Two types of developmental surface dysgraphia: to bee but not to bea.

We report on two types of developmental surface dysgraphia. One type, exhibited by 8 participants, is orthographic lexicon surface dysgraphia, which involves an impairment in the orthographic output lexicon, leading to nonword phonologically-plausible misspellings. The other type, shown by 3 participants, is disconnection surface dysgraphia. In this type, the orthographic output lexicon is disconnected from the semantic system and from the phonological input lexicon, but still contributes to spelling via support to the orthographic output buffer, resulting in mainly lexical phonologically-plausible misspellings (writing be as "bee" but not "bea").The specific localization of the impairment in spelling, in the lexicon or in its connections, allowed us to examine the question of one or two orthographic lexicons; four participants who had a deficit in the orthographic output lexicon itself in writing had intact orthographic-input-lexicon in reading. They made surface errors in writing but not in reading the same words, supporting separate input and output orthographic lexicons.

An access deficit or a deficit in the phonological representations themselves: What can we learn from naming errors?

Anomic aphasia is characterized by good comprehension and non-word repetition but poor naming. Two sub-types of deficits might be hypothesized: faulty access to preserved phonological representations or preserved access to impaired representations. Phonological errors may occur only when representations are impaired or in post-lexical deficits (conduction aphasia). We analysed the incidence of phonological naming errors of 30 individuals, 25 with anomic aphasia based on poor naming but good repetition and comprehension, and five with conduction aphasia based on poor naming and poor repetition. Individuals with anomic aphasia produced very few phonological errors compared to individuals with conduction aphasia (0-19.1% versus 42-66%). However, six individuals with anomia produced more than 11% phonological errors, suggesting two patterns of deficit: either impaired lexical representations or impaired access to them. The lack of phonological errors in most individuals with anomic aphasia suggests that access to the phonological output lexicon is semantically, not phonologically driven.

Language in Healthy Ageing: A Comparison across Language Domains.

INTRODUCTION: Life expectancy has been increasing in recent decades. Therefore, it is important to understand the functional changes during healthy ageing. Most research has mainly focused on one linguistic domain at a time. The current study aimed at investigating whether changes in language performance in healthy ageing occur in some language domains more than in others. METHODS: Twenty-three older healthy Hebrew-speaking adults, exhibiting no cognitive decline, were examined on tasks aimed at testing their performance in different language and cognitive domains: lexical retrieval, complementation information, syntax, theory of mind (a domain related to pragmatic aspects of language), and short-term memory. We compared their performance at both the group and the individual levels. Comparisons were made between the performance of the older adults and control data of young adults, and between the older adults' performance in the different linguistic domains. In addition, correlations between the older adults' phonological short-term memory abilities and their performance in various linguistic domains were examined. RESULTS: A decline was found in several linguistic domains among the older adults, while in other domains no decline was found. However, no unequivocal decline in linguistic functioning was found due to relatively large variance in their performance. CONCLUSION: Not all linguistic domains are equally vulnerable in ageing, and not all older adults are equally affected. The research has both clinical and theoretical implications.

Speech and language therapists' management of ventilated patients and patients with tracheostomy in Israel.

