Nonword Processing Research Articles

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.

Effects of reading skill and CaSe MiXiNg on nonword reading in German

Many low‐skill readers have problems with visual word recognition. In particular, low‐skill readers show a substantial nonword reading deficit that is attributed to deficits in sub‐lexical processing. In this study, I examined whether the nonword deficits of German 14‐year‐old low‐skill readers were associated with inefficient use of multi‐letter information. In a lexical‐decision experiment, words and nonwords were presented in standard format and in MiXeD cAsE format which has been shown to be especially disrupting for sub‐lexical processing. When the stimuli were presented in standard format, low‐skill readers showed a substantial nonword reading deficit, that is they were generally slower than high‐skill readers, but had special problems with decoding nonwords. However, when stimuli were presented in MiXeD cAsE, low‐ and high‐skill readers showed equal impairments in nonword processing. This finding indicates that low‐skill readers do not use context‐sensitive multi‐letter rules during phonological assembly in normal reading.

Adult word recognition and visual sequential memory

Two experiments were conducted investigating the role of visual sequential memory skill in the word recognition efficiency of undergraduate university students. Word recognition was assessed in a lexical decision task using regularly and strangely spelt words, and nonwords that were either standard orthographically legal strings or items made from words with internal transposed letters. Symbol memory was evaluated in a recognition procedure in which sequences of three to five unfamiliar complex symbols were presented, each followed by a subsequent array containing the symbols either in the same order or with an order transposition. In Experiment 1, there was no independent contribution of symbol memory to either word or nonword processing independently of the ability to discriminate the symbols from one another. In Experiment 2, although symbol memory made a significant contribution to word recognition independently of symbol discrimination and letter identification for two conditions—long strangely spelt words and short transposed-letter items, the effects were extremely small. It was concluded that non-verbal visual sequential memory skill does not play a central role in underpinning efficiency of word recognition in experienced adult readers.

Speech perception and phonological short‐term memory capacity in language impairment: preliminary evidence from adolescents with specific language impairment (SLI) and autism spectrum disorders (ASD)

The cognitive bases of language impairment in specific language impairment (SLI) and autism spectrum disorders (ASD) were investigated in a novel non-word comparison task which manipulated phonological short-term memory (PSTM) and speech perception, both implicated in poor non-word repetition. This study aimed to investigate the contributions of PSTM and speech perception in non-word processing and whether individuals with SLI and ASD plus language impairment (ALI) show similar or different patterns of deficit in these cognitive processes. Three groups of adolescents (aged 14-17 years), 14 with SLI, 16 with ALI, and 17 age and non-verbal IQ matched typically developing (TD) controls, made speeded discriminations between non-word pairs. Stimuli varied in PSTM load (two- or four-syllables) and speech perception load (mismatches on a word-initial or word-medial segment). Reaction times showed effects of both non-word length and mismatch position and these factors interacted: four-syllable and word-initial mismatch stimuli resulted in the slowest decisions. Individuals with language impairment showed the same pattern of performance as those with typical development in the reaction time data. A marginal interaction between group and item length was driven by the SLI and ALI groups being less accurate with long items than short ones, a difference not found in the TD group. Non-word discrimination suggests that there are similarities and differences between adolescents with SLI and ALI and their TD peers. Reaction times appear to be affected by increasing PSTM and speech perception loads in a similar way. However, there was some, albeit weaker, evidence that adolescents with SLI and ALI are less accurate than TD individuals, with both showing an effect of PSTM load. This may indicate, at some level, the processing substrate supporting both PSTM and speech perception is intact in adolescents with SLI and ALI, but also in both there may be impaired access to PSTM resources.

Phonemic Awareness in Chinese L1 Readers of English: Not Simply an Effect of Orthography

The current study investigates the phonemic awareness and nonword processing of English as a foreign language students from Hong Kong and Mainland China, with reference to factors considered the main facilitators of phonemic awareness: written language experience, spoken language experience, and metalinguistic training. The Mainland Chinese students were literate in Pinyin, an alphabetic representation of Chinese, and were first language (L1) speakers of Mandarin. Half of the Mainland Chinese students had also been exposed to the International Phonetic Alphabet (IPA) in their second language (L2) reading education. The Hong Kong students were not Pinyin literate and spoke Cantonese. The Mainland Chinese IPA‐trained participants performed better than both the Hong Kong participants and the Mainland Chinese non‐IPA‐trained participants in initial phoneme deletion. However, both Mainland Chinese groups outperformed the Hong Kong group on a phoneme‐grapheme nonword matching task. This pattern of results suggests that phonemic awareness in Chinese L1 readers of English is not simply an effect of orthography, but rather, may be interpreted in terms of access to explicit demonstration of phonemes. Further, tests carried out in L2 which are intended to assess metalinguistic awareness may be susceptible to artefacts introduced by the participants' L1 spoken language.

