Hyper Lexi A

Cognitive and language correlates of hyperlexia:evidence from children with autism spectrum disorders

Claudia Cardoso-Martins Æ Juliane Ribeiro da Silva

Published online: 3 December 2008

� Springer Science+Business Media B.V. 2008

Abstract Two studies were conducted to investigate the correlates of hyperlexia

in Brazilian Portuguese-speaking children with the diagnosis of autism spectrum

disorder (ASD). Study 1 involved 3 groups of school age children individually

matched for word reading ability: 6 ASD hyperlexic children, 6 ASD non-hyper-

lexic children, and 6 typically developing children. Study 2 involved 2 ASD

preschool hyperlexic boys, and a group of 21 typical children of similar word

reading ability. In both studies, participants were administered several reading

measures as well as measures of cognitive and linguistic abilities that have been

associated with variations in typical and dyslexic reading, namely, vocabulary,

phonological processes, and rapid naming. Results suggest that ASD hyperlexic

reading differs from both typical and ASD non-hyperlexic reading. In particular,

they suggest that hyperlexics learn to compute letter-sound relations implicitly, on

the basis of statistical learning. Although the hyperlexic children could read non-

words as well as the typical and the ASD non-hyperlexic children, they performed

significantly worse than these groups of children on a letter-sound knowledge task.

They also performed relatively poorly on a phonological awareness task. It is

suggested that hyperlexics’ indifference to language as a meaningful, communi-

cative device may be the key to their exceptionally good and precocious

development of word reading ability.

Keywords Hyperlexia � Autism spectrum disorders � Phonological processes

C. Cardoso-Martins (&)

Universidade Federal de Minas Gerais, Av. Antonio Carlos 6627, FAFICH—UFMG-Campus

Pampulha, 31270-901 Belo Horizonte, MG, Brazil

e-mail: [email protected]; [email protected]

J. R. da Silva

Prefeitura Municipal de Belo Horizonte, Belo Horizonte, MG, Brazil

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Read Writ (2010) 23:129–145

DOI 10.1007/s11145-008-9154-6

Introduction

Reading is a complex activity that depends on the integrity of at least two abilities:

decoding and language comprehension (Gough & Wren, 1998). Although these two

abilities typically work in tandem, they often dissociate in disabled readers.

Developmental dyslexia is a case in point. As it is amply described in the literature,

the key defining feature of developmental dyslexia is impaired decoding skills

despite average or above average language comprehension (Snowling, 2000). The

opposite pattern, impaired reading comprehension in the presence of average or

above average decoding skills, is the focus of the present manuscript. Specifically,

we describe two studies investigating the correlates of word reading ability in a

subset of children whose decoding skills are far above their cognitive and language

comprehension skills—the so-called hyperlexic children.

Although the key defining feature of hyperlexia is word decoding skill in advance

of reading comprehension, hyperlexia is often associated with autism spectrum

disorders (ASD). Grigorenko, Klin, and Volkmar (2003) have indeed suggested that

the term hyperlexia be restricted to children with ASD. In their view, the more

general term ‘‘reading comprehension disorders’’ should be used for readers who

show a discrepancy between decoding and comprehension but who do not show the

features commonly associated with ASD.

Two features of ASD may help explain the discrepancy between word decoding

skills and reading comprehension seen in hyperlexia (Nation, 1999). These are weak

central coherence, and restricted and compulsive interests. Central coherence refers

to the cognitive tendency to rely on context to interpret information, a tendency that

is relevant for language comprehension and whose deficiency in ASD may help

explain hyperlexics’ reading comprehension impairments.

On the other hand, ASD children’s restricted and compulsive interests likely

contribute to hyperlexics’ strong word decoding abilities. Many researchers have

indeed noted that hyperlexic children manifest a strong interest in reading to the

exception of everything else. For example, Healy, Aram, Horwitz, and Kessler

(1982) reported that reading seemed to replace all other activities in their sample of

children with hyperlexia. Together with ASD’s social and communicative

impairments, a strong interest in reading might result in extensive reading

experience and practice, thus contributing to hyperlexics’ exceptional word

decoding abilities.

However, not all readers with ASD show the discrepancy between word reading

and reading comprehension that is typical of hyperlexia. As described below, word

decoding ability varies considerably in ASD, and the same is true of reading

comprehension (e.g., Nation, Clarke, Wright, & Williams, 2006). An important

question concerns the factor or factors that, in addition to weak central coherence

and restricted and compulsive interests, contribute to hyperlexic reading among

individuals with ASD. In other words, what are the differences between ASD

readers with and without the characteristic behavior pattern of hyperlexia?

Nation et al. (2006) addressed this question in a study investigating component

reading skills in ASD children, some of whom showed reading comprehension

appropriate for their chronological age. Nation et al. compared these good

130 C. Cardoso-Martins, J. R. D. Silva

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comprehenders with a group with the characteristic feature of hyperlexia—that is,

poor reading comprehension despite average or above average word-reading skills.

