Processing effort during reading texts in young adults: text simplification, readability assessment and preliminary eye-tracking data
Authors: Maria De Martino (Università di Salerno, 2023)
Topic: Text Simplification

Abstract
The paper reports empirical data about the impact of text simplification procedures supported by readability assessment measures on processing effort during reading. Sixty-six Italian native undergraduate students read original and simplified versions of TV news texts and answered a comprehension question. Accuracy data, single word-based and sentence-based measures collected by means of an eye-tracker show that reading simplified texts requires less cognitive demands than their original versions.

Introduction
Reading is a recent achievement in human evolution, but reading proficiency is considered an important component of success and life outcome. The ability to read and understand with minimum effort depends on both reader characteristics (e.g., literacy, multilingualism, presence/absence of cognitive disorders) and text properties (e.g., length, topic, lexical and syntactic complexity, cohesion, coherence). One approach to improve inclusion by coping with disadvantage in reading skills is to match readers with texts appropriate to their reading abilities. This goal can be accomplished by exploiting readability formulas to predict the reading and comprehension difficulty of a text for a given target audience and, then, to obtain simplified, i.e. easy-to-understand, texts. Different readability formulas are available for several languages. Many of them rely on text linguistic features such as lexical and syntactic features. Lexical features include the values of frequency, familiarity, imageability and age of acquisition of words within a text. Syntactic features include the complexity of syntactic structures such as the incidence of types of clauses and phrases in the text. Both lexical and syntactic features have been shown to impact cognitive demands in reading processes. Hence, more recent readability formulas take into account measures of natural text processing and try to express readability in terms of cognitive processing effort. Actually, reading texts is a complex behavior subserved by automated interactions between different cognitive processes: visual perception, attention, lexical access, working memory, semantic processing. All these processes are involved in the two main aspects of reading: visual information decoding and meaning construction (comprehension). One of the techniques that has been extensively used to study the reading behavior is the recording of eye movements. During reading, the reader’s eyes move from one position to the next in order to process different levels of information that can be extracted from words’ visual form. Psycholinguists assume that eye movements during reading reflect different stages of language processing. Some movement have a perceptual function: saccades are rapid movements that shift the eye’s focus between two fixed points and are necessary to bring the visual information into the zone of the visual field where acuity is best. Other movements have more complex functions. Fixations are short periods of steadiness of the eye on a word and their duration is a marker of the ease of accessing the meaning of the word and integrating this into the current sentence. Regressions are backward-directed saccades and are related to the necessity of the reader to re-analyze previously explored portions of the text because of processing difficulties. Gaze behavior during reading is exploited in several contexts and for different aims both in cognitive psychology and in Natural Language Processing (NLP) literature. For instance, eye-tracking metrics are exploited to unfold mechanisms of reading in L2 learners, typical and atypical readers. Corpora of eye-tracking data are available in many languages and are profitably used to implement language models that can predict human reading behavior. A less investigated issue is to what extent the use of specific text simplification strategies reduces the processing effort as measured through eye-movements. The aim of the present study is to test the impact of texts’ simplification and readability assessment on young adults reading behavior through the analysis of eye-movements.

Conclusion
The paper investigates to what extent the application of text simplification strategies improves the readability of texts and reduces the reading processing effort as it emerges from cognitive indexes that are out of the awareness of the reader, i.e. eye movements patterns. The preliminary data reported in the paper show that accuracy in comprehension questions increases significantly when texts undergo simplification procedures based on the reduction of the reader’s amount of processing inferences (i.e., event reordering or coreference chains explaining). On the other hand, the physiological and cognitive measures related to the processing effort during reading are affected by simplification strategies that involve both the lexical-syntactic level and the content level. Moreover, the metrics collected at the sentence-level and single-word level are found to be suitable and sensitive measures to detect respectively the efficacy of simplification procedures in modulating the strategic controlled processes involved in comprehension and the attentional and lexical processing effort during reading. Interestingly, the data were obtained by analyzing the performance of young adult skilled readers that are supposed to be less likely influenced by the readability of texts.