Whole-word phonological representations of disyllabic words in the Chinese lexicon: data from acquired dyslexia

This study addresses the issue of the existence of whole-word phonological representations of disyllabic and multisyllabic words in the Chinese mental lexicon. A Cantonese brain-injured dyslexic individual with semantic deficits, YKM, was assessed on his abilities to read aloud and to comprehend disyllabic words containing homographic heterophonous characters, the pronunciation of which can only be disambiguated in word context. Superior performance on reading to comprehension was found. YKM could produce the target phonological forms without understanding the words. The dissociation is taken as evidence for whole-word representations for these words at the phonological level. The claim is consistent with previous account for discrepancy of the frequencies of tonal errors between reading aloud and object naming in Cantonese reported of another case study of similar deficits. Theoretical arguments for whole-word form representations for all multisyllabic Chinese words are also discussed.     

The interaction of multiple routes in oral reading: evidence from dissociations in naming and oral reading in phonological dyslexia

During oral reading we hypothesized that lexical representations are activated and selected for output by the simultaneous activation of the semantic, the direct lexical orthography to phonology, and the sublexical grapheme-to-phoneme conversion (GPC) routes (Southwood & Chatterjee, 1999). Serial models of reading argue that the semantic route governs oral reading with minimal influence from the nonlexical direct route and the sublexical GPC route. These models predict that semantic errors should occur in reading when the semantic route and GPC are both impaired. The Simultaneous Activation Hypothesis predicts few semantic errors in oral reading but many during picture naming. Semantic errors are infrequent in reading because information from all three reading routes constrains activation of a phonological entry. By contrast phonological selection in picture naming is constrained primarily by the semantic route and if damaged additional information is unavailable to select the appropriate phonological code. In agreement with the Simultaneous Activation Hypothesis five phonological dyslexics produced semantic errors during picture naming but not when reading aloud. Phonological errors were present during oral reading and minimal during picture naming.     

Optic aphasia and the right hemisphere: a replication and extension.

Optic aphasia is a rare, visual modality-specific naming disorder. We describe a patient who developed this disorder subsequent to a left occipital lobe infarction. Like another case that we described previously, this patient performed normally on a variety of tasks assessing the recognition of objects he could not name. Additionally, although he never read aloud a single word, his performance on lexical decision and word comprehension tasks was far better than chance. We suggest that his performance was mediated by a right hemisphere semantic system.     

The relationship between knowing a word and reading it aloud in children’s word reading development

This experiment examined the item-level relationship between 7-year-olds’ ability to read words aloud and their knowledge of the same words in the oral domain. Two types of knowledge were contrasted: familiarity with the phonological form of the word (lexical phonology), measured by auditory lexical decision, and semantic knowledge, measured by a definitions task. Overall, there was a robust relationship between word knowledge and reading aloud success. The association was stronger when words contained irregular spelling-sound correspondences. There was no evidence that a deeper or more semantic knowledge of words was more closely related to reading aloud success beyond the association between reading success and familiarity with the phonological form of the same words. This finding is not compatible with models that see semantics as contributing directly to the reading aloud process, at least during the relatively early stages of reading development. More critical was whether or not a word was considered a lexical item, as indexed by auditory lexical decision performance.     

Semantic involvement in reading aloud: evidence from a nonword training study

The current research uses a novel methodology to examine the role of semantics in reading aloud. Participants were trained to read aloud 2 sets of novel words (i.e., nonwords such as bink): some with meanings (semantic) and some without (nonsemantic). A comparison of reading aloud performance between these 2 sets of novel words was used to provide an indicator of the importance of semantic information in reading aloud. In Experiment 1, in contrast to expectations, reading aloud performance was not better for novel words in the semantic condition. In Experiment 2, the training of novel words was modified to reflect more realistic steps of lexical acquisition: Reading aloud performance became faster and more accurate for novel words in the semantic condition, but only for novel words with inconsistent pronunciations. This semantic advantage for inconsistent novel words was again observed when a subset of participants from Experiment 2 was retested 6-12 months later (in Experiment 3). These findings provide support for a limited but significant role for semantics in the reading aloud process.     

