Word skipping during sentence reading: effects of lexicality on parafoveal processing

Two experiments examined how lexical status affects the targeting of saccades during reading by using the boundary technique to vary independently the content of a letter string when seen in parafoveal preview and when directly fixated. Experiment 1 measured the skipping rate for a target word embedded in a sentence under three parafoveal preview conditions: full preview (e.g., brain–brain), pseudohomophone preview (e.g., brane–brain), and orthographic nonword control preview (e.g., brant–brain); in the first condition, the preview string was always an English word, while in the second and third conditions, it was always a nonword. Experiment 2 investigated three conditions where the preview string was always a word: full preview (e.g., beach–beach), homophone preview (e.g., beech–beach), and orthographic control preview (e.g., bench–beach). None of the letter string manipulations used to create the preview conditions in the experiments disrupted sublexical orthographic or phonological patterns. In Experiment 1, higher skipping rates were observed for the full (lexical) preview condition, which consisted of a word, than for the nonword preview conditions (pseudohomophone and orthographic control). In contrast, Experiment 2 showed no difference in skipping rates across the three types of lexical preview conditions (full, homophone, and orthographic control), although preview type did influence reading times. This pattern indicates that skipping not only depends on the presence of disrupted sublexical patterns of orthography or phonology, but also is critically dependent on processes that are sensitive to the lexical status of letter strings in the parafovea.     

Phonological and orthographic factors in the word-superiority effect

Phonological and orthographic aspects of a letter string were found to affect the identification of a component letter in three experiments. All involved a fixed set of target vowels presented in a fixed position in letter strings. Manipulations of the phonological nature of the target or the orthographic character of the string were made by adding a letter with the postexposure mask to the original CVC trigram. In Experiment 1, the addition of an E with the mask as a final letter to the string changed the pronunciation of the target vowel, whereas the addition of an S did not. Identification accuracy was higher with the S mask. In Experiment 2, either E or D could be added to CVCs that were equally orthographic but differentially pronounceable. The same added letter had quite different effects on accuracy, depending on its effect on target pronunciation and the orthographic regularity of the string. In Experiment 3, performance on targets in orthographic CVCs was lowered to the level of nonorthographic CVCs by adding a letter that rendered the entire string nonorthographic. The results are explained by assuming that phonological and graphemic codes are developed simultaneously but maintained in a nonindependent manner.     

Tracking the transition from sublexical to lexical processing: On the creation of orthographic and phonological lexical representations

Participants read aloud nonword letter strings, one at a time, which varied in the number of letters. The standard result is observed in two experiments; the time to begin reading aloud increases as letter length increases. This result is standardly understood as reflecting the operation of a serial, left-to-right translation of graphemes into phonemes. The novel result is that the effect of letter length is statistically eliminated by a small number of repetitions. This elimination suggests that these nonwords are no longer always being read aloud via a serial left-to-right sublexical process. Instead, the data are taken as evidence that new orthographic and phonological lexical entries have been created for these nonwords and are now read at least sometimes by recourse to the lexical route. Experiment 2 replicates the interaction between nonword letter length and repetition observed in Experiment 1 and also demonstrates that this interaction is not seen when participants merely classify the string as appearing in upper or lower case. Implications for existing dual-route models of reading aloud and Share's self-teaching hypothesis are discussed.     

Do transposed-letter similarity effects occur at a prelexical phonological level?

Nonwords created by transposing two letters (e.g., RELOVUTION) are very effective at activating the lexical representation of their base words (Perea & Lupker, 2004). In the present study, we examined whether the nature of transposed-letter (TL) similarity effects was purely orthographic or whether it could also have a phonological component. Specifically, we examined transposed-letter similarity effects for nonwords created by transposing two nonadjacent letters (e.g., relovución-REVOLUCION) in a masked form priming experiment using the lexical decision task (Experiment 1). The controls were (a) a pseudohomophone of the transposed-letter prime (relobución-REVOLUCION; note that B and V are pronounced as /b/ in Spanish) or (b) an orthographic control (relodución-REVOLUCION). Results showed a similar advantage of the TL nonword condition over the phonological and the orthographic control conditions. Experiment 2 showed a masked phonological priming effect when the letter positions in the prime were in the right order. In a third experiment, using a single-presentation lexical decision task, TL nonwords produced longer latencies than the orthographic and phonological controls, whereas there was only a small phonological effect restricted to the error data. These results suggest that TL similarity effects are orthographic--rather than phonological--in nature.     

