Visual Lexical Decision Task Research Articles

What’s in a word? A parametric study of semantic influences on visual word recognition

To what extent does semantic information play a functional role in visual word recognition? Theories of word recognition vary in the importance assigned to semantic information in visual lexical decision, with past research suggesting that the nature of the foils is a crucial determinant of semantic reliance. Here, we explored the conditions under which semantic variables influence lexical decision. Normal readers performed visual lexical decision tasks in which imageability and semantic priming were manipulated, with nonword foils varying systematically in their orthographic and phonological similarity to the real words. The effects of imageability and semantic priming increased in magnitude as nonword foils became progressively more wordlike. These findings provide a clear illustration of the flexible use of semantic information to support normal visual word recognition.

Evidence for Early Morphological Decomposition: Combining Masked Priming with Magnetoencephalography

Are words stored as morphologically structured representations? If so, when during word recognition are morphological pieces accessed? Recent masked priming studies support models that assume early decomposition of (potentially) morphologically complex words. The electrophysiological evidence, however, is inconsistent. We combined masked morphological priming with magneto-encephalography (MEG), a technique particularly adept at indexing processes involved in lexical access. The latency of an MEG component peaking, on average, 220 msec post-onset of the target in left occipito-temporal brain regions was found to be sensitive to the morphological prime-target relationship under masked priming conditions in a visual lexical decision task. Shorter latencies for related than unrelated conditions were observed both for semantically transparent (cleaner-CLEAN) and opaque (corner-CORN) prime-target pairs, but not for prime-target pairs with only an orthographic relationship (brothel-BROTH). These effects are likely to reflect a prelexical level of processing where form-based representations of stems and affixes are represented and are in contrast to models positing no morphological structure in lexical representations. Moreover, we present data regarding the transitional probability from stem to affix in a post hoc comparison, which suggests that this factor may modulate early morphological decomposition, particularly for opaque words. The timing of a robust MEG component sensitive to the morphological relatedness of prime-target pairs can be used to further understand the neural substrates and the time course of lexical processing.

Word or Word-like? Dissociating Orthographic Typicality from Lexicality in the Left Occipito-temporal Cortex

Prior lesion and functional imaging studies have highlighted the importance of the left ventral occipito-temporal (LvOT) cortex for visual word recognition. Within this area, there is a posterior-anterior hierarchy of subregions that are specialized for different stages of orthographic processing. The aim of the present fMRI study was to dissociate the effects of subword orthographic typicality (e.g., cider [high] vs. cynic [low]) from the effect of lexicality (e.g., pollen [word] vs. pillen [pseudoword]). We therefore orthogonally manipulated the orthographic typicality of written words and pseudowords (nonwords and pseudohomophones) in a visual lexical decision task. Consistent with previous studies, we identified greater activation for pseudowords than words (i.e., an effect of lexicality) in posterior LvOT cortex. In addition, we revealed higher activation for atypical than typical strings, irrespective of lexicality, in a left inferior occipital region that is posterior to LvOT cortex. When lexical decisions were made more difficult in the context of pseudohomophone foils, left anterior temporal activation also increased for atypical relative to typical strings. The latter finding agrees with the behavior of patients with progressive anterior temporal lobe degeneration, who have particular difficulty recognizing words with atypical orthography. The most novel outcome of this study is that, within a distributed network of regions supporting orthographic processing, we have identified a left inferior occipital region that is particularly sensitive to the typicality of subword orthographic patterns.

The effects of inter-stimulus interval and prime modality in a semantic priming task

