Distinct subsystems for the parafoveal processing of spatial and linguistic information during eye fixations in reading

Two experiments examined readers' use of parafoveally obtained word length information for word recognition. Both experiments manipulated the length (number of constituent characters) of a parafoveally previewed target word so that it was either accurately or inaccurately specified. In Experiment 1, previews also either revealed or denied useful orthographic information. In Experiment 2, parafoveal targets were either high- or low-frequency words. Eye movement contingent display changes were used to show the intact target upon its fixation. Examination of target viewing duration showed completely additive effects of word length previews and of ortho-graphic previews in Experiment 1, viewing duration being shorter in the accurate-length and the orthographic preview conditions. Experiment 2 showed completely additive effects of word length and word frequency, target viewing being shorter in the accurate-length and the high-frequency conditions. Together these results indicate that functionally distinct subsystems control the use of parafoveally visible spatial and linguistic information in reading. Parafoveally visible spatial information appears to be used for two distinct extralinguistic computations: visual object selection and saccade specification.     

Prosodic phonological representations early in visual word recognition

Two experiments examined the nature of the phonological representations used during visual word recognition. We tested whether a minimality constraint (R. Frost, 1998) limits the complexity of early representations to a simple string of phonemes. Alternatively, readers might activate elaborated representations that include prosodic syllable information before lexical access. In a modified lexical decision task (Experiment 1), words were preceded by parafoveal previews that were congruent with a target's initial syllable as well as previews that contained 1 letter more or less than the initial syllable. Lexical decision times were faster in the syllable congruent conditions than in the incongruent conditions. In Experiment 2, we recorded brain electrical potentials (electroencephalograms) during single word reading in a masked priming paradigm. The event-related potential waveform elicited in the syllable congruent condition was more positive 250-350 ms posttarget compared with the waveform elicited in the syllable incongruent condition. In combination, these experiments demonstrate that readers process prosodic syllable information early in visual word recognition in English. They offer further evidence that skilled readers routinely activate elaborated, speechlike phonological representations during silent reading.     

Phonological codes are assembled before word fixation: evidence from boundary paradigm in sentence reading

This experiment employed the boundary paradigm during sentence reading to explore the nature of early phonological coding in reading. Fixation durations were shorter when the parafoveal preview was the correct word than when it was a spelling control pseudoword. In contrast, there was no significant difference between correct word and pseudohomophone previews. These results suggest that the phonological codes are assembled before word fixation and are used for lexical access. Moreover, there was evidence that orthographic codes influence the activation of word meaning. We found that fixation durations were shorter for orthographically similar parafoveal previews, and this orthographic priming effect is limited to pseudohomophones. Thus, it seems that both the orthographic and the phonological similarities of the parafoveal preview to the target play a part in the facilitative effects of the preview.     

Previewing the neighborhood: the role of orthographic neighbors as parafoveal previews in reading

In 2 experiments, a boundary technique was used with parafoveal previews that were identical to a target (e.g., sleet), a word orthographic neighbor (sweet), or an orthographically matched nonword (speet). In Experiment 1, low-frequency words in orthographic pairs were targets, and high-frequency words were previews. In Experiment 2, the roles were reversed. In Experiment 1, neighbor words provided as much preview benefit as identical words and greater benefit than nonwords, whereas in Experiment 2, neighbor words provided no greater preview benefit than nonwords. These results indicate that the frequency of a preview influences the extraction of letter information without setting up appreciable competition between previews and targets. This is consistent with a model of word recognition in which early stages largely depend on excitation of letter information, and competition between lexical candidates becomes important only in later stages.     

Lexical priming from partial-word previews

Two naming and two lexical decision experiments examined the use of partial-word preview in visual word recognition. Replicating results of an earlier reading study, the results of Experiments 1 and 2 revealed significant benefits from position-specific beginning- and ending-letter previews. Furthermore, benefits from beginning letters were greater for words than for pseudowords. Ending-letter previews showed no corresponding lexical superiority. Experiment 3 revealed that preview of position-specific letters from the beginning plus the ending part of target stimuli, which did not reveal a unique word-beginning letter sequence, facilitated the classification of words but not pseudowords. The results support a two-route model of lexical access in which some partial-word previews afford activation of specific lexical representations, and some partial-word previews afford activation of subword representations.     

