Models Of Morphological Processing Research Articles

The Curious Role of Morphological Family Size in Language Minority Learners’ Problem Solving of Unfamiliar Words

ABSTRACT Given that words from the academic layer of English typically carry bound roots (min in diminish) rather than free-standing base words (small in smaller), there is a need to understand the factors that make bound roots more or less accessible for morphological problem-solving unfamiliar words. We investigated the contributions of learner characteristics and morpheme/word characteristics to the morphological problem-solving skill of 87 language minority learners. Participants analyzed 18 morphologically complex, unfamiliar words on a Morphological Analysis Task. Among learner characteristics, results from multilevel logistic models indicated that only English proficiency predicted difficulty. For root characteristics, semantic opaqueness, phonological shift, and orthographic neighborhood size predicted difficulty as expected. Morphological family size also predicted difficulty, but in unexpected ways, with larger family size predicting greater difficulty. Exploratory analyses suggested that family size may interact with other root characteristics to further influence difficulty. Findings hold implications for models of morphological processing and literacy intervention design.

Statistical models of morphology predict eye-tracking measures during visual word recognition

We studied how statistical models of morphology that are built on different kinds of representational units, i.e., models emphasizing either holistic units or decomposition, perform in predicting human word recognition. More specifically, we studied the predictive power of such models at early vs. late stages of word recognition by using eye-tracking during two tasks. The tasks included a standard lexical decision task and a word recognition task that assumedly places less emphasis on postlexical reanalysis and decision processes. The lexical decision results showed good performance of Morfessor models based on the Minimum Description Length optimization principle. Models which segment words at some morpheme boundaries and keep other boundaries unsegmented performed well both at early and late stages of word recognition, supporting dual- or multiple-route cognitive models of morphological processing. Statistical models based on full forms fared better in late than early measures. The results of the second, multi-word recognition task showed that early and late stages of processing often involve accessing morphological constituents, with the exception of short complex words. Late stages of word recognition additionally involve predicting upcoming morphemes on the basis of previous ones in multimorphemic words. The statistical models based fully on whole words did not fare well in this task. Thus, we assume that the good performance of such models in global measures such as gaze durations or reaction times in lexical decision largely stems from postlexical reanalysis or decision processes. This finding highlights the importance of considering task demands in the study of morphological processing.

Stem and whole-word frequency effects in the processing of inflected verbs in and out of a sentence context

The relationship between stem and whole-word frequency was investigated by simultaneously manipulating both frequency measures in a set of inflected verbs. In Experiment 1, these verbs were presented in isolation as part of a lexical decision task, and an effect of stem frequency only was observed. In Experiment 2, the same verbs were presented in sentences in a self-paced reading task, and an interaction between stem and whole-word frequency was observed. These findings contradict “either–or” models of morphological processing that assume two separate and independent processing routes for morphologically complex words, and also provide further evidence that the relationship between stem and whole-word frequency effects is context-sensitive.

How do roots and suffixes influence reading of pseudowords: A study of young Italian readers with and without dyslexia

The study explored the different influences of roots and suffixes in reading aloud morphemic pseudowords (e.g., vetr-ezza, “glass-ness”). Previous work on adults showed a facilitating effect of both roots and suffixes on naming times. In the present study, pseudoword stimuli including roots and suffixes in different combinations were administered to sixth-grade children with dyslexia (N=22) and skilled readers (N=44), matched for chronological age. Indeed, the sequential reading strategy of less proficient readers (particularly for pseudowords) should favour the emergence of differences between left and right constituents (root and suffix, respectively) in reading performance. Results showed that for both children with dyslexia and skilled young readers the onset of pronunciation depended exclusively on roots, while there was no significant effect of suffixes. However, both roots and suffixes led to higher levels of accuracy than matched orthographic strings of letters. Posthoc regression analyses confirmed the morphological nature of the root and suffix effects, over and above the effects of the frequency of their orthographic patterns. Results indicate that the position of the reading units within the letter string, as well as their differential effects on latencies and accuracy, should be taken into account by models of morphological processing in word recognition and reading and by applied intervention research.