According to Nation et al., although these children were as skilled as the good

comprehenders on measures of word and nonword decoding ability, they performed

significantly worse on a measure of reading comprehension. They also performed

significantly worse than the good comprehenders on two measures of oral language

comprehension: a picture vocabulary test and the comprehension subtest of the

Wechsler Intelligence Scale for Children (WISC)-III (Wechsler, 1992). In contrast,

the two groups did not differ in either age (M = 10.06 years; SD = 2.87 for the

group of less skilled comprehenders and M = 10.5 years; SD = 2.47 for the group

of skilled comprehenders) or nonverbal intelligence, as measured by the block

subtest of the WISC-III (Wechsler, 1992) (M = 7.66; SD = 6.62 for the group of

less skilled comprehenders and M = 11.89, SD = 5.06 for the group of skilled

comprehenders).

Newman, Macomber, Babitz, Volkmar, and Grigorenko (2007) contrasted ASD

children with hyperlexia (ASD ? HPL) to ASD children without hyperlexia

(ASD - HPL) as well as to a group of typical readers. The group with hyperlexia

was recruited among children with the diagnosis of ASD who had a documented

report of precocious word decoding ability. In contrast, the ASD - HPL children

were recruited among a sample of high functioning children with ASD whose

parents did not report any exceptional or precocious single word reading ability. The

two groups were matched for age (ASD ? HPL children: M = 10.41 years;

SD = 4.65; ASD - HPL children: M = 12.33 years; SD = 3.39). They also had

equivalent IQs (M = 99.4; SD = 20.15 and M = 89.25; SD = 18.17, for the

ASD ? HPL and the ASD - HPL children, respectively).

The 18 typically developing children were matched with the ASD ? HPL

children on the basis of their performance on a standardized word reading task.

They varied in age from 6.57 to 9.21 years. Even though only the ASD ? HPL

children and the typically developing children had been matched for single word

reading ability, the three groups performed similarly on this measure.

In addition to reading and spelling tasks, participants were administered a

receptive vocabulary task and several tasks designed to assess processes that have

been found to correlate with word reading ability in typical and dyslexic reading,

namely, phonological awareness (PA) and rapid naming skills. Results of the

comparisons of the two groups of children with ASD differed from Nation et al.’s

(2006) in a number of ways. First, in contrast to the results in the Nation et al. study,

the ASD ? HPL children performed significantly better than the ASD - HPL on

the nonword reading task. The same also was true for the PA and spelling of sounds

tasks, leading Newman et al. to suggest that ASD ? HPL children have stronger

phonological processing skills than ASD - HPL children.

The comparisons involving the measures of language comprehension also

yielded different findings. In marked contrast with the results reported by Nation

et al. (2006), the ASD ? HPL children in Newman et al.’s (2007) study performed

significantly better than the ASD - HPL children on the receptive vocabulary test.

As a matter of fact, they performed at average or above average levels, not differing

from the typical children on that task. This may account for Newman et al.’s (2007)

Correlates of hyperlexia in asd 131

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results for the reading comprehension task. Although the ASD ? HPL read, on

average, as many words as the ASD - HPL children on the word reading task and,

despite the fact that the two groups had been matched for age, the ASD ? HPL

children performed significantly better than the ASD - HPL children on the

reading comprehension task.

These discrepancies likely resulted from differences in the criteria used to match

the hyperlexic and non-hyperlexic ASD readers in the two studies. Whereas the two

groups were matched for word reading ability in Nation et al.’s (2006) study,

Newman et al. (2007) used chronological age as their matching criterion. In

addition, the two studies used different procedures to recruit their participants with

hyperlexia. In Nation et al.’s (2006) study, the hyperlexic group was selected on the

basis of their poor scores on a reading comprehension task, whereas in Newman

et al.’s study, they were chosen on the basis of a history of precocious word reading

ability. Hyperlexics’ early and spontaneous onset of word decoding ability has been

frequently alluded to in the literature (e.g., Grigorenko et al., 2003; Sparks, 2001,

2004) and it is thus no wonder that Newman et al. used this criterion to recruit their

group of ASD ? HPL participants. However, in contrast to the less skilled

comprehenders in Nation et al.’s (2006) study, it is not clear that the ASD ? HPL

children in Newman et al.’s (2007) study complied with two other common features

of hyperlexia (see, e.g., Healy et al., 1982), namely, impaired listening and reading

comprehension skills, and exceptional word decoding ability on the basis of

cognitive and/or linguistic abilities.

As a matter of fact, Newman et al.’s (2007) hyperlexic children did not differ

from the typical children on their measures of oral language comprehension.

Furthermore, although word reading ability was ahead of reading comprehension,

truly exceptional word reading ability—that is, word reading ability above what

might be expected on the basis of both chronological age and verbal intelligence—

was observed only among the younger children in the sample. Among the

ASD ? HPL children 10 years of age or older, the ability to read single words was

apparently tantamount to what might be expected on the basis of both age and

verbal intelligence.