Acquired dyslexia in Spanish: a review and some observations on a new case of deep dyslexia

Readers and writers of Spanish use an orthography that is highly transparent. It has been proposed that readers of Spanish can rely on grapheme-phoneme correspondences, alone, to access meaning or phonology from print. In recent years, a number of case studies have yielded evidence inconsistent with this idea. We review these studies with particular focus on those that report evidence for reading based on direct lexical mappings between print, orthographic representations, and meaning or phonology. We report a new case of acquired literacy impairment in Spanish, MJ, who presents a pattern of preserved abilities and deficits symptomatic of deep dyslexia. The patient is unable to read nonwords, but can read a substantial number of words. Her reading is characterized by the production of semantic, visual, and derivational errors. We argue that MJ has a deficit in her lexical selection ability, common to both her reading and her naming problems. We propose that MJ, and the other cases we review, demonstrate that lexical reading is adopted by skilled readers even in a transparent language.     

Disruption of semantic influence on writing following a left prefrontal lesion

We report a patient with impaired spontaneous writing, written naming, and homophone spelling, consistent with a disruption of semantic influence on writing. However, writing to dictation by both the phonological and lexical spelling systems was intact. In addition, general semantic abilities were spared, as indicated by preserved auditory and reading comprehension. We propose that our patient could not incorporate meaning into writing because of a disruption of both direct and indirect connections between semantics and the orthographic output lexicon. The writing dysfunction was accompanied by a similar impairment of speech output, suggesting that it was part of a more general disturbance of semantic influence on language production following left prefrontal damage.     

Stimulus-specific neglect in a deep dyslexic patient

We report a patient (B.V.) who appears to suffer from two dyslexic disorders. First, B.V. showed a severe impairment in reading aloud nonwords (e.g., reading TREST as TREE), in addition to making several semantic errors when reading aloud words (e.g., reading ILL as SICK) and in picture naming (e.g., responding KNIFE to a picture of a FORK). These results suggest that B.V. suffers from deep dyslexia. Second, B.V. showed an impairment in reading the final letters of both words and nonwords (e.g., reading SHOWN as SHORT and reading PROGE as PROOF). Thus, it appears that B.V. also suffers from neglect dyslexia. We discuss how these two forms of dyslexia could be interacting to account for B.V.'s pattern of errors in reading aloud words and nonwords and in picture naming.     

Accurate reading by nonlexical means: A case study

Accurate reading of irregular words is generally assumed to require intact lexical reading mechanisms. A nonlexical mechanism is usually deemed insufficient for this type of stimulus processing. The maximum level of accuracy attainable by nonlexical means, however, has not been adequately evaluated. We now describe a patient with acquired dyslexia due to impaired lexical reading mechanisms who retained the ability to read irregular words. The patient's poor performance on tasks requiring lexical decision and access to word meaning provided evidence that his lexical mechanisms were impaired. Nevertheless, errors on irregular words became apparent only with special tests that circumvented the patient's ability to use his intact speaking vocabulary to ensure that reading responses were words. The results demonstrate that relatively accurate reading of irregular words is possible despite damage to lexical mechanisms and that this can be achieved by filtering potential responses through the speaking vocabulary.     

Simultaneous activation of reading mechanisms: evidence from a case of deep dyslexia

We report the performance of LC, a deep dyslexic. We investigated extensively her errors according to serial cognitive neuropsychological models of oral reading. Initial evaluation of her reading suggested impaired access to the phonological output lexicon (POL). Impaired grapheme-to-phoneme conversion (GPC) and semantic errors in reading suggested that LC read via an impoverished semantic route. However, a serial model of oral reading could not explain error differences in reading, picture naming, spontaneous speech, and repetition. Neologisms occurred in oral reading but not in spontaneous speech and repetition. Semantic errors in naming exceeded those in oral reading. To account for these different error patterns we propose that the semantic route, the direct route from the orthographic input lexicon to the POL, and GPC activate simultaneously during reading, converging at the POL to constrain phonological selection. These routes are modular but not functionally encapsulated. For LC, the POL receives ambiguous information due to degradation of all routes, causing reading errors.     

