The influence of phonological neighborhood on visual word perception

In the research reported here, we investigated the influence of phonological neighborhood density on the processing of words in the visual lexical decision task. The results of the first experiment revealed that words with large phonological neighborhoods were verified more rapidly than words with small phonological neighborhoods. In the second experiment, we replicated this effect with a more tightly controlled set of stimuli. These results demonstrate the importance of phonological codes when processing visually presented letter strings. We relate this research to previous results on semantic and orthographic neighborhoods and discuss the results within the context of a model in which lexical decisions are based on stimulus familiarity.     

Familiarity affects visual processing of words.

While previous research has demonstrated that words can be processed more rapidly and/or more accurately than random strings of letters, it has not been convincingly demonstrated that the superior processing of words is a visual effect. In the present experiment, the cases of letters were manipulated in letter strings that were to be compared on the basis of physical identity. Mean response time was shorter for words than for nonwords even for pairs of letter strings that differed only in case (e.g., site-site). This finding implies that the advantage of words over nonwords (the familiarity effect) typically observed in the simultaneous matching task is not due solely to comparison of either the word names or the letter names and, thus, that at least part of the familiarity effect must be due to more rapid formation and/or comparison of visual representations of the two letter strings when they are words. Further analysis failed to reveal a significant involvement of phonemic or lexical codes in the comparison judgments.     

The effects of graphemic,phonetic, and semantic relationships on access to lexical structures

The question of whether or not lexical information is accessed directly from a visual code or by a process of phonetic mediation was investigated in three lexical decision experiments. Phonetic similarity influenced decisions about visually presented words only when they were to be discriminated from orthographically regular nonwords. When consonant strings or random letter strings were used as nonwords, phonetic similarity effects were absent, and graphemic similarity exerted a powerful effect while evidence of semantic priming was found. This pattern was interpreted as evidence of direct lexical access, which is probably the normal processing mode for skilled readers. Phonetic coding, when it occurs, may be a storage strategy rather than a part of the addressing chain for lexical structures.     

What the reader’s eye tells the mind’s ear: Silent reading activates inner speech

Although copious research has investigated the role of phonology in reading, little research has investigated the precise nature of the entailed speech representations. The present study examined the similarity of “inner speech” in reading to overt speech. Two lexical decision experiments (in which participants gave speeded word/nonword classifications to letter strings) assessed the effects of implicit variations in vowel and word-initial consonant length. Responses were generally slower for phonetically long stimuli than for phonetically short stimuli, despite equal orthographic lengths. Moreover, the phonetic length effects displayed principled interactions with common factors known to affect lexical decisions, such as word frequency and the similarity of words to nonwords. Both phonetic length effects were stronger among slower readers. The data suggest that acoustic representations activated in silent reading are best characterized as inner speech rather than as abstract phonological codes.     

The acronym superiority effect

The visual world is replete with noisy, continuous, perceptually variant linguistic information, which fluent readers rapidly translate from percept to meaning. What are the properties the language comprehension system uses as cues to initiate lexical/semantic access in response to some, but not all, orthographic strings? In the behavioral, electromagnetic, and neuropsychological literatures, orthographic regularity and familiarity have been identified as critical factors. Here, we present a study in the Reicher—Wheeler tradition that manipulates these two properties independently through the use of four stimulus categories: familiar and orthographically regular words, unfamiliar but regular pseudowords, unfamiliar illegal strings, and familiar but orthographically illegal acronyms. We find that, like letters in words and pseudowords, letters in acronyms enjoy an identification benefit relative to similarly illegal, but unfamiliar strings. This supports theories of visual word recognition in which familiarity, rather than orthographic regularity, plays a critical role in gating processing.     

Processing lexical ambiguity and visual word recognition in a deep orthography

We investigated the effect of semantic and phonemic ambiguity on lexical decision and naming performance in the deep Hebrew orthography. Experiment 1 revealed that lexical decisions for ambiguous consonant strings are faster than those for any of the high- or low-frequency voweled alternative meanings of the same strings. These results suggested that lexical decisions for phonemically and semantically ambiguous Hebrew consonant strings are based on the ambiguous orthographic information. However, a significant frequency effect for both ambiguous and unambiguous words suggested that if vowels are present, subjects do not ignore them completely while making lexical decisions. Experiment 2 revealed that naming low-frequency voweled alternatives of ambiguous strings took significantly longer than naming the high-frequency alternatives or the unvoweled strings without a significant difference between the latter two string types. Voweled and unvoweled unambiguous strings, however, were named equally fast. We propose that semantic and phonological disambiguation of unvoweled words in Hebrew is achieved in parallel to the lexical decision, but is not required by it. Naming Hebrew words usually requires a readout of phonemic information from the lexicon.     

