Charles A. Perfetti

Reading Ability: Lexical Quality to Comprehension

The lexical quality hypothesis (LQH) claims that variation in the quality of word representations has consequences for reading skill, including comprehension. High lexical quality includes well-specified and partly redundant representations of form (orthography and phonology) and flexible representations of meaning, allowing for rapid and reliable meaning retrieval. Low-quality representations lead to specific word-related problems in comprehension. Six lines of research on adult readers demonstrate some of the implications of the LQH. First, large-scale correlational results show the general interdependence of comprehension and lexical skill while identifying disassociations that allow focus on comprehension-specific skill. Second, word-level semantic processing studies show comprehension skill differences in the time course of form-meaning confusions. Studies of rare vocabulary learning using event-related potentials (ERPs) show that, third, skilled comprehenders learn new words more effectively and show stronger ERP indicators for memory of the word learning event and, fourth, suggest skill differences in the stability of orthographic representations. Fifth, ERP markers show comprehension skill differences in meaning processing of ordinary words. Finally, in text reading, ERP results demonstrate momentary difficulties for low-skill comprehenders in integrating a word with the prior text. The studies provide evidence that word-level knowledge has consequences for word meaning processes in comprehension.

How Psychological Science Informs the Teaching of Reading

This monograph discusses research, theory, and practice relevant to how children learn to read English. After an initial overview of writing systems, the discussion summarizes research from developmental psychology on childrens language competency when they enter school and on the nature of early reading development. Subsequent sections review theories of learning to read, the characteristics of children who do not learn to read (i.e., who have developmental dyslexia), research from cognitive psychology and cognitive neuroscience on skilled reading, and connectionist models of learning to read. The implications of the research findings for learning to read and teaching reading are discussed. Next, the primary methods used to teach reading (phonics and whole language) are summarized. The final section reviews laboratory and classroom studies on teaching reading. From these different sources of evidence, two inescapable conclusions emerge: (a) Mastering the alphabetic principle (that written symbols are associated with phonemes) is essential to becoming proficient in the skill of reading, and (b) methods that teach this principle directly are more effective than those that do not (especially for children who are at risk in some way for having difficulty learning to read). Using whole-language activities to supplement phonics instruction does help make reading fun and meaningful for children, but ultimately, phonics instruction is critically important because it helps beginning readers understand the alphabetic principle and learn new words. Thus, elementary-school teachers who make the alphabetic principle explicit are most effective in helping their students become skilled, independent readers.

Cross-cultural effect on the brain revisited: Universal structures plus writing system variation

Recognizing printed words requires the mapping of graphic forms, which vary with writing systems, to linguistic forms, which vary with languages. Using a newly developed meta‐analytic approach, aggregated Gaussian‐estimated sources (AGES; Chein et al. [ 2002 ]: Psychol Behav 77:635–639), we examined the neuroimaging results for word reading within and across writing systems and languages. To find commonalities, we compiled 25 studies in English and other Western European languages that use an alphabetic writing system, 9 studies of native Chinese reading, 5 studies of Japanese Kana (syllabic) reading, and 4 studies of Kanji (morpho‐syllabic) reading. Using the AGES approach, we created meta‐images within each writing system, isolated reliable foci of activation, and compared findings across writing systems and languages. The results suggest that these writing systems utilize a common network of regions in word processing. Writing systems engage largely the same systems in terms of gross cortical regions, but localization within those regions suggests differences across writing systems. In particular, the region known as the visual word form area (VWFA) shows strikingly consistent localization across tasks and across writing systems. This region in the left mid‐fusiform gyrus is critical to word recognition across writing systems and languages. Hum Brain Mapp 25:92–104, 2005.

Biological abnormality of impaired reading is constrained by culture.

Developmental dyslexia is characterized by a severe reading problem in people who have normal intelligence and schooling. Impaired reading of alphabetic scripts is associated with dysfunction of left temporoparietal brain regions. These regions perform phonemic analysis and conversion of written symbols to phonological units of speech (grapheme-to-phoneme conversion); two central cognitive processes that mediate reading acquisition. Furthermore, it has been assumed that, in contrast to cultural diversities, dyslexia in different languages has a universal biological origin. Here we show using functional magnetic resonance imaging with reading-impaired Chinese children and associated controls, that functional disruption of the left middle frontal gyrus is associated with impaired reading of the Chinese language (a logographic rather than alphabetic writing system). Reading impairment in Chinese is manifested by two deficits: one relating to the conversion of graphic form (orthography) to syllable, and the other concerning orthography-to-semantics mapping. Both of these processes are critically mediated by the left middle frontal gyrus, which functions as a centre for fluent Chinese reading that coordinates and integrates various information about written characters in verbal and spatial working memory. This finding provides an insight into the fundamental pathophysiology of dyslexia by suggesting that rather than having a universal origin, the biological abnormality of impaired reading is dependent on culture.

