Rhyme Priming in Aphasia: The Role of Phonology in Lexical Access

The present experiment was conducted to explore the facilitory effects of rhyme in lexical processing in brain-damaged individuals. Normal subjects and non-fluent and fluent aphasic subjects performed auditory lexical decision and rhyme judgement tasks, in which prime-target pairs were phonologically related (either identical or rhyming) or unrelated. Results revealed rhyme facilitation of lexical decisions to real-word targets for normal and non-fluent aphasic subjects; for fluent aphasic subjects, results were equivocal. In the rhyme judgement task, facilitory effects of rhyme were found for all three groups with real-word targets. None of the groups showed clear rhyme facilitation effects with non-word targets in either task. Findings are discussed with reference to the role of phonology in lexical processing in normal and aphasic populations.     

Orthographic effects in the word substitutions of aphasic patients: an epidemic of right neglect dyslexia?

Aphasic patients with reading impairments frequently substitute incorrect real words for target words when reading aloud. Many of these word substitutions have substantial orthographic overlap with their targets and are classified as "visual errors" (i.e., sharing 50% of targets' letters in the same relative position). Fifteen chronic aphasic patients read a battery of words and non-words; non-word reading was poor for all patients, and more than 50% of errors on words involved the substitution of a non-target word. An investigation of the factors conditioning these word substitutions, as well as the production of visual errors, identified a number of similarities to patterns previously reported for patients with right neglect dyslexia, which has been said to occur relatively rarely. These included a strong tendency for errors to overlap targets in initial letter positions, maintenance of target length in errors, and the substitution of words higher in imageability than targets. It is proposed that left hemisphere damage frequently leads to disruption of a level of representation for written words in which letter position is ordinally coded, resulting in exacerbation of a normal processing advantage for early letter positions. A computational model is discussed that incorporates this level of representation and successfully simulates relevant normal and patient data.     

A Swedish non-word repetition test for preschool children

A Swedish non-word repetition test for preschool children was constructed with the aim of measuring short-term phonological memory, which has been shown to correlate with language development and language proficiency. Normative data based on results for 200 children four to six years of age are presented. An item analysis of the original 30-item test resulted in a shortened 24 non-word version found suitable for four- to six-year old children. Results for this shortened version, which had a Cronbach's alpha of 0.73, showed longer non-words to be more difficult to repeat than shorter ones, and significant effects of age and compatibility of the tester's and the child's accent, but not of gender. The results are discussed within the framework of Baddeley's working memory model.     

Orthographic analogy use and phonological priming effects in non-word reading

The orthographic analogy effect for rime-based analogies has been debated, and theoretical arguments relating to the role of rhyme awareness in reading development have been questioned. This study assessed whether children beginning to read are able to make genuine orthographic analogies based on rime similarity. A non-word version of the clue word task was used to compare children’s performance at reading orthographically and phonologically similar target items and phonologically similar items only. They were also assessed on their ability to make analogies between the beginnings and endings of words. The results were consistent with the suggestion that orthographic analogy use is available to beginning readers as a reading strategy, and that rime-based analogies are easier to make than analogies at the beginning of words. However, rhyme awareness was found to account for variance in orthographic analogy use between the beginnings of words, but not for rime-based analogies. The implications of this for the theoretical role of rhyme awareness in reading development are discussed.     

Phonologically related lexical repetition disorder: a case study

Errors of repetition in aphasia are most often nonword substitutions. Phonologically related lexical errors, or formal errors, are real-word substitutions that overlap with target words in sound. In the present research we present the case of an aphasic patient, MMB, who produced an unusually high rate of formal paraphasias in repetition. Six experiments were conducted to investigate the combination of impairments contributing to MMB's pattern of repetition and to test the predictions made by two theories of formal errors. MMB's formal errors in repetition were influenced by target frequency, but not by target length or imageability. Formal errors tended to be more frequent than their targets and showed greatest phonological overlap with targets at initial consonant. These findings provided partial support for Martin and Saffran's fully interactive spreading activation account of formal errors and did not support Blanken's phonological interactive encoding account. In Experiment 6, the effect on repetition of increasing auditory verbal short-term memory (AVSTM) demands was examined using a paired word repetition experiment. Under these conditions, MMB produced semantic paraphasias for the first time, providing strong support for the Martin-Saffran hypothesis that phonologically related, and semantic, lexical repetition disorders lie on a continuum of severity moderated by the degree of AVSTM impairment.     