Reading aloud: The cumulative lexical interference effect

Picture naming shows a cumulative semantic interference effect: Latency for naming a target picture increases as a function of the number of pictures semantically similar to the target that have previously been named (Howard, Nickels, Coltheart, & Cole-Virtue, Cognition 100:464-482, 2006). Howard and colleagues, and also Oppenheim, Dell, and Schwartz (Cognition 114:227-252, 2010), argued that this occurs because of the joint presence in the picture-naming system of three critical properties: shared activation, priming, and competition. They also discussed the possibility that whenever any cognitive system possesses these three properties, a cumulative similarity-based interference effect from repeated use of that cognitive system will occur. We investigated this possibility by looking for a cumulative lexical interference effect when the task is reading aloud: Will the latency of reading a target word aloud increase as a function of the number of words orthographically/phonologically similar to the target that have previously been read aloud? We found that this was so. This supports the general idea that cumulative similarity-based interference effects will arise whenever any cognitive system that possesses the three key properties of shared activation, priming, and competition is repeatedly used.     

Age-of-acquisition affects word naming in Italian only when stress is irregular

In Italian, effects of age of acquisition (AoA) have been found in object naming, semantic categorization of words and lexical decision, but not in word naming (reading aloud). The lack of an AoA effect in Italian word naming is replicated in Experiment 1 which involved reading aloud two-syllable words which all have regular spelling-sound correspondences and regular stress patterns. Studies of English word naming have reported stronger effects of AoA for irregular or exception words than for words with regular, consistent spelling-sound correspondences. There are no grapheme-phoneme irregularities in Italian, but words containing three or more syllables can carry either regular stress on the penultimate syllable or irregular stress on the antepenultimate syllable. Experiment 2 found effects of AoA on reading three-syllable words for words with irregular stress. The results are interpreted in terms of the 'mapping hypothesis' of AoA, with effects arising as a result of a difficulty to generalize earlier-acquired patterns to irregular late-acquired words.     

Contextual control over lexical and sublexical routines when reading English aloud

Are the processes responsible for reading aloud single well-formed letter strings under contextual control? Despite the widespread contention that the answer to this question is “yes,” it has been remarkably difficult to provide a compelling demonstration to that effect. In a speeded naming experiment, skilled readers read aloud exception words (such asPint) that are atypical in terms of their spelling sound correspondences and nonwords (such asFlad) that appeared in a predictable sequence. Subjects took longer to name both words and nonwords when the item on the preceding trial was from the other lexical category, relative to when the preceding item was from the same lexical category. This finding is consistent with the relative contributions of lexical and sublexical knowledge being controlled. We note a number of different ways that this control could arise and suggest some directions for future research.     

Frequency,not age of acquisition,affects Italian word naming

The purpose of this study was to evaluate the claim that age of acquisition (AoA) and word frequency effects are reduced or nonexistent in languages that have very regular letter-to-sound mappings, like Italian. The first two experiments (Exp. 1, Exp. 2) showed that frequency variables affect reading aloud and lexical decision in Italian. Variables interpretable as pertaining to a semantic component, including AoA, affected lexical decision but not reading aloud. In Experiments 3 and 4, a measure of frequency—child written word frequency (ChFreq)—and AoA were manipulated. Reading performance was affected by word frequency but not by AoA (Exp. 3), whereas lexical decision was affected by both variables (Exp. 4). In Experiments 5 and 6, ChFreq and AoA were manipulated orthogonally. Only frequency affected reading aloud, with no main effect or interaction involving AoA (Exp. 5). The effects of AoA and frequency interacted in Experiment 6 for lexical decision due to a larger effect of AoA for low frequency words than high frequency words. These results show that in languages with a transparent orthography word frequency may affect reading aloud in the absence of an effect of AoA because Italian readers employ lexical nonsemantic reading aloud. The effect of child written frequency points to the efficiency of the mappings between those orthographic and phonological word forms that were frequently encountered when learning to read.     