BACKGROUND: There is increased involvement of speech and language therapists (SLTs) in critical care and long-term units supporting patients with ventilatory needs and complex dysphagia. SLTs have a range of specialist knowledge in the function of the pharynx and larynx to enable them to support therapeutic interventions and contribute to the management of those patients. In Israel, there are currently no designated courses or training programmes for SLTs to establish advanced clinical skills in tracheostomy and ventilator management. There are currently standards of care for SLT working in designated wards for ventilated patients, however not in acute wards, critical care, and internal medicine wards where ventilated patients can be hospitalized. AIMS: To identify the skills and expertise of the Israeli SLT workforce working with tracheostomy patients. Specifically, to identify their level of training, access to training, client population, work settings, and level of work confidence. METHODS: The study involved electronic distribution of a 55-item online survey to SLTs in Israel. The questions included demographic information, training, confidence, and clinical support. RESULTS: Responses were received from 47 SLTs. The majority (40.4%) spent between 1% and 9% of their clinical time with ventilated patients. Almost 80% work with seniors (≥65 years) and almost 70% work with adults (18-65 years) half the time or more. In inpatient rehabilitation, 46.8% reported that they manage patients with tracheostomy half the time or more. In outpatient rehabilitation settings, 21.3% reported that they manage patients with tracheostomy half the time or more. Prior to managing complex airway patients independently, 55.3% received less than 5 h formal tracheostomy training whilst 68.1% received less than 5 h training on ventilated patients. Multidisciplinary teams (MDTs) existed for tracheostomy patients (85.1%) and ventilated patients (70.2%) and high levels of confidence were reported for managing patients with tracheostomies (mode of 4 in a scale of 0-5, where 5 means fully confident) and ventilated patients (mode of 3 in a scale of 0-5). A significant relationship was found between level of confidence and presence of an MDT. CONCLUSIONS: Limited training access was found for SLTs working with this complex population. A competency framework needs to be established with access to training and supervision. MDT existence contributes to confidence. Most respondents worked in rehabilitation settings, and very few worked in acute care, critical care, and internal medicine wards. It seems reasonable that in order to change this, minimal standards of care should be established on these wards. WHAT THIS PAPER ADDS: What is already known on the subject Speech and language therapists (SLTs) have an important role in critical care and long-term units supporting patients with complex dysphagia and undergo formal training and supervision in UK and Australia. What this paper adds to existing knowledge In Israel, most SLTs work with tracheostomy and ventilated adult patients in rehabilitation settings, whilst few work in acute, critical care, and internal medicine wards. There are limited opportunities for formal training and supervision, although MDT support enhances clinical confidence. What are the potential or actual clinical implications of this work? SLTs in Israel would benefit from establishing a competency framework for tracheostomy and ventilator patient management to support training, standards of care, and increase clinical involvement in acute settings. This will enhance clinical outcomes for their large population of complex airway patients.

Real-time monitoring of barriers to patient engagement for improved rehabilitation: a protocol and representative case reports.

PURPOSE: There is ample evidence that patient engagement is of major clinical importance in rehabilitation, and it seems this engagement is based upon effective allocation of attention to the tasks during the rehabilitation session. It is possible to discern two types of barriers which hinder attentive engagement: (1) dysfunctional affective coping and (2) limited cognitive recruitment and specifically attention deficit. These barriers might be general for a given patient, due to pre-morbid or co-morbid dysfunctions. But more often they are evoked by tasks or challenges during the rehabilitation session which might be too complicated or stressing for the specific patient who copes with potentially grave impairments. These barriers hinder rehabilitation progress and should be monitored and overcome, by the therapist, throughout the session. METHODS: We have developed an easy-to-use tool for monitoring a patient's attentive engagement in real-time throughout a rehabilitation session based on analysing the electrophysiological signal sampled from a simple headset. The tool then analyzes the dynamics of the marker over time to identify cognitive and affective barriers during the session. It enables the therapist to insert feedback regarding the patient's functional performance and to combine it with the analysed barriers, in order to derive automatic recommendations for overcoming the cognitive and affective barriers (if identified) for significant enhancement of the rehabilitation session. RESULTS AND CONCLUSIONS: In this work we present the principles of the tool as well as three detailed case reports to demonstrate its potential usefulness.IMPLICATIONS FOR REHABILITATIONCognitive and affective barriers hinder patient engagment and rehabilitation success.In this work we present an easy to use electrophysiology-based tool which monitors these barriers.Based on the measured barriers and patient's performance, the tool derives treatment suggestions.

Non-word writing does not require the phonological output buffer: Neuropsychological evidence for a direct phonological-orthographic route.