Phonology and orthography in visual word recognition: Evidence from masked non-word priming

Three lexical decision experiments in French investigated the effects of briefly presented forward-masked non-word primes on latencies to phonologically and/or orthographically related targets. At 64-msec prime presentation durations, primes that are pseudohomophones of the target produced facilitatory effects compared to orthographic controls, but these orthographically similar non-word primes did not facilitate target recognition compared to unrelated controls. These results were obtained independently of target word frequency and independently of the presence or absence of pseudohomophone targets in the experimental lists. With a 32-msec prime duration, on the other hand, pseudohomophone and orthographic primes had similar effects on target recognition, both producing facilitation relative to unrelated controls. The results are discussed in terms of the time course of phonological and orthographic code activation in the processing of pronounceable strings of letters.     

What underlies the neuropsychological pattern of irregular > regular past-tense verb production?

The disadvantage in producing the past tense of regular relative to irregular verbs shown by some patients with non-fluent aphasia has been alternatively attributed (a) to the failure of a specific rule-based morphological mechanism, or (b) to a more generalised phonological impairment that penalises regular verbs more than irregular owing to the on-average greater phonological complexity of regular past-tense forms. Guided by the second of these two accounts, the current study was designed to identify more specific aspects of phonological deficit that might be associated with the pattern of irregular > regular past-tense production. Non-fluent aphasic patients (N = 8) were tested on past-tense verb production tasks and assessed with regard to the impact of three main manipulations in other word-production tasks: (i) insertion of a delay between stimulus and response in repetition; (ii) presence/number of consonant clusters in a target word in repetition; (iii) position of stress within a bi-syllabic word in repetition and picture naming. The performance of all patients deteriorated in delayed repetition; but the patients with the largest discrepancy between regular and irregular past-tense production showed greater sensitivity to the other two manipulations. The phonological nature of the factors that correlated with verb-inflection performance emphasises the role of a phonological deficit in the observed pattern of irregular > regular.     

Impairment in processing meaningless verbal material in several modalities: The relationship between short-term memory and phonological skills

Phonological processing abilities were studied in a patient who, following focal brain damage, showed selective impairment in non-word reading, writing, and repetition and also a severe short-term memory (STM) deficit specific for auditorily presented verbal material. The patient could execute tasks involving phonemic manipulation and awareness perfectly. Our data, in contrast with earlier observations in a case of developmental phonological dyslexia, show that acquired impairment in non-word reading, writing, repetition, and immediate memory may occur despite good phonological processing abilities. The role of STM in processing meaningless verbal material is discussed.     

Why is "Red Cross" different from "Yellow Cross"?: a neuropsychological study of noun-adjective agreement within Italian compounds

This study investigates the performance of two Italian nonfluent aphasic patients on noun-adjective agreement in compounds and in noun phrases. A completion, a reading, and a repetition task were administered. Results show that both patients were able to correctly inflect adjectives within compounds, but not in noun phrases. Moreover, they were sensitive to constituent order (noun-adjective vs adjective-noun) within noun phrases, but less so within compounds. These results suggest differential processing for compounds as compared to noun phrases: While the latter require standard morphosyntactic operations that are often impaired in aphasic patients, the former can be accessed as whole words at the lexical level.     