Levels of representation in word processing

Abstract

Four experiments are described examining the effects of words frequency, orthographic structure, and letter spacing on a range of tasks designed to tap different levels of representation in word processing. In Experiment 1, the task was lexical decision. Effects of both frequency (high-frequency words were recognized faster than low-frequency words) and orthographic regularity (illegal non-words were rejected faster than legal non-words) were found. In Experiment 2 subjects had to detect a rotated letter within the letter strings. Effects of orthographic structure emerged, with a marked disadvantage for illegal non-words with respect to the other types of string. No difference was found among high-frequency words, lowfrequency words and legal non-words. In Experiment 3, subjects had to detect a letter elevated above the horizontal plan with respect to the rest of the string. Effects of both spatial arrangement of letters and number of letters were found (spaced strings were responded to less accurately than non-spaced strings and seven-letter extra-spaced strings were responded to slower than the other strings). Neither lexical nor orthograpic variables affected this task. In Experiment 4 subjects had to detect the presence of a bold segment contained in one of the letters in the strings. Performance was unaffected by both lexical and spatial variables. The pattern of results is discussed with reference to a multi-stage model of word recognition in which lexical and spatial variables affect processing at different stages. At a feature map level, in which features are extracted from the discontinuities of light intensities, processing is independent of both spatial and lexical factors. At a letter-shape map level, in which spatial relationships between features are coded, spacing between letters affects encoding. At a graphemic map level, in which letter identities and their relative positions within strings are coded, orthographic variables have an effect. Lexicality and frequency affect only subsequent stages of processing, when stored lexical information is retrieved (e.g. for lexical decision).     

The role of orthographic and phonological codes in the word and the pseudoword superiority effect: an analysis by means of multinomial processing tree models

Central to the current accounts of the word and the pseudoword superiority effect (WSE and PWSE, respectively) is the concept of a unitized code that is less susceptible to masking than single-letter codes. Current explanations of the WSE and PWSE assume that this unitized code is orthographic, explaining these phenomena by the assumption of dual read-out from unitized and single-letter codes. In this article, orthographic dual read-out models are compared with a phonological dual read-out model (which is based on the assumption that the 1st unitized code is phonological). From this phonological code, an orthographic code is derived, through either lexical access or assembly. Comparison of the orthographic and phonological dual read-out models was performed by formulating both models as multinomial processing tree models. From an application of these models to the data of 2 letter identification experiments, it was clear that the orthographic dual read-out models are insufficient as an explanation of the PWSE, whereas the phonological dual read-out model is sufficient.     

Do transposed-letter similarity effects occur at a prelexical phonological level?

Nonwords created by transposing two letters (e.g., RELOVUTION) are very effective at activating the lexical representation of their base words (Perea & Lupker, 2004). In the present study, we examined whether the nature of transposed-letter (TL) similarity effects was purely orthographic or whether it could also have a phonological component. Specifically, we examined transposed-letter similarity effects for nonwords created by transposing two nonadjacent letters (e.g., relovución–REVOLUCIÓN) in a masked form priming experiment using the lexical decision task (Experiment 1). The controls were (a) a pseudohomophone of the transposed-letter prime (relobución–REVOLUCIÓN; note that B and V are pronounced as /b/ in Spanish) or (b) an orthographic control (relodución–REVOLUCIÓN). Results showed a similar advantage of the TL nonword condition over the phonological and the orthographic control conditions. Experiment 2 showed a masked phonological priming effect when the letter positions in the prime were in the right order. In a third experiment, using a single-presentation lexical decision task, TL nonwords produced longer latencies than the orthographic and phonological controls, whereas there was only a small phonological effect restricted to the error data. These results suggest that TL similarity effects are orthographic—rather than phonological—in nature.     

Reading aloud pseudohomophones in Italian: Always an advantage

In the present article, the lexical contribution to nonword reading was evaluated using Italian pseudohomophones that contained atypical letters or letter sequences. Pseudohomophones were read faster than orthographically matched nonwords in both mixed (Experiment 1) and pure (Experiment 2) lists; in addition, a base-word frequency effect was obtained in both conditions. The same pseudohomophone advantage was observed when nonwords without atypical letter sequences were mixed in the experimental list (Experiment 3 ), and it disappeared only in lexical decision, in which pseudohomophones were rejected as quickly as control nonwords. The pattern of results was explained by assuming that, due to their orthographic properties, the Italian pseudohomophones did not benefit from an orthographic lexical contribution and were mainly processed through the interaction system between the sublexical mechanisms and the phonological output lexicon.     

The role of syllabic and orthographic properties of letter cues in solving word fragments

The present research examined the role of phonological and orthographic properties of cues in mediating the retrieval of words from the mental lexicon. The task required subjects to resolve fragmented words when provided with semantically related cues (e.g., spiteful:---DIC----). Phonological properties of the letter cues were manipulated such that the letters either corresponded to the syllables (e.g., DIC in vindictive) or nonsyllables (NDI) in the word. Orthographic properties of the letter cues were manipulated by selecting letter groups that either co-occurred frequently in the language or did not. In two experiments, results revealed little or no effect of the phonological variable (syllables) but a reliable effect of the orthographic variable (letter-cue frequency). Letter cues with a low frequency of co-occurrence in the language led to better completion of the fragmented words. We interpret these findings as support for models of lexical representation that are based on orthographic properties (e.g., Seidenberg & McClelland, 1989) rather than those based on phonological constraints.     