The studies described below constitute another attempt to identify the correlates

of hyperlexia in ASD children. Study 1 was designed after Newman et al.’s (2007)

study. In other words, it compared ASD ? HPL children, ASD - HPL children,

and typically developing children, individually matched for word reading ability,

with regard to performance on various cognitive and language measures. In contrast

to Newman et al.’s study, however, the ASD ? HPL group satisfied the three

criteria proposed by Healy et al. (1982) as defining features of hyperlexia:

spontaneous and precocious onset of single word decoding, poor listening and

reading comprehension skills, and exceptional single word ability on the basis of

cognitive or language abilities. It is thus possible that its results contribute to our

understanding of the nature of hyperlexic reading, many aspects of which are still

equivocal. In particular, it is not clear whether hyperlexic reading is qualitatively

different from typical reading or if it is best conceptualized in terms of variations in

typical reading, which themselves are correlated with differences in various

language and cognitive skills (Nation, 1999). Part of this confusion may result from


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the fact that, similar to Newman et al. (2007), several researchers have used the

term hyperlexia to refer to children whose word reading ability is out of proportion

with reading comprehension, regardless of whether the children are poor or good

language comprehenders, and regardless of whether their single word reading is

truly exceptional (e.g., Goldberg & Rothermel, 1984; Richman & Kitchell, 1981;

O’Connor & Hermelin, 1994; Silberberg & Silberberg, 1968, 1971) By limiting the

hyperlexic group to children with the characteristic features proposed by Healy

et al. (1982), the current may help disentangle that question.

Only school age children participated in Study 1. Since hyperlexic reading may

modify over time (Newman et al., 2007; Sparks, 2001; Welsh, Pennington, &

Rogers, 1987), Study 2 compared ASD hyperlexics of preschool age with a group of

typically developing children of similar word reading ability with regard to most of

the cognitive and linguistic measures used in Study 1.

Study 1

Method

Participants

Three groups of children individually matched for word reading ability, as measured

by a Brazilian standardized single word reading test (see below) participated in the

study: six ASD ? HPL boys, six ASD - HPL children (5 boys, 1 girl), and six

typically developing boys (M = 6.2 years; SD = .41).

The ASD children were participating in a study investigating reading ability in

ASD (Silva, 2006) and were referred to us through a mental health center for

children with severe developmental disorders. They were all enrolled in public

schools. Similar to Newman et al.’s (2007) procedure, the ASD ? HPL group was

selected on the basis of a history of spontaneous and precocious word reading

ability. On the other hand, the ASD - HPL children were recruited among ASD

children who, based on parental report, learned to read in school. The two groups

with ASD did not differ with regard to either age (M = 10.9 years; SD = 4.6 and

M = 11.9 years; SD = 3.8 for the ASD ? HPL and ASD - HPL children,

respectively) or nonverbal IQ, as measured by the performance subtests of the

WISC-III (see below) (M = 66.33; SD = 8.64 and 74.67; SD = 21.40, for the

ASD ? HPL and ASD - HPL children, respectively).

The typically developing children were recruited among children enrolled in

preschool and first grade classrooms of a private school on the basis of their

performance on the word reading test. They all came from middle class families

and, according to their teachers, behaved typically for their ages. They were

significantly younger than the children with ASD (M = 6.17, SD = .41). As

illustrated in Table 1, they also had significantly higher performance IQs than both

the ASD ? HPL and the ASD - HPL children (M = 115.25; SD = 16.82).


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Procedure

Both Study 1 and Study 2 were approved by the Animal and Human Subjects

Review Committee of the Federal University of Minas Gerais, Belo Horizonte,

Brazil. After parental consent was obtained, participants were administered tasks

designed to assess word reading ability as well as phonological processing and rapid

naming skills. In addition, they were administered the Peabody Picture Vocabulary

Test-III (Dunn & Dunn, 1997), and the performance subtests of the WISC-III

(Wechsler, 2000). Two of the typical children were not administered the WISC-III

and the Word reading-II task (see below), because they were not available when

these tests were administered. All tasks were administered individually. Controls

were tested in a quiet room in their school, and the ASD children were tested at the

health center.

Measures

Receptive vocabulary

Form A of the Peabody Picture Vocabulary Test (PPVT)-III (Dunn & Dunn, 1997)

was translated and adapted to Portuguese and used as a measure of children’s

receptive vocabulary. The test consists of four training cards and 204 test cards,

each one of which contains four pictures. For each card, the child is asked to choose

the picture that best matches a word pronounced by the examiner. The test was

administered according to the instructions in the manual. Split-half reliability in

the group of typically developing children who participated in Study 1 and Study 2

was .95.

Table 1 Mean scores (and standard deviations) for various measures as a function of group

Measures Group

ASD ? HPL (N = 6) ASD - HPL (N = 6) Controls (N = 6)

Performance IQ 66.33 (8.64)a 74.67 (21.40)a 115.25 (16.8)b

Receptive vocabulary (Max. = 204) 59.83 (34.98)b 101.83 (45.49)a,b 108.00 (22.72)a

