Neighborhood effects in reading aloud: new findings and new challenges for computational models

A word from a dense neighborhood is often read aloud faster than a word from a sparse neighborhood. This advantage is usually attributed to orthography, but orthographic and phonological neighbors are typically confounded. Two experiments investigated the effect of neighborhood density on reading aloud when phonological density was varied while orthographic density was held constant, and vice versa. A phonological neighborhood effect was observed, but not an orthographic one. These results are inconsistent with the predominant role ascribed to orthographic neighbors in accounts of visual word recognition and reading aloud. Consistent with this interpretation, 6 different computational models of reading aloud failed to simulate this pattern of results. The results of the present experiments thus provide a new understanding of some of the processes underlying reading aloud, and new challenges for computational models.     

DRC: a dual route cascaded model of visual word recognition and reading aloud

This article describes the Dual Route Cascaded (DRC) model, a computational model of visual word recognition and reading aloud. The DRC is a computational realization of the dual-route theory of reading, and is the only computational model of reading that can perform the 2 tasks most commonly used to study reading: lexical decision and reading aloud. For both tasks, the authors show that a wide variety of variables that influence human latencies influence the DRC model's latencies in exactly the same way. The DRC model simulates a number of such effects that other computational models of reading do not, but there appear to be no effects that any other current computational model of reading can simulate but that the DRC model cannot. The authors conclude that the DRC model is the most successful of the existing computational models of reading.     

Paired-associate learning, phoneme awareness, and learning to read

We report two studies examining the relations among three paired-associate learning (PAL) tasks (visual-visual, verbal-verbal, and visual-verbal), phoneme deletion, and single-word and nonword reading ability. Correlations between the PAL tasks and reading were strongest for the visual-verbal task. Path analyses showed that both phoneme deletion and visual-verbal PAL were unique predictors of a composite measure of single-word reading and of irregular word reading. However, for nonword reading, phoneme deletion was the only unique predictor (and visual-verbal PAL was not a significant predictor). These results are consistent with the view that learning visual (orthography) to phonological mappings is an important skill for developing word recognition skills in reading and that individual differences in this ability can be tapped experimentally by a PAL task.     

Age-of-acquisition effects in reading aloud: Tests of cumulative frequency and frequency trajectory

Several studies have reported that the age at which a word is learned affects skilled reading. This age-of-acquisition effect is potentially important for theories of reading and learning. The effect has been difficult to pin down, however, because the age at which a word is learned is correlated with many other lexical properties. Zevin and Seidenberg (2002) analyzed these phenomena, using connectionist models that distinguished between cumulative frequency (the total number of times a word is experienced) and frequency trajectory (the distribution of these experiences over time). The models prompted a reevaluation of the empirical literature on this topic. The present research tested and confirmed three behavioral predictions derived from these models. First, cumulative frequency has an impact on skilled word naming, more so than standard measures of frequency derived from such norms as those of Kucera and Francis (1967). Second, frequency trajectory affects age of acquisition: The timing of exposure to words affects how rapidly they are learned. However, frequency trajectory does not affect skilled reading aloud, because the consistencies in mapping between spelling and sound eventually wash out the effects of early differences in frequency of exposure. Thus, in skilled performance, the timing of exposure to words is less important than the amount of exposure. The results clarify the conditions under which age-dependent learning effects occur in reading aloud.     

The relationship between knowing a word and reading it aloud in children’s word reading development

This experiment examined the item-level relationship between 7-year-olds’ ability to read words aloud and their knowledge of the same words in the oral domain. Two types of knowledge were contrasted: familiarity with the phonological form of the word (lexical phonology), measured by auditory lexical decision, and semantic knowledge, measured by a definitions task. Overall, there was a robust relationship between word knowledge and reading aloud success. The association was stronger when words contained irregular spelling-sound correspondences. There was no evidence that a deeper or more semantic knowledge of words was more closely related to reading aloud success beyond the association between reading success and familiarity with the phonological form of the same words. This finding is not compatible with models that see semantics as contributing directly to the reading aloud process, at least during the relatively early stages of reading development. More critical was whether or not a word was considered a lexical item, as indexed by auditory lexical decision performance.     

