Digit Naming Research Articles

Predictors of Response to Intervention of Word Reading Fluency in Dutch

The objective of this study was to investigate the contribution of rapid digit naming, phonological memory, letter sound naming, and orthographic knowledge to the prediction of responsiveness to a school-based, individual intervention of word reading fluency problems of 122 Dutch second and third graders whose reading scores were below the 10th percentile in comparison with the normative group. Degree of responsiveness was determined by comparison of a pre- and posttest measure of word reading fluency with a 6-month interval. At posttest, 38% of the children had improved their reading scores above the 10th percentile. Maintenance scores revealed no significant growth on average, confirming that word reading fluency skills of poor readers are hard to remediate. Except rapid digit naming, none of the measures predicted responsiveness after controlling for the autoregressive effect of initial performance on fluency of word reading. A large part of the variance remained unexplained, supporting the advantage of a response-to-intervention approach above traditional psychometric testing to identify severe reading disabilities.

Selective effects of number processing context on number naming

Naming of Arabic digits can utilise semantic or asemantic pathways but neuropsychological evidence suggests that number-fact retrieval (2×3 = ?) can inhibit the semantic route for digit naming. Consistent with this, Campbell and Metcalfe (in press) demonstrated with neurologically intact participants that Arabic digit naming time was about 15 ms slower when performed in the context of number-fact retrieval (multiplication) than in the context of a task requiring semantic processing (magnitude comparison). Experiment 1 here tested whether this context effect generalised to naming a feature incidentally associated with an Arabic digit (font colour). Experiment 2 tested if the effect generalised to a salient semantic feature associated with Arabic digits (parity). In Experiment 1, the context effect on digit naming was greater than on naming the font colour of digits. Experiment 2 demonstrated that the effect occurred selectively for stating the digit name and did not generalise to parity naming. The results suggest that the effect of context (multiplication vs. comparison) on numeral naming arises in a dedicated digit naming circuit and reinforce the view that number processing context can reconfigure the functional architecture for number naming.

Perception of tone and aspiration contrasts in Chinese children with dyslexia

Previous research has shown a relationship between speech perception and dyslexia in alphabetic writing. In these studies speech perception was measured using phonemes, a prominent feature of alphabetic languages. Given the primary importance of lexical tone in Chinese language processing, we tested the extent to which lexical tone and aspiration, two fundamental dimensions of Cantonese speech not represented in writing, would distinguish dyslexic from non-dyslexic 8-year-old Chinese children. Tone and aspiration were tested in addition to other phonological processing skills across groups to determine the importance of different aspects of phonological sensitivity in relation to reading disability. Dyslexic children and age-matched and reading-level controls were tested on their categorical perception of minimal pairs contrasting in tone and aspiration, phonological awareness, rapid digit naming, and Chinese reading abilities. While performing similarly to reading-level controls, dyslexic children perceived tone and aspiration contrasts less categorically and accurately than age-matched controls. They also performed more poorly than the age-matched controls on rapid digit naming and a measure of phonological awareness testing children's sensitivity to different grain size units. Dyslexia in non-alphabetic Chinese correlates with the categorical organization and accuracy of Cantonese speech perception, along the tone and aspiration dimensions. This association with reading is mediated by its association with phonological awareness. Therefore, dyslexia is universally at least partly a function of basic speech and phonological processes independent of whether the speech dimensions in question are coded in writing.

Context-dependent semantic priming in number naming.

Previous research has shown that time to name single-digit Arabic numbers is about 15 ms slower when naming trials are interleaved with simple multiplication (e.g., state product of 2 x 3) than when naming digits is interleaved with magnitude comparison (e.g., state larger; 2 upward arrow 3). To explain this phenomenon, J. I. D. Campbell and A. W. S. Metcalfe (2008) proposed that the comparison context enables both semantic and asemantic pathways for digit naming but that number-fact retrieval inhibits the semantic route and slows digit naming relative to the comparison context. To test this hypothesis, the authors modified the naming context paradigm by introducing a semantic priming manipulation. They replicated the digit-naming response time advantage for comparison relative to the multiplication context and observed semantic priming only in the comparison context. In comparison blocks, digit naming was 8 ms faster immediately after naming near digit primes (+/-1) compared to far primes (>or=3), but in multiplication blocks there was no priming. The results reinforce the theory that number-fact retrieval can inhibit the semantic route for digit naming (L. Cohen & S. Dehaene, 1995) and thereby reconfigure the cognitive architecture for naming digits.