Reading comprehension (Max. = 204) 40.83 (9.43)b 95.67 (48.78)a 95.83 (24.24)a

Letter name knowledge (Max. = 48) 47.33 (.52)a 46.67 (1.75)a 47.17 (1.17)a

TDE word reading (Max. = 70) 59.00 (6.69)a 57.17 (5.56)a 59.33 (7.34)a

Word reading II (Max. = 121) 108.33 (6.86)a 106.83 (10.32)a 108.50 (4.76)a

Reading nonwords (Max. = 20) 15.33 (2.73)a,b 15.00 (1.09)b 17.00 (.89)a

Spelling letters names (Max. = 24) 22.00 (3.46)a 23.67 (0.52)a 23.67 (.52)a

Spelling letters sounds (Max. = 23) 17.33 (4.18)b 21.17 (1.17)a 21.67 (1.03)a

Phonological awareness (Max. = 12) 7.83 (3.87)b 9.67 (2.42)b 11.67 (.52)a

Verbal STM (Max. = 9) 5.00 (1.26)a 4.50 (0.84)a 4.50 (.55)a

Rapid naming: Digits (s) 37.83 (11.23)a 34.00 (7.64)a 35.50 (5.54)a

Rapid naming: Letters (s) 36.00 (10.06)a 32.33 (12.91)a 32.67 (5.16)a

Note: STM: Short-Term Memory. Cells with different superscripts differ significantly at p \ .05


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Non-verbal intelligence

The performance subtests of the WISC-III (Wechsler, 2000) test were administered

to assess non-verbal intelligence. The Brazilian version of the WISC-III has been

standardized on a sample of 801 6- to 16-year old children. Mean reliability

(Guttman’s Lambda 2) for the performance subtests is reported to be .81.

Reading and spelling ability

Letter naming and spelling tasks Children were asked to name and spell all letters

of the alphabet. The letter naming task was administered after the letter spelling

tasks (see below). Capital letters were shown first, followed by lower case letters. In

both cases, letters were printed on individual cards and were presented to the child

in a random order. The same order was used for all children. The child’s score

consisted of the number of capital and lower-case letters named correctly

(Maximum score = 48).

There were two letter spelling tasks. In the letter-name spelling task, the child

was asked to write the letter names pronounced by the examiner. In the letter sound

task, the examiner pronounced the sound typically represented by the letters of the

alphabet, and asked the child to spell them. In both tasks, the letters of the alphabet

were dictated in a random order. The child’s score consisted of the number of letters

spelled correctly (Maximum score = 24 and 23, for the letter name and letter sound

spelling tasks, respectively).

TDE-Word reading The reading subtest of Stein’s (1994) test of achievement was

used to assess children’s ability to read single words. The subtest consists of 70 words

of increasing difficulty (e.g., pato ‘duck’, fita ‘ribbon’, guitarra ‘electric guitar’,

hospedaria ‘inn’, etc.), printed in lower-case letters on a card. Reliability (alfa) is

reported to be .86. The score consisted of the number of words read correctly.

Word reading-II Participants were asked to read 121 words (e.g., casa ‘house’,

carro ‘car’, cachorro ‘dog’, reu ‘culprit’, febril ‘feverish’, tornozelo ‘ankle’, etc.)

varying in frequency of occurrence in books for children (Pinheiro, 1996). Words were

printed in lower-case letters at the center of individual cards, and the child was asked to

read them. The child’s score consisted of the number of words read correctly. Split-

half reliability in the group of typically developing children who participated in Study

1 was .97 for the frequent words, and .94 for the infrequent words.

Nonword reading The task consisted of three training and 20 experimental

nonwords (e.g., nila, puca, calvilho, etc.). We told the child that we would ask him

or her to read some ‘‘funny’’ words that did not have any meaning. Incorrect

responses to the training trials were corrected, and corrected responses were praised.

No feedback was given to the child’s responses to the experimental nonwords. Split-

half reliability in the group of typically developing children who participated in

Study 1 and Study 2 was .84.


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Word reading comprehension Form B of the PPVT-III test (Dunn & Dunn, 1997)

was adapted to evaluate children’s word reading comprehension skills. Following

Welsh et al. (1987), Form B target words were printed on individual cards, and

presented along with the corresponding cards. The child’s task consisted of

identifying the picture that best represented the printed word. Except for this

modification, the test was administered according to the instructions in the manual.

Split-half reliability in the group of typically developing children who participated

in studies 1 and 2 was .97.

Phonological processing

Phonemic awareness The child’s task consisted of identifying, among three

different words (e.g., livro ‘book’—vestido ‘dress’—tomate ‘tomato’), the one that

started with a consonant sound enunciated by the examiner (e.g., [v]). There were

three training trials followed by 12 experimental trials. Words in each trial were

represented by pictures in order to minimize working memory load. Incorrect

responses to the training trials were corrected, and correct responses were praised.

No feedback was given to the child’s responses during the experimental trials. Split-

half reliability in the group of typically developing children who participated in

Study 1 and Study 2 was .48.

Verbal short-term memory (STM) Verbal STM was measured with the digits

forward part of the digit-span subtest of the WISC-III (Wechsler, 2000). The child’s

task consisted in repeating lists of single digits in exactly the same order enunciated

by the examiner. The task began with a list of three digits, with the number of digits

increasing by one in each successive list up to a maximum of nine digits. For any

particular length, there were two lists. If any of the two lists was repeated correctly,

the next list length was presented. The task was discontinued when the child failed

to repeat both lists of a particular length. The score corresponded to the number of

digits in the last list passed by the child.