Individual differences in visual word recognition: insights from the English Lexicon Project

Empirical work and models of visual word recognition have traditionally focused on group-level performance. Despite the emphasis on the prototypical reader, there is clear evidence that variation in reading skill modulates word recognition performance. In the present study, we examined differences among individuals who contributed to the English Lexicon Project (http://elexicon.wustl.edu), an online behavioral database containing nearly 4 million word recognition (speeded pronunciation and lexical decision) trials from over 1,200 participants. We observed considerable within- and between-session reliability across distinct sets of items, in terms of overall mean response time (RT), RT distributional characteristics, diffusion model parameters (Ratcliff, Gomez, & McKoon, 2004), and sensitivity to underlying lexical dimensions. This indicates reliably detectable individual differences in word recognition performance. In addition, higher vocabulary knowledge was associated with faster, more accurate word recognition performance, attenuated sensitivity to stimuli characteristics, and more efficient accumulation of information. Finally, in contrast to suggestions in the literature, we did not find evidence that individuals were trading-off their utilization of lexical and nonlexical information.     

Orthographically mediated inhibition effects: evidence of activational feedback during visual word recognition

Models of visual word recognition that have adopted an interactive activation framework (e.g., Coltheart, Curtis, Atkins, & Haller, 1993; Grainger & Jacobs, 1996) assume that activation can spread from semantic to orthographic representations via a feedback mechanism during visual word recognition. The present study used a mediated priming paradigm to test whether such feedback exists and, if so, under what conditions. Participants named aloud targets that were preceded either by a semantically related prime (e.g., dog-cat) or by a prime that was related to the target via a mediating word (e.g., cat-[dog]-bog). Direct evidence of activational feedback was obtained in the form of orthographically mediated inhibition effects. These mediated inhibition effects are consistent with activational feedback and support models of visual word recognition that have adopted an interactive activation framework.     

Development of Lexical and Sentence Level Context Effects for Dominant and Subordinate Word Meanings of Homonyms

Nine-ten-and twelve-year-old children (N = 75) read aloud dominant, subordinate or ambiguous bias sentences (N = 120) that ended in a homonym (BALL). After the sentence (1,000 ms), children read aloud targets that were related to the dominant (BAT) or subordinate (DANCE) meaning of the homonym or control targets. Participants were also divided into three reading skill groups based on an independent measure of single word oral reading accuracy. There were three main developmental and reading skill findings. First, 9-year-olds and low skill readers showed lexical level facilitation in accuracy. Second, 9- and 10-year-olds or low and moderate skill readers showed lexical level facilitation in reaction time. Third, 12-year-olds or high skill readers showed sentence level facilitation in reaction time with high skill readers additionally showing sentence level inhibition in reaction time. These results show that lexical level context effects decreased and that sentence level context effects increased with development and skill. These results are discussed in terms of connectionist models of visual word recognition that incorporate distributed attractor principles.     

The relationship between reading ability and lateralized lexical decision

Although lexical decision remains one of the most extensively studied cognitive tasks, very little is known about its relationship to broader linguistic performance such as reading ability. In a correlational study, several aspects of lateralized lexical decision performance were related to vocabulary and reading comprehension measures, as assessed using the Nelson-Denny Reading Test. This lateralized lexical decision task has been previously shown to demonstrate (1) independent contributions from both hemispheres, as well as (2) interhemispheric interactions during word recognition. Lexical decision performance showed strong relationships with both reading measures. Specifically, vocabulary performance correlated significantly with left visual field (LVF) word accuracy and LVF non-word latency, both measures of right hemisphere performance. There were also significant, though somewhat weaker, correlations between reading comprehension and RVF non-word latency. Lexicality priming, a measure of interhemispheric communication during lexical decision, was also correlated with reading comprehension. These results suggest that hemispheric interaction during word recognition is common, and that lexical processing contribution from the right hemisphere, something commonly taken as minor and inconsequential, can lead to significant performance benefits and to individual differences in reading.     

