Compound word processing: development and disorder

Abstract

Compounding is one of the most productive methods to construct words in different

languages, e.g. joining the words “super” and “man” gives the compound word

“superman”. For decades, researchers are interested to know how compound words are

stored and retrieved in the lexicon. Different theories of lexical storage and retrieval of

compound words were proposed to explain the compound word processing observed in

both normal and abnormal adult subjects. However, little studies have attempted to apply

these theories to explain the developmental pattern of storage and retrieval of compound

words. To fill the gap, the major aim of the current study is to investigate the power of

different theories of lexical storage and retrieval of compound words in explaining the

typical and atypical development of compound word processing in Chinese children.

Altogether, 20 grade 2 children, 22 grade 4 children, and 17 grade 6 children

screened to have normal non-verbal intelligence and reading abilities were recruited from

a local mainstream school. Three experiments were conducted to investigate the existence

of the holistic representations of compound words and the representations of their

constituent morphemes in the lexicon, and their involvement during the compound word

retrieval processes across different grade levels.

Results show that grade 4 and grade 6 children demonstrate significant whole-word

frequency, morphological family size and semantic transparency effects in all three

experiments, a pattern which resembles that observed in normal adult subjects. The grade

2 children, however, only demonstrate significant whole-word frequency effect but not

the morphological family size and the semantic transparency effect. The results indicate

that grade 4 and grade 6 children adopt the partial-decomposed approach of compound

word storage and retrieval (e.g. Taft, 2003). As for the grade 2 children, it is hypothesized

that their performances represent a developing stage of the partial-decomposed approach,

where networks of morphological relations between family members were underdeveloped

in their lexicon.

Further investigation of the compatibility of the partial-decomposed approach in

explaining the compound word storage and retrieval pattern resulted from atypical

development was conducted. The three experiments mentioned above were administered

on 16 poor readers (PR), 16 reading-level-matched (RL) peers and 16 chronological-agematched

(CA) peers. Interestingly, the PR group’s performances resemble that of the RL

and CA group in experiments of whole-word frequency and morphological family size

but not in experiment of semantic transparency. The PR group’s performances can be

explained by assuming a deficit in identifying shared semantic features between

compound words and their constituents in the partial-decomposed approach. It is

proposed that the PR group identifies frequently occurring morphemes as salient

orthographic reading units without recognizing the shared semantic features between

compound words and their constituents.

In summary, results of the current study support the partial-decomposed approach of

lexical storage and retrieval of compound words. The current study further proposes (i) a

developing stage of the partial-decomposed approach to explain the compound word

processing within an under-developed lexicon and (ii) a deviated partial-decomposed

approach to explain the compound word processing of children with reading difficulties.