The oral and written side of word production in young and older adults: generation of lexical neighbors

The aim of the present study was to investigate the effects of aging on both spoken and written word production by using analogous tasks. To do so, a phonological neighbor generation task (Experiment 1) and an orthographic neighbor generation task (Experiment 2) were designed. In both tasks, young and older participants were given a word and had to generate as many words as they could think of by changing one phoneme in the target word (Experiment 1) or one letter in the target word (Experiment 2). The data of the two experiments were consistent, showing that the older adults generated fewer lexical neighbors and made more errors than the young adults. For both groups, the number of words produced, as well as their lexical frequency, decreased as a function of time. These data strongly support the assumption of a symmetrical age-related decline in the transmission of activation within the phonological and orthographic systems.     

On the nature of consonant/vowel differences in letter position coding: Evidence from developing and adult readers

In skilled adult readers, transposed‐letter effects (jugde ‐JUDGE ) are greater for consonant than for vowel transpositions. These differences are often attributed to phonological rather than orthographic processing. To examine this issue, we employed a scenario in which phonological involvement varies as a function of reading experience: A masked priming lexical decision task with 50‐ms primes in adult and developing readers. Indeed, masked phonological priming at this prime duration has been consistently reported in adults, but not in developing readers (Davis, Castles, & Iakovidis, 1998). Thus, if consonant/vowel asymmetries in letter position coding with adults are due to phonological influences, transposed‐letter priming should occur for both consonant and vowel transpositions in developing readers. Results with adults (Experiment 1) replicated the usual consonant/vowel asymmetry in transposed‐letter priming. In contrast, no signs of an asymmetry were found with developing readers (Experiments 2–3). However, Experiments 1–3 did not directly test the existence of phonological involvement. To study this question, Experiment 4 manipulated the phonological prime‐target relationship in developing readers. As expected, we found no signs of masked phonological priming. Thus, the present data favour an interpretation of the consonant/vowel dissociation in letter position coding as due to phonological rather than orthographic processing.     

On recognizing proper names: the orthographic cue hypothesis

Five experiments investigated the recognition of proper names and common nouns using the lexical decision paradigm. In Experiments 1-3 the case of the initial letter of written stimuli was systematically varied. An advantage was consistently found for proper names written with the first letter in capital. Crucially, response times to proper names with the first letter in lowercase and to common nouns irrespective of the case of the first letter did not differ from each other. No difference between proper names and common nouns emerged in Experiment 4 where the stimuli were presented auditorily, and in Experiment 5 where a visual lexical decision task was performed with illegal non-words. The pattern of results shows that the proper name advantage is orthographic in nature and rules out an account in terms of semantic, morphological or other lexical variables. A model is proposed in which information about the case of the first letter is specified in the abstract multidimensional orthographic representation mediating written word recognition.     

Basic processes in reading: can functional phonological recoding be blocked?

A widely held view is that phonological processing is always involved in lexical access from print, and is automatic in that it cannot be prevented. This claim was assessed in the context of a priming paradigm. In Experiment 1, repetition priming was observed for both pseudohomophone-word pairs (e.g., brane-brain) and morphologically related word pairs (e.g., marked-mark) in the context of lexical decision. In Experiment 2, subjects searched the prime for the presence of a target letter and then made a lexical decision to a subsequent letter string. Phonological priming from a pseudohomophone was eliminated following letter search of the prime, whereas morphological priming persisted. These results are inconsistent with the claim that a) lexical access from print requires preliminary phonological processing, and b) functional phonological processing cannot be blocked. They are, however, consistent with the conclusion that, for intact skilled readers, lexical access can be accomplished on the basis of orthographic processing alone. These results join a growing body of evidence supporting the claim that there exist numerous points in visual word recognition at which processing can be stopped.     

On visual access to letter case and lexical/semantic information

Four experiments were designed to investigate automatic processing of letter case and lexical/ semantic information under forward and backward masking conditions that disallowed a visible image. Stimulus displays were letter string pairs; the letter case for each pair matched or mismatched, and the relationship between the two strings within pairs varied. Experiment I required direct Same-Different responses to stimulus pairs, and the results indicate that tasks requiring direct responses to stimulus inputs cannot distinguish between conscious response biases and unconscious use of information. Experiments 2 and 3 employed an indirect index of automatic prerecognition analyses of verbal-linguistic parameters and showed that, with 30-msec pre- and postmasked presentations, letter case, orthographic regularity, and lexical/semantic information are all analyzed in unconscious operations. Experiment 4 demonstrated that, under the viewing conditions of Experiments 2 and 3, subjects had no awareness of the stimulus input.     