Grammaticality and Ungrammaticality in Phonology

In this article, I make two theoretical claims. (i) For some form to be grammatical in language L , it is not necessary that the form satisfy all constraints that are active in L ; that is, even grammatical forms can violate constraints. (ii) There are degrees of ungrammaticality; that is, not all ungrammatical forms are equally ungrammatical. I first show that these claims follow straightforwardly from the basic architecture of an optimality-theoretic grammar. I then show that the surface sound patterns used most widely in formal phonology cannot be used to test the truth of these two claims, but argue that results from speech processing experiments can. Finally, I discuss three experiments on the processing of nonwords of the form [stVt], [skVk], and [spVp] in English that were designed to test these claims, and show that both claims are confirmed by the results of the experiments.

Conflict monitoring engages the mediofrontal cortex during nonword processing

The current study investigated the role played by conflict monitoring in a lexical-decision task involving competing word representations, using event-related potentials. We extended the multiple read-out model (Grainger and Jacobs, 1996), a connectionist model of word recognition, to quantify conflict by means of Hopfield Energy, which is defined as the sum of the products of all orthographic word node pair activations within the artificial mental lexicon of this model. With increasing conflict levels in nonwords, a late negativity increased in amplitude (400-600 ms) accompanied by activation of the anterior cingulate cortex and the medial frontal gyrus. The simulated conflict predicted the amplitudes associated with this mediofrontal conflict-monitoring network on an item level, and is consistent with the conflict-monitoring theory.

Inhibition and facilitation in visual word recognition: Prefrontal contribution to the orthographic neighborhood size effect

The recognition of words is a central component of language processing. A major role for visual word recognition has been attributed to the orthographic neighbors of a word, i.e., words that are orthographically similar to a target word. It has been demonstrated that the presence of orthographic neighbors facilitates the recognition of words, but hinders the rejection of nonwords. It is therefore assumed that representations of orthographic neighbors are at least partially activated during word recognition, and that they influence word recognition depending on the specific task context. In the present study, we used fMRI to examine the neural bases of the effect of orthographic neighborhood size on speeded lexical decisions to words and nonwords. Our results demonstrate lexicality×neighborhood size interactions in mid-dorsolateral and medial prefrontal cortex, suggesting the involvement of a domain-general, extra-lexical process for orthographic neighborhood effects on word and nonword processing. This result challenges computational models that offer purely lexical accounts of the orthographic neighborhood effect and suggests an important role for executive control functions during visual word recognition.

Lexical inhibition and sublexical facilitation are surprisingly long lasting.

When a listener hears a word (beef), current theories of spoken word recognition posit the activation of both lexical (beef) and sublexical (/b/, /i/, /f/) representations. No lexical representation can be settled on for an unfamiliar utterance (peef). The authors examined the perception of nonwords (peef) as a function of words or nonwords heard 10-20 min earlier. In lexical decision, nonword recognition responses were delayed if a similar word had been heard earlier. In contrast, nonword processing was facilitated by the earlier presentation of a similar nonword (baff-paff). This pattern was observed for both word-initial (beef-peef), and word-final (job-jop) deviation. With the word-in-noise task, real word primes (beef) increased real word intrusions for the target nonword (peef), but only consonant-vowel (CV) or vowel-consonant (VC) intrusions were increased with similar pseudoword primes (baff-paff). The results across tasks and experiments support both a lexical neighborhood view of activation and sublexical representations based on chunks larger than individual phonemes (CV or VC sequences).

Becoming a fluent and automatic reader in the early elementary school years

The goals of this study were to (a) develop an empirically based model regarding the development of fluent and automatic reading in the early elementary school years and (b) determine whether fluent text-reading skills provided benefits for reading comprehension beyond those accounted for by fluent word decoding. First-, second-, and third-grade children completed a series of reading tasks targeting word and nonword processing, text reading, spelling knowledge, autonomous reading, and reading comprehension. Structural equation modeling was carried out to evaluate how these skills operated together to produce fluent text reading and good comprehension. Evidence supported a simple reading fluency model for the early elementary school years suggesting that fluent word and text reading operate together with autonomous reading to produce good comprehension.