Individual differences in skilled adult readers reveal dissociable patterns of neural activity associated with component processes of reading

We used fMRI to examine patterns of brain activity associated with component processes of visual word recognition and their relationships to individual differences in reading skill. We manipulated both the judgments adults made on written stimuli and the characteristics of the stimuli. Phonological processing led to activation in left inferior frontal and temporal regions whereas semantic processing was associated with bilateral middle frontal activation. Individual differences in reading subskills were reflected in differences in the degree to which cortical regions were engaged during reading. Variation in sight word reading efficiency was associated with degree of activation in visual cortex. Increased phonological decoding skill was associated with greater activation in left temporo-parietal cortex. Greater reading comprehension ability was associated with decreased activation in anterior cingulate and temporal regions. Notably, associations between reading ability and neural activation indicate that brain/behavior relationships among skilled readers differ from patterns associated with dyslexia and reading development.     

Magnifying effects on visual word recognition: a dynamic display for internet-based experiments

A visual presentation procedure is introduced that presents target words followed by a dynamic mask until recognition. This form of stimulus degradation prolongs the word recognition process. Differences in word recognition latencies—which are usually quite small—are magnified, and thus can be more easily observed. The results of two experiments on the Internet with a total of 141 participants establish the task’s ability to magnify differences in word recognition latencies stemming from word familiarity (Experiment 1) and word prototypicality (Experiment 2). Both factors interact with stimulus degradation, but at different presentation intervals; these results are discussed as evidence for comparing models of word recognition. The new procedure can be used for assessing individual differences, such as implicit motives and self-focused attention. Further applications are discussed.     

The DRC model of visual word recognition and reading aloud: An extension to German

The dual-route cascaded (DRC) model of word recognition and reading aloud was implemented in German. In this paper, we describe crosslinguistic differences and similarities between the German and the English DRC. The German DRC was evaluated with respect to its ability to correctly pronounce all German monosyllabic words and to simulate the loan word (regularity) effect. Furthermore, we obtained DRC predictions concerning a number of benchmark effects previously investigated in English, namely effects of word frequency, word length, and neighbourhood size.     

BRINGING COMPUTATIONAL MODELS OF WORD NAMING DOWN TO THE ITEM LEVEL

Abstract— Early noncomputational models of word recognition have topically attempted to account for effects of categorical factors such as word frequency (high vs low) and spelling-to-sound regularity (regular vs irregular) More recent computational models that adhere to general connections: principles hold the promise of being sensitive to underlying item differences that are only approximated by these categorical factors In contrast to earlier models, these connectionist models provide predictions of performance for individual items In the present study, we used the item-level estimates from two connectionist models (Plaut, McClelland, Seidenberg, & Patterson, 1996, Seidenberg & McClelland, 1989) to predict naming latencies on the individual items on which the models were trained The results indicate that the models capture, at best, slightly more variance than simple log frequency and substantially less than the combined predictive power of log frequency, neighborhood density, and orthographic length. The discussion focuses on the importance of examining the item-level performance of word-naming models and possible approaches that may improve the models' sensitivity to such item differences     

Eye-fixation behavior, lexical storage, and visual word recognition in a split processing model

Some of the implications of a model of visual word recognition in which processing is conditioned by the anatomical splitting of the visual field between the two hemispheres of the brain are explored. The authors investigate the optimal processing of visually presented words within such an architecture, and, for a realistically sized lexicon of English, characterize a computationally optimal fixation point in reading. They demonstrate that this approach motivates a range of behavior observed in reading isolated words and text, including the optimal viewing position and its relationship with the preferred viewing location, the failure to fixate smaller words, asymmetries in hemisphere-specific processing, and the priority given to the exterior letters of words. The authors also show that split architectures facilitate the uptake of all the letter-position information necessary for efficient word recognition and that this information may be less specific than is normally assumed. A split model of word recognition captures a range of behavior in reading that is greater than that covered by existing models of visual word recognition.     

