Dyslexic and nondyslexic reading fluency: Rapid automatized naming and the importance of continuous lists

Rapid automatized naming (RAN; Denckla & Rudel, 1976) tasks are consistent predictors of fluency that also discriminate between dyslexic and nondyslexic reading groups. The component processes of RAN that are responsible for its relationship with reading ability remain underspecified, however. We report a study on dyslexic and nondyslexic adult groups that experimentally manipulated RAN formats to elucidate how different components of RAN differentially influence dyslexic and nondyslexic performance. The dyslexic group showed a pervasive deficit in rapid access of individually presented items. Additionally, they showed a significant impairment when multiple items were presented, whereas nondyslexic readers showed marginal facilitation for this format. We discuss the implications of these findings with respect to reading-group differences in reading fluency.     

中央凹加工负荷与副中央凹信息在汉语阅读眼跳目标选择中的作用

研究探讨汉语读者选择眼跳目标时, 中央凹注视词的加工负荷是否影响副中央凹获取信息量, 进而调节随后的眼跳长度。采用眼动追踪技术, 操纵了中央凹注视词的词频(高频、低频)和副中央凹词的笔画数(多笔画、少笔画)。结果发现：从中央凹词到副中央凹少笔画词的眼跳长度显著地长于到多笔画词的, 且这种笔画数效应并不受中央凹加工负荷的调节; 从高频中央凹词到副中央凹词的眼跳长度显著地长于低频词的。在本实验条件下结果提示：中央凹加工负荷在眼跳目标选择中的作用不是通过调节副中央凹获取信息量的多少来实现的。     

The effect of varying stimulus context on word-finding ability: Dyslexia further differentiated from other learning disabilities

All learning-disabled children, dyslexic and nondyslexic, were found to be impaired relative to controls on a variety of naming tests: (1) naming pictured objects (visual name), (2) responding with an object name to a definition (auditory definition), (3) completing a sentence with an object name (auditory sentence), or (4) naming palpated objects (tactual). Only on the sentence completion task (auditory sentence), which has been found to be the simplest response mode, were the dyslexic subjects selectively less accurate than the nondyslexic learning disabled, relative to the control group. Although dyslexic subjects tend to circumlocute when naming objects, they did not find it easier, relative to other groups, to give the function rather than the name of objects. Time scores were not in the same direction. The nondyslexic learning-disabled group responded more rapidly than either the dyselxic subjects or controls and made more perceptual errors, findings that may be related to some other factor, possibly the hyperactivity of many of the children in the nondyslexic learning-disabled group. The finding, also, that most of their naming error scores correlate highly with each other as well as with standardized language measures (WISC-R Vocabulary and PPVT), whereas those of the dyslexic and control groups do not, further suggests some underlying pathology to which their language disability is related. Language impairment, then, may be a common factor in all learning disability, dyslexic and nondyslexic, possibly for different reasons.     

Fluency and response speed in recognition judgments

Previous research has suggested that perceptual fluency can contribute to recognition judgments. In this study, we examined whether fluency in recognition is based upon the speed of preceding operations, as suggested by studies of perceptual fluency. Subjects studied items in both lexical decision and naming tasks, and were then tested on two blocks of lexical decision trials with probe recognition trials. Jacoby’s process dissociation procedure was used, and results from this procedure suggested that recognition judgments in the task were based largely upon familiarity. However, the estimated discriminability available from response time distributions was significantly less than the observed recognition discriminability. Simulated memory operating characteristics confirmed this underdetermination of recognition by response times. The results demonstrate, contrary to previous suggestions, that fluency in recognition is not based upon speed.     