Background: Semantic priming studies are employed in order to examine how various semantic contexts can influence visual word recognition processes. Although research has shown numerous factors can have an influence on the magnitude of the semantic priming effects found in lexical decision tasks, the majority of these factors have been related to the prime–target relationship itself. However, other factors have also been shown to alter the priming effect. Two such factors are the inter-stimulus interval (ISI) and presentation modality. The inter-stimulus interval may be used to independently assess automatic and strategic processes, whereas presentation modality is typically used to assess the different processing time courses that occur with spoken or written words. These factors have not been adequately investigated in the normal population. A more in-depth understanding of the relationships between prime modality, inter-stimulus interval, and word recognition processes in a sample of individuals with typical language abilities may provide valuable when examining lexical access and storage in language disordered populations such as those with aphasia. Aims: The focus of the present study was to examine the impact of relatively short and long inter-stimulus intervals on processing time in a visual and cross-modal lexical decision task. Previous research has not fully addressed whether convergent processes occur during cross-modal tasks or if an amodal semantic system exists. The utilisation of slow and fast inter-stimulus intervals should allow for a clearer distinction relative to processing. Methods & Procedures: A series of four lexical decision tasks was used to investigate reaction time and accuracy. The four tasks resulted from the combination of the independent variables ISI (0 ms or 400 ms) and prime modality (auditory or visual). Outcomes & Results: Results indicated that participants exhibited a larger priming effect when stimuli were presented in the 0 ms condition. Results also indicated that participants responded more accurately when the target word was presented auditorily. Conclusions: It was concluded that automatic spreading activation occurred in both the visual and auditory modalities, providing further evidence of an amodal semantic system. These observations are helpful in developing a clearer understanding of lexical storage and access in language impairments such as aphasia.

The Time Course of Emotion Effects in First and Second Language Processing: A Cross Cultural ERP Study with German?Spanish Bilinguals

To investigate whether second language processing is characterized by the same sensitivity to the emotional content of language – as compared to native language processing – we conducted an EEG study manipulating word emotional valence in a visual lexical decision task. Two groups of late bilinguals – native speakers of German and Spanish with sufficient proficiency in their respective second language – performed each a German and a Spanish version of the task containing identical semantic material: translations of words in the two languages. In contrast to theoretical proposals assuming attenuated emotionality of second language processing, a highly similar pattern of results was obtained across L1 and L2 processing: event related potential waves generally reflected an early posterior negativity plus a late positive complex for words with positive or negative valence compared to neutral words regardless of the respective test language and its L1 or L2 status. These results suggest that the coupling between cognition and emotion does not qualitatively differ between L1 and L2 although latencies of respective effects differed about 50–100 ms. Only Spanish native speakers currently living in the L2 country showed no effects for negative as compared to neutral words presented in L2 – potentially reflecting a predominant positivity bias in second language processing when currently being exposed to a new culture.

On advantage of seeing text and hearing speech

The aim of this study was to examine the effect of congruence between the sensory modality through which a concept can be experienced and the modality through which the word denoting that concept is perceived during word recognition. Words denoting concepts that can be experienced visually (e.g. ?color?) and words denoting concepts that can be experienced auditorily (e.g. ?noise?) were presented both visually and auditorily. We observed shorter processing latencies when there was a match between the modality through which a concept could be experienced and the modality through which a word denoting that concept was presented. In visual lexical decision task, ?color? was recognized faster than ?noise?, whereas in auditory lexical decision task, ?noise? was recognized faster than ?color?. The obtained pattern of results can not be accounted for by exclusive amodal theories, whereas it can be easily integrated in theories based on perceptual representations. <br><br><font color="red"><b> This article has been corrected. Link to the correction <u><a href="http://dx.doi.org/10.2298/PSI1602211E">10.2298/PSI1602211E</a><u></b></font>

Whole body lexical decision

When a person standing upright raises an arm on cue, muscles of the left and right sides of the body exhibit changes prior to and specific to the responding arm. We had standing participants perform a visual lexical decision task (“is this letter string a word?”), responding yes by raising one arm and no by raising the other arm. We recorded onset of the arm movement and onset of electromyographic activity in thigh, trunk, and shoulder muscles. We observed the expected responding arm specificity and found that the onset difference favoring word decisions was evident in similar magnitude at all measurement sites, with the difference at the levels of thigh, trunk and shoulder muscles available 225, 189, and 120 ms, respectively, prior to its manifestation at the level of arm movement. We discuss including (a) whole body reaction time along with event-related potentials in determining the decision-response, brain–body temporal relation and (b) response execution along with response initiation in investigating mental chronometry.