What is the route that is used for writing non-words to dictation? Does it have to pass through phonological output? Two possibilities are found in the literature. In one, writing non-words requires access from the phonological input buffer to the phonological output buffer and from there, via phoneme-to-grapheme conversion, to the orthographic output buffer. The second approach maintains that writing non-words can proceed directly from the phonological input buffer to the orthographic output buffer. In this study, we discriminate between these two options using a cognitive neuropsychological approach. Specifically, we present a multiple case study of 24 individuals with a developmental impairment to the phonological output buffer, who nevertheless show unimpaired non-word writing. These data lead to the conclusion that the phonological output buffer is not necessary when writing non-words and that writing non-words to dictation can proceed directly from the phonological input buffer to the orthographic output buffer. We suggest that the cognitive assumption that non-word writing proceeds through the phonological output buffer may have resulted from graphic conventions and the depiction of the lexical processing model: in the common depiction of the model drawing a line through the phonological output buffer is visually simpler than a direct line (which would require lines to cross or long bypass lines).

[FROM THEORY TO THE CLINIC - IS IT POSSIBLE TO DETECT DIFFERENT TYPES OF ANOMIA ACCORDING TO THE LEXICAL RETRIEVAL MODEL?]

INTRODUCTION: The lexical retrieval model describes the process of naming - from the level of an abstract concept representation to the production of the word. Lexical retrieval includes several distinct levels. A deficit in any of these levels causes anomia, a naming deficit, and deficits in different levels cause different types of anomia. AIMS: To examine whether the theoretical model can be applied in the clinic. Namely, whether it is possible to identify, for a specific patient, the exact impaired lexical retrieval level, and to show that different patients are impaired in different levels. METHODS: The performance of 24 participants with aphasia, with lexical retrieval deficits, were analyzed. The analysis included performance on a naming test - including analysis of error types and of the effects that modulate naming errors. We also analyzed the performance in other language tasks that examine the different levels of lexical retrieval, including tasks that do not involve naming. RESULTS: Different types of anomia were found for the different participants. The various types of anomia are reflected in different sorts of naming errors, in different effects that modulate naming errors, and in different performance patterns in the other language tasks. CONCLUSIONS: The theoretical model of lexical retrieval can underpin descriptions of clinical phenomena. The findings support the view that the relations between theory and clinic are bidirectional - theories constitute an anchor for the description of clinical phenomena, and clinical findings can support, or refute, theory. DISCUSSION: The distinction between the different types of anomia is important for choosing the appropriate treatment for each patient.

[CHANGES IN THE WAY WE OBSERVE, ASSESS AND TREAT APHASIA: FROM THE TRADITIONAL APPROACH TO THE PSYCHOLINGUISTIC AND SOCIAL APPROACHES].

INTRODUCTION: Aphasia is an acquired language impairment, initially identified and described before the 19th century. According to traditional models (Wernicke-Lichtheim-Geschwind) the aphasic symptoms can be clustered into particular syndromes, such as Broca's, Wernicke's, Conduction aphasias, and more. Each syndrome is allegedly associated with a specific anatomical site. The major motivation for this model was to use the behavioral symptoms to learn about language and brain relationships. However, current advanced imaging techniques identify more precisely the loci of the deficit. Moreover, the model frequently fails to adequately describe the clinical symptoms, a description that is crucial for understanding the language deficit and for choosing the relevant treatment. For more than three decades, two alternative models are being used in the clinical setting and in research. First, the psycholinguistic model, which describes the normal stages that are involved in language processing. On the basis of this model it is possible to detect, for each individual with aphasia, the specific impaired stage or stages underlying the language deficits. Second, the social model of aphasia based on the ICF definitions of the World Health Organization. According to this model, it is suggested that the speech therapy intervention should focus not only on the language deficits but also on communication per se in order to enable the individual with aphasia to communicate with others despite the language deficits. In the current paper we will review these two models and their clinical implications.

Students' Evaluation of Simulation-Based Training in a Communication Sciences and Disorders Program.