Rapid serial naming skills Rapid serial naming was assessed with two tasks that

required the child to quickly name matrices of letters (a, d, o, s, p) and numbers (2,

4, 6, 7, 9), respectively (see Denckla & Rudel, 1976). Each matrix was comprised of

five different stimuli, with each stimulus appearing 10 times in a random order.

Before the administration of each matrix, the child was shown a card containing the

five relevant stimuli, and was asked to name them. The dependent variable consisted

of the time taken to name the stimuli in each one of the two matrices.

Results

Table 1 lists the mean scores on the various measures, separately for the three

groups of children. Given the small size of the groups, the Kruskal–Wallis test was

used to evaluate whether the three groups differed significantly on the various

measures. Pairwise comparisons were tested with the Mann–Whitney test.


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All children performed equivalently on the word reading-II task, suggesting that

they had been appropriately matched for word reading ability. In contrast, the three

groups differed significantly on the word reading comprehension task

(v2(2) = 11.278, p = .004) and they tended to differ significantly on the nonword

reading task, v2(2) = 5.755, p = .056. Follow-up tests revealed that the ASD -

HPL children performed significantly worse than the typical children on the nonword

reading task (U = 2.000, p = .008, two-tailed), but did not differ from them on the

word reading comprehension task, U = 14.000, p = .522, two-tailed. The opposite

pattern was found for the comparisons involving the ASD ? HPL and the typical

children. That is, while these two groups did not differ significantly with regard to the

ability to read nonwords (U = 10.000, p = .193, two-tailed), the ASD ? HPL

children performed significantly worse than the typical children on the word reading

comprehension task, U = .000, p = .004, two-tailed. They also performed signif-

icantly worse than the ASD - HPL children on that task, U = .500, p = .005, two-

tailed. In other words, the ASD ? HPL, but not the ASD - HPL children, showed

the discrepancy between word decoding and reading comprehension that is typical of

hyperlexia. As can be seen in Table 1, the ASD ? HPL children also performed

worse than both the typical children and the ASD - HPL children on the receptive

vocabulary task, although only the difference involving the typical children was

statistically significant, U = 5.00, p \ .05, two-tailed.

Only two other measures differentiated the three groups of participants: the

phoneme awareness (v2(2) = 5.93, p = .05) and the letter-sound spelling task,

v2(2) = 6.79, p \ .05. As illustrated in Table 1, both groups of readers with ASD

performed significantly worse than the typical children performed on the phoneme

awareness task, U = 6.000, p \ .05, two-tailed, and U = 5.000, p \ .05, two-

tailed, for the ASD ? HPL and the ASD - HPL children, respectively. On the

other hand, the difference found for the letter-sound spelling task resulted from the

relatively low performance of the ASD ? HPL children. As a matter of fact, these

children performed significantly worse than did both the ASD - HPL children

(U = 5.500, p \ .05, two-tailed) and the control children, U = 4.000, p \ .05, two-

tailed. In contrast, no differences were found among the three groups’ performances

on the letter-name spelling task. These results are discussed below.

Discussion

Similar to Newman et al.’s (2007) findings, our results suggest that ASD ? HPL

children learn to read by processing and remembering letter-sound relations in

words. On the other hand, except for the results of an analysis of the reading errors

in the TDE word reading test, we did not find evidence for Newman et al.’s (2007)

suggestion that ASD ? HPL children have stronger phonological abilities than

ASD - HPL children.

We coded each incorrect response on the word reading test as either phonological

or visual. Phonological errors consisted of nonwords sharing many sounds in

common with the target word. In fact, some of these errors consisted of

regularization errors (e.g., /trow$i/ instead of /trowsi/ for trouxe ‘brought’). Visual

errors consisted of real words sharing many letters in common with the target word


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(e.g., atras ‘behind’ for atlas ‘atlas’). Table 2 lists the proportion of reading errors

that were coded as phonological and visual, separately for the three groups of

children. As illustrated, phonological errors were more frequent than visual errors

for all groups of children. However, there was a trend for the ASD ? HPL group to

present more phonological errors than the ASD - HPL group, U = 7.500, p = .09,

two-tailed. In contrast, the ASD - HPL children tended to present more visual

errors than the ASD ? HPL children, U = 7.500, p = .09, two-tailed.

Despite these results, we did not find a difference favoring the ASD ? HPL

children on the nonword reading, PA, and letter-sound spelling tasks. Similar to the

results reported by Nation et al. (2006), the ASD ? HPL children who participated

in the present study did not differ from the ASD - HPL children on the nonword

reading task. In addition, they performed worse than both the ASD - HPL and the

typical children on the PA and the letter-sound spelling task. Last, but not least, no

differences were found between the two groups on the verbal short-term memory

and rapid naming tasks.

Very likely, the differences between the present results and those of Newman

et al.’s (2007) study can be accounted for in terms of differences in the intelligence of

the ASD children who participated in the two studies. While Newman et al.’s

ASD ? HPL children performed as well as the typical children and significantly better

than the ASD - HPL children on a receptive vocabulary task, the ASD ? HPL

children who participated in the present study performed very poorly on a similar test.

It is possible that they had trouble understanding some of those tasks.