Modulation of brain regions involved in word recognition by homophonous stimuli: An fMRI study

We used rapid event-related fMRI to explore factors modulating the activation of orthographic and phonological representations of print during a visual lexical decision task. Stimuli included homophonous word and nonword stimuli (MAID, BRANE), which have been shown behaviorally to produce longer response times due to phonological mediation effects. We also manipulated participants' reliance on orthography by varying the extent to which nonword foils were orthographically typical (wordlike context) or atypical (non-wordlike context) of real words. Key findings showed that reading low-frequency homophones in the wordlike context produced activation in regions associated with phonological processing (i.e., opercular region of the left inferior frontal gyrus [IFG; BA 44]), the integration of orthography and phonology (i.e., the inferior parietal lobule (IPL), and lexicosemantic processing (i.e., left middle temporal gyrus, [MTG]). Pseudohomophones in the wordlike context produced greater activity relative to other nonword trials in regions engaged during both phonological processing (i.e., left IFG/precentral gyrus; BA 6/9]), and semantic processing (triangular region of the left IFG; BA 47). Homophonous effects in the non-wordlike context were primarily isolated to medial extrastriate regions, hypothesized to be involved in low level visual processing and not reading-related processing per se. These findings demonstrate that the degree to which phonological and orthographic representations of print are activated depends not only on homophony, but also on the word-likeness of nonword stimuli. Implications for models of visual word recognition are discussed.

Graded Effects of Regularity in Language Revealed by N400 Indices of Morphological Priming

Differential electrophysiological effects for regular and irregular linguistic forms have been used to support the theory that grammatical rules are encoded using a dedicated cognitive mechanism. The alternative hypothesis is that language systematicities are encoded probabilistically in a way that does not categorically distinguish rule-like and irregular forms. In the present study, this matter was investigated more closely by focusing specifically on whether the regular-irregular distinction in English past tenses is categorical or graded. We compared the ERP priming effects of regulars (baked-bake), vowel-change irregulars (sang-sing), and "suffixed" irregulars that display a partial regularity (suffixed irregular verbs, e.g., slept-sleep), as well as forms that are related strictly along formal or semantic dimensions. Participants performed a visual lexical decision task with either visual (Experiment 1) or auditory prime (Experiment 2). Stronger N400 priming effects were observed for regular than vowel-change irregular verbs, whereas suffixed irregulars tended to group with regular verbs. Subsequent analyses decomposed early versus late-going N400 priming, and suggested that differences among forms can be attributed to the orthographic similarity of prime and target. Effects of morphological relatedness were observed in the later-going time period, however, we failed to observe true regular-irregular dissociations in either experiment. The results indicate that morphological effects emerge from the interaction of orthographic, phonological, and semantic overlap between words.

Semantic priming in French children with varying comprehension skills

Semantic priming was analysed in two groups of French children contrasted on comprehension skills with a visual lexical-decision task using a long SOA (800 ms). Two relation types between related primes and targets were examined: pure semantic relation (categorical vs. functional), and lexical association strength (strong vs. weak). Targets were preceded by related, unrelated, and neutral primes. Skilled comprehenders showed semantic priming only for category-related words, whatever their association strength, and without any evidence of an associative boost. Less-skilled comprehenders also showed semantic priming for category-related words, irrespective of their association strength, but with an indication of an associative boost. They also displayed semantic priming for function-related awords that are strongly associated, but not for those that are weakly associated. These results are discussed within the theoretical frame proposed by Plaut and Booth (2000).

Disturbed Functional Connectivity of Cortical Activation during Semantic Discrimination in Patients with Schizophrenia and Subjects at Genetic High-risk