The current study aimed to evaluate simulation-based medical education (SBME) training and its contribution to the learning process of students in a communication sciences and disorders (CSD) program. The training was integrated in different stages of the program, over 4 years, with different students. The content and complexity of each of the simulation activities targeted specific skills, tailored to the students' learning phase. Students completed a nine-item survey at the end of the first and second semesters of the second year, evaluating the simulation training program structure and students' self-efficacy relating to the building of relationships between care givers and patients. A total of 246 questionnaires were analyzed. Students reported significantly increased self-efficacy in a range of clinical skills and perceived the inclusion of simulated patients (SPs) into a clinical skills program as valuable. Our data suggest that scenarios that reflect real-life situations (environment, atmosphere, equipment, etc.) have the strongest impact on the students' ability to implement professional and communication skills. A strong positive correlation was found between the video-based debriefing and students' perception of the improvement in their professional and communication skills. These findings suggest that this is a feasible and powerful training approach that can be applied in the CSD curriculum.

A Principled Relation between Reading and Naming in Acquired and Developmental Anomia: Surface Dyslexia Following Impairment in the Phonological Output Lexicon.

Lexical retrieval and reading aloud are often viewed as two separate processes. However, they are not completely separate-they share components. This study assessed the effect of an impairment in a shared component, the phonological output lexicon, on lexical retrieval and on reading aloud. Because the phonological output lexicon is part of the lexical route for reading, individuals with an impairment in this lexicon may be forced to read aloud via the sublexical route and therefore show a reading pattern that is typical of surface dyslexia. To examine the effect of phonological output lexicon deficit on reading, we tested the reading of 16 Hebrew-speaking individuals with phonological output lexicon anomia, eight with acquired anomia following brain damage and eight with developmental anomia. We established that they had a phonological output lexicon deficit according to the types of errors and the effects on their naming in a picture naming task, and excluded other deficit loci in the lexical retrieval process according to a line of tests assessing their picture and word comprehension, word and non-word repetition, and phonological working memory. After we have established that the participants have a phonological output lexicon deficit, we tested their reading. To assess their reading and type of reading impairment, we tested their reading aloud, lexical decision, and written word comprehension. We found that all of the participants with phonological output lexicon impairment showed, in addition to anomia, also the typical surface dyslexia errors in reading aloud of irregular words, words with ambiguous conversion to phonemes, and potentiophones (words like "now" that, when read via the sublexical route, can be sounded out as another word, "know"). Importantly, the participants performed normally on pseudohomophone lexical decision and on homophone/potentiophone reading comprehension, indicating spared orthographic input lexicon and spared access to it and from it to lexical semantics. This pattern was shown both by the adults with acquired anomia and by the participants with developmental anomia. These results thus suggest a principled relation between anomia and dyslexia, and point to a distinct type of surface dyslexia. They further show the possibility of good comprehension of written words when the phonological output stages are impaired.

Insights from letter position dyslexia on morphological decomposition in reading.

We explored morphological decomposition in reading, the locus in the reading process in which it takes place and its nature, comparing different types of morphemes. We assessed these questions through the analysis of letter position errors in readers with letter position dyslexia (LPD). LPD is a selective impairment to letter position encoding in the early stage of word reading, which results in letter migrations (such as reading "cloud" for "could"). We used the fact that migrations in LPD occur mainly in word-interior letters, whereas exterior letters rarely migrate. The rationale was that if morphological decomposition occurs prior to letter position encoding and strips off affixes, word-interior letters adjacent to an affix (e.g., signs-signs) would become exterior following affix-stripping and hence exhibit fewer migrations. We tested 11 Hebrew readers with developmental LPD and 1 with acquired LPD in 6 experiments of reading aloud, lexical decision, and comprehension, at the single word and sentence levels (compared with 25 age-matched control participants). The LPD participants read a total of 12,496 migratable words. We examined migrations next to inflectional, derivational, or bound function morphemes compared with migrations of exterior letters. The results were that root letters adjacent to inflectional and derivational morphemes were treated like middle letters, and migrated frequently, whereas root letters adjacent to bound function morphemes patterned with exterior letters, and almost never migrated. Given that LPD is a pre-lexical deficit, these results indicate that morphological decomposition takes place in an early, pre-lexical stage. The finding that morphologically complex nonwords showed the same patterns indicates that this decomposition is structurally, rather than lexically, driven. We suggest that letter position encoding takes place before morphological analysis, but in some cases, as with bound function morphemes, the complex word is re-analyzed as two separate words. In this reanalysis, letter positions in each constituent word are encoded separately, and hence the exterior letters of the root are treated as exterior and do not migrate.