Differences in intelligence may not, however, be the only relevant factor. As a

matter of fact, the ASD ? HPL children performed as well as the ASD - HPL and the

typical children on the letter-name spelling task, despite the fact that its instructions

were similar to the instructions in the letter-sound task. Another possible reason for the

difference between Newman et al.’s (2007) results and ours is that not all children in

their ASD ? HPL group seemed to be hyperlexics, at least according to Healy et al.’s

(1982) list of defining criteria. For example, even though their word reading ability

was ahead of their reading comprehension skills, it is unlikely that they were impaired

in either listening or reading comprehension. In fact, judging from the figures reported

in Table 2 of their article, most, if not all of their ASD ? HPL children had average or

above average scores on measures of oral and reading comprehension. In contrast, the

ASD ? HPL children who participated in the present study performed significantly

worse than controls on both the picture vocabulary and the word reading compre-

hension measures. In addition, even though the ASD ? HPL and the ASD - HPL

groups were equivalent with regard to nonverbal IQ and age, the ASD ? HPL children

Table 2 Mean proportion of phonological and visual errors on the TDE word reading test as a function

of group

Errors Group

ASD ? HPL (N = 6) ASD - HPL (N = 6) Controls (N = 6)

Phonological .91 .75 .90

Visual .08 .24 .09


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tended to perform significantly worse than the ASD - HPL children on the receptive

vocabulary measure.

Furthermore, not all ASD ? HPL children in Newman et al.’s (2007) study

seemed to have single word reading ability out of proportion to their cognitive and/

or language comprehension ability. As noted previously, exceptional word reading

ability seemed to be a characteristic feature of only the younger children in the

ASD ? HPL group, particularly the preschool children. Newman et al. suggested

that single word reading ability levels off with development. However, it is not clear

that their younger and older ASD ? HPL children were comparable with regard to

cognitive and language skills that may also influence word reading ability. It is

therefore possible that the differences found between the younger and the older

ASD ? HPL children resulted from differences in those abilities.

A limitation of the present study is that, similar to most studies in the literature

(e.g., Cobrinik, 1982; Goldberg and Rothermel, 1984; Healy et al., 1982; Nation

et al., 2006; Patti & Lupinetti, 1993; Siegel, 1984; Snowling & Frith, 1986; Sparks,

2001, 2004), it only included school age children. Given that spontaneous and

precocious onset of word reading is an important feature of hyperlexia, the

investigation of the correlates of reading ability in preschool children with

hyperlexia may contribute to our understanding of the true nature of hyperlexic

reading. The reason for this is that, as Newman et al. (2007) suggested, hyperlexic

reading may change as a result of both development and formal instruction.

As far as we are aware, only a handful of studies (Atkin & Lorch, 2006; Newman

et al., 2007; O’Connor & Hermelin, 1994; Welsh et al., 1987) have included young,

preschool hyperlexic children. The results of these studies suggest that, similar to

what has been found for school age children, preschool hyperlexic children learn to

read by processing and remembering letter-sound relations in words. Except for this

knowledge, however, very little is known about the cognitive and linguistic

correlates of hyperlexia among preschool age children. For example, even though

Newman et al.’s (2007) ASD ? HPL group included a few preschool age children,

they were not administered several of the cognitive and language measures. Yet,

such information is necessary if we want to understand the nature and development

of hyperlexic reading.

Study 2 is an attempt to fulfill this gap. As described below, it investigates the

cognitive and linguistic correlates of word reading ability in two 3-year-old

ASD ? HPL children, in relation to a group of typically developing children of the

same word decoding ability.

Study 2

Method

Participants

Participants were two 3-year-old Brazilian boys with the diagnosis of ASD

(ages = 3; 09 and 3; 11 years), referred to us through a mental health center for


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children with severe developmental disorders. According to their parents, they had

started to read around their second birthday. At the time of our evaluation, they

showed the characteristic features associated with ASD: both were echolalic, and

showed extreme language and communicative impairments. They also showed

compulsive reading of letters and words.

Twenty-one typically developing children (11 girls, 10 boys) were also recruited

for the study. They varied in age from 5.08 to 7.01 years (M = 6.14 years;

SD = .52). They all were attending preschool or kindergarten classes in private

schools in a large Brazilian city.

Procedure

Participants were administered the same measures used in Study 1, except for the

Word Reading-II task and the subtests of the WISC-III. As in Study 1, all tasks were

administered individually in a quiet place. The two ASD boys were tested at the

mental health center and the typical children in their school.

Results and discussion

Table 3 lists the results for the various measures, separately for the ASD and the

typical readers. Both the mean and the range of scores are presented.