The primacyof visual information inthe analysis of letter strings

In Experiment 1, orthographic and phonetic information were separated by using artificial letters to represent English pseudowords and random letter strings. Subjects could learn to distinguish combinations of artificial letters on the basis of (1) orthographic, but not phonetic, information, (2) orthographic and phonetic information, (3) paired-associate verbal labels without orthographic information, and (4) neither orthographic nor phonetic information. By imposing a variety of response deadlines it appeared that subjects quickly exploited orthographic information without any contribution from phonetic correspondences. The only suggestion of a phonetic effect occurred in the absence of orthographic information and at longer latencies. Experiment 3 (using English letters) also suggested that phonetic information influenced the analysis of letter string pairs at only longer latencies, after visual analysis. Experiment 2 provided a demonstration that orthographic rules similar to those exploited in Experiment 1 were useful in visual discriminations regardless of the particular letter position affected by those rules. The results strain phonetic mediation models of performance in word-related tasks (e. g., Spoehr & Smith, 1975)and support models that emphasize visual analysis(Barron & Baron, 1977; Massaro, 1975; Pollatsek, Well, & Schindler, 1975).     

Deficits in lexical and semantic processing: implications for models of normal language

The investigation of language processing following brain damage may be used to constrain models of normal language processing. We review the literature on semantic and lexical processing deficits, focusing on issues of representation of semantic knowledge and the mechanisms of lexical access. The results broadly support a componential organization of lexical knowledge—the semantic component is independent of phonological and orthographic form knowledge, and the latter are independent of each other. Furthermore, the results do not support the hypothesis that word meaning is organized into modality-specific subcomponents. We also discuss converging evidence from functional imaging studies in relation to neuropsychological results.     

Visual and phonological codes in letter and word recognition: Evidence from incremental priming

Critical issues in letter and word priming were investigated using the novel incremental priming technique . This technique adds a parametric manipulation of prime duration (or prime intensity) to the traditional design of a fast masked priming study. By doing so, additional information on the time course and nature of priming effects can be obtained. In Experiment 1, cross-case letter priming (a-A) was investigated in both alphabetic decision (letter/non-letter classification) and letter naming. In Experiment 2, cross-case word priming was investigated in lexical decision and naming. Whereas letter priming in alphabetic decision was most strongly determined by visual overlap between prime and target, word priming in lexical decision was facilitated by both orthographic and phonological information. Orthographic activation was stronger and occurred earlier than phonological activation. In letter and word naming, in contrast, priming effects were most strongly determined by phonological/articulatory information. Differences and similarities between letter and word recognition are discussed in the light of the incremental priming data.     

Lexical and sublexical processes in the perception of transposed-letter anagrams

Evidence from priming and lexical decision tasks suggests that nonwords created by transposing adjacent letter pairs (TL nonwords) are very effective in activating lexical representations of their base words, because the process of orthographic matching tolerates minor changes in letter position. However, this account disregards the possible role of sublexical processing in reading. TL nonwords are perceptually ambiguous, with lexical and sublexical processing giving rise to conflicting interpretations. The consequences of this ambiguity were investigated in a lexical decision experiment with primes that were either high or low bigram frequency TL versions of target words. Priming effects were much larger for low BF primes (e.g., pucnh-PUNCH) than for high BF primes (e.g., panit-PAINT). This finding is interpreted as evidence that lexical activation can be inhibited by competing output resulting from sublexical processing of TL letter string. We conclude that phonological processing is an important determinant of responses to TL stimuli, and we consider how this interpretation might be accommodated within the dual-route cascaded (DRC) model of word recognition.     

Activation of multiple phoneme associates of graphemes in visual word recognition

One general issue in the domain of visual word recognition is to delineate the nature of readers' knowledge of the print-sound mapping. A more specific question is to determine whether multiple grapheme-phoneme associations are available and activated during the phonological transcoding of a letter string. Evidence for the activation of irregular associations during print-to-sound transcoding, independently from lexical influences, was assessed in a letter detection task by examining performance on target-absent pseudowords. We contrasted two types of pseudowords that could be considered homophone with a real word by application of either grapheme-phoneme correspondence rules or of multiple phonemic activation. Performance on both types of homophones was compared to nonhomophone control pseudowords, strictly equivalent in terms of orthographic similarity to the base words. The finding of a homophony disadvantage for the homophones by multiple activation was interpreted as evidence for multiple phonemic activation in the print-to-sound conversion system.