The incidence of dyslexia among young offenders in Kuwait

This paper investigates the incidence of dyslexia among young offenders in Kuwait. A total of 91 children/young adults from 8 juvenile delinquent welfare centres across Kuwait were interviewed and tested. A measure of non-verbal reasoning ability was used to exclude those with low general ability. The remaining 53 participants were tested on their ability to identify alliteration and rhyme, retain and manipulate sequences of digit and letter names, decode novel letter strings and identify words within letter chains. Participants' reading accuracy, rate of reading, reading comprehension and ability to spell correctly dictated text were also assessed. These measures were used to determine those with indicators of dyslexia. The results indicated that the percentage of individuals presenting evidence of dyslexia was much larger (greater than 20%) in this population of young offenders than would be expected based on the national average (around 6%) of dyslexics in Kuwait derived from a nationwide study (A survey study of dyslexia in Kuwait, Kuwait Dyslexia Association: Kuwait City; 2002). These findings replicate previous evidence for an increased frequency of dyslexia among young offenders. The implications of such findings are discussed in terms of dyslexia awareness, socio-cultural factors, education and intervention, particularly in Kuwait juvenile delinquent welfare centres.

Differences in the correlates of reading accuracy and speed in young Dutch readers

In this study the differential relationships of phonological awareness and rapid naming (serial and discrete) with reading accuracy and speed were examined. Participants were 52 Dutch second grade children. Measures of phonological awareness, serial rapid naming (objects and digits) and discrete rapid digit naming were administered. Also, various aspects of reading ability were measured: reading accuracy and speed for words and nonwords, and text reading fluency. The results indicated that second grade Dutch children were not fully accurate readers. A clear dissociation was found between phonological awareness and serial rapid naming, the former being mainly related to reading accuracy and the latter to reading speed. However, both were related to text reading fluency. A dissociation was also observed between serial and discrete rapid digit naming. The latter was particularly associated with word reading speed. The implications for the interpretation of cross-linguistic studies on the correlates of reading are discussed.

Arabic digit naming speed: Task context and redundancy gain

There is evidence for both semantic and asemantic routes for naming Arabic digits, but neuropsychological dissociations suggest that number-fact retrieval (2 × 3 = 6) can inhibit the semantic route for digit naming. Here, we tested the hypothesis that such inhibition should slow digit naming, based on the principle that reduced access to multiple routes would counteract redundancy gain (the response time advantage expected from parallel retrieval pathways). Participants named two single digit numbers and then performed simple addition or magnitude comparison (Experiment 1), multiplication or magnitude comparison (Experiment 2), and multiplication or subtraction (Experiment 3) on the same or on a different pair of digits. Addition and multiplication were expected to inhibit the semantic route, whereas comparison and subtraction should enable the semantic route. Digit naming time was approximately 15 ms slower when participants subsequently performed addition or multiplication relative to comparison or subtraction, regardless of whether or not the same digit pair was involved. A letter naming control condition in Experiment 3 demonstrated that the effect was specific to digit naming. Number fact retrieval apparently can inhibit Arabic digit naming processes.