The role of phonological storage deficits in specific language impairment: A reconsideration

In her Keynote Article, Gathercole (2006) presents a theoretical framework intended to account for evidence regarding the relation between nonword repetition and word learning. This framework stems from an impressive amount and breadth of research on this topic, including findings from adults and children with typical language abilities as well as language learning disorders. In this commentary we focus on claims relative to the interpretation of nonword repetition deficits in children with specific language impairment (SLI). One issue we address pertains to the nature of the proposed model of nonword processing and word learning, particularly with respect to phonological sensitivity and storage. The second issue we address relates to the assumption that a phonological storage deficit, although not sufficient, is necessary for SLI.

The processing of lexical stress during visual word recognition: Typicality effects and orthographic correlates

Many studies that have examined reading at the single-word level have been restricted to the processing of monosyllabic stimuli, and, as a result, lexical stress has not been widely investigated. In the experiments reported here, we used disyllabic words and nonwords to investigate the processing of lexical stress during visual word recognition. In Experiments 1 and 2, we found an effect of stress typicality in naming and lexical decision. Typically stressed words (trochaic nouns and iambic verbs) elicited fewer errors than atypically stressed words (iambic nouns and trochaic verbs). In Experiment 3, we carried out an analysis of 340 word endings and found clear orthographic correlates of both grammatical category and lexical stress in word endings. In Experiment 4, we demonstrated that readers are sensitive to these cues in their processing of nonwords during two tasks: sentence construction and stress assignment. We discuss the implications of these findings with regard to psycholinguistic models of single-word reading.

Neighbourhood density effects in auditory nonword processing in aphasia

Utrecht institute of Linguistics OTS, Utrecht University, The NetherlandsAccepted 8 July 2005Available online 29 August 2005IntroductionThe question how prior knowledge of words affects processing ofnonwords is important with respect to the study of lexical access andlexical competition. According to the Neighbourhood Activationmodel (Luce & Pisoni, 1998), the auditory presentation of a word ornonword yields automatic activation of all words in the mental lexiconthat sound similar. Experimental results with unimpaired listeners ona lexical decision task showed that nonwords with dense lexicalneighbourhoods led to slower responses and lower accuracy rates thannonwords with sparse neighbourhoods: the nonword must be com-pared against existing entries, which takes more time when there aremore neighbours.The present study examined these effects of neighbourhood densityon auditory lexical decision performance for nonwords with threegroups of listeners: Broca’s aphasic patients, Wernicke’s aphasic pa-tients, and age-matched nonbrain-damaged participants.Broca’s and Wernicke’s aphasic patients have been shown to bedifferentially impaired in lexical access: whereas a number of auditorylexical access studies have shown that lexical activation levels arereduced in Broca’s aphasic patients (Aydelott Utman, Blumstein, S Milberg, Blumstein, & Dworetzky, 1988), these levelsare increased in Wernicke’s aphasic patients (Milberg et al., 1988)who may thus be impaired in selecting one winning word candidateamong the activated candidates. In unimpaired speech processing,words are activated relative to the overall goodness of fit with theauditory input. In Wernicke’s aphasia, less appropriate acousticforms seem to be able to activate lexical items almost to the sameextent as exact-match items. Broca’s aphasics, on the other hand, didnot activate words such as coat when presented with an acousticallydistorted form (VOT-manipulated c*oat) if there was a lexical com-petitor (such as goat: cf. Aydelott Utman et al., 2001). If overalllexical activation is reduced for Broca’s aphasic patients, the differ-ence between nonwords from dense neighbourhoods and from sparseneighbourhoods may be reduced as well. For Wernicke’s aphasicpatients with increased lexical activation levels, however, neighbour-hood density may exert a bigger influence.Thus, based on the assumption that the magnitude of the neigh-bourhood density effect is influenced by the overall level of lexicalactivation, smaller neighbourhood density effects on lexical decisionperformance were expected for Broca’s aphasic patients, whereas en-larged density effects were expected for Wernicke’s aphasic patients,compared to age-matched control participants.MethodEighty monosyllabic Dutch CVC nonwords were constructed: 40with a high number of real-word neighbours (16 or more neighbours)and 40 with a low number of real-word neighbours (10 or less neigh-bours). In addition, 80 Dutch monosyllabic real words were chosen tobalance for lexical status. The words and nonwords were spoken inisolation by a male native speaker of Dutch. An experimental softwareprogramme randomised the order of presentation of the words andnonwords for each participant. Participants were presented with thematerials via headphones. They were asked to provide a lexical deci-sion response after each auditory presentationby pressing either of twobuttons (labelled YES and NO) on a response box as fast and accu-rately as possible.Participants included 8 patients classified as Broca’s aphasic pa-tients (on the basis of the Dutch version of the Aachen Aphasia Test),five patients classified as Wernicke’s aphasic patients, and 11 age-matched nonbrain-damaged control participants.ResultsLexical decision times were initially measured from target onset.However, because Low Density nonwords were generally longer thanHigh Density nonwords, each item’s duration was subtracted from thelexical decision time. Subsequently, the mean item duration of 606 mswas added again to avoid negative response times. The obtained re-sponse times (collapsed over correct NO responses) and accuracypercentages are presented in Fig. 1.Analyses of accuracy rates showed a main effect of Density:accuracy scores were significantly lower for the High Densitynonwords than for the Low Density nonwords (F (1, 21) = 6.30,Brain and Language 95 (2005) 24–25www.elsevier.com/locate/b&lE-mail address: esther.janse@let.uu.nl.0093-934X/$ - see front matter 2005 Elsevier Inc. All rights reserved.doi:10.1016/j.bandl.2005.07.027

