How do we segment text? Two-stage chunking operation in reading

Chunking in language comprehension is a process that segments continuous linguistic input into smaller chunks that are in reader’s mental lexicon. Effective chunking during reading facilitates disambiguation and enhances efficiency for comprehension. However, the mechanisms of chunking remain elusive, especially in reading given that information arrives simultaneously yet the written systems may not have explicit cues for labeling boundaries such as Chinese. What are the mechanisms of chunking operation that mediates the reading of the text that normally contains hierarchical information? We investigated this question by manipulating the lexical status of the chunks at distinct levels of grain-size in four-character Chinese strings, including the two-character local chunk and four-character global chunk. Participants were asked to make lexical decision on these strings in a behavioral experiment, followed by a passive reading task when their electroencephalography (EEG) were recorded. The behavioral results showed that the lexical decision time of lexicalized two-character local chunks was influenced by the lexical status of four-character global chunk, but not vice versa, which indicated that the processing of global chunks possessed priority over the local chunks. The EEG results revealed that familiar lexical chunks were detected simultaneously at both levels and further processed in a different temporal order -- the onset of lexical access for the global chunks was earlier than that of local chunks. These consistent behavioral and EEG results suggest that chunking in reading occurs at multiple levels via a two-stage operation -- simultaneous detection and global-first recognition.Significance StatementThe learners of a new language often read word by word. But why can proficient readers read multiple words at a time? The current study investigates how we efficiently segment a complicate text into smaller pieces and how we process these pieces. Participants read Chinese strings with different structures while their key-press responses and brain EEG signals were recorded. We found that texts were quickly (about 100 ms from their occurrences) segmented to varied sizes of pieces, and larger pieces were then processed earlier than small pieces. Our results suggest that readers can use existing knowledge to efficiently segment and process written information.

Valency, secondary frequency, and lexical access: A Japanese study

This study examines the effect of valency (defined as the associative value that represents the number of two-kanji words containing in first or second position the first-positional kanji of the word) on the recognition of two-kanji words in Japanese. Lexical decisions were 24 ms faster for words in the high-valency condition than in the low-valency condition, but were 26 ms slower for nonwords in the high-valency condition than in the low-valency condition. While these results suggested a significant interaction between valency and wordness, a regression analysis indicated that the frequency and valency of the first constituent kanji are significant factors for word recognition, and that the frequency of the first constituent kanji is a significant factor for nonword recognition. The secondary-frequency effect hypothesis is put forth to explain the effects of valency and other variables on lexical decision time.

Effects of Memory Load on Joke and Lexical Decision Tasks

The effects of a five-digit memory load on joke and lexical decision tasks were measured. 72 college students read jokes ending with punchlines, consistent endings, or inconsistent endings and decided whether the endings produced jokes. Memory-loaded subjects were slower than nonloaded subjects, particularly on inconsistent endings which were surprising but not coherent with the body of the joke. Memory load had no effect on lexical decision time and did not interact with word frequency. The results supported the claim that working memory serves an integrating role in language comprehension.

Effect of Prime and Target Repetition on Lexical Decision Time

On a prime-target lexical decision task we manipulated the relatedness between prime and target (semantically related or unrelated), the number of repetitions (from 1 to 5), the type of the repeated stimulus (only the prime, only the target, or both), and the stimulus onset asynchrony (within a range of automatic activation from 60 to 400 msec.) to find whether semantic and repetition priming are additive (or interact), and whether there is episodic priming in an automatic, nonconscious way. Analysis showed repetition and semantic priming were additive rather than interactive. No episodic automatic priming was found. Results are discussed in terms of the predictions made from the main theoretical positions about the repetition effect.

Effect of Prime Type on Lexical Decision Time

The present investigation concerns the issues of the control condition and type of related prime-target relationship operationalization in the lexical-decision paradigm. It is shown that the use of a row of asterisks produces strong inhibitory effects on reaction time to the target relative to a control condition formed with the word “neutro” (“neutral”). The operationalization of prime-target relatedness by means of association of category norms seems equally adequate, although category exemplars do not prime category exemplar targets. Both sets of data are discussed in relation to current research trends using lexical-decision time.