Schizophrenia has a strong genetic component that is relevant to the understanding of the pathophysiology of the syndrome. Thus, recent investigations have shifted from studies of diagnosed patients with schizophrenia to examining their unaffected relatives. Previous studies found that during language processing, relatives thought to be at genetic high-risk for the disorder exhibit aberrant functional activation in regions of language processing, specifically in the left inferior frontal gyrus (Broca's area). However, functional connectivity among the regions involved in language pathways is not well understood. In this study, we examined the functional connectivity between a seed located in Broca's area and the remainder of the brain during a visual lexical decision task, in 20 schizophrenia patients, 21 subjects at genetic high risk for the disorder and 21 healthy controls. Both the high-risk subjects and patients showed significantly reduced activation correlations between seed and regions related to visual language processing. Compared to the high-risk subjects, the schizophrenia patients showed even fewer regions that were correlated with the seed regions. These results suggest that there is aberrant functional connectivity within cortical language circuitry in high-risk subjects and patients with schizophrenia. Broca's area, which is one of the important regions for language processing in healthy controls, had a significantly reduced role in the high-risk subjects and patients with schizophrenia. Our findings are consistent with the existence of an underlying biological disturbance that begins in genetically at risk individuals and progresses to a greater extent in those who eventually develop schizophrenia.

Remediation effects on N170 and P300 in children with developmental dyslexia.

This study aimed at investigating the ERP correlates (N170 and P300 components) of a multimodal training program focused in dyslexia. ERPs were obtained from 32 electrodes in 24 French children with developmental dyslexia (mean age 10 years 7 months) during a visual lexical decision task. All the children received two intensive two-month evidence-based training programs: one based on phonemic awareness and the other on visual and orthographic processing in a cross-over design. Ten control children matched on chronological age were also tested. We showed dissociation between N170, P300 and behavioral improvement. In the dyslexic group, P300 amplitude decreased for non-words and words as the latter yielded performance improvement. In the control group, the same effect was observed for pseudo-words. At the same time, the opposite pattern occurred for the N170 latency, which was shortened for pseudo-words and pseudo-homophones in the dyslexic group and for words in the typically achieving children. We argue that training might modulate cortical activity in dyslexic children in a visual word recognition task. Considering the well-known implication of P300 in attentional processes, our results reflect the strong link between reading skill improvement after remediation and visual attentional process maturation.

Remediation Effects on N170 and P300 in Children with Developmental Dyslexia

This study aimed at investigating the ERP correlates (N170 and P300 components) of a multimodal training program focused in dyslexia. ERPs were obtained from 32 electrodes in 24 French children with developmental dyslexia (mean age 10 years 7 months) during a visual lexical decision task. All the children received two intensive two-month evidence-based training programs: one based on phonemic awareness and the other on visual and orthographic processing in a cross-over design. Ten control children matched on chronological age were also tested. We showed dissociation between N170, P300 and behavioral improvement. In the dyslexic group, P300 amplitude decreased for non-words and words as the latter yielded performance improvement. In the control group, the same effect was observed for pseudo-words. At the same time, the opposite pattern occurred for the N170 latency, which was shortened for pseudo-words and pseudo-homophones in the dyslexic group and for words in the typically achieving children. We argue that training might modulate cortical activity in dyslexic children in a visual word recognition task. Considering the well-known implication of P300 in attentional processes, our results reflect the strong link between reading skill improvement after remediation and visual attentional process maturation.

Language-specific activations in the brain: Evidence from inflectional processing in bilinguals

We investigated the neural correlates of morphological processing in two structurally different languages within the same individuals. An interesting contrast is provided by Finnish and Swedish where most inflected Finnish nouns tend to show a processing cost (i.e., longer reaction times and higher error rates) compared to monomorphemic nouns, while most inflected Swedish nouns do not show such a cost. This has been taken as evidence for morphological decomposition in Finnish and full-form recognition of inflected nouns in Swedish. While most previous imaging studies had studied the two morphological processing routes (decomposition and storage) within the same language and often by comparing regular vs. irregular forms, we employed a cross-language setting and a direct contrast between morphologically complex vs. simple words. We subjected high-proficient Finnish–Swedish early bilinguals to a visual lexical decision task with inflected vs. monomorphemic Finnish and Swedish nouns while measuring their brain activation by fMRI. The participants showed an inflectional processing cost and related left fronto-temporal activation increases in Finnish but not in Swedish. This suggests a language-specific processing difference in the brain, possibly reflecting the structural difference between these two languages. In addition, the activations appeared in regions related to lexical-semantic and syntactic processing rather than visual word form processing. This is in line with previous studies in Finnish, suggesting that the morphological processing cost stems primarily from the later, semantic-syntactic stage.