Speed of processing of the visual-orthographic and auditory-phonological systems in adult dyslexics: the contribution of "asynchrony" to word recognition deficits

This study investigated whether "asynchrony" in speed of processing (SOP) between the visual-orthographic and auditory-phonological modalities contributes to word recognition deficits among adult dyslexics. Male university students with a history of diagnosed dyslexia were compared to age-matched normal readers on a variety of experimental measures while event-related potentials and reaction time data were collected. Measures were designed to evaluate auditory and visual processing for non-linguistic (tones and shapes) and linguistic (phonemes and graphemes) low-level stimuli as well as higher-level orthographic and phonological processing (in a lexical decision task). Data indicated that adult dyslexic readers had significantly slower reaction times and longer P300 latencies than control readers in most of the experimental tasks and delayed P200 latencies for the lexical decision task. Moreover, adult dyslexics revealed a systematic SOP gap in P300 latency between the auditory/phonological and visual/orthographic processing measures. Our data support and extend previous work that found SOP asynchrony to be an underlying factor of childhood dyslexia. The present data suggests, however, that among adult dyslexics the between modalities asynchrony occurs at later processing stages than in children.     

Word processing in the parafoveal region

This study examined the role of words viewed in the parafoveal region during reading. In contrast to previous work, the present experiments used a reading-aloud paradigm that was postulated to encourage letter-to-sound processing, as is typical for beginning readers and for skilled readers who are reading difficult material. The three experiments in this study examined the role of orthographic and semantic information in the parafoveal region on the processing of a word in the foveal region. For this, two words, one in the foveal region and the other in the parafoveal region, were presented side by side to resemble normal reading. Participants were instructed to read aloud the word on the left side, ignoring the word on the right side. Experiments 1 and 2 showed that the presence of a word in the parafoveal region slowed naming of target words, and that this delay was attributable to linguistic interference. This pattern indicates that the information in the parafoveal region affect the processing of the target. Experiment 3 showed an effect of parafoveal semantic information on processing of the target word. In sum the results of the current study suggest that information in the parafoveal region appears to be linguistically processed but to a weaker degree than the focused word. In sum, the results of the experiments in the current study indicate that the influence of parafoveal information is quite lexical and semantic information in the parafoveal region affects processing of the target in the foveal region.     

The influence of parafoveal typographical errors on eye movements in reading

Three experiments are reported, examining the effects of a typographical error in parafoveal vision on aspects of foveal inspection time and saccade targeting. All the experiments involved reading for comprehension. A contingent presentation procedure ensured that typographical errors were restored to their correct form before they were viewed in foveal vision: They were never available for foveal processing. In Experiment 1, the error was formed by replacing the first letter of the target word with a second occurrence of its second letter, producing an illegal nonword. This manipulation had no significant effect on foveal inspection time, but lowered the probability that a short word (“de” or “du”) prior to the target would be skipped. In Experiment 2 the familiarity of the target's initial letters was maintained constant across conditions. This manipulation removed the target 1 skipping effect, suggesting that the outcome of Experiment 1 was due to orthographic rather than lexical illegality, but revealed shorter foveal inspection times as a function of the presence of the error. Experiment 3 manipulated lexical and sublexical properties of the parafoveal typing error. Properties of the parafoveal error again influenced prior foveal inspection times. The pattern of results suggested that the determining properties were sublexical rather than lexical. The results as a whole are incompatible with a view of information processing in reading in which foveal processing remains immune from concurrent parafoveal influences.     

发展性阅读障碍者的快速命名缺陷

快速命名任务是一种需要命名多个高熟悉项目的认知任务,尤其适合用来对成因复杂的发展性阅读障碍进行研究。许多研究者使用不同类型的快速命名任务发现,发展性阅读障碍者的快速命名缺陷在眼动过程表现为中央凹和副中央凹的加工困难,在认知过程中表现为抑制能力较差等。未来的研究中应该注意到快速命名缺陷的复杂性,采用多种方法相结合的方式来探究快速命名缺陷的本质,从而建立系统性的假说。     

Integrating information across eye movements

A series of experiments was conducted in which a word initially appeared in parafoveal vision, followed by the subject's eye movement to the stimulus. During the eye movement, the initially displayed word was replaced by a word which the subject read. Under certain conditions, the prior parafoveal word facilitated naming the foveal word. Three alternative hypotheses were explored concerning the nature of the facilitation. The verbalization hypothesis suggests that information acquired from the parafoveal word permits the subject to begin to form the speech musculature properly for saying the word. The visual features integration hypothesis suggests that visual information obtained from the parafoveal word is integrated with foveal information after the saccade. The preliminary letter identification hypothesis suggests that some abstract code about the letters of the parafoveal word is stored and integrated with information available in the fovea after the saccade. The results of the experiments supported the latter hypothesis in that information about the beginning letters of words was facilitatory in the task. The other two hypotheses were disconfirmed by the results of the experiments.     