Lexical decision and aphasia: Evidence for semantic processing

Wernicke's and Broca's-Conduction aphasics and a Global aphasic were presented with a lexical-decision task in which English words and pronounceable nonwords were preceded by semantically related, unrelated, or nonword primes. The patients were also given a simple semantic-judgment task using the word pairs from the lexical-decision task. Wernicke's aphasics performed similar to normals and Broca's-Conduction aphasics showing significantly shorter latencies in making real-word identifications when preceded by a semantically related word. In addition, both superordinate and coordinate associates showed semantic-priming effects. Performance on the semantic-judgment task showed significantly more impairment in the aphasic group than in the normal controls. These results suggest that aphasics with even severe language impairments retain stored semantic information that may be automatically activated, yet is inaccessible to conscious semantic decision during metalinguistic tasks.     

The mapping from sound structure to the lexicon in aphasia: evidence from rhyme and repetition priming

Two studies were conducted to explore the hypothesis that Broca's and Wernicke's aphasics have deficits arising from the processes involved in activating the lexicon from phonological form. The first study explored whether phonologically similar lexical entries differing only in their initial consonants show "rhyme priming." Results revealed that Broca's aphasics failed to show facilitation when the target was identical to the prime (i.e. identity priming) and they showed significant inhibition when targets were preceded by rhyming words. Wernicke's aphasics showed a pattern of results similar to that of normal subjects, i.e., identity priming and rhyme priming as well as significantly slower reaction-times in the rhyming condition compared to the identity condition. The second study investigated form-based repetition priming in aphasic patients at a number of intervals including when no other stimuli intervened between repeated stimuli (0 lag) or when 4, 8, or 12 stimuli intervened. Results showed that, unlike old normal subjects who showed repetition priming for both words and nonwords, both Broca's and Wernicke's aphasics showed repetition priming for word targets only. Moreover, in contrast to old normal subjects who showed a greater magnitude of priming at 0 lag for word targets, neither Broca's aphasics or Wernicke's aphasics showed priming at 0 lag. Implications of these findings are considered with respect to the hypotheses that Broca's and Wernicke's aphasics have deficits in the nature of the activation patterns within the lexicon itself and in auditory (working) memory.     

Spoken-word processing in aphasia: effects of item overlap and item repetition

Two studies were carried out to investigate the effects of presentation of primes showing partial (word-initial) or full overlap on processing of spoken target words. The first study investigated whether time compression would interfere with lexical processing so as to elicit aphasic-like performance in non-brain-damaged subjects. The second study was designed to compare effects of item overlap and item repetition in aphasic patients of different diagnostic types. Time compression did not interfere with lexical deactivation for the non-brain-damaged subjects. Furthermore, all aphasic patients showed immediate inhibition of co-activated candidates. These combined results show that deactivation is a fast process. Repetition effects, however, seem to arise only at the longer term in aphasic patients. Importantly, poor performance on diagnostic verbal STM tasks was shown to be related to lexical decision performance in both overlap and repetition conditions, which suggests a common underlying deficit.     

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.     

汉语阅读障碍高危儿童的早期筛选

通过对309名平均年龄为3岁半的儿童(35～49个月)进行词汇、语素识别、句法、非词重复和看图说词5个任务的测试,探索了汉语阅读障碍高危儿童的早期筛选方法。结果显示高危儿童在所有任务上都显著落后于正常儿童;句法缺陷和语音缺陷所占比例最大;高危儿童存在的缺陷数量越多,则测验成绩越差。这一结果对汉语阅读障碍高危儿童的早期干预具有一定的理论和实践意义。     

Phonological, Semantic, and Mediated Priming in Aphasia

An auditory lexical decision task was conducted to examine rhyme, semantic, and mediated priming in nonfluent and fluent aphasic patients and normal controls. Overall, monosyllabic word targets were responded to faster when preceded by rhyming word and nonword primes than unrelated primes. Similarly, semantically related primes facilitated lexical decisions to word targets. No evidence of mediated priming emerged. Results for individual subjects suggest differences in patterns across the subject groups. Implications of the findings for the integrity of lexical access in aphasic patients are considered.     