Paradigmatic and extraparadigmatic morphology in the mental lexicon

The present study discusses psycholinguistic evidence for a difference between paradigmatic and extraparadigmatic morphology by investigating the processing of Finnish inflected and cliticized words. The data are derived from three sources of Finnish: from single-word reading performance in an agrammatic deep dyslectic speaker, as well as from visual lexical decision and wordness/learnability ratings of cliticized vs. inflected items by normal Finnish speakers. The agrammatic speaker showed awareness of the suffixes in multimorphemic words, including clitics, since he attempted to fill in this slot with morphological material. However, he never produced a clitic — either as the correct response or as an error — in any morphological configuration (simplex, derived, inflected, compound). Moreover, he produced more nominative singular errors for case-inflected nouns than he did for the cliticized words, a pattern that is expected if case-inflected forms were closely associated with their lexical heads, i.e., if they were paradigmatic and cliticized words were not. Furthermore, a visual lexical decision task with normal speakers of Finnish, showed an additional processing cost (longer latencies and more errors on cliticized than on case-inflected noun forms). Finally, a rating task indicated no difference in relative wordness between these two types of words. However, the same cliticized words were judged harder to learn as L2 items than the inflected words, most probably due to their conceptual/semantic properties, in other words due to their lack of word-level translation equivalents in SAVE languages. Taken together, the present results suggest that the distinction between paradigmatic and extraparadigmatic morphology is psychologically real.

Is lexical access autonomous? Evidence from combining overlapping tasks with recording event-related brain potentials

In order to test the frequent assumption that lexical access in visual word recognition would proceed independent of central attention, the overlapping task paradigm has recently been employed with somewhat contradictory results. Here we combined overlapping tasks with the recording of event-related brain potentials to assess task load dependent modulations of lexical access in more detail. The study was carried out in Spanish with native Spanish speaking participants. They performed a high-priority pitch discrimination task followed by a visual lexical decision task, in which the difficulty of lexical access was manipulated by means of word frequency. Increasing task load by reducing the stimulus onset asynchrony between both tasks from 700 to 100 ms resulted in considerable slowing of lexical decisions. Word frequency effects were underadditive with the slowing induced by task overlap, indicating lexical access to take place although central attention was dedicated to the high-priority task. The effect of word frequency on the event-related potentials, used as electrophysiological indicator of lexical access, was much less delayed than the lexical decision responses in conditions of high task overlap, providing converging evidence for the independence of lexical access from central attention. On the other hand, this slight delay and an amplitude reduction of the effect with high task load show that lexical access may not be completely autonomous, but subject to some additional early source of interference.

Can I have a quick word? Early electrophysiological manifestations of psycholinguistic processes revealed by event-related regression analysis of the EEG

We applied multiple linear regression analysis to event-related electrophysiological responses to words and pseudowords in a visual lexical decision task, yielding event-related regression coefficients (ERRCs) instead of the traditional event-related potential (ERP) measure. Our main goal was to disentangle the earliest ERP effects of the length of letter strings (“word length”) and orthographic neighbourhood size (Coltheart's “ N”). With respect to N, existing evidence is still ambiguous with respect to whether effects of N reflect early access to lexico-semantic information, or whether they occur at later decision or verification stages. In the present study, we found distinct neurophysiological manifestations of both N and word length around 100 ms after word onset. Importantly, the effect of N distinguished between words and pseudowords, while the effect of word length did not. Minimum norm source estimation revealed the most dominant sources for word length in bilateral posterior brain areas for both words and pseudowords. For N, these sources were more left-lateralised and consistent with perisylvian brain areas, with activation peaks in temporal areas being more anterior for words compared to pseudowords. Our results support evidence for an effect of N at early and elementary stages of word recognition. We discuss the implications of these results for the time line of word recognition processes, and emphasise the value of ERRCs in combination with source analysis in psycholinguistic and cognitive brain research.