Compound reading in Hebrew text-based neglect dyslexia: the effects of the first word on the second word and of the second on the first.

In many Hebrew compounds, which are two-word phrases, the first word is marked morphophonologically, and often also orthographically, as the head of the compound. Because Hebrew is read from right to left, this allowed us to ask whether a right-hand word that is marked orthographically as a compound-head, and hence signals that another word is expected, causes readers with text-based neglect to continue shifting attention to the left and read the second word. We also asked whether the second, left-hand, word affects the reading of the first word. The effect of the second word was assessed in a condition in which the second word semantically disambiguated the first word, a biased heterophonic homograph, and a condition in which the second word formed a compound with the first and hence required reading the first in the morphophonological form of a compound-head. The two participants were Hebrew-speaking men with acquired left text-level neglect dyslexia, without word-based neglect dyslexia. They read 294 two-word compounds and control phrases, composed of five conditions that assessed the effect of the first word on the second word, and of the second on the first. The results indicated that morphosyntax modulates reading in neglect dyslexia. When the first, right-hand, word included an orthographic cue indicating that a second word follows, fewer words on the left were omitted than when no such cue existed. The second word, however, did not affect the reading of the first, and the first word was read as if the patients did not look ahead to the second.

A selective deficit in imageable concepts: a window to the organization of the conceptual system.

Nissim, a 64 years old Hebrew-speaking man who sustained an ischemic infarct in the left occipital lobe, exhibited an intriguing pattern. He could hold a deep and fluent conversation about abstract and complex issues, such as the social risks in unemployment, but failed to retrieve imageable words such as ball, spoon, carrot, or giraffe. A detailed study of the words he could and could not retrieve, in tasks of picture naming, tactile naming, and naming to definition, indicated that whereas he was able to retrieve abstract words, he had severe difficulties when trying to retrieve imageable words. The same dissociation also applied for proper names-he could retrieve names of people who have no visual image attached to their representation (such as the son of the biblical Abraham), but could not name people who had a visual image (such as his own son, or Barack Obama). When he tried to produce imageable words, he mainly produced perseverations and empty speech, and some semantic paraphasias. He did not produce perseverations when he tried to retrieve abstract words. This suggests that perseverations may occur when the phonological production system produces a word without proper activation in the semantic lexicon. Nissim evinced a similar dissociation in comprehension-he could understand abstract words and sentences but failed to understand sentences with imageable words, and to match spoken imageable words to pictures or to semantically related imageable words. He was able to understand proverbs with imageable literal meaning but abstract figurative meaning. His comprehension was impaired also in tasks of semantic associations of pictures, pointing to a conceptual, rather than lexical source of the deficit. His visual perception as well as his phonological input and output lexicons and buffers (assessed by auditory lexical decision, word and sentence repetition, and writing to dictation) were intact, supporting a selective conceptual system impairment. He was able to retrieve gestures for objects and pictures he saw, indicating that his access to concepts often sufficed for the activation of the motoric information but did not suffice for access to the entry in the semantic lexicon. These results show that imageable concepts can be selectively impaired, and shed light on the organization of conceptual-semantic system.

An even more universal model of reading: various effects of orthography on dyslexias.

The properties of a specific orthography dictate the way people read it. We bring considerations from dyslexia to suggest that the claim can be extended further. First, the effect of orthographic neighborhood density can be extended beyond letter-position encoding and beyond the orthographic lexicon. Second, Hebrew and Arabic differ with respect to letter forms, and hence, in letter-position encoding.

Patterns of visual dyslexia.