Letter identification and lateral masking in dyslexic and average readers

Lateral masking and letter identification in dyslexic and average readers were investigated with a methodology that corrected for some of the weaknesses of the Geiger and Lettvin studies (1986, 1987). Target letters were presented alone or embedded within three-letter arrays at retinal locations from 0 degrees to 15 degrees to the right or left of a fixation point. A foveal letter, which was the same as or different from a target letter, appeared as a distractor, and comparisons were made between scaled and unscaled stimuli. Dyslexic readers were found to be better than average readers at detecting scaled letters embedded in an array in some of the peripheral locations tested. Unlike the results of Geiger and Lettvin, however, this finding of better letter detection in the periphery by dyslexics was limited to selected conditions of the study. Reading groups were also found to differ in responding to the foveal distractor in the letter task. Detection of letters by average readers was affected by the type of distractor, but this variable was not found to influence the dyslexic readers. These findings suggest some differences between dyslexic and average readers in attention to stimuli presented at multiple locations in the visual field.     

聋人句子阅读中的视觉功能补偿现象：副中央凹−中央凹效应的证据

聋人阅读过程中的视觉功能补偿现象是由于听觉信息的缺失,聋人的视觉功能会发生补偿性改变,表现为对副中央凹视野内文本信息的加工效率更高。本研究采用边界范式,测量聋人的副中央凹-中央凹重复效应,以探究聋人的副中央凹视觉功能补偿现象能否促进其中央凹的词汇识别过程。结果发现,聋人的副中央凹-中央凹重复效应出现在早期阅读指标凝视时间,而阅读能力匹配组只出现在晚期阅读指标总注视时间。因此,相比阅读能力匹配的健听读者,聋人的副中央凹-中央凹重复效应出现得更早,表现出副中央凹视觉功能补偿现象。     

快速与慢速读者的中央凹加工对副中央凹预视的影响

在中文阅读中, 预视量是否存在个体差异及其是否受中央凹加工调节, 尚不清楚。本研究采用眼动技术和边界范式, 通过操纵前目标词的加工负荷(高、低)与目标词的预视(相同、假字)来考察快速与慢速读者的中央凹加工对副中央凹预视的影响。结果显示, 中央凹负荷主效应显著; 快速读者对低负荷词的首次和单次注视短于高负荷词, 而慢速读者对两种负荷词的首次和单次注视无差异, 表明快速读者能更快利用词汇特性加工中央凹词汇。预视主效应显著, 即与假字预视相比, 相同预视使两组读者都对目标词的注视更短、向前眼跳更长、跳读率更高; 而且该效应与中央凹负荷没有交互作用。这表明快速读者与慢速读者提取了等量预视, 且不受其中央凹加工的调节。E-Z读者模型和SWIFT模型不能完全解释当前结果。     

Assessing the role of different spatial frequencies in word perception by good and poor readers

Numerous studies indicate that dyslexic and nondyslexic individuals exhibit different patterns of sensitivity to spatial frequency. However, the extension of this effect to normal (nondyslexic) adults of good and poor reading abilities and the role played by different spatial frequencies in word perception have yet to be determined. In this study, using normal (nondyslexic) adults, we assessed reading ability, spatial frequency sensitivity, and perception of spatially filtered words and nonwords (using a two-alternative forced choice paradigm to avoid artifactual influences of nonperceptual guesswork). Good and poor readers showed different patterns of spatial frequency sensitivity. However, no differences in accuracy of word and nonword perception were found between good and poor readers, despite their differences in spatial frequency sensitivity. Indeed, both reading abilities showed the same superior perceptibility for spatially filtered words over nonwords across different spatial frequency bands. These findings indicate that spatial frequency sensitivity differences extend to normal (nondyslexic) adult readers and that a range of spatial frequencies can be used for word perception by good and poor readers. However, spatial frequency sensitivity may not accurately reveal an individual's ability to perceive words.     

