Event-related Potential Measures of Visual Word Processing in Monolingual and Bilingual Children and Adults: A Focus on Word Frequency Effects.

How does language background influence the neural correlates of visual word recognition in children? To address this question, we used an ERP lexical decision task to examine first-language (L1) and second-language (L2) visual word processing in monolingual and bilingual school-aged children and young adults (n = 123). In particular, we focused on the effects of word frequency (an index of lexical accessibility) on RTs and the N400 ERP component. Behaviorally, we found larger L1 versus L2 word frequency effects among bilingual children, driven by faster and more accurate responses to higher-frequency words (no other language or age group differences were observed). Neurophysiologically, we found larger L1 word frequency effects in bilinguals versus monolinguals (across both age groups), reflected in more negative ERP amplitudes to lower-frequency words. However, the bilingual groups processed L1 and L2 words similarly, despite lower levels of subjective and objective L2 proficiency. Taken together, our findings suggest that divided L1 experience (but not L2 experience) influences the neural correlates of visual word recognition across childhood and adulthood.

Eye movements and the perceptual span in disordered reading: A comparison of schizophrenia and dyslexia.

Increasing evidence of a common neurodevelopmental etiology between schizophrenia and developmental dyslexia suggests that neurocognitive functions, such as reading, may be similarly disrupted. However, direct comparisons of reading performance in these disorders have yet to be conducted. To address this gap in the literature, we employed a gaze-contingent moving window paradigm to examine sentence-level reading fluency and perceptual span (breadth of parafoveal processing) in adults with schizophrenia (dataset from Whitford et al., 2013) and psychiatrically healthy adults with dyslexia (newly collected dataset). We found that the schizophrenia and dyslexia groups exhibited similar reductions in sentence-level reading fluency (e.g., slower reading rates, more regressions) compared to matched controls. Similar reductions were also found for standardized language/reading and executive functioning measures. However, despite these reductions, the dyslexia group exhibited a larger perceptual span (greater parafoveal processing) than the schizophrenia group, potentially reflecting a disruption in normal foveal-parafoveal processing dynamics. Taken together, our findings suggest that reading and reading-related functions are largely similarly disrupted in schizophrenia and dyslexia, providing additional support for a common neurodevelopmental etiology.

Bilingual Language Experience and Its Effect on Conflict Adaptation in Reactive Inhibitory Control Tasks.

We used machine-learning techniques to assess interactions between language and cognitive systems related to inhibitory control and conflict adaptation in reactive control tasks. We built theoretically driven candidate models of Simon and Number Stroop task data (N = 777 adult bilinguals ages 18-43 years living in Montréal, Canada) that differed in whether bilingual experience interacted with inhibitory control, including two forms of conflict adaptation: shorter term sequential congruency effects and longer term trial order effects. Models with continuous aspects of bilingual experience provided signal in predicting new, unmodeled data. Specifically, mixed language usage predicted trial order adaptation to conflict. This effect was restricted to Number Stroop, which overtly involves linguistic or symbolic information and relatively higher language- and response-related uncertainty. These results suggest that bilingual experience adaptively tunes aspects of the control system and offers a novel integrative modeling approach that can be used to pursue other complex individual difference questions within the psychological sciences.

Eye Movement Measures of Within-Language and Cross-Language Activation During Reading in Monolingual and Bilingual Children and Adults: A Focus on Neighborhood Density Effects.

We used eye movement measures of first-language (L1) and second-language (L2) paragraph reading to investigate how the activation of multiple lexical candidates, both within and across languages, influences visual word recognition in four different age and language groups: (1) monolingual children; (2) monolingual young adults; (3) bilingual children; and (4) bilingual young adults. More specifically, we focused on within-language and cross-language orthographic neighborhood density effects, while controlling for the potentially confounding effects of orthographic neighborhood frequency. We found facilitatory within-language orthographic neighborhood density effects (i.e., words were easier to process when they had many vs. few orthographic neighbors, evidenced by shorter fixation durations) across the L1 and L2, with larger effects in children vs. adults (especially the bilingual ones) during L1 reading. Similarly, we found facilitatory cross-language neighborhood density effects across the L1 and L2, with no modulatory influence of age or language group. Taken together, our findings suggest that word recognition benefits from the simultaneous activation of visually similar word forms during naturalistic reading, with some evidence of larger effects in children and particularly those whose words may have differentially lower baseline activation levels and/or weaker links between word-related information due to divided language exposure: bilinguals.

