Letters, Words, Sentences, and Reading

Abstract

In this personal, and therefore highly selective, review article I summarize work performed in collaboration with numerous colleagues on how skilled adult readers perform identification tasks and speeded binary decision tasks involving single letters and visually presented words and sentences. The overarching aim is to highlight similarities in the processing performed at three key levels involved in written language comprehension (in languages that use an alphabetic script): letters, words, and sentences. The comparisons are made using behavioral data obtained with: i) speeded (response-limited) binary decision tasks; and ii) the effects of simultaneous surrounding context on letter and word identification using both data-limited (non-speeded) and response-limited procedures. I then propose a general framework that combines the three levels of processing, and that connects core processes at each level with the processing involved in tasks designed to reflect those core processes, and I end by suggesting possible avenues for future research with an aim to extend this general framework.

Keywords: Letter identification; Reading; Sentence processing; Word recognition.

Figure 1

From Massol and Grainger (2022). Stimuli are first encoded via location-specific gaze-centered complex feature detectors. Location-specific complex features then activate location-invariant object identities that are assigned an order in the string. Crucial is the hypothesized distinction between two different location-invariant order-encoding mechanisms: a generic order encoding mechanism, illustrated here by a simple ordinal representation (e.g., R(3), there is the letter R at the 3rd position), and a letter-specific order encoding mechanism – open-bigram coding (e.g., R-H, there is an R before an H, possibly with other letters/characters in between). Note that although the component letters of open-bigrams are ordered, the bigrams themselves are not.

Figure 2

Extension of Grainger and van Heuven’s (2004) model of orthographic processing to the case of multiple words (letter strings separated by spaces). Location-specific letter detectors operate in parallel across multiple words, signaling the evidence that a given letter identity or inter-word space is present at a given location relative to eye fixation. This information is used to activate ordered pairs of contiguous and non-contiguous character combinations (26 letters augmented with the space character—#) stored as an unordered set of open-bigrams (a bag of bigrams). Bigrams then activate whole-word orthographic representations for unique word identification.

Figure 3

Connecting processing at the letter, word, and sentence levels during reading by using comparable paradigms to investigate processing at each level (Figure from Brossette et al., 2022).

Figure 4

A “box and arrows” representation of the main processing phases involved in transitioning from a visual representation of strings of letters to meaning during skilled adult reading in a language that uses an alphabetic script. In red are “read-out” mechanisms that connect core processes with decision-level processing required to perform a particular task (Grainger & Jacobs, 1996).