The role of phonological codes in integrating information across saccadic eye movements in Chinese character identification

Prior research has generally assumed either that phonological codes do not contribute to Chinese character identification or that they do so only through a look-up process at the character level. In 3 experiments, a homophone seen parafoveally aided the identification of a target character that was fixated following an eye movement to the preview location. Moreover, high-frequency phonetically regular characters were named faster than high-frequency, phonetically irregular characters. Thus, both lexical and sublexical phonological codes of Chinese characters are involved early in the process of character identification. Orthographic information from the preview was also used in character identification, as orthographically similar previews facilitated target identification as well. The evidence for the extraction of semantic information from parafoveal previews was mixed, as synonym previews facilitated in Experiment 2 but not in Experiment 1.     

Use of phonological codes for Chinese characters: evidence from processing of parafoveal preview when reading sentences

The role of phonological coding for character identification was examined with the benefit of processing parafoveal characters in eye fixations while reading Chinese sentences. In Experiment 1, the orthogonal manipulation of phonological and orthographic similarity can separate two types of phonological benefits for homophonic previews, according to whether these previews share the same phonetic radical with the targets or not. The significant phonological benefits indicate that phonological coding is activated early when the character is in the parafovea. Experiment 2 manipulated the character's consistency value and found that the phonological preview benefits are reliable only when the targets are high consistency characters. The results of two experiments suggest that phonological computation is rapid and early at both character and radical levels for Chinese character identification.     

Parafoveal processing of transposed-letter words and nonwords: evidence against parafoveal lexical activation

The current experiments explored the parafoveal processing of transposed-letter (TL) neighbors by using an eye-movement-contingent boundary change paradigm. In Experiment 1 readers received a parafoveal preview of a target word (e.g., calm) that was either (1) identical to the target word (calm), (2) a TL-neighbor (clam), or (3) a substituted-letter (SL) nonword (chem). In Experiment 2 a further set of parafoveal preview conditions was explored including (4) an SL-word condition (chum) and (5) a TL-nonword condition (caml). Across both experiments, readers' fixation durations on the target words were significantly longer when the previews were SL previews than when they were TL neighbors, suggesting that TL neighbors (when presented in the parafovea) facilitate processing rather than inhibit processing. Experiments 3 and 4 showed that this is in contrast to the inhibitory effects that are seen when TL neighbor previews appear in the fovea.     

Prelexical facilitation and lexical interference in auditory word recognition.

Phonological priming effects were examined in an auditory single-word shadowing task. In 6 experiments, target items were preceded by auditorily or visually presented, phonologically similar, word or nonword primes. Results revealed facilitation in response time when a target was preceded by a word or nonword prime having the same initial phoneme when the prime was auditorily presented but not when it was visually presented. Second, modality-independent interference was observed when the phonological overlap between the prime and target increased from 1 to 3 phonemes for word primes but not for nonword primes. Taken together, these studies suggest that phonological information facilitates word recognition as a result of excitation at a prelexical level and increases response time as a result of competition at a lexical level. These processes are best characterized by connectionist models of word recognition.     

Eye movements and word skipping during reading revisited

The authors examined word skipping in reading in 2 experiments. In Experiment 1, skipping rates were higher for a preview of a predictable word than for a visually similar nonword, indicating there is full recognition in parafoveal vision. In Experiment 2, foveal load was manipulated by varying the frequency of the word preceding either a 3-letter target word or a misspelled preview. There was again a higher skipping rate for a correct preview and a lower skipping rate when there was a high foveal load, but there was no interaction, and the pattern of effects in fixation times was the same as in the skipping data. Experiment 2 also showed significant skipping of nonwords similar to the target word, indicating skipping based on partial information.     