Cognitive profiling in Chinese developmental dyslexia with attention-deficit/hyperactivity disorders

The cognitive profiles of children with Developmental Reading Disorder (RD) and Attention-Deficit/Hyperactivity Disorders (ADHD) have been extensively studied in alphabetic language communities. Deficits in phonological processing and rapid naming have been implicated as core features of RD although whether the latter is a deficit specific to RD remains controversial. Similar research aiming to explore the cognitive profiles of children with both RD and ADHD in non-alphabetic language communities is limited. The specificity of rapid naming deficit to RD among Chinese has yet to be studied. In the first study, 43 Chinese children with confirmed diagnoses of RD + ADHD were assessed on their cognitive abilities in relating to reading. In the second study, the specificity deficit hypothesis of rapid naming to RD but not ADHD was examined. A digit naming test was administered to the RD + ADHD group (43 subjects) and an ADHD only group (49 subjects). In regard to cognitive profiling, rapid naming and orthographic knowledge were found to be the most common deficits among the Chinese RD + ADHD group. This co-morbid group was also found to have a significant deficit performance on the rapid naming task than the ADHD only group. The present findings support the double dissociation hypothesis in cognitive deficit between RD and ADHD. The results of both studies are discussed with reference to the findings of the Western counterparts.

Inhibitory processes in language switching: Evidence from switching language-defined response sets

We used language-defined response sets (digit names from 1 to 9 in different languages) to explore inhibitory processes in language switching. Subjects were required to switch between two (Experiment 1) or among three (Experiment 2) languages. In Experiment 1, we obtained a shift cost when subjects switched between their first and second language, between their first and third language, or between their second and third language. For each language pairing, the shift cost was larger for the relatively dominant language than for the nondominant language (i.e., asymmetric shift cost). In Experiment 2, we assessed inhibition of response sets as reflected in n-2 repetition cost (i.e., the difference between ABA and CBA language sequences). We discuss both effects with respect to inhibitory processes in language switching. The results suggest different functional characteristics of the processes underlying asymmetric shift cost and n-2 repetition cost.

Multimodal access to verbal name codes

Congruent information conveyed over different sensory modalities often facilitates a variety of cognitive processes, including speech perception (Sumby & Pollack, 1954). Since auditory processing is substantially faster than visual processing, auditory-visual integration can occur over a surprisingly wide temporal window (Stein, 1998). We investigated the processing architecture mediating the integration of acoustic digit names with corresponding symbolic visual forms. The digits "1" or "2" were presented in auditory, visual, or bimodal format at several stimulus onset asynchronies (SOAs; 0, 75, 150, and 225 msec). The reaction times (RTs) for echoing unimodal auditory stimuli were approximately 100 msec faster than the RTs for naming their visual forms. Correspondingly, bimodal facilitation violated race model predictions, but only at SOA values greater than 75 msec. These results indicate that the acoustic and visual information are pooled prior to verbal response programming. However, full expression of this bimodal summation is dependent on the central coincidence of the visual and auditory inputs. These results are considered in the context of studies demonstrating multimodal activation of regions involved in speech production.