Frequency effects with visual words and syllables in a dyslexic reader

The present study investigated the nature of the inhibitory syllable frequency effect, recently reported for normal readers, in a German-speaking dyslexic patient. The reading impairment was characterized as a severe deficit in naming single letters or words in the presence of spared lexical processing of visual word forms. Three visual lexical decision experiments were conducted with the dyslexic patient, an unimpaired control person matched to the patient and a control group: Experiment 1 manipulated the frequency of words and word-initial syllables and demonstrated systematic effects of both factors in normal readers and in the dyslexic patient. The syllable frequency effect was replicated in a second experiment with a more strictly controlled stimulus set. Experiment 3 confirmed the patient's deficit in activating phonological forms from written words by demonstrating that a pseudohomophone effect as observed in the unimpaired control participants was absent in the dyslexic patient.     

Retinal location and its effect on the processing of target and distractor information

Two experiments were conducted to study the perceptual facilitation and inhibition that occurs between foveal and parafoveal or peripheral regions of the eye. Experiment 1 used a Stroop task to compare color detection latencies of foveal and parafoveal targets. The target and distractor components of the Stroop stimuli were separated and presented with varied stimulus onset asynchronies. Experiment 2 used a Stroop-like task to replicate and extend the findings into the visual periphery. Subjects were found to process foveally presented distractor information while attending to targets presented in parafoveal or peripheral regions of the eye. Distractor information that was incompatible was suppressed while compatible information was used to facilitate target processing. When the targets were presented foveally along with the distractor information, subjects appeared to automatically process the distractor information. The findings are discussed within the framework of past studies that presented subjects with competing tasks across retinal location. The implications of these findings to a two-process theory of attention are also considered.     

How strongly do word reading times and lexical decision times correlate? Combining data from eye movement corpora and megastudies

We assess the amount of shared variance between three measures of visual word recognition latencies: eye movement latencies, lexical decision times, and naming times. After partialling out the effects of word frequency and word length, two well-documented predictors of word recognition latencies, we see that 7–44% of the variance is uniquely shared between lexical decision times and naming times, depending on the frequency range of the words used. A similar analysis of eye movement latencies shows that the percentage of variance they uniquely share either with lexical decision times or with naming times is much lower. It is 5–17% for gaze durations and lexical decision times in studies with target words presented in neutral sentences, but drops to 0.2% for corpus studies in which eye movements to all words are analysed. Correlations between gaze durations and naming latencies are lower still. These findings suggest that processing times in isolated word processing and continuous text reading are affected by specific task demands and presentation format, and that lexical decision times and naming times are not very informative in predicting eye movement latencies in text reading once the effect of word frequency and word length are taken into account. The difference between controlled experiments and natural reading suggests that reading strategies and stimulus materials may determine the degree to which the immediacy-of-processing assumption and the eye–mind assumption apply. Fixation times are more likely to exclusively reflect the lexical processing of the currently fixated word in controlled studies with unpredictable target words rather than in natural reading of sentences or texts.     

Reaction time reduction after parafoveal preview in a lexical decision task

Time and the accuracy of a lexical decision performed on a letter string (either a word or nonword), presented foveally after a parafoveal preview displayed at 5 degrees of eccentricity and 100 msec. duration were measured. Students of Padova University, 10 women and 7 men, ages 19 to 23 years were subjects. The hypothesis investigated was whether the facilitatory effect, a reduction in lexical decision time due to the parafoveal preview, was tied to global visual information acquired in the visual periphery during the preview presentation. In Exp. 1, eight subjects performed the task either with no preview (No Preview) or with a preview presented at 5 degrees eccentricity in two conditions, preview of the same foveal string (Preview-Letters) and preview of symbols ("x xx...") of the same length as the foveal string (Preview Symbols). In Exp. 2, 9 subjects performed the task with two preview conditions, No Preview and preview of the foveal string in uppercase letters at 5 degrees of eccentricity (Preview Uppercase). Analyses suggested the reduction in lexical decision time due to the Preview with respect to the No Preview condition is tied to global information extracted during parafoveal presentation. The reduction in lexical decision time depends on word texture, i.e., letters' identities and also word boundary, in addition to word length.     