Influences of spoken word planning on speech recognition

In 4 chronometric experiments, influences of spoken word planning on speech recognition were examined. Participants were shown pictures while hearing a tone or a spoken word presented shortly after picture onset. When a spoken word was presented, participants indicated whether it contained a prespecified phoneme. When the tone was presented, they indicated whether the picture name contained the phoneme (Experiment 1) or they named the picture (Experiment 2). Phoneme monitoring latencies for the spoken words were shorter when the picture name contained the prespecified phoneme compared with when it did not. Priming of phoneme monitoring was also obtained when the phoneme was part of spoken nonwords (Experiment 3). However, no priming of phoneme monitoring was obtained when the pictures required no response in the experiment, regardless of monitoring latency (Experiment 4). These results provide evidence that an internal phonological pathway runs from spoken word planning to speech recognition and that active phonological encoding is a precondition for engaging the pathway.     

Use of parafoveally visible characters during the reading of Chinese sentences

Chinese readers' use of parafoveal character previews was examined. In Experiment 1, the preview of target characters consisted of targets or of graphemically similar, homophonic, or dissimilar characters. Each preview was replaced with the corresponding target when the eyes reached the target location. Oculomotor measures revealed preview benefits for targets, for graphemically similar characters, and for homophonic characters. Experiment 2 showed that parafoveal preview of graphemically similar characters yielded benefits primarily when they shared the phonetic radical with their targets. The phonological relationship between previewed radicals and subsequently viewed targets was ineffective. Chinese character processing thus involves the initial use of orthographic information from the phonetic radical and the activation of the character's phonological form.     

Flexible parafoveal encoding of character order supports word predictability effects in Chinese reading: Evidence from eye movements

Several eye-movement studies have revealed flexibility in the parafoveal processing of character-order information in Chinese reading. In particular, studies show that processing a two-character word in a sentence benefits more from parafoveal preview of a nonword created by transposing rather than replacing its two characters. One issue that has not been investigated is whether the contextual predictability of the target word influences this processing of character order information. However, such a finding would provide novel evidence for an early influence of context on lexical processing in Chinese reading. Accordingly, we investigated this issue in an eye-movement experiment using the boundary paradigm and sentences containing two-character target words with high or low contextual predictability. Prior to the reader’s gaze crossing an invisible boundary, each target word was shown normally (i.e. a valid preview) or with its two characters either transposed or replaced by unrelated characters to create invalid nonword previews. These invalid previews reverted to the target word once the reader’s gaze crossed the invisible boundary. The results showed larger preview benefits (i.e. a decrease in fixation times) for target words following transposed-character than substituted-character previews, revealing a transposed-character effect similar to that in previous research. In addition, a word predictability effect (shorter fixation times for words with high than low predictability) was observed following both valid and transposed-character previews, but not substituted-character previews. The findings therefore reveal that context can influence an early stage of lexical processing in Chinese reading during which character order is processed flexibly.

     

Transposed-letter effects in reading: evidence from eye movements and parafoveal preview

Three eye movement experiments were conducted to examine the role of letter identity and letter position during reading. Before fixating on a target word within each sentence, readers were provided with a parafoveal preview that differed in the amount of useful letter identity and letter position information it provided. In Experiments 1 and 2, previews fell into 1 of 5 conditions: (a) identical to the target word, (b) a transposition of 2 internal letters, (c) a substitution of 2 internal letters, (d) a transposition of the 2 final letters, or (e) a substitution of the 2 final letters. In Experiment 3, the authors used a further set of conditions to explore the importance of external letter positions. The findings extend previous work and demonstrate that transposed-letter effects exist in silent reading. These experiments also indicate that letter identity information can be extracted from the parafovea outside of absolute letter position from the first 5 letters of the word to the right of fixation. Finally, the results support the notion that exterior letters play important roles in visual word recognition.     

Phonological codes are used in integrating information across saccades in word identification and reading.