Cross-language activation and executive control modulate within-language ambiguity resolution: Evidence from eye movements.

An important question within psycholinguistics is how knowledge of multiple languages impacts the coactivation of word forms and meanings during language comprehension. To the extent that a bilingual's known languages are always partially active, as predicted by models such as the bilingual interactive activation plus model (Dijkstra & Van Heuven, 2002), cross-language activation should influence which meanings are accessed and in which order. Here, we monitored the eye movements of 48 French-English and 40 English-French bilingual adults as they read within-language homonyms embedded in more or less semantically constraining English sentences. The within-language homonyms were either cognate homonyms, whose subordinate meanings were also French cognates (e.g., sage, "herb" or, less frequently, "wise man" in English and, also, "wise man" in French), or uniquely English (e.g., chest). French-English bilinguals processed cognate homonyms with subordinate meanings more quickly than uniquely English homonyms with subordinate meanings, and individual differences in executive control capacity modulated their processing of uniquely English homonyms only. In contrast, English-French bilinguals processed all within-language homonyms similarly, regardless of cognate status and executive control capacity. Our findings suggest that cross-language activation impacts within-language ambiguity resolution by changing the relative dominance of the meanings associated with a word form, and that cross-language activation varies as a function of the language tested (first or second language). (PsycINFO Database Record (c) 2020 APA, all rights reserved).

Figuring Out How Verb-Particle Constructions Are Understood During L1 and L2 Reading.

The aim of this paper was to investigate first-language (L1) and second-language (L2) reading of verb particle constructions (VPCs) among English-French bilingual adults. VPCs, or phrasal verbs, are highly common collocations of a verb paired with a particle, such as eat up or chew out, that often convey a figurative meaning. VPCs vary in form (eat up the candy vs. eat the candy up) and in other factors, such as the semantic contribution of the constituent words to the overall meaning (semantic transparency) and frequency. Much like classic forms of idioms, VPCs are difficult for L2 users. Here, we present two experiments that use eye-tracking to discover factors that influence the ease with which VPCs are processed by bilingual readers. In Experiment 1, we compared L1 reading of adjacent vs. split VPCs, and then explored whether the general pattern was driven by item-level factors. L1 readers did not generally find adjacent VPCs (eat up the candy) easier to process than split VPCs (eat the candy up); however, VPCs low in co-occurrence strength (i.e., low semantic transparency) and high in frequency were easiest to process in the adjacent form during first pass reading. In Experiment 2, we compared L2 reading of adjacent vs. split VPCs, and then explored whether the general pattern varied with item-level or participant-level factors. L2 readers generally allotted more second pass reading time to split vs. adjacent forms, and there was some evidence that this pattern was greater for L2 English readers who had less English experience. In contrast with L1 reading, there was no influence of item differences on L2 reading behavior. These data suggest that L1 readers may have lexicalized VPC representations that are directly retrieved during comprehension, whereas L2 readers are more likely to compositionally process VPCs given their more general preference for adjacent particles, as demonstrated by longer second pass reading time for all split items.

Do eye movements reveal differences between monolingual and bilingual children's first-language and second-language reading? A focus on word frequency effects.

An extensive body of research has examined reading acquisition and performance in monolingual children. Surprisingly, however, much less is known about reading in bilingual children, who outnumber monolingual children globally. Here, we address this important imbalance in the literature by employing eye movement recordings to examine both global (i.e., text-level) and local (i.e., word-level) aspects of monolingual and bilingual children's reading performance across their first-language (L1) and second-language (L2). We also had a specific focus on lexical accessibility, indexed by word frequency effects. We had three main findings. First, bilingual children displayed reduced global and local L1 reading performance relative to monolingual children, including larger L1 word frequency effects. Second, bilingual children displayed reduced global and local L2 versus L1 reading performance, including larger L2 word frequency effects. Third, both groups of children displayed reduced global and local reading performance relative to adult comparison groups (across their known languages), including larger word frequency effects. Notably, our first finding was not captured by traditional offline measures of reading, such as standardized tests, suggesting that these measures may lack the sensitivity to detect such nuanced between-group differences in reading performance. Taken together, our findings demonstrate that bilingual children's simultaneous exposure to two reading systems leads to eye movement reading behavior that differs from that of monolingual children and has important consequences for how lexical information is accessed and integrated in both languages.

