Best practices for cleaning eye movement data in reading research.

One challenge that comes with studying eye movement behavior is deciding how to clean the eye movement data (e.g., fixation durations) before conducting analyses. Reading researchers must decide which data cleaning methods they will use and which thresholds they will set to remove eye movements that are not reflective of lexical processing. The purpose of this project was to determine what data cleaning methods are typically used and if there are any consequences of using different data cleaning methods. In the first study, an analysis of 192 recently published articles indicated that there is inconsistency in the reporting and application of data cleaning methods. In the second study, three different data cleaning methods were applied based on the literature analysis in the first study. Analyses were conducted to determine the impact of different data cleaning methods on three commonly studied effects in reading research (frequency, predictability, and length). Overall, standardized estimates decreased for each effect when more data were removed; however, removing more data also resulted in decreased variance. As a result, effects remained significant with each data cleaning method, and simulated power remained high for both a moderate and small sample size. Effect sizes remained consistent for most effects but decreased for the length effect as more data were removed. Seven suggestions are provided that are based on open science practices with the intention of helping researchers, reviewers, and the field as a whole.

Precision in the measurement of lexical expertise: the selection of optimal items for a spelling assessment.

Skilled adult readers vary in many skills related to visual word form processing such as phonological processing, vocabulary size, comprehension skill, and spelling skill (Kuperman & Van Dyke, 2011). Spelling skill in particular has received much attention because low- and high-skill spellers show different patterns of lexical processing as measured through eye movement behavior, reaction times, and word learning (Eskenazi et al., 2018; Veldre & Andrews, 2014). Researchers commonly use a spelling dictation task to measure lexical expertise; however, there is limited evidence for its psychometric properties and room for improvement in item selection (Andrews et al., 2020). The purpose of this study was to assess the precision of 110 words as measures of lexical expertise, to compare various subsets of words in a spelling dictation task, and to provide a set of words that more precisely measure lexical expertise. In Study 1, a spelling dictation task with 110 words was administered to 682 participants. In Study 2, that same task and measures of vocabulary and comprehension were administered to 786 participants. Results indicated that the set of 110 words contains many words that are imprecise measures of spelling skill. Through an iterative process of removing words with high error variance, a set of 20 words was selected that minimizes measurement error and demonstrates discriminant validity from vocabulary and comprehension ability. We recommend this set of words as a more precise measure of spelling skill, which will provide more power to detect moderating effects of lexical expertise on reading processes.

Individual differences in the desirable difficulty effect during lexical acquisition.

Reading in difficult or novel fonts results in slower and less efficient reading (Slattery & Rayner, 2010); however, these fonts may also lead to better learning and memory (Diemand-Yauman, Oppenheimer, & Vaughan, 2011). This effect is consistent with a desirable difficulty effect such that more effort during encoding results in better long term retention (Bjork, 1994). The effect is robust and found in many contexts; however, it has not yet been applied to the process of lexical acquisition. The purpose of the current study was to investigate whether readers would learn words better when presented in Sans Forgetica, a font designed to induce desirable difficulty. One hundred sixty participants were randomly assigned to one font type and read sentences with 15 very low-frequency English words presented in two different informative contexts while their eye movements were monitored. They completed a spelling skill assessment and tests of their orthographic and semantic acquisition of the words. Linear mixed effects analyses were conducted and indicate that high-skill spellers learned the spelling and meaning of words better in the desirable difficulty font, but low-skill spellers did not show the same benefit. This pattern highlights the importance of individual differences in learning such that a desirable difficulty for one reader may be an undesirable difficulty for another. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Word skipping during the lexical acquisition process.

During reading, most words are identified in the fovea through a direct fixation; however, readers also identify some words in the parafovea without directly fixating them. This word skipping process is influenced by many lexical and visual factors including word length, launch position, frequency, and predictability. Although these factors are well understood, there is some disagreement about the process that leads to word skipping and the degree to which skipped words are processed. The purpose of this study was to investigate the word skipping process when readers are exposed to novel words in an incidental lexical acquisition paradigm. Participants read 18 three-letter novel words (i.e., pru, cho) in three different informative contexts each while their eye movements were monitored. They then completed a surprise test of their orthographic and semantic acquisition and a spelling skill assessment. Mixed-effects models indicated that participants learned spellings and meanings of words at the same rate regardless of the number of times that they were skipped. However, word skipping rates increased across the three exposures and reading times decreased. Results indicate that readers appear to process skipped words to the same degree as fixated words. However, this may be due to a more cautious skipping process used during lexical acquisition of unfamiliar words compared to processing of already known words.

tDCS as a treatment for anxiety and related cognitive deficits.

INTRODUCTION: Anxiety is characterized by psychological, physiological, and cognitive complaints. Current treatments have significant limitations, and often overlook any potential benefits to common cognitive symptoms, notably attention and executive function issues. The current study aimed to investigate the use of transcranial direct current stimulation (tDCS) on both common anxiety symptoms and executive function abilities in a college aged sample. METHOD: As this is one of the first large scale anxiety studies utilizing tDCS, participants were given a single session of tDCS (anodal, cathodal, or sham) for 20 min at 2 mA over the left dorsolateral prefrontal cortex (lDLPFC). Participants also completed a series of self-reported anxiety measures and measures of executive functioning (Rey-O Copy and Wisconsin Card Sorting Task). RESULTS: While there were no differences in anxiety between tDCS groups, a trend was noted demonstrating better performance on Rey-O Copy for the cathodal group. Anxiety increased pre to post for all groups. CONCLUSION: Overall, results suggest that while anodal stimulation of the lDLPFC may benefit cognitive abilities for this population, targeting psychological symptoms of anxiety likely requires stimulation over other cortex, possibly right DLPFC. Further, the use of tDCS, whether active or sham, may be distressing to patients.