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).     

The effects of lexical and semantic information on same-different visual comparison of words

Previous research has indicated that phonemic and orthographic factors cannot account for the fact that words (clear/clear) are responded to more rapidly than orthographically legal nonwords (creal/creal) in a same-different visual comparison task. However, the role of semantic and lexical factors is less certain. The effects of semantic similarity on both same and different judgments were evaluated in several experiments. In the first experiment, subjects were not any slower on semantically related (rang/rung) than on unrelated (rang/rank) different judgments even with a 3,000-msec interval between the first and second word. In Experiment 2, subjects based their judgments on whether or not the first letter of each word was visually identical. Same judgments were not any faster for semantically related than unrelated items even though other evidence indicated that subjects were processing the whole word and not just the first letter. Experiment 3 showed that the word/orthographically legal nonword difference could be replicated with the first-letter visual comparison task employed in Experiment 2. These and related results were discussed with reference to the idea that the word/orthographically legal nonword difference is due to the facilitating effects of a lexical entry upon the encoding, but not the comparison of an item.     

Subcategorical phonetic mismatches and lexical access.

The place of phonetic analysis in the perception of words is unclear. While some theories assume fully specified phonemic strings as input, other theories assume that little analysis occurs. An earlier experiment by Streeter and Nigro (1979) produced evidence, based on auditorily presented words with misleading acoustic cues, that lexical decisions were based on mostly unanalyzed patterns, since word judgments were delayed by misleading information whereas nonword judgments were not. The present studies expand that work to a different set of cues, and to cases in which the overriding cue came first. An additional task, auditory naming, was used to examine the effects when the decision stage is less demanding. For the lexical decision task, misleading information slowed the responses, for both words and nonwords. In the auditory naming task, only the slower responses were affected. These results suggest that phonetic conflicts are resolved prior to lexical access.     

Subcategorical phonetic mismatches and lexical access

The place of phonetic analysis in the perception of words is unclear. While some theories assume fully specified phonemic strings as input, other theories assume that little analysis occurs. An earlier experiment by Streeter and Nigro (1979) produced evidence, based on auditorily presented words with misleading acoustic cues, that lexical decisions were based on mostly unanalyzed patterns, since word judgments were delayed by misleading information whereas non word judgments were not. The present studies expand that work to a different set of cues, and to cases in which the overriding cue came first. An additional task, auditory naming, was used to examine the effects when the decision stage is less demanding. For the lexical decision task, misleading information slowed the responses, for both words and nonwords. In the auditory naming task, only the slower responses were affected. These results suggest that phonetic conflicts are resolved prior to lexical access.     

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).     

Access to identity-specific semantic codes from familiar faces

Information codes that can specify the surface form of a face are contrasted with semantic codes describing the properties of the person to whom the face belongs. Identity-specific semantic codes that specify characteristics of familiar people based on personal knowledge are in turn contrasted with the visually derived semantic codes and expression codes that can be derived even from unfamiliar faces. The idea that familiarity decisions (i.e., categorizing faces as belonging to known or unknown people) can be based on surface form, whereas certain types of semantic decision demand additional access to identity-specific semantic codes was investigated in four experiments. Experiments 1 and 3 showed that decisions based on identity-specific semantic codes (semantic decisions) usually take longer than decisions that do not demand access to an identity-specific semantic code (familiarity decisions). Experiment 2 showed that the use of familiar faces drawn from consistent or mixed categories affected reaction times for semantic decisions but not for familiarity decisions. Experiment 4 showed that semantic decisions to faces are taken more quickly (primed) when the faces have been recently seen, whereas there is no differential effect on semantic decisions to faces from previous semantic decisions involving the same people's names. These findings are consistent with the view that identity-specific semantic codes are accessed via face recognition units, and that outputs from face recognition units (which respond to the face's surface form) can be used as the basis for familiarity decisions.     