Bilingual experience and resting-state brain connectivity: Impacts of L2 age of acquisition and social diversity of language use on control networks.

We investigated the independent contributions of second language (L2) age of acquisition (AoA) and social diversity of language use on intrinsic brain organization using seed-based resting-state functional connectivity among highly proficient French-English bilinguals. There were two key findings. First, earlier L2 AoA related to greater interhemispheric functional connectivity between homologous frontal brain regions, and to decreased reliance on proactive executive control in an AX-Continuous Performance Task completed outside the scanner. Second, greater diversity in social language use in daily life related to greater connectivity between the anterior cingulate cortex and the putamen bilaterally, and to increased reliance on proactive control in the same task. These findings suggest that early vs. late L2 AoA links to a specialized neural framework for processing two languages that may engage a specific type of executive control (e.g., reactive control). In contrast, higher vs. lower degrees of diversity in social language use link to a broadly distributed set of brain networks implicated in proactive control and context monitoring.

Reading deficits in schizophrenia and their relationship to developmental dyslexia: A review.

Although schizophrenia and developmental dyslexia are considered distinct disorders in terms of clinical presentation and functional outcome, they both involve disruption in the processes that support skilled reading, including language, auditory perception, visual perception, oculomotor control, and executive function. Further, recent work has proposed a common neurodevelopmental basis for the two disorders, as suggested by genetic and pathophysiological overlap. Thus, these lines of research suggest that reading may be similarly impacted in schizophrenia and dyslexia. In this review, we survey research on reading abilities in individuals with schizophrenia, and review the potential mechanisms underlying reading deficits in schizophrenia that may be shared with those implicated in dyslexia. Elucidating the relationship between reading impairment in schizophrenia and dyslexia could allow for a better understanding of the pathophysiological underpinnings of schizophrenia, and could facilitate remediation of cognitive deficits that impact day-to-day functioning.

The effects of word frequency and word predictability during first- and second-language paragraph reading in bilingual older and younger adults.

We used eye movement measures of paragraph reading to examine how word frequency and word predictability impact first-language (L1) and second-language (L2) word processing in matched bilingual older and younger adults, varying in amount of current L2 experience. Our key findings were threefold. First, across both early- and late-stage reading, word frequency effects were generally larger in older than in younger adults, whereas word predictability effects were generally age-invariant. Second, across both age groups and both reading stages, word frequency effects were larger in the L2 than in the L1, whereas word predictability effects were language-invariant. Third, graded differences in current L2 experience modulated L1 and L2 word processing in younger adults, but had no impact in older adults. Specifically, greater current L2 experience facilitated L2 word processing, but impeded L1 word processing among younger adults only. Taken together, we draw 2 main conclusions. First, bilingual older adults experience changes in word-level processing that are language-non-specific, potentially because lexical accessibility decreases with age. Second, bilingual older adults experience changes in word-level processing that are insensitive to graded differences in current L2 experience, potentially because lexical representations reach a functional ceiling over time. (PsycINFO Database Record

Eye movements and the perceptual span during first- and second-language sentence reading in bilingual older adults.