A major issue in reading is the extent to which phonological information is used in visual word perception. The present experiments demonstrated that phonological information acquired on 1 fixation from a word in the parafovea is used to help identify that word when it is later fixated. A homophone of a target word, when presented as a preview in the parafovea, facilitated processing of the target word seen on the next fixation more than a preview of a word matched with the homophone in visual similarity to the target word. This facilitation was observed both in the time to name an isolated target word and in the fixation time on the target word while silently reading a sentence; the preview was virtually never consciously identified in either task. Because the visual similarity of the preview to the target also plays a part in the facilitative effect on the preview, however, codes other than phonological codes are preserved across saccades.     

Parafoveal processing of words and saccade computation during eye fixations in reading

Studied parafoveal word processing during eye fixations in reading to answer two questions: (a) Is the processing of parafoveally available words limited to the identification of beginning letters? (b) Does the parafoveal processing of words affect the following interword saccade? Reading afforded either no parafoveal preview, preview of beginning trigrams, preview of ending trigrams, or preview of the whole parafoveal word. Previews were controlled by replacing original letters either with X's or dissimilar letters. Preview benefits were larger for the whole word previews than for beginning or ending trigram previews. X-masks yielded preview benefits from intact beginning and ending trigrams but dissimilar letter masks yielded benefits from beginning trigrams only. Saccades were larger for whole word previews than for no previews. These results support Logogen-type models of word recognition and a model of saccade computation that posits a time-locked functional relation between the acquisition of parafoveal word information and the positioning of each fixation.     

Phonological priming in auditory word recognition

Cohort theory, developed by Marslen-Wilson and Welsh (1978), proposes that a "cohort" of all the words beginning with a particular sound sequence will be activated during the initial stage of the word recognition process. We used a priming technique to test specific predictions regarding cohort activation in three experiments. In each experiment, subjects identified target words embedded in noise at different signal-to-noise ratios. The target words were either presented in isolation or preceded by a prime item that shared phonological information with the target. In Experiment 1, primes and targets were English words that shared zero, one, two, three, or all phonemes from the beginning of the word. In Experiment 2, nonword primes preceded word targets and shared initial phonemes. In Experiment 3, word primes and word targets shared phonemes from the end of a word. Evidence of reliable phonological priming was observed in all three experiments. The results of the first two experiments support the assumption of activation of lexical candidates based on word-initial information, as proposed in cohort theory. However, the results of the third experiment, which showed increased probability of correctly identifying targets that shared phonemes from the end of words, did not support the predictions derived from the theory. The findings are discussed in terms of current models of auditory word recognition and recent approaches to spoken-language understanding.     

Isolating phonological components that increase tip-of-the-tongue resolution

Three experiments investigated the role of specific phonological components in priming tip-of-the-tongue (TOT) resolution. When in a TOT state, participants read a list of words that included phonological primes intermixed among unrelated words. The phonological primes contained either the same first letter as the target (Experiment 1), a single syllable (first, middle, or last) of the target (Experiment 2), or the first phoneme or first syllable of the target (Experiment 3). Reading first-letter primes in Experiment 1 did not help to resolve TOTs, whereas reading first-syllable primes significantly increased word retrieval in Experiment 2. Experiment 3 replicated the results of Experiments 1 and 2 using first-phoneme primes instead of first-letter primes and using two primes instead of three, although first-syllable priming occurred only for primes read silently. The results of these experiments support a transmission deficit model, where TOTs are caused by weak connections among phonological representations and can be resolved through internal or overt production of specific phonology.     

Semantic processing of previews within compound words

Previous studies have suggested that previews of words prior to fixation can be processed orthographically, but not semantically, during reading of sentences (K. Rayner, D. A. Balota, & A. Pollatsek, 1986). The present study tested whether semantic processing of previews can occur within words. The preview of the second constituent of 2-constituent Finnish compound nouns was manipulated. The previews were either identical to the 2nd constituent or they were incorrect in the form of a semantically related word, a semantically unrelated word, or a semantically meaningless nonword. The results indicate that previews of 2nd constituents within compound words can be semantically processed. The results have important implications for understanding the nature of preview and compound word processing. These issues are crucial to developing comprehensive models of eye-movement control and word recognition during reading.