts of 250 words each were read and the results analysed. One text was in basic Braille and the other in contracted Braille. Results of the analysis are discussed with regard to processes in reading Braille and problems of dyslexia.