Correlations of glucose metabolism and structural damage to language function in aphasia

Studies of aphasic patients using [18F]fluorodeoxyglucose positron computed tomographs have shown areas of metabolic depression in the left hemisphere larger than the area of infarction noted on CT. To evaluate these metabolic differences in relationship to language abnormalities, 11 patients had metabolic scans, CT, and were administered the Boston Diagnostic Aphasia Battery and the Porch Index of Communicative Ability. Correlation analyses were computed between metabolic, CT, and language data. CT demonstrated reliable correlations of speaking, oral reading, and repetition to Wernicke' area, consistent with current anatomic language models, while metabolic data from areas posterior, inferior, and superior to the traditional Wernicke's area and the head of the caudate nucleus also had reliable correlations with aphasic language function. The utilization of both structural and metabolic brain measures may improve our understanding of the anatomy of language as related to aphasia.     

Behavioral and brain wave evidence for automatic processing of orthographically regular letter strings

Evidence for the automatic processing of nonword letter strings was sought in subjects who performed two different perceptual tasks. Twelve subjects detected valid words. Twelve other subjects detected Gestalt patterns that contained no letters. The targets and two types of nonword letter strings were interspersed in a stream of nonletter images. Behavioral data showed significant effects of orthographic regularity of letter strings in the group that detected words, but not in the group that detected Gestalt patterns. Brain-wave responses showed the effect of orthographic regularity in both groups. The responses were significantly larger for regular than for irregular strings. This showed that brain waves can be used to study the operation of reading processes in subjects who are performing a task that does not require reading ability.     

Acute conduction aphasia: an analysis of 20 cases

In this study, the linguistic performance of 20 patients with acute conduction aphasia (CA) is described. CA presented as a relatively homogeneous aphasic syndrome characterized by a severe impairment of repetition and fluent expressive language functions with frequent phonemic paraphasias, repetitive self-corrections, word-finding difficulties, and paraphrasing. Language comprehension as assessed by tests of auditory and reading comprehension was only mildly impaired, whereas most patients performed poorly on the Token Test. Verbal-auditory short-term memory was reduced in all patients except one and seems to play a role in associated cognitive deficits, such as impaired syntactic comprehension or reduced mental arithmetics. A follow-up examination of 12 patients showed that CA often resulted in a chronic language deficit. Lesion locations were the posterior temporal and inferior parietal lobe.     

Mental representation of prepositional compounds: evidence from Italian agrammatic patients

The processing of Prepositional compounds (typical Neo-latin noun--noun modifications where a head noun is modified by a prepositional phrase, e.g., mulino a vento, windmill) was preliminarily studied with a group of six agrammatic aphasic patients, and, in more detail, with a further agrammatic patient (MB). Omission was the most frequent error type in naming, whereas in the other tasks (repetition, reading, writing, and completion) errors were mostly substitutions of the target preposition. This happened even with fully lexicalized compound forms, i.e., those forms where the linking preposition is syntactically and semantically opaque. These findings are interpreted in terms of a dual-route theory of lexical access to morphologically complex words.     

Better the DVL you know: acronyms reveal the contribution of familiarity to single-word reading

Current theories of reading are divided between dual-route accounts, which propose that separable processes subserve word recognition for orthographically regular and irregular strings, and connectionist models, which propose a single mechanism mapping form to meaning. These theories make distinct predictions about the processing of acronyms, which can be orthographically illegal and yet familiar, as compared with the processing of pseudowords, which are regular but unfamiliar. This study examined whether acronyms are processed like pseudowords and words. Event-related potentials (ERPs) were recorded as subjects viewed familiar and unfamiliar acronyms, words, pseudowords, illegal strings, and--as the targets of the substantive behavioral task--proper names. Familiar acronyms elicited repetition effects on the N400 component, a functionally specific index of semantic activation processes; repetition effects for familiar acronyms were similar in magnitude, timing, and scalp distribution to those for words and pseudowords. The similarity of the brain response to familiar--but--illegal and unfamiliar--but--legal classes of stimuli is inconsistent with predictions of dual-route models of reading.