Persistent Difference in Short-Term Memory Span Between Sign and Speech

Short-term memory (STM) is thought to be limited in capacity to about 7 ± 2 items for linguistic materials and 4 ± 1 items for visuospatial information (Baddeley & Logie, 1999; Cowan, 2001). Recently, we (Boutla, Supalla, Newport, & Bavelier, 2004) challenged this dichotomy between linguistic and visuospatial STM by showing that STM capacity in users of American Sign Language (ASL) is also limited to about 4 or 5 items. This finding suggests that although longer spans appear for speech, spans are not necessarily longer for linguistic materials across all modalities. Wilson and Emmorey (2006) responded that because we evaluated span using digits for English speakers and letters for ASL signers, the difference we reported might have stemmed from stimulus selection rather than language modality. Here we address this claim by reporting an experiment in which we reexamined STM span in English speakers using letters and compared the outcome with results we and Wilson and Emmorey have obtained for ASL signers. It is important to note that the discrepancy between our previous results and those of Wilson and Emmorey is not in the obtained span in signers found by all parties to be around 4 to 5 items (Fig. la). Rather, Wilson and Emmorey disputed whether the digit span of 7 ± 2 in speakers is an appropriate benchmark for comparison with signers. Using letters to measure span in speakers, they found a span of only 5.3, comparable to that of signers. They suggested that there is no difference in span between the two languages. Here we show that their result is not due to their use of letters instead of digits. Rather, in selecting letters that are translations of one another in English and ASL, Wilson and Emmorey failed to control the stimuli in each language for phonological factors known to affect span size. One such crucial factor is phonological similarity. The finding that span is longer for digits than for letters in English speakers is not new (Cavanaugh, 1972). However, this difference has been attributed to the greater phonological similarity of letter names than digit names in English (Conrad & Hull, 1964; Mueller, Seymour, Kieras, & Meyer, 2003). In our previous study, we used letters with signers and digits with speakers to match stimuli in this important regard. Finger-spelled letters are less phonologically similar than number signs in ASL and therefore are more comparable to digits in English speakers. To demonstrate that there is nothing special about letters versus digits, other than the fact that many letter names are highly similar in English (e.g., bee, dee, ee, gee) and thus prone to produce shorter spans, we show here that when phonologically controlled letter materials are used with English speakers, the span of speakers returns to the typical 7 ± 2 range and continues to contrast with the span of signers.

Beyond Phonology

The difficulties experienced by below-average readers in phonological decoding tasks are well documented. Recent research has suggested that additional deficits in perceptual-motor fluency, handedness, and memory may also exist among below-average readers. To evaluate these claims, average and below-average readers and spellers were compared on a range of phonological processing, verbal short-term and working memory, rapid naming, handedness, and perceptual-motor fluency tasks. Average and below-average readers were sampled in a comparable manner and were also comparable on age, gender, nonverbal ability, socioeconomic status, and ethnicity. Below-average readers and spellers performed lower than average readers and spellers on rhyme detection, pseudoword decoding, and rapid digit (but not picture) naming tasks, but showed no differences in handedness tasks or on a range of other perceptual-motor tasks.

Literacy ability and phonological processing skills amongst dyslexic and non-dyslexic speakers of Arabic

This paper investigates the relationship between phonological processing and reading ability amongst grade 4 and grade 5 Arabic speaking children in Egypt. In addition to measuring reading level, the study assessed the children’s ability to identify rhymes, delete individual phonemes from words, retain and manipulate sequences of digit names and rapidly access verbal labels. Further literacy and literacy-related tasks required children to decode novel letter strings, to distinguish similar words, to identify words within letter chains and to correctly spell dictated text. A non-verbal ability measure was also included to allow comparisons to be made between a group of poor readers with good non-verbal skills (dyslexics) with a control group of chronological-age-matched normal readers with equivalent average scores on the non-verbal task. Results indicated relationships between literacy ability, decoding and phonological processing within this cohort, as well as identifying differences between dyslexic and control groups that suggest Arabic dyslexics show signs of poor phonological skills. The study supports the view that Arabic dyslexic children have impairments in the phonological processing domain.

Functional architecture of naming dice, digits, and number words

Five chronometric experiments examined the functional architecture of naming dice, digits, and number words. Speakers named pictured dice, Arabic digits, or written number words, while simultaneously trying to ignore congruent or incongruent dice, digit, or number word distractors presented at various stimulus onset asynchronies (SOAs). Stroop-like interference and facilitation effects were obtained from digits and words on dice naming latencies, but not from dice on digit and word naming latencies. In contrast, words affected digit naming latencies and digits affected word naming latencies to the same extent. The peak of the interference was always around SOA = 0 ms, whereas facilitation was constant across distractor-first SOAs. These results suggest that digit naming is achieved like word naming rather than dice naming. WEAVER++simulations of the results are reported.