Morphophonological categories of noun plurals in Hebrew: a developmental study

The study analyzes command of noun plurals and phonological awareness of Hebrew-speaking children at the beginning and end of the first year of formal schooling. Our aims were to trace the development of noun plurals during a crucial year in children's life, when they are exposed to a considerable amount of spoken and written language; to determine the impact of different morphophonological plural categories on pace of acquisition; and to determine the relationship between morphological awareness (as measured in the Plural Task) and phonological awareness. Research population consisted of 110 Hebrew-speaking first graders aged 6–7, who were tested twice on pluralization and phonological awareness at the beginning and the end of the school year. Results show that learning of noun plurals is still under way in first grade, side by side with clear improvement in phonological skills. Plural acquisition is paced by morphophonological category: Nouns with nonchanging stems and regular suffixes are already at ceiling at age 6 and are not correlated with phonological skills; but nouns with nonchanging stems and irregular suffixes and both categories of changing stems improve significantly, and are correlated with phonology. These results are discussed in terms of different models of morphological processing and acquisition.

Morphological effects in auditory word recognition: Evidence from Danish

In this study, we investigate the processing of morphologically complex words in Danish using auditory lexical decision. We document a second critical point in auditory comprehension in addition to the Uniqueness Point (UP), namely the point at which competing morphological continuation forms of the base cease to be compatible with the input, henceforth the Complex Uniqueness Point (CUP). Suffixed words with later CUP elicited longer response latencies. We also observed an interaction between suffix frequency and whole-word frequency. Both suffix and whole-word frequency were facilitatory, except for words for which both frequencies are high. For such words, we observed inhibition, and most clearly so for female compared with male participants. Finally, a comparison of complex with simple words revealed that, other things being equal, complex words have a processing advantage compared to simple words. We discuss the consequences of these findings for models of morphological processing.

Role of inflectional regularity and semantic transparency in reading morphologically complex words: Evidence from acquired dyslexia

We report two patients with acquired phonological dyslexia who have great difficulty reading affixed words. Experiment 1 demonstrates that both patients' reading performance is influenced by the apparent morphological status of words by comparing the patients' reading of suffixed and pseudo-suffixed words. Experiment 2 was designed to examine reading performance of both regularly and irregularly inflected words. Experiment 3 examines the patients' reading of derivational forms with particular emphasis of the role of ‘semantic transparency’. Experiment 4 tested both patients' reading of prefixed words. Finally, Experiment 5 examined performance on a lexical decision task using affixed words. These data support models in which regularly formed inflections and semantically transparent derived forms are subjected to decomposition during processing, whereas irregularly inflected forms and semantically opaque forms may be represented independently. Data are discussed with regard to current ‘dual mechanism’ models of morphological processing as well as connectionist perspectives, with particular emphasis of the types of data that will ultimately be necessary to arbitrate between the rival theories.

Lexical frequency in morphology: is everything relative?

While it is widely assumed that high-frequency morphologically complex forms tend to display characteristics of noncompositionality, models of morphological processing do not predict a direct relationship between absolute frequency and decomposition. Rather, they predict a relationship between decomposition and the relative frequency of the derived form and the base. This paper argues that such a relative frequency effect does, indeed, exist. First, the results of a simple experiment demonstrate that subjects perceive derived forms that are more frequent than their bases to be significantly less complex than matched counterparts that are less frequent than their bases. And second, dictionary calculations reveal that derived forms that are more frequent than their bases are significantly more likely to display symptoms of semantic drift than derived forms containing higher-frequency bases. High-frequency forms, however, are no more prone to semantic drift than low-frequency forms. These results provide evidence that it is relative frequency, rather than absolute frequency, that affects the decomposability of morphologically complex words A low-frequency form is likely to be nontransparent if it is composed of even-lower-frequency parts. And a high-frequency form may be highly decomposable if the base word it contains is higher frequency still.