This study addressed a central yet previously unexplored issue in the psychological science of aging, namely, whether the advantages of healthy aging (e.g., greater lifelong experience with language) or disadvantages (e.g., decreases in cognitive and sensory processing) drive L1 and L2 reading performance in bilingual older adults. To this end, we used a gaze-contingent moving window paradigm to examine both global aspects of reading fluency (e.g., reading rates, number of regressions) and the perceptual span (i.e., allocation of visual attention into the parafovea) in bilingual older adults during L1 and L2 sentence reading, as a function of individual differences in current L2 experience. Across the L1 and L2, older adults exhibited reduced reading fluency (e.g., slower reading rates, more regressions), but a similar perceptual span compared with matched younger adults. Also similar to matched younger adults, older adults' reading fluency was lower for L2 reading than for L1 reading as a function of current L2 experience. Specifically, greater current L2 experience increased L2 reading fluency, but decreased L1 reading fluency (for global reading measures only). Taken together, the dissociation between intact perceptual span and impaired global reading measures suggests that older adults may prioritize parafoveal processing despite age-related encoding difficulties. Consistent with this interpretation, post hoc analyses revealed that older adults with higher versus lower executive control were more likely to adopt this strategy.

Second-language experience modulates eye movements during first- and second-language sentence reading: evidence from a gaze-contingent moving window paradigm.

Eye movement measures demonstrate differences in first-language (L1) and second-language (L2) paragraph-level reading as a function of individual differences in current L2 exposure among bilinguals (Whitford & Titone, 2012). Specifically, as current L2 exposure increases, the ease of L2 word processing increases, but the ease of L1 word processing decreases. Here, we investigate whether current L2 exposure also relates to more general aspects of reading performance, including global eye movement measures and how bilinguals use parafoveal information to the right of fixation during L1 and L2 sentence-level reading, through use of a gaze-contingent moving window paradigm (McConkie & Rayner, 1975). We found that bilinguals with high versus low current L2 exposure exhibited increased L2 reading fluency (faster reading rates, shorter forward fixation durations), but decreased L1 reading fluency (slower reading rates, longer forward fixation durations). We also found that bilinguals with high versus low current L2 exposure were more affected by reductions in window size during L2 reading (indicative of a larger L2 perceptual span), but were less affected by reductions in window size during L1 reading (indicative of a smaller L1 perceptual span). Taken together, these findings suggest that individual differences in current L2 exposure among bilinguals also modulate more general aspects of reading behavior, including global measures of reading difficulty and the allocation of visual attention into the parafovea during both L1 and L2 sentence-level reading.

Perisaccadic perception of visual space in people with schizophrenia.

Corollary discharge signals are found in the nervous systems of many animals, where they serve a large variety of functions related to the integration of sensory and motor signals. In humans, an important corollary discharge signal is generated by oculomotor structures and communicated to sensory systems in concert with the execution of each saccade. This signal is thought to serve a number of purposes related to the maintenance of accurate visual perception. The properties of the oculomotor corollary discharge can be probed by asking subjects to localize stimuli that are flashed briefly around the time of a saccade. The results of such experiments typically reveal large errors in localization. Here, we have exploited these well-known psychophysical effects to assess the potential dysfunction of corollary discharge signals in people with schizophrenia. In a standard perisaccadic localization task, we found that, compared with controls, patients with schizophrenia exhibited larger errors in localizing visual stimuli. The pattern of errors could be modeled as an overdamped corollary discharge signal that encodes instantaneous eye position. The dynamics of this signal predicted symptom severity among patients, suggesting a possible mechanistic basis for widely observed behavioral manifestations of schizophrenia.

The effects of reading comprehension and launch site on frequency-predictability interactions during paragraph reading.

We used eye movement measures of paragraph reading to examine whether word frequency and predictability interact during the earliest stages of lexical processing, with a specific focus on whether these effects are modulated by individual differences in reading comprehension or launch site (i.e., saccade length between the prior and currently fixated word--a proxy for the amount of parafoveal word processing). The joint impact of frequency and predictability on reading will elucidate whether these variables additively or multiplicatively affect the earliest stages of lexical access, which, in turn, has implications for computational models of eye movements during reading. Linear mixed effects models revealed additive effects during both early- and late-stage reading, where predictability effects were comparable for low- and high-frequency words. Moreover, less cautious readers (e.g., readers who engaged in skimming, scanning, mindless reading) demonstrated smaller frequency effects than more cautious readers. Taken together, our findings suggest that during extended reading, frequency and predictability exert additive influences on lexical and postlexical processing, and that individual differences in reading comprehension modulate sensitivity to the effects of word frequency.