This study reports two Hebrew-speaking individuals with acquired visual dyslexia. They made predominantly visual errors in reading, in all positions of the target words. Although both of them produced visual errors, their reading patterns crucially differed in three respects. KD had almost exclusively letter substitutions, and SF also made letter omissions, additions, letter position errors, and between-word migrations. KD had difficulties accessing abstract letter identity in single-letter tasks, and in letter naming, unlike SF, who named letters well. KD did not show lexical effects such as frequency and orthographic neighbourhood effects and produced nonword responses, whereas SF showed lexical effects, with a strong tendency to produce word responses. We suggest that these two patterns stem from two different deficits - KD has letter identity visual dyslexia, which results from a deficit in abstract letter identification in the orthographic-visual analysis system, yielding erroneous letter identities, whereas SF has visual-output dyslexia, which results from a deficit at a later stage, a stage that combines the outputs of the various functions of the orthographic-visual analyzer.

The effect of syntax on reading in neglect dyslexia.

Individuals with text-based neglect dyslexia omit words on the neglected side of the sentence or text, usually on the left side. This study tested whether the syntactic structure of the target sentence affects reading in this type of neglect dyslexia. Because Hebrew is read from right to left, it enables testing whether the beginning of the sentence and its syntactic properties determine if the final, leftmost, constituent is omitted or not. The participants were 7 Hebrew-speaking individuals with acquired left text-based neglect dyslexia, without syntactic impairments. Each participant read 310 sentences, in which we compared 5 types of minimal pairs of sentences that differed in the obligatoriness of the final (left) constituent. Complements were compared with adjuncts, obligatory pronouns were compared with optional resumptive pronouns, and the object of a past tense verb was compared with the object of a present tense verb, which can also be taken to be an adjective, which does not require an object. Questions that require a verb were compared with questions that can appear without a verb, and clauses that serve as sentential complements of a verb were compared with coordinated clauses, which are not required by the verb. In addition, we compared the reading of noun sequences to the reading of meaningful sentences, and assessed the neglect point in reading 2 texts. The results clearly indicated that the syntactic knowledge of the readers with neglect dyslexia modulated their sentence reading. They tended to keep on reading as long as the syntactic and lexical-syntactic requirements of the sentence had not been met. In 4 of the conditions twice as many omissions occurred when the final constituent was optional than when it was obligatory. Text reading was also guided by a search for a "happy end" that does not violate syntactic or semantic requirements. Thus, the syntactic structure of the target sentence modulates reading and neglect errors in text-based neglect dyslexia, suggesting that the best stimuli to diagnose mild text-based neglect dyslexia are sentences in which the leftmost constituent is optional, and not required by syntax. Another finding of this study is dissociation between neglect dyslexia at the text and at the word levels. Two of the participants had neglect dyslexia at the text level, manifested in omissions of words on the left side of text, without neglect dyslexia at the word level (namely, without omissions, substitutions, or additions of letters on the left side of words).

Dyscravia: voicing substitution dysgraphia.

We report a new type of dysgraphia, which we term dyscravia. The main error type in dyscravia is substitution of the target letter with a letter that differs only with respect to the voicing feature, such as writing "coat" for "goat", and "vagd" for "fact". Two Hebrew-speaking individuals with acquired dyscravia are reported, TG, a man aged 31, and BG, a woman aged 66. Both had surface dysgraphia in addition to their dyscravia. To describe dyscravia in detail, and to explore the rate and types of errors made in spelling, we administered tests of writing to dictation, written naming, and oral spelling. In writing to dictation, TG made voicing errors on 38% of the words, and BG made 17% voicing errors. Voicing errors also occurred in nonword writing (43% for TG, 56% for BG). The writing performance and the variables that influenced the participants' spelling, as well as the results of the auditory discrimination and repetition tasks indicated that their dyscravia did not result from a deficit in auditory processing, the graphemic buffer, the phonological output lexicon, the phonological output buffer, or the allographic stage. The locus of the deficit is the phoneme-to-grapheme conversion, in a function specialized in the conversion of phonemes' voicing feature into graphemes. Because these participants had surface dysgraphia and were forced to write via the sublexical route, the deficit in voicing was evident in their writing of both words and nonwords. We further examined whether the participants also evinced parallel errors in reading. TG had a selective voicing deficit in writing, and did not show any voicing errors in reading, whereas BG had voicing errors also in the reading of nonwords (i.e., she had dyslegzia in addition to dyscravia). The dissociation TG demonstrated indicated that the voicing feature conversion is separate for reading and writing, and can be impaired selectively in writing. BG's dyslegzia indicates that the grapheme-to-phoneme conversion also includes a function that is sensitive to phonological features such as voicing. Thus the main conclusion of this study is that a separate function of voicing feature conversion exists in the phoneme-to-grapheme conversion route, which may be selectively impaired without deficits in other functions of the conversion route, and without a parallel deficit in reading.