Visual rapid naming and phonological abilities: different subtypes in dyslexic children

One implication of the double-deficit hypothesis for dyslexia is that there should be subtypes of dyslexic readers that exhibit rapid naming deficits with or without concomitant phonological processing problems. In the current study, we investigated the validity of this hypothesis for Portuguese orthography, which is more consistent than English orthography, by exploring different cognitive profiles in a sample of dyslexic children. In particular, we were interested in identifying readers characterized by a pure rapid automatized naming deficit. We also examined whether rapid naming and phonological awareness independently account for individual differences in reading performance. We characterized the performance of dyslexic readers and a control group of normal readers matched for age on reading, visual rapid naming and phonological processing tasks. Our results suggest that there is a subgroup of dyslexic readers with intact phonological processing capacity (in terms of both accuracy and speed measures) but poor rapid naming skills. We also provide evidence for an independent association between rapid naming and reading competence in the dyslexic sample, when the effect of phonological skills was controlled. Altogether, the results are more consistent with the view that rapid naming problems in dyslexia represent a second core deficit rather than an exclusive phonological explanation for the rapid naming deficits. Furthermore, additional non-phonological processes, which subserve rapid naming performance, contribute independently to reading development.     

A dual-route perspective on eye movements of dyslexic readers

This study assessed eye movement abnormalities of adolescent dyslexic readers and interpreted the findings by linking the dual-route model of single word reading with the E-Z Reader model of eye movement control during silent sentence reading. A dysfunction of the lexical route was assumed to account for a reduced number of words which received only a single fixation or which were skipped and for the increased number of words with multiple fixations and a marked effect of word length on gaze duration. This pattern was interpreted as a frequent failure of orthographic whole-word recognition (based on orthographic lexicon entries) and on reliance on serial sublexical processing instead. Inefficiency of the lexical route was inferred from prolonged gaze durations for singly fixated words. These findings were related to the E-Z Reader model of eye movement control. Slow activation of word phonology accounted for the low skipping rate of dyslexic readers. Frequent reliance on sublexical decoding was inferred from a tendency to fixate word beginnings and from short forward saccades. Overall, the linkage of the dual-route model of single word reading and a model of eye movement control led to a useful framework for understanding eye movement abnormalities of dyslexic readers.     

How preview space/time translates into preview cost/benefit for fixation durations during reading

Eye-movement control during reading depends on foveal and parafoveal information. If the parafoveal preview of the next word is suppressed, reading is less efficient. A linear mixed model (LMM) reanalysis of McDonald (2006) confirmed his observation that preview benefit may be limited to parafoveal words that have been selected as the saccade target. Going beyond the original analyses, in the same LMM, we examined how the preview effect (i.e., the difference in single-fixation duration, SFD, between random-letter and identical preview) depends on the gaze duration on the pretarget word and on the amplitude of the saccade moving the eye onto the target word. There were two key results: (a) The shorter the saccade amplitude (i.e., the larger preview space), the shorter a subsequent SFD with an identical preview; this association was not observed with a random-letter preview. (b) However, the longer the gaze duration on the pretarget word, the longer the subsequent SFD on the target, with the difference between random-letter string and identical previews increasing with preview time. A third pattern—increasing cost of a random-letter string in the parafovea associated with shorter saccade amplitudes—was observed for target gaze durations. Thus, LMMs revealed that preview effects, which are typically summarized under “preview benefit”, are a complex mixture of preview cost and preview benefit and vary with preview space and preview time. The consequence for reading is that parafoveal preview may not only facilitate, but also interfere with lexical access.