Reading impairments in schizophrenia relate to individual differences in phonological processing and oculomotor control: evidence from a gaze-contingent moving window paradigm.

Language and oculomotor disturbances are 2 of the best replicated findings in schizophrenia. However, few studies have examined skilled reading in schizophrenia (e.g., Arnott, Sali, Copland, 2011; Hayes & O'Grady, 2003; Revheim et al., 2006; E. O. Roberts et al., 2012), and none have examined the contribution of cognitive and motor processes that underlie reading performance. Thus, to evaluate the relationship of linguistic processes and oculomotor control to skilled reading in schizophrenia, 20 individuals with schizophrenia and 16 demographically matched controls were tested using a moving window paradigm (McConkie & Rayner, 1975). Linguistic skills supporting reading (phonological awareness) were assessed with the Comprehensive Test of Phonological Processing (R. K. Wagner, Torgesen, & Rashotte, 1999). Eye movements were assessed during reading tasks and during nonlinguistic tasks tapping basic oculomotor control (prosaccades, smooth pursuit) and executive functions (predictive saccades, antisaccades). Compared with controls, schizophrenia patients exhibited robust oculomotor markers of reading difficulty (e.g., reduced forward saccade amplitude) and were less affected by reductions in window size, indicative of reduced perceptual span. Reduced perceptual span in schizophrenia was associated with deficits in phonological processing and reduced saccade amplitudes. Executive functioning (antisaccade errors) was not related to perceptual span but was related to reading comprehension. These findings suggest that deficits in language, oculomotor control, and cognitive control contribute to skilled reading deficits in schizophrenia. Given that both language and oculomotor dysfunction precede illness onset, reading may provide a sensitive window onto cognitive dysfunction in schizophrenia vulnerability and be an important target for cognitive remediation.

Second-language experience modulates first- and second-language word frequency effects: evidence from eye movement measures of natural paragraph reading.

We used eye movement measures of first-language (L1) and second-language (L2) paragraph reading to investigate whether the degree of current L2 exposure modulates the relative size of L1 and L2 frequency effects (FEs). The results showed that bilinguals displayed larger L2 than L1 FEs during both early- and late-stage eye movement measures, which are taken to reflect initial lexical access and postlexical access, respectively. Moreover, the magnitude of L2 FEs was inversely related to current L2 exposure, such that lower levels of L2 exposure led to larger L2 FEs. In contrast, during early-stage reading measures, bilinguals with higher levels of current L2 exposure showed larger L1 FEs than did bilinguals with lower levels of L2 exposure, suggesting that increased L2 experience modifies the earliest stages of L1 lexical access. Taken together, the findings are consistent with implicit learning accounts (e.g., Monsell, 1991), the weaker links hypothesis (Gollan, Montoya, Cera, Sandoval, Journal of Memory and Language, 58:787-814, 2008), and current bilingual visual word recognition models (e.g., the bilingual interactive activation model plus [BIA+]; Dijkstra & van Heuven, Bilingualism: Language and Cognition, 5:175-197, 2002). Thus, amount of current L2 exposure is a key determinant of FEs and, thus, lexical activation, in both the L1 and L2.

Bilingual lexical access during L1 sentence reading: The effects of L2 knowledge, semantic constraint, and L1-L2 intermixing.

Libben and Titone (2009) recently observed that cognate facilitation and interlingual homograph interference were attenuated by increased semantic constraint during bilingual second language (L2) reading, using eye movement measures. We now investigate whether cross-language activation also occurs during first language (L1) reading as a function of age of L2 acquisition and task demands (i.e., inclusion of L2 sentences). In Experiment 1, participants read high and low constraint English (L1) sentences containing interlingual homographs, cognates, or control words. In Experiment 2, we included French (L2) filler sentences to increase salience of the L2 during L1 reading. The results suggest that bilinguals reading in their L1 show nonselective activation to the extent that they acquired their L2 early in life. Similar to our previous work on L2 reading, high contextual constraint attenuated cross-language activation for cognates. The inclusion of French filler items promoted greater cross-language activation, especially for late stage reading measures. Thus, L1 bilingual reading is modulated by L2 knowledge, semantic constraint, and task demands.