What is right with “deep” dyslexic patients?

Two aphasic adults with a specific acquired dyslexia were given tests requiring the processing of written words and sentences. Despite the general severity of the patients' deficits, some aspects of such processing appear to be relatively well preserved. The patients have particular difficulty reading aloud function words and abstract words; yet in word/nonword discrimination tests, both patients showed normal recognition of function words and one showed normal performance with abstract words. The patients do have a deficit in comprehension of visually presented words and sentences; yet their performance on comprehension tests was considerable and, moreover, showed meaningful relationships with their ability to read aloud.     

Formal paraphasias: A single case study

A case study is reported of an aphasic patient, RB, who showed frequent form-related whole-word substitutions in oral naming, writing to dictation, and reading aloud. In both written language tasks, the abstractness of the targets influenced the number of formal errors. In oral naming, a high proportion of formal paraphasias was related to the intended words in both form and meaning. A comparison between targets and formal paraphasias indicated a high agreement both in word class, number of syllables, stress pattern, and in basic (stressed) vowels. The agreement in consonants (including word-initial consonants), however, was low. It is argued that RB's formal substitutions are not caused solely by errors of lexical selection but that semantic, lexical, and segmental factors contribute to the error outcome.     

Semantic ambiguity and the failure of inhibition hypothesis as an explanation for reading errors in deep dyslexia

We report evidence for dissociation between explicit and implicit access to word representations in a deep dyslexic patient (JO). JO read aloud a series of ambiguous (e.g., bank) and unambiguous (e.g., food) words and performed a lexical decision task using these same items. When required to explicitly access the items (i.e., naming), JO showed relative impairment for ambiguous compared with unambiguous words. In contrast, the same stimuli produced an advantage for ambiguous words in lexical decision. The results are discussed within a framework of deep dyslexia that considers errors in production to arise through a failure to inhibit spuriously activated candidate representations.     

Deep dysphasia: analysis of a rare form of repetition disorder

"Deep dysphasia" is the parallel in repetition to the reading impairment deep dyslexia. Our patient, S.M., showed part of speech, word/nonword, and concreteness effects in repetition, and he made semantic errors, but his oral reading was relatively spared. Further testing indicated that S.M. did not have difficulty perceiving spoken stimuli or deciding their lexical status, but he was deficient at semantically processing spoken words. Moreover, his phonemic memory was severely impaired. We argue that the routes for repetition (lexical and nonlexical) that function without semantic mediation were defective and that deficits in phonemic memory further diminished their effectiveness, since initial phonological encoding of spoken words was not available to guide the output stages of phonological processing. In addition, the semantically mediated route for repetition was unreliable because semantic processing was faulty and S.M. could not accurately label concepts.     

Stress regularity or consistency? Reading aloud Italian polysyllables with different stress patterns

Stress assignment to three- and four-syllable Italian words is not predictable by rule, but needs lexical look-up. The present study investigated whether stress assignment to low-frequency Italian words is determined by stress regularity, or by the number of words sharing the final phonological segment and the stress pattern (stress neighborhood or consistency). Experiment 1 showed an effect of stress neighborhood: words were read aloud faster and more accurately when they had a prevalence of stress "friends," irrespective of stress regularity. Moreover, when irregularly stressed words have a higher number of stress friends compared to regularly stressed words, they are read even faster (Experiment 2). In Experiment 3, using visual lexical decision, no difference related to the numerosity of stress friends was found. It is concluded that reading aloud Italian low-frequency words with different stress patterns is mainly affected by the numerosity of lexical types that share a given final sequence and the stress pattern. The phonological nature of the numerosity of lexical representations affecting reading aloud finds support in the absence of such effect in visual lexical decision. These results have implications for models of reading aloud that go beyond monosyllables.