Letter position dysgraphia.

The article describes AE, a Hebrew-speaking individual with acquired dysgraphia, who makes mainly letter position errors in writing. His dysgraphia resulted from impairment in the graphemic buffer, but unlike previously studied patients, most of his errors related to the position of letters rather than to letter identity: 80% of his errors were letter position errors in writing, and only 7% of his errors were letter omissions, substitutions, and additions. Letter position errors were the main error type across tasks (writing to dictation and written naming), across output modalities (writing and typing), and across stimuli, e.g., migratable words (words in which letter migration forms another word), irregular words, and nonwords. Letter position errors occurred mainly in the middle letters of a word. AE's writing showed a significant length effect, and no lexicality, migratability, or frequency effects. His letter position deficit was manifested selectively in writing; he made no letter position errors in reading, demonstrating the dissociability of letter position encoding in reading and writing. These data support the existence of a letter order function in the graphemic buffer that is separate from the function responsible for activating letter identities.

Letter form as a constraint for errors in neglect dyslexia and letter position dyslexia.

Does letter-form constrain errors in peripheral dyslexia? In Hebrew, 5 of the 22 letters have two different letter forms, one is used only when the letter occurs in word-final position, the other form is used in initial and middle positions. Is the information on final-forms encoded in the letter identity information and used for word identification, or is it discarded? The current research explored this question through the effect of final vs. non final letter form on the error pattern in neglect dyslexia (neglexia) and letter position dyslexia (LPD). Left word-based neglexia results in errors of omission, substitution and addition of letters in the left side of words, which in Hebrew is the end of the word. We examined whether final letter form blocks the addition of letters to the end of the word and whether omissions of letters after letters in non-final form are avoided. The predominant error type in LPD is migration of letters within words. We tested whether migrations also occur when they cause form change of either final-form letters that move to middle position or middle-form letters that move to final position. These questions were assessed in both acquired and developmental neglexia and LPD. The results indicated a strong effect of final letter-form on acquired neglexia and on acquired and developmental LPD, which almost completely prevented form-changing errors. This effect was not found in developmental neglexia, where words that end in final-form letters were actually more impaired than other words, probably because final-form letters appear only on the neglected side of the word for Hebrew-reading children with left developmental neglexia. These data show that early visuo-orthographic analysis is sensitive to final letter form and that final letter form constrains errors in peripheral dyslexia.

Sentence comprehension and working memory limitation in aphasia: a dissociation between semantic-syntactic and phonological reactivation.

The relation between working memory (WM) limitation and sentence comprehension was assessed in Hebrew-speaking aphasics, three conduction aphasics and three agrammatics. The study compared sentences that required different types of reactivation-syntactic-semantic reactivation, in relative clauses, and word form/phonological reactivation, in sentences with reanalysis of lexical ambiguity. The effect of phonological memory load, manipulated by number of words intervening between the activation and the reactivation, on comprehension of the two sentence types was examined. The findings were that agrammatic aphasics failed in the comprehension of object relatives but not on subject relatives irrespective of their antecedent-gap distance. Conduction aphasics, on the other hand, who showed severe WM limitation, comprehended well all types of relative clauses and were unaffected by antecedent-gap distance. The conduction aphasics failed to understand the sentences that required phonological reactivation when the phonological distance was long. These results suggest that the type of reactivation required by the sentence, as well as the type of memory overload are crucial in determining the effect of WM limitation on sentence comprehension.