My research falls in the fields of cognitive psychology and cognitive neurosciences. More precisely, I work on language and reading processes. Even more precisely, most of my work is dedicated to understand the different aspects of written word processing, from letter feature perception to lexical competition, including relationships between the orthographic, phonological, and semantic features of letter strings.
I usually investigate such questions both in skilled and beginning readers, trying to use a wide range of behavioral paradigms (e.g., lexical decision, naming, discrimination, eye movements, length judgment,…). When it’s relevant, I collect electrophysiological data (mostly EEG) in addition to behavioral data. Here are some issues I’ve worked on so far.
Visual word recognition and perceptual structure of words
This line of research was developed mostly during my Ph.D. I investigated to what extent the properties of syllables composing letter strings influence visual word recognition. Especially, I showed that readers recognized words more rapidly when their syllables were made salient by priming or color matching (e.g., palace and palmier, /pa-las/ and /pal.mje/ respectively) rather than other letter groups (e.g., palace and palmier) (e.g., Chetail & Mathey, 2009a; Chetail & Mathey, 2009b). I also examined competition effects between syllabic neighbours (words sharing a syllable at a same position: e.g., the syllable /ka/ in first position in café, canard, caméléon) during lexical access. Especially, I showed that the strongest syllabic competitors are those sharing the same number of syllables (Chetail & Mathey, 2011) and those which are much more frequent that the other potential competitors (Chetail, Colin, & Content, 2012). I’m still interested in reading units and this has led me in the end to question the role of phonological syllables in visual word recognition (Chetail, 2014).
Consonant and vowel letter processing
This line of research is linked to the previous one. I spent several years to examine the nature of the cues that support word parsing into multiletter units. This has led me and colleagues to test a new hypothesis according to which the consonant-vowel (CV) organization of letter strings is a powerful cue to determine their internal orthographic structure. For example, we showed that although a word like REACTION has three syllables, readers often erroneously report that there are only two. This is due to the fact that the CV alternation leads to two groups of adjacent vowels (EA and IO, vowel clusters) (e.g., Chetail & Content, 2012). Consistently, REACTION (2 vowel clusters) was estimated shorter than EVASION (3 vowel clusters) despite strict identical length on the screen (Chetail & Content, 2014). Although the CV pattern may not be the only cue used to extract the structure of letter strings, these results challenge current models that consider orthographic representations in the initial stages of written word processing as mere concatenations of letters.
Orthographic regularities and statistical learning
Humans are known to continuously extract regularities from the flow of stimulation, helping them to perceive the structure of the world, and thus to decrease uncertainty, to repeat successful strategies, and to reduce the information load. The continuous extraction of regularities from the flowing array of stimulation occurs in many facets of behavior, including reading. For example, we know that the letters C and I co-occur more frequently than the letters K and I, although we have never been explicitly taught. In a recent article, I proposed that orthographic regularities could have a functional role at different level of written word processing (Chetail, 2015). I’m currently conducting several experiments to test the different hypotheses and see whether we can find reliable evidence of orthographic redundancy effects. Doing that has led me to use artificial scripts, situation of new word learning and paradigms of statistical learning. For example, to avoid the natural confounds between orthographic regularities and other linguistic variables known to influence visual word recognition, we test the effect of regularities in new scripts to which participants are exposed during a few minutes (Chetail, 2017).
Novel word learning
Individuals with an extended vocabulary understand a broader range of texts and conversations than those with less lexical knowledge. In young readers, we know that the growth of vocabulary is driven by incidental learning of new words during reading. Such learning continues in adults who are frequently exposed to new words during reading. A new line of research I’m starting aimed at examining how orthographic representations of new words emerge in skilled readers. This question has been little investigated in adults, and most of the time with laboratory experimental designs very different from what happens in daily life. In contrast the aim here is to use ecological designs to examine three main issues: To what extent the new orthographic representations stored in memory are initially fragmented, to what extend they remains plastic over time, and how they are gradually integrated in the pre-existing network of orthographic representations.
Reading motivation, engagement and language abilities
Many studies reported a positive link between the amount of reading practice and reading efficiency: The more one reads, the better reader one becomes. The poor performance of one quarter of students in the international surveys could therefore be accounted for by a low level of print exposure. This hypothesis is supported by the fact that the poorest readers actually declare reading less and being surrounded by fewer books than the better ones. Understanding the relationship between reading activity and reading efficiency thus constitutes the cornerstone of reading skill improvement. In this recent line of research, I investigate to what extent fostering reading motivation is sufficient to increase the amount of independent reading and print exposure, which in turn improves neurocognitive reading processes, increases reading efficiency, and enriches world knowledge and emotional life. These effects are examined in both adults and children.
Spelling abilities and variabilities
Learning to read goes with learning to spell. Yet, despite good reading efficiency, spelling abilities of individuals drastically varies and depend on the quality of orthographic representations. In this line of research, I try to understand what the factors explaining this variability are (sublexical orthographic knowledge, memory capacities, print exposure ?…). Moreover, this issue is also examined in children and specifically in deaf children known to have lower reading (and sometimes spelling) abilities than hearing children. This line of research is conducted by Elodie Sabatier during her Ph.D.
Task and tool development
This is not a line of research but rather a way to do. Effects we are looking for in cognitive psychology are usually small and subtle. They occur sometimes just in a few situations (that we struggle to identify) and can be hard to replicate. I think that to understand complex processes such as those involved in word recognition we need a broad range of paradigms/tasks taping onto different levels of processing. When relevant, I therefore try to use or develop different tasks to address specific questions (Chetail & Content, 2012; Chetail & Content, 2014) or I combine methods coming from other fields. Furthermore, we sometimes need tools and databases to examine some issues. I thus participated to the general effort and created some of such tools to help future research, such as a syllabic database (Chetail & Mathey, 2010), a set of pseudoletter fonts (Vidal et al., 2017) or a spelling test in adults (Chetail et al., 2019).