The two ASD children showed the characteristic feature of hyperlexia. That is,

although they did not differ from controls on the word reading measures, they

performed very poorly and significantly below controls on the word reading

comprehension task. As illustrated in Table 3, while controls had a mean word

reading comprehension score of 81.76 (range: 59–122), the mean word reading

Table 3 Mean scores for various measures as a function of group

Measures Group

ASD ? HPL (N = 2) Typical children (N = 21)

Mean Range Mean (SD) Range

Receptive vocabulary (Max. = 204) 12.50 11–14 92.76 (16.64) 53–127

Reading comprehension (Max. = 204) 12.50 4–21 81.76 (17.48) 59–122

Reading words (Max. = 70) 41.00 41–41 41.43 (3.38) 35–47

Reading nonwords (Max. = 20) 15.00 13–17 14.29 (3.55) 3–20

Letter name knowledge (Max. = 24) 23.00 22–24 23.19 (.60) 22–24

Spelling letter names (Max. = 24) 22.50 22–23 23.43 (.68) 22–24

Spelling letter sounds (Max. = 23) 8.00 5–11 21.52 (1.54) 18–23

Phonological awareness (Max. = 12) 0 0–0 11.29 (1.06) 8–12

Verbal STM (Max. = 9) 5.00 5–5 4.95 (.86) 4–7

Rapid naming: Digits (s) 47.50 43–52 43.86 (7.83) 32–63

Rapid naming: Letters (s) 50.50 45–56 44.48 (12.05) 29–86

Note: STM: Verbal Short-Term Memory


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comprehension score for the ASD children was only 12.50. In fact, their scores were

well below the smallest score in the control group.

The results for the nonword reading task confirm the results of previous studies

(e.g., Newman et al., 2007; Welsh et al., 1987) that preschool age hyperlexic

children learn to read by processing letter-sound relations in words. As can be seen

in Table 3, the mean number of nonwords read by the two hyperlexic boys was well

within controls’ range of scores. An analysis of the reading errors on the word

reading measure also suggests that preschool age hyperlexics rely on phonological

processes to read words, just as typical children of the same word reading level.

Similar to the results of Study 1, both the hyperlexic boys and the typical children

who participated in the present study showed a preponderance of phonological

errors (91.4% for hyperlexics and 91.2% for controls) as opposed to visual errors

(8.6%, for hyperlexics and 8.8%, for controls).

In addition to replicating the findings of previous studies with preschool children,

the results of the present study suggest that the hyperlexics’ ability to read by

phonological recoding is not restricted to preschool children of average or above

average intelligence (e.g., Newman et al., 2007; O’Connor & Hermelin, 1994). In

effect, the two hyperlexic boys performed very poorly on the PPVT-III test. Judging

from US norms, they performed below the level that would be expected of a typical

2-year-old child.

Only two other differences were found between the hyperlexic children and the

typical children. First, the hyperlexic boys performed well below the typical

children on the letter-sound spelling task. In addition, while the typical children

performed at ceiling on the PA measure, the hyperlexic boys did not even attempt to

perform it. Interestingly, the same differences, although much less pronounced,

were found between the ASD ? HPL children and the typical children who

participated in Study 1. The implications of these findings for our understanding of

hyperlexic reading are discussed below.

General discussion

Two studies were conducted to investigate the correlates of hyperlexia in Brazilian

Portuguese-speaking children with the diagnosis of ASD. The first study, designed

after Newman et al.’s (2007) study, involved three groups of school age children

individually matched for word reading ability: ASD hyperlexic children, ASD non-

hyperlexic children, and finally, typically developing children. The second study

involved two ASD preschool hyperlexic boys, and a group of 21 typical children of

similar word reading ability. In both studies, participants were administered several

reading measures as well as measures of cognitive and linguistic abilities that have

been associated with variations in typical and dyslexic reading, namely, vocabulary,

phonological awareness, and rapid naming.

Results strongly question the hypothesis that hyperlexic children learn to read

words visually (Cobrinik, 1982). Instead, similar to the results of previous studies

with preschool and school age children (e.g., Healy et al., 1982; Nation et al., 2006;

Newman et al., 2007; Sparks, 2001, 2004; Welsh et al., 1987), our findings suggest

that hyperlexic children learn to read by processing and remembering letter sound


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relations in words. In both studies, the ASD children with hyperlexia performed as

well as controls on the nonword reading measure. In addition, just like controls,

most of their reading errors were phonological, as opposed to visual.

Newman et al. (2007) suggested that ASD ? HPL children have stronger

phonological abilities than ASD - HPL children of the same word reading level.

One might therefore conceive that, together with other characteristics of ASD (e.g.,

restricted and obsessive interests), such strong phonological abilities might

contribute to the early and exceptional development of single word reading ability

that is characteristic of hyperlexia. However, we did not find evidence of stronger

phonological skills in our ASD ? HPL children.

Newman et al. based this claim on the fact that their ASD ? HPL children

performed better than the ASD - HPL children on their PA, nonword reading, and

spelling of sounds measures. In contrast to their findings, the ASD ? HPL children

who participated in our Study 1 did not differ from the ASD - HPL children on the

nonword reading task. In addition, they performed worse, not better, than the

ASD - HPL children on both the PA task and the letter-sound spelling task.

Finally, no difference was found between the two groups on either the verbal STM

or the rapid naming tasks.

As discussed previously, part of these differences may be explained in terms of

the fact that, in contrast to Newman et al.’s ASD ? HPL group, the ASD ? HPL

children who participated in Study 1 performed very poorly on a test of verbal

intelligence, the PPVT-III (Dunn & Dunn, 1997). In Newman et al.’s (2007) study,

the ASD ? HPL children performed at average or above average levels and

significantly better than the ASD - HPL children on a similar test. Very likely,

their relatively good oral language comprehension skills gave them an advantage on

the various cognitive and language tests.