Cognitive, linguistic and affective disturbances following a right superior cerebellar artery infarction: A case study

The cerebellar cognitive affective syndrome (CCAS) is a neurobehavioral syndrome that may develop after congenital and acquired cerebellar lesions. The syndrome consists of deficits in executive functioning, spatial cognition, visual–spatial memory and language and also involves personality and behavioral changes. We describe a 58-year-old right-handed man who in addition to affective disturbances presented with a unique combination of cognitive and linguistic deficits following an ischemic infarction in the vascular territory of the right superior cerebellar artery (SCA). Neurocognitive and neurolinguistic examinations were performed in the acute phase (10 days post-onset) and lesion phase (four weeks post-onset) of the stroke. A Tc-99m-ECD SPECT study was performed five weeks after the stroke. Acute phase data revealed a generalized cognitive decline and mild transcortical sensory aphasia. In the lesion phase, the neurobehavioral tableau was dominated by executive dysfunctions, disrupted divided attention, disturbed visual–spatial organization and behavioral abnormalities. Neurolinguistic investigations disclosed visual dyslexia and surface dysgraphia. Reading of words and visual lexical decision tasks of words and nonwords were severely defective and predominantly characterized by visual errors. In addition, writing irregular and ambiguous words resulted in regularization errors (phonologically plausible errors based on phoneme-grapheme correspondence rules). In the absence of any structural damage in the supratentorial brain regions, a quantified SPECT study showed a relative hypoperfusion in the right cerebellar hemisphere and the left medial frontal lobe. CCAS is for the first time reported in association with visual dyslexia and surface dysgraphia. We hypothesize that the cognitive and linguistic deficits might result from functional disruption of the cerebellar-encephalic pathways, connecting the cerebellum to the frontal supratentorial areas which subserve attentional and planning processes. This phenomenon of crossed cerebellar–cerebral diaschisis is supported by SPECT findings revealing a hypoperfusion in the anatomoclinically suspected brain regions. The constellation of cognitive, linguistic and behavioral symptoms adds new evidence to the multifaceted area of cerebellar neurocognition and demonstrates that the cerebellum might play a crucial role in cognitive, linguistic, and affective processing.

Do Italian dyslexic children use the lexical reading route efficiently? An orthographic judgment task

The study uses an orthographic judgment task to evaluate the efficiency of the lexical reading route in Italian dyslexic children. It has been suggested that Italian dyslexic children rely prevalently on the sub-word-level routine for reading. However, it is not easy to test the lexical reading route in Italian directly because of the lack of critical items (irregular words), so visual lexical decision tasks and the comprehension/detection of pseudo-homophones are often used. While the former may also be solved on the basis of visual familiarity or phonological re-codification, the latter also involves conceptual and syntactic skills. Eleven dyslexic children participated in the study, performing an orthographic judgment task on stimuli with two phonologically plausible spellings, of which only one was orthographically correct. Their performance was compared with those of 11 proficient readers. The dyslexic children showed selective impairment in detecting phonologically plausible errors, but their performance was normal when required to judge errors inserted in words with regular orthography, i.e., devoid of orthographic ambiguity, and for which a sub-word-level reading procedure is sufficient to guarantee a good performance. Overall, data are coherent with a diagnosis of surface dyslexia, with most children showing defective orthographic lexical processing.

I see what you mean: Theta power increases are involved in the retrieval of lexical semantic information

An influential hypothesis regarding the neural basis of the mental lexicon is that semantic representations are neurally implemented as distributed networks carrying sensory, motor and/or more abstract functional information. This work investigates whether the semantic properties of words partly determine the topography of such networks. Subjects performed a visual lexical decision task while their EEG was recorded. We compared the EEG responses to nouns with either visual semantic properties (VIS, referring to colors and shapes) or with auditory semantic properties (AUD, referring to sounds). A time–frequency analysis of the EEG revealed power increases in the theta (4–7 Hz) and lower-beta (13–18 Hz) frequency bands, and an early power increase and subsequent decrease for the alpha (8–12 Hz) band. In the theta band we observed a double dissociation: temporal electrodes showed larger theta power increases in the AUD condition, while occipital leads showed larger theta responses in the VIS condition. The results support the notion that semantic representations are stored in functional networks with a topography that reflects the semantic properties of the stored items, and provide further evidence that oscillatory brain dynamics in the theta frequency range are functionally related to the retrieval of lexical semantic information.