Effect of uncertainty on the time course for selection of verbal name codes

Response selection takes time. Hick's law (Hick, 1952) predicts that the time course of response selection is a logarithmic function of the number of equally likely response alternatives. However, recent work has shown that oculomotor responses constitute noteworthy exceptions in that the latencies of saccades (Kveraga, Boucher, & Hughes, 2002) and smooth pursuit movements (Berryhill, Kveraga, Boucher, & Hughes, 2004) are completely independent of response uncertainty. This finding extends to the case in which the required response was known in advance (i.e., simple reaction times [RTs] were equivalent to choice RTs). In view of these results, we reevaluated reports that latencies to name visually presented digits (Experiment 1) and/or repeat aurally presented digits (Experiment 2) are similarly independent of the size of the response set. We found that naming latencies were equivalent for response set sizes from one to eight, but simple RTs (response set of one) were faster. Thus, the overlearned task of digit naming is indeed highly automatic but has not reached the level of automaticity characteristic of the oculomotor system.

Evaluating Current Deficit Theories of Poor Reading: Role of Phonological Processing, Naming Speed, Balance Automaticity, Rapid Verbal Perception and Working Memory

To clarify the nature of cognitive deficits experienced by poor readers, 9-10-yr.-old poor readers were matched against 9 chronological age and 9 younger reading age-matched controls screened and selected from regular classrooms. Poor readers performed significantly more poorly than chronological age-matched peers on digit naming speed, spoonerisms, and nonsense word reading. Poor readers were also significantly poorer than reading age-matched controls on nonword reading but were significantly better than reading age-matched controls on postural stability. Analyses of effect sizes were consistent with these findings, showing strong effects for digit naming speed, spoonerisms, and nonword reading. However, effect size analysis also suggested that poor readers experienced moderate difficulties with balance automatisation but did not show verbal speech perception deficits relative to either control

How Reading Research Can Inform Mathematics Difficulties

ersten, Jordan, and Flojo's (inthis issue) article is importantkand provocative in severalways. First, they have done an excel-lent job in discussing some of the char-acteristics of young children withmathematics difficulties (MD). Second,they have presented some practicalimplications of their findings. Morespecifically, they have identified somepromising measures for the early iden-tification of children at risk for MD, aswell as instructional strategies thatshow potential as approaches for inter-vention. These are important contribu-tions, and they point the field inpromising directions for both under-standing and meeting the needs ofchildren with MD. However, they ac-knowledge that the study of MD is inits infancy, whereas reading researchhas matured and shown tremendousprogress in the last 25 years. In thiscommentary, I will discuss how the as-sumptions, models, and methodolo-gies developed by reading researcherscan guide MD research. By heedinglessons learned from the field of read-ing disabilities (RD), investigators canavoid many of the challenges thatreading researchers had to overcome.Gersten et al. (in this issue) haveoutlined the wide array of deficitsshown by children with MD. This in-cludes low mastery of and fluency inthe retrieval of arithmetic combina-tions, slow digit naming speeds, ineffi-cient and immature counting strate-gies, low number sense, and impairednonverbal working memory. Readingresearchers were also faced with abroad range of tasks that differentiatedchildren with RD. For example, chil-dren with RD showed impaired per-formance on tasks that assessed phono-logical processing, vocabulary, syntacticprocessing, and verbal working mem-ory. However, reading researchers tookthe important step of distinguishingbetween those factors that play acausal role in reading failure and thosethat are consequences of these fac-tors. There is considerable consensusthat the causal deficit in RD is im-paired phonological processing, whichis most evident as impaired phonolog-ical awareness-the ability to identifyand manipulate phonemes (Adams,1990; Cunningham & Stanovich, 1997;Stanovich & Siegel, 1994). Deficits inphonological awareness directly inter-fere with the acquisition and masteryof the spelling-sound correspondencesthat underlie fluent reading (Goswami& Bryant, 1990; Tunmer & Hoover,1992). However, because children withRD tend to avoid reading, their expo-sure to print is limited. This providesthem with fewer opportunities to ac-quire the breadth of vocabulary andsyntactic structures that skilled readersacquire (Stanovich, 1986). In short,deficits in phonological awareness havea direct relationship with decodingability and an indirect relationship withother correlates of RD.By exploiting the variables thatplay a direct causal role in reading fail-ure, researchers have been able to de-velop reading readiness tests that havepredictive validities in the range of.6 to .7, and an array of interventionsthat prevent reading difficulties beforethe onset of formal reading instruction,thereby avoiding the cognitive and lin-guistic consequences associated withreading failure. The field of MD willmake similar progress once investiga-tors can distinguish between thosevariables that cause MD and thosethat are consequences of MD. Becausemathematics is a broad domain withmany subdisciplines, more than onevariable may play a causal role in MD.However, it may be possible to identifyone that is relevant to the developmentof arithmetic skills.The task for the field of MD istherefore to identify a core deficit ordeficits. Furthermore, this deficit mustsatisfy the assumption of specificity(Stanovich, 1993; Stanovich & Siegel,1994). This is the assumption that chil-dren with learning disabilities have acognitive deficit that involves a domain-specific process, rather than a domain-general one, such as processingspeed, general auditory processing, orautomaticity. The concept of learningdisabilities requires that the deficitsnot extend too far into other domainsof cognitive abilities. Otherwise, thedeficits would depress cognitive func-tioning in all domains, and not just,say, reading or mathematics. In short,if the cause of MD fails to satisfy the as-sumption of specificity, significant dif-ficulties in mathematics would befound only in individuals with low in-telligence, which research suggests isnot the case (Siegel, 1988; Stanovich,1999). The underlying deficit of MDmust therefore be assumed to be a