A quantitative and qualitative assessment of verbal short-term memory and phonological processing in 8-year-olds with a history of repetitive otitis media

Language outcome in children experiencing fluctuant hearing loss due to otitis media (OME) remains highly equivocal. In the current study, we assessed performance on highly sensitive verbal short-term memory (STM), new word learning and phonological processing tasks in 8-year-old children who had suffered from recurrent OME before the age of 3. Relative to a control group with no history of OME, we observed strictly normal performance for different STM and new word learning tasks. Performance on these tasks was also normally influenced by phonotactic, lexical and semantic variables. However, at the level of phonological processing, a small but significant decrease of performance was found in a speeded nonword identification task and a rhyme judgment task. The results of this study suggest that outcome of OME is characterized by subtle impairments at the level of perceptual-phonological analysis, but there is no significant impact on verbal STM and new word learning abilities. Learning outcomes: As a result of this activity, the participant will be able to (1) explain the outcome of recurrent OME before age 3 on later language and verbal STM development, (2) be aware of the complex relationships that link language development and verbal STM, (3) explain how fluctuant hearing loss during infancy and early childhood could affect verbal STM development and learning capacity for new phonological information, (4) describe different verbal STM measures that distinguish retention capacities for phonological and lexico-semantic information, and (5) explain the influence of phonotactic frequency on nonword processing in language and verbal STM tasks.

Processing of Japanese morphogram and syllabogram in the left basal temporal area: electrical cortical stimulation studies

Language functions in the left basal temporal area (LBTA) were investigated using electrical cortical stimulation during functional mapping in six Japanese patients with refractory epilepsy. This study provides the first direct evidence that kana (Japanese syllabogram) is processed in the LBTA. Electrical stimulation of some areas within LBTA induced disturbance in overt reading of kana words only in the first trials, with no errors in the subsequent trials. By contrast, stimulation of the same area caused obvious disturbance in kana non-word reading in all trials. Since a kana word carries both meaning and sound while a kana non-word carries only sounds of a letter string, the contrasting results of partial and complete disturbance imply a possibility that there are two distinct pathways for kana reading: one dealing with both phonological and semantic aspects of the words and the other dealing only with phonological aspect. Kanji words (Japanese morphogram) and objects/pictures were found to be processed in an area different from the area for the kana non-word processing. Furthermore, the present study also identified the common area for processing kanji reading and object/picture naming. There were no errors in matching pictures with kanji words, indicating that concepts of pictures and meanings of kanji words were not interfered by the electrical stimulation of that area. The new insight provides a clue for partial description of processing pathways for language-related visual information in LBTA. Three types of information (morphological, phonological, and semantic) are conveyed together at some stages and are separated into different routes at some other stages.

Increases in phonotactic probability facilitate spoken nonword repetition

Lipinski and Gupta (2005) report the results of 12 experiments and numerous analyses that attempted to examine further the effects of phonotactic probability originally reported in Vitevitch and Luce (1998, and further explored in Vitevitch & Luce 1999). They suggested that Vitevitch and Luce’s results were due to differences in the duration of the stimuli rather than to differences in phonotactic probability. The present report describes the results from another nonword naming experiment—employing a new set of duration-matched stimuli—that demonstrate a facilitative effect of phonotactic probability above and beyond that of stimulus duration. The current results provide support for Vitevitch and Luce’s original claims. Possible sources of the discrepancies between Lipinski and Gupta’s data and those in the present report are discussed. Although many factors may mediate the facilitative effect of phonotactic probability on nonword repetition latency, we believe there is still sufficient evidence to support the claim that increases in phonotactic probability for nonwords are associated with decreases in nonword processing times, even when stimulus duration is controlled.