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 neurobiology of adaptive learning in reading: A contrast of different training conditions

fMRI was used to investigate the separate influences of orthographic, phonological, and semantic processing on the ability to learn new words and the cortical circuitry recruited to subsequently read those words. In a behavioral session, subjects acquired familiarity for three sets of pseudowords, attending to orthographic, phonological, or (learned) semantic features. Transfer effects were measured in an event-related fMRI session as the subjects named trained pseudowords, untrained pseudowords, and real words. Behaviorally, phonological and semantic training resulted in better learning than did orthographic training. Neurobiologically, orthographic training did not modulate activation in the main reading regions. Phonological and semantic training yielded equivalent behavioral facilitation but distinct functional activation patterns, suggesting that the learning resulting from these two training conditions was driven by different underlying processes. The findings indicate that the putative ventral visual word form area is sensitive to the phonological structure of words, with phonologically analytic processing contributing to the specialization of this region.     

Phonological and semantic information in adults' orthographic learning

A training paradigm was used to assess the early stages of the acquisition of novel letter strings in adults. Provision of either phonological or semantic information during training improved spelling recognition (Experiment 1). Manipulation of the processing required during training (phonological, semantic, or both) produced no consistent effects on spelling when both phonology and meaning were provided (Experiment 2). An advantage of phonological over orthographic processing on spelling recognition and cued recall was found when meaning was provided during training but phonology was not (Experiment 3). The experiments support the role of phonological information in early learning of orthography, but additional research is required to clarify when and how semantic information supports the formation of new orthographic representations.     

Adaptive specialization in position encoding while learning to read

The present experiments focused on how orthographic processing develops during reading acquisition. Specifically, a large, cross‐sectional sample of children from grade 2 to grade 4 was exposed to pairs of words, pseudowords, digit strings, and pseudo‐letter (Armenian) strings while their sensitivity to transpositions (T) and substitutions (S) of internal characters was investigated in a perceptual matching task. The results showed that the development of identity and position decoding diverged between the four stimulus categories. Most importantly, sensitivity improved with longer exposure to formal education and higher reading level to both S and T pairs for digit strings, but only to S pairs for words and pseudowords. The results were successfully reproduced in two small independent samples. We propose a general framework, the Adaptive Specialization Hypothesis, to accommodate the results. According to this hypothesis, the transposed‐letter effect is not a hard‐wired feature of the orthographic processing system but an adaptive response of the developing orthographic system to the constraints of lexical access in several orthographies.     

Lexical processes and eye movements in neglect dyslexia

Neglect dyslexia is a disturbance in the allocation of spatial attention over a letter string following unilateral brain damage. Patients with this condition may fail to read letters on the contralesional side of an orthographic string. In some of these cases, reading is better with words than with non-words. This word superiority effect has received a variety of explanations that differ, among other things, with regard to the spatial distribution of attention across the letter string during reading. The primary goal of the present study was to explore the interaction between attention and lexical processes by recording eye movements in a patient (F.C.) with severe left neglect dyslexia who was required to read isolated word and non-word stimuli of various length. F.C.'s ocular exploration of orthographic stimuli was highly sensitive to the lexical status of the letter string. We found that: (1) the location to which F.C. directed his initial saccade (obtained approximately 230 ms post-stimulus onset) differed between word and non-word stimuli; (2) the patient spent a greater amount of time fixating the contralesional side of word than non-word strings. Moreover, we also found that F.C. failed to identify the left letters of a string despite having fixated them, thus showing a clear dissociation between eye movement responses and conscious access to orthographic stimuli. Our data suggest the existence of multiple interactions between lexical, attentional and eye movement systems that occur from very initial stages of visual word recognition.     

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.     

The effect of orthographic structure and lexical meaning on “same-different” judgments

Pairs of high frequency English words, orthographically acceptable pseudo-words, and non-word letter strings were presented in a “same”-“different” task. The mean reaction times for “same” judgments were ordered; real words were faster than pseudo-words, and pseudo-words were faster than non-words. The RTs for the “different”, judgments showed no differences among the three types of words, except in the first two days of practice in a blocked presentation condition when the difference between the real words and non-words was marginally significant. These and other results suggest that “same” judgments are based upon a comparison process which efficiently uses higher order semantic and orthographic information in words, whereas “different” judgments are based upon comparison process which performs a self-terminating search of the graphemic information in words. The results were also discussed with reference to hierarchical models of word perception and reading.     

Letter detection: A window to unitization and other cognitive processes in reading text

Experiments are reviewed that use the letter-detection task, in which subjects read text and circle target letters. Evidence is provided that the letter-detection task reveals the processing units used in reading text and is influenced as well by visual, phonetic, and a combination of semantic and syntactic factors. Specifically, it is shown that circling a target letter in a word depends on the familiarity of the word’s visual configuration, the location of the word in the reader’s visual field, the phonetic representation of the letter in the word, and a combination of the word’s meaning and its grammatical function.