Poor readers of chinese respond slower than good readers in phonological, rapid naming, and interval timing tasks

The role of information processing deficits in poor readers of nonalphabetic scripts such as Chinese is not well documented. Here, we examined perceptual processing in good and poor readers of Chinese. Specifically, two groups of third grade children comprising 20 "good readers" and 19 "poor readers," drawn from a larger pool of 254 students, were tested using an auditory version of the Stop Reaction Time (Stop-RT) interval timing task, a phoneme perception task, and several measures of phonological awareness and orthographic processing. Mean Stop RTs for good readers were significantly faster than those for poor readers, and good readers were also faster in a test of rapid digit naming, but good and poor readers did not differ on measures of phoneme onset awareness or orthographic processing. Although good and poor readers did not differ in overall categorical perception of /pa5/ and /pha5/ stimuli, the good readers responded significantly faster than the poor readers. Taken together, the group differences obtained here are consistent with a slowing of information processing and behavioral output in poor readers of Chinese, rather than a loss of temporal resolution of perceptual processing.

Individual differences in RAN and reading: a response timing analysis

Thirty 8–11‐year‐old children were administered tests of rapid naming (RAN letters and digits) and reading‐related skills. Consistent with the hypothesis that RAN predicts reading because it assesses the ability to establish arbitrary mappings between visual symbols and verbal labels, RAN accounted for independent variance in exception word reading when phonological skills were controlled. Response timing analysis of different components of RAN digits and letters revealed that neither average item duration nor average pause duration were unique predictors of reading skill. However, the number of pauses on digit naming predicted unique variance in exception word reading. Moreover, better readers paused more strategically than poorer readers (e.g. more often at the ends of lines). We suggest that rapid automatised naming may in part reflect differences in strategic control that are a result of differences in reading practice and experience.

Asymmetrical language switching costs in Chinese–English bilinguals' number naming and simple arithmetic

Meuter and Allport (1999) demonstrated greater RT (response time) costs for bilinguals to switch to their first language (L1) from their second language (L2) relative to switching to L2 from L1. Here, analyses of digit naming and simple arithmetic (from 2+2 to 9+9 and from 2×2 to 9×9) by Chinese–English bilinguals demonstrated that these asymmetrical language switching costs can vary with stimulus format (Arabic or Mandarin numerals), and that the asymmetry is observed both with direct retrieval (e.g. naming the digit “8”) and indirect retrieval from the lexicon (e.g. answering “2+6”). Inhibitory processes in language selection entail format- and task-specific skills.