Eye-tracking to Distinguish Comprehension-based and Oculomotor-based Regressive Eye Movements During Reading.

Regressive eye movements are eye movements that move backwards through the text and comprise approximately 10-25% of eye movements during reading. As such, understanding the causes and mechanisms of regressions plays an important role in understanding eye movement behavior. Inhibition of return (IOR) is an oculomotor effect that results in increased latency to return attention to a previously attended target versus a target that was not previously attended. Thus, IOR may affect regressions. This paper describes how to design materials to distinguish between regressions caused by comprehension-related and oculomotor processes; the latter is subject to IOR. The method allows researchers to identify IOR and control the causes of regressions. While the method requires tightly controlled materials and large numbers of participants and materials, it allows researchers to distinguish and control the types of regressions that occur in their reading studies.

Uninformative contexts support word learning for high-skill spellers.

The current study investigated how high-skill spellers and low-skill spellers incidentally learn words during reading. The purpose of the study was to determine whether readers can use uninformative contexts to support word learning after forming a lexical representation for a novel word, consistent with instance-based resonance processes. Previous research has found that uninformative contexts damage word learning; however, there may have been insufficient exposure to informative contexts (only one) prior to exposure to uninformative contexts (Webb, 2007; Webb, 2008). In Experiment 1, participants read sentences with one novel word (i.e., blaph, clurge) embedded in them in three different conditions: Informative (six informative contexts to support word learning), Mixed (three informative contexts followed by three uninformative contexts), and Uninformative (six uninformative contexts). Experiment 2 added a new condition with only three informative contexts to further clarify the conclusions of Experiment 1. Results indicated that uninformative contexts can support word learning, but only for high-skill spellers. Further, when participants learned the spelling of the novel word, they were more likely to learn the meaning of that word. This effect was much larger for high-skill spellers than for low-skill spellers. Results are consistent with the Lexical Quality Hypothesis (LQH) in that high-skill spellers form stronger orthographic representations which support word learning (Perfetti, 2007). Results also support an instance-based resonance process of word learning in that prior informative contexts can be reactivated to support word learning in future contexts (Bolger, Balass, Landen, & Perfetti, 2008; Balass, Nelson, & Perfetti, 2010; Reichle & Perfetti, 2003). (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Regressions during reading: The cost depends on the cause.

The direction and duration of eye movements during reading is predominantly determined by cognitive and linguistic processing, but some low-level oculomotor effects also influence the duration and direction of eye movements. One such effect is inhibition of return (IOR), which results in an increased latency to return attention to a target that has been previously attended (Posner & Cohen, Attention and Performance X: Control of Language Processes, 32, 531-556, 1984). Although this is a low level effect, it has also been found in the complex task of reading (Henderson & Luke, Psychonomic Bulletin & Review, 19(6), 1101-1107, 2012; Rayner, Juhasz, Ashby, & Clifton, Vision Research, 43(9), 1027-1034, 2003). The purpose of the current study was to isolate the potentially different causes of regressive eye movements: to adjust for oculomotor error and to assist with comprehension difficulties. We found that readers demonstrated an IOR effect when regressions were caused by oculomotor error, but not when regressions were caused by comprehension difficulties. The results suggest that IOR is primarily associated with low-level oculomotor control of eye movements, and that regressive eye movements that are controlled by comprehension processes are not subject to IOR effects. The results have implications for understanding the relationship between oculomotor and cognitive control of eye movements and for models of eye movement control.

Skipped words and fixated words are processed differently during reading.

The purpose of this study was to investigate whether words are processed differently when they are fixated during silent reading than when they are skipped. According to a serial processing model of eye movement control (e.g., EZ Reader) skipped words are fully processed (Reichle, Rayner, Pollatsek, Behavioral and Brain Sciences, 26(04):445-476, 2003), whereas in a parallel processing model (e.g., SWIFT) skipped words do not need to be fully processed (Engbert, Nuthmann, Richter, Kliegl, Psychological Review, 112(4):777-813, 2005). Participants read 34 sentences with target words embedded in them while their eye movements were recorded. All target words were three-letter, low-frequency, and unpredictable nouns. After the reading session, participants completed a repetition priming lexical decision task with the target words from the reading session included as the repetition prime targets, with presentation of those same words during the reading task acting as the prime. When participants skipped a word during the reading session, their reaction times on the lexical decision task were significantly longer (M = 656.42 ms) than when they fixated the word (M = 614.43 ms). This result provides evidence that skipped words are sometimes not processed to the same degree as fixated words during reading.

Reading skill and word skipping: Implications for visual and linguistic accounts of word skipping.

We investigated whether high-skill readers skip more words than low-skill readers as a result of parafoveal processing differences based on reading skill. We manipulated foveal load and word length, two variables that strongly influence word skipping, and measured reading skill using the Nelson-Denny Reading Test. We found that reading skill did not influence the probability of skipping five-letter words, but low-skill readers were less likely to skip three-letter words when foveal load was high. Thus, reading skill is likely to influence word skipping when the amount of information in the parafovea falls within the word identification span. We interpret the data in the context of visual-based (extended optimal viewing position model) and linguistic based (E-Z Reader model) accounts of word skipping. The models make different predictions about how and why a word and skipped; however, the data indicate that both models should take into account the fact that different factors influence skipping rates for high- and low-skill readers.