Another possible reason for the discrepant results between the two studies is that

it is not clear that all of the children in Newman et al.’s ASD ? HPL group were

indeed hyperlexics. For example, not all of them seemed to comply with two of

Healy et al.’s (1982) list of defining criteria, namely, impaired listening and reading

comprehension, and single word reading ability above the level that would be

expected on the basis of cognitive or language skills. To be true, Healy et al.’s

(1982) definition of hyperlexia is not universally accepted (e.g., Grigorenko et al.,

2003). However, even if we restrict the definition of hyperlexia to early

development of word reading ability that is ahead of reading comprehension skills

(Newman et al., 2007, p. 761), it is still questionable that all of Newman et al.’s

ASD ? HPL participants qualified as hyperlexics. As a matter of fact, no difference

was found between them and the typical children on the reading comprehension test,

even though the two groups had been matched for word reading ability.1

1 According to Newman et al. (2007), the characteristic discrepancy between single word reading and

reading comprehension is revealed in an analysis controlling for differences in word reading ability

between the hyperlexic and the typical children. This procedure is, however, surprising, given the authors’

assertion that the hyperlexics did not differ from controls on word reading ability, not even when taking

into account differences in their chronological age. It is also not clear why the authors did not control for

differences in single word reading ability in the other comparisons.


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Of course, this may not be true of all ASD ? HPL children in Newman et al.’s

(2007) study. For example, there can be little doubt that their preschool and a few of

their school age children were truly exceptional single word readers. Unfortunately,

however, Newman et al. did not present data separately for these children. It is thus

not possible to check if they differed from the other children in the ASD ? HPL

group with regard to other characteristics. For the same reason, it is not clear that the

differences between the older and the preschool ASD ? HPL children reflect

developmental differences in hyperlexic reading or differences between the two

groups in other characteristics.

The two ASD preschool boys who participated in Study 2 shared some important

features with the school age ASD ? HPL children in Study 1. For example, both

groups of children seemed to have impaired verbal intelligence, as measured by the

PPVT-III task. Furthermore, although neither group differed from controls on the

ability to read words and nonwords, both performed significantly worse on the

reading comprehension task. Although there was progress with age in most

measures, exactly the same pattern of results was found in Study 1 and Study 2.

Specifically, no differences were found between hyperlexics and controls on either

the verbal STM or the rapid naming tests. On the other hand, a significant difference

favoring controls was found for the vocabulary, PA, and letter sound spelling tasks.

These results suggest continuity between early and late forms of word reading in

hyperlexia.

Although some of the differences between the ASD ? HPL children and controls

who participated in our studies likely resulted from dissimilarities in their verbal

intelligence, other factors may also be involved. For example, it is unlikely that the

relatively poor performance of the hyperlexics on the letter-sound spelling task

resulted from their failure to understand the task. The reason for this is that the two

groups performed similarly and indeed at ceiling on the similar letter-name spelling

task. This was true for both Study 1 and Study 2.

Together with the evidence that hyperlexic children have well developed

phonological skills, as measured by the more implicit phonological processing

tasks, the results for the PA and letter-sound spelling tasks suggest that hyperlexic

children may learn to compute letter-sound relations implicitly, on the basis of

statistical learning mechanisms. As a matter of fact, hyperlexics’ indifference to

language as a meaningful, symbolic device may be the key to their exceptionally

good and early developing word decoding ability. In contrast to typical children

who need to learn to disregard meaning in order to pay attention to the formal

features of language (e.g., Cardoso-Martins & Duarte, 1994), hyperlexic children

may only gradually learn to attend to meaning. As a result, they may be more

susceptible to using their good phonological processing skills for the purpose of

exploring and discovering letter-sound regularities in words. In other words,

hyperlexic children may treat reading as a ‘‘statistical learning problem’’, precisely

because they are so indifferent to meaning.

The correlations between performance on the oral and reading versions of the

picture vocabulary measures are indeed consistent with this hypothesis. Judging

from our results in Study 1 and Study 2, it seems that hyperlexics’ comprehension

ability, at least at the word level, is tantamount with their vocabulary skills.


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Interestingly, however, while the two measures were highly and significantly

correlated among both the typical (rho = .83, p \ .05, two-tailed) and the ASD -

HPL readers who participated in Study 1 (rho = .94, p \ .01, two-tailed), they were

only moderately correlated among the ASD ? HPL readers, rho = .49; p = .33,

two-tailed.

In summary, our results suggest that, when all three criteria proposed by Healy

et al. (1982) are satisfied, hyperlexic ASD readers may differ from typical and ASD

non-hyperlexic readers in an important way. Specifically, it is possible that, in

contrast to what seems to be the case among most readers, children with hyperlexia

treat reading as a statistical learning task (Seidenberg, 2005). In addition to testing if

this is indeed the case, it is important that future research evaluates the extent to

which hyperlexics’ ability to compute letter-sound relations on the basis of

statistical learning is associated with their difficulty in using language as a

meaningful, communicative device.

Acknowledgments The studies reported in this manuscript were possible thanks to a grant from the

Conselho Nacional de Ciencia e Tecnologia (CNPq, Brazil) to the first author. We thank the children, and

both their parents and teachers, for their collaboration.

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