Veronica Whitford

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.

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.

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.

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.

Eye Movement Methods to Investigate Bilingual Reading

This chapter provides a general overview of the use of eye movement recordings to investigate the cognitive processes that underlie natural reading, including first- (L1) and second-language (L2) reading in bilinguals. We focus on two important issues arising from bilinguals’ divided L1/L2 knowledge and use: cross-language activation (i.e., nonselective activation of both L1 and L2 lexical representations) and reduced lexical entrenchment (i.e., delayed lexical access resulting from lower baseline activation levels of L1 and L2 words and/or weakened L1 and L2 lexical memory representations). Prior work has used eye movement recordings to independently examine these two issues; however, in a reanalysis of recent work from our laboratory (Whitford and Titone, Psychon Bull Rev 19:73–80, 2012), we examine their joint impact on eye movement measures of bilingual reading. We find that cross-language activation and reduced lexical entrenchment mutually constrain L1 and L2 reading in bilinguals, which suggests that they may be two sides of the same coin.

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.

Doubling down on multifactorial approaches to the study of bilingualism & executive control

The study of bilingualism has generated great interest about a core issue: does the experience of using two or more languages lead to enduring changes in the bilingual brain. This issue is often framed as a search for bilingual advantages in cognition, most notably behavioral performance on executive control tasks. Valians timely keynote (2014) adopts this framing.

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

ABSTRACT 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. HighlightsBilingual experience adaptively tunes neural networks involved in executive control.Early L2 AoA relates to greater frontal interhemispheric functional connectivity.Greater diversity of language use relates to greater subcortical connectivity.Frontal and subcortical connectivity relate to proactive‐reactive shifts in behavior.Historical and ongoing language experience impact functional brain connectivity.