Phonemic activation during the first 40 ms of word identification: Evidence from backward masking and priming

When a briefly exposed target word is followed by a pseudoword mask, the disruptive masking effect is reduced when the mask shares graphemes with the target word and is further reduced when the mask shares phonemes with the target word (Perfetti, Bell, & Delaney, 1988,Journal of Memory and Language27, 59–70). These results implicate early (prelexical) phonemic activation during word identification. In Experiment 1, this phonemic masking effect was found to hold through target exposure durations ranging from 35 to 55 ms and to be independent of word frequency and spelling pattern consistency. In Experiment 3, completely convergent results were found in a masked priming paradigm that varied the exposure of a masked pseudoword prime from 25 to 65 ms. Phonemic priming effects were found by 45 ms correcting earlier conclusions favoring direct visual access based on this paradigm. Together, the masking and priming results strongly support a process of early phonemic activation prior to word identification. The results are most naturally handled by a single-mechanism activation model, but are also consistent with restricted versions of dual route theories.

The Lexical Constituency Model: Some Implications of Research on Chinese for General Theories of Reading

The authors examine the implications of research on Chinese for theories of reading and propose the lexical constituency model as a general framework for word reading across writing systems. Word identities are defined by 3 interlinked constituents (orthographic, phonological, and semantic). The implemented model simulates the time course of graphic, phonological, and semantic priming effects, including immediate graphic facilitation followed by graphic inhibition with simultaneous phonological facilitation, a pattern unique to the Chinese writing system. Pseudocharacter primes produced only facilitation, supporting the models assumption that lexical thresholds determine phonological and semantic, but not graphic, effects. More generally, both universal reading processes and writing system constraints exist. Although phonology is universal, its activation process depends on how the writing system structures graphic units.

Automatic (prelexical) phonetic activation in silent word reading: Evidence from backward masking

Abstract Visual access to a printed word may be accompanied by a very rapid activation of phonetic properties of the word as well as its constituent letters. We suggest that such automatic activation during word identification, rather than only postlexical recoding, routinely occurs in reading. To demonstrate such activation, we varied the graphemic and phonetic properties shared by a word target and a following pseudoword mask. Graphemic ( mard ) and homophonic ( mayd ) masks, equated for number of letters shared with a word target ( made ), both showed a masking reduction effect relative to a control mask. There was an additional effect of the homophonic mask over the graphemic mask, attributable to phonetic activation. A second experiment verified this pattern of mask reduction effects using conditions that ruled out any explanation of the effect that does not take account of the target-mask relationship. We take the results to suggest that a phonetic activation nonoptionally occurs (prelexically) during lexical access.

The knowledge-learning-instruction framework: bridging the science-practice chasm to enhance robust student learning.

Despite the accumulation of substantial cognitive science research relevant to education, there remains confusion and controversy in the application of research to educational practice. In support of a more systematic approach, we describe the Knowledge-Learning-Instruction (KLI) framework. KLI promotes the emergence of instructional principles of high potential for generality, while explicitly identifying constraints of and opportunities for detailed analysis of the knowledge students may acquire in courses. Drawing on research across domains of science, math, and language learning, we illustrate the analyses of knowledge, learning, and instructional events that the KLI framework affords. We present a set of three coordinated taxonomies of knowledge, learning, and instruction. For example, we identify three broad classes of learning events (LEs): (a) memory and fluency processes, (b) induction and refinement processes, and (c) understanding and sense-making processes, and we show how these can lead to different knowledge changes and constraints on optimal instructional choices.

Brain activation in the processing of Chinese characters and words: A functional MRI study

Functional magnetic resonance imaging was used to identify the neural correlates of Chinese character and word reading. The Chinese stimuli were presented visually, one at a time. Subjects covertly generated a word that was semantically related to each stimulus. Three sorts of Chinese items were used: single characters having precise meanings, single characters having vague meanings, and two‐character Chinese words. The results indicated that reading Chinese is characterized by extensive activity of the neural systems, with strong left lateralization of frontal (BAs 9 and 47) and temporal (BA 37) cortices and right lateralization of visual systems (BAs 17–19), parietal lobe (BA 3), and cerebellum. The location of peak activation in the left frontal regions coincided nearly completely both for vague‐ and precise‐meaning characters as well as for two‐character words, without dissociation in laterality patterns. In addition, left frontal activations were modulated by the ease of semantic retrieval. The present results constitute a challenge to the deeply ingrained belief that activations in reading single characters are right lateralized, whereas activations in reading two‐character words are left lateralized. Hum. Brain Mapping 10:16–27, 2000.

THE EFFECTS OF LONG-TERM VOCABULARY INSTRUCTION ON READING COMPREHENSION: A REPLICATION

A study that investigated the relationship between vocabulary instruction and reading comprehension was replicated and extended. The original study showed substantial gains in accuracy of word knowledge and speed of lexical access, but only marginal gains in comprehension. This latter result was attributable to methodological problems, and thus the comprehension measure was revised. In the present study, fourth graders were taught 104 words over a five-month period. Following instruction, these children and a group of uninstructed children matched on pre-instruction vocabulary and comprehension ability performed tasks to measure accuracy of word knowledge, speed of lexical access, and comprehension of stories containing taught words. Instructed children showed substantial advantage in all tasks. Reasons for these results, in contrast to studies that have failed to improve comprehension through vocabulary instruction, are discussed.