Eye-Fixation-Related Potentials: Insight into Parafoveal Processing

Abstract. This paper presents a new methodology for studying cognition, which combines eye movements (EM) and event-related potentials (ERP) to track the cognitive processes that occur during a single eye fixation. This technique, called eye-fixation-related potentials (EFRP), has the advantage of coupling accurate time measures from ERPs and the location of the eye on the stimulus, so it can be used to disentangle perceptual/attentional/cognitive factors affecting reading. We tested this new technique to describe the controversial parafoveal-on-foveal effects on reading, which concern the question of whether two consecutive words are processed in parallel or sequentially. The experiment directly addressed this question by looking at whether semantic relatedness on a target word in a reading-like situation might affect the processing of a prime word. Three pair-word conditions were tested: A semantically associated target word (horse-mare), a semantically nonassociated target word (horse-table) and a nonword (horse-twsui); EFRPs were compared for all conditions. The results revealed that early ERP components differentiated word and nonword processing within 119 ms postfixation (N1 component). Moreover, the amplitude of the right centrofrontal P140 varied as a function of word type, being larger in response to nonassociated words than to nonwords. This component might index a spatial attention shift to the target word and its visual categorization, being highly sensitive to orthographic regularity and “ill-formedness” of words. The P2 consecutive component (peaking at 215 ms) differentiated associated words and nonassociated words, which can account for the semantic parafoveal effect. The EFRP technique, therefore, appears to be fruitful for establishing a time-line of early cognitive processes during reading.

The interaction between vocabulary size and phonotactic probability effects on children's production accuracy and fluency in nonword repetition.

Adults' performance on a variety of tasks suggests that phonological processing of nonwords is grounded in generalizations about sublexical patterns over all known words. A small body of research suggests that children's phonological acquisition is similarly based on generalizations over the lexicon. To test this account, production accuracy and fluency were examined in nonword repetitions by 104 children and 22 adults. Stimuli were 22 pairs of nonwords, in which one nonword contained a low-frequency or unattested two-phoneme sequence and the other contained a high-frequency sequence. For a subset of these nonword pairs, segment durations were measured. The same sound was produced with a longer duration (less fluently) when it appeared in a low-frequency sequence, as compared to a high-frequency sequence. Low-frequency sequences were also repeated with lower accuracy than high-frequency sequences. Moreover, children with smaller vocabularies showed a larger influence of frequency on accuracy than children with larger vocabularies. Taken together, these results provide support for a model of phonological acquisition in which knowledge of sublexical units emerges from generalizations made over lexical items.

The processing of pseudohomophones by adults with a history of developmental language disabilities

Psuedohomophones are nonwords that sound like real words (e.g., BRANE). These items were used to gauge phonological access in adults who have experienced developmental language processing deficits (DLD). The standard effect for these items in lexical decision is an increase in response times over nonpseudohomophone nonwords. This disadvantage reflects phonological processing. In our first experiment the DLD group did not produce this pseudohomophone effect whereas in a second experiment they showed semantic priming effects when pseudohomophones were used as primes in lexical decision. The results therefore indicate that phonological processing of nonwords by adults with DLD can be uncovered under certain carefully controlled experimental conditions.

Neural correlates of lexical access during visual word recognition.

People can discriminate real words from nonwords even when the latter are orthographically and phonologically word-like, presumably because words activate specific lexical and/or semantic information. We investigated the neural correlates of this identification process using event-related functional magnetic resonance imaging (fMRI). Participants performed a visual lexical decision task under conditions that encouraged specific word identification: Nonwords were matched to words on orthographic and phonologic characteristics, and accuracy was emphasized over speed. To identify neural responses associated with activation of nonsemantic lexical information, processing of words and nonwords with many lexical neighbors was contrasted with processing of items with no neighbors. The fMRI data showed robust differences in activation by words and word-like nonwords, with stronger word activation occurring in a distributed, left hemisphere network previously associated with semantic processing, and stronger nonword activation occurring in a posterior inferior frontal area previously associated with grapheme-to-phoneme mapping. Contrary to lexicon-based models of word recognition, there were no brain areas in which activation increased with neighborhood size. For words, activation in the left prefrontal, angular gyrus, and ventrolateral temporal areas was stronger for items without neighbors, probably because accurate responses to these items were more dependent on activation of semantic information. The results show neural correlates of access to specific word information. The absence of facilitatory lexical neighborhood effects on activation in these brain regions argues for an interpretation in terms of semantic access. Because subjects performed the same task throughout, the results are unlikely to be due to task-specific attentional, strategic, or expectancy effects.