Reading aloud: qualitative differences in the relation between stimulus quality and word frequency as a function of context

Virtually all theories of visual word recognition assume (typically implicitly) that when a pathway is used, processing within that pathway always unfolds in the same way. This view is challenged by the observation that simple variations in list composition are associated with qualitative changes in performance. The present experiments demonstrate that when reading aloud, the joint effects of stimulus quality and word frequency on response time are driven by the presence/absence of nonwords in the list. Interacting effects of these factors are seen when only words appear in the experiment, whereas additive effects are seen when words and nonwords are randomly intermixed. One way to explain these and other data appeals to the distinction between cascaded processing (or interactive activation) on the one hand versus a thresholded mode of processing on the other, with contextual factors determining which mode of processing dominates.     

Eye movements in developing readers: A comparison of silent and oral sentence reading

We present sentence reading data from a large-scale study with children (N = 632), focusing on three key research questions. (1) What are the trajectories of reading development in oral as compared to silent reading? (2) How are word frequency effects developing and are changes differentially affected by reading mode? (3) Are there systematic differences between better and weaker comprehenders when reading silently vs. aloud? Results illuminate a number of differences between reading modes, including more and prolonged fixations in oral reading, along with less inter-word regressions and attenuated effects of word frequency. Weaker comprehenders were slower, especially in oral reading and showed less flexibility in the allocation of word processing time. Differences between reading modes can be explained by additional processing demands imposed by concurrent articulation and eye–voice coordination when reading aloud.     

Frequency,not age of acquisition,affects Italian word naming

The purpose of this study was to evaluate the claim that age of acquisition (AoA) and word frequency effects are reduced or nonexistent in languages that have very regular letter-to-sound mappings, like Italian. The first two experiments (Exp. 1, Exp. 2) showed that frequency variables affect reading aloud and lexical decision in Italian. Variables interpretable as pertaining to a semantic component, including AoA, affected lexical decision but not reading aloud. In Experiments 3 and 4, a measure of frequency—child written word frequency (ChFreq)—and AoA were manipulated. Reading performance was affected by word frequency but not by AoA (Exp. 3), whereas lexical decision was affected by both variables (Exp. 4). In Experiments 5 and 6, ChFreq and AoA were manipulated orthogonally. Only frequency affected reading aloud, with no main effect or interaction involving AoA (Exp. 5). The effects of AoA and frequency interacted in Experiment 6 for lexical decision due to a larger effect of AoA for low frequency words than high frequency words. These results show that in languages with a transparent orthography word frequency may affect reading aloud in the absence of an effect of AoA because Italian readers employ lexical nonsemantic reading aloud. The effect of child written frequency points to the efficiency of the mappings between those orthographic and phonological word forms that were frequently encountered when learning to read.     

Retrieval practice improves learning in children with diverse visual word recognition skills

ABSTRACT

A large body of research shows that performing tests is more beneficial for the retention of studied materials than restudying those materials, a phenomenon termed “testing-effect”. A contemporary debate on the testing effect literature concerns whether the benefits of tests are equivalent for individuals with different cognitive skills, as the capacity to decode written words, for example. In the current study, we approached this issue in two experiments by examining whether testing is equally beneficial for children with diverse visual word decoding skills. To achieve this goal, we recruited sixth and fourth grade children (experiments 1 and 2, respectively) and administered a reading aloud task to assess their visual word recognition skills, and administered a memory task about an encyclopedic text to promote the testing effect. Memory for the restudied/tested contents of the encyclopedic text were probed after a seven-day interval, and although children from both experiments showed robust testing effects, such effects were not associated with their visual word decoding skills. These findings suggest that children with diverse word decoding skills can be benefited by retrieval practice.     

Naming the color of a word: is it responses or task sets that compete?

Subjects named the colors in which high- and low-frequency words and pronounceable nonwords, otherwise matched, were displayed. Color naming was slower for all three item types than for visually equivalent strings of nonalphanumeric symbols but was no slower for words than for nonwords, nor for high-frequency words than for low-frequency words. Unpronounceable letter strings had intermediate color-naming latencies. However, frequency and lexical status had large effects on latency for reading the same words and pseudowords aloud. Interference is thus predicted not by the strength of association between a letter string and its pronunciation but by the presence of word-like constituents. We argue that the interference from an unprimed noncolor word is due to, and isolates, one of two components of the classic Stroop effect: competition from the whole task set of reading. The other component, response competition, occurs only when lexical access is sufficiently primed.