Marcus Taft

LEXICAL STORAGE AND RETRIEVAL OF PREFIXED WORDS

Three experiments are described which support the hypothesis that in a lexical decision task, prefixed words are analyzed into their constituent morphemes before lexical access occurs. The results show that nonwords that are stems of prefixed words (e.g., juvenate ) take longer to classify than nonwords which are not stems (e.g., pertoire ), suggesting that the nonword stem is directly represented in the lexicon. Further, words which can occur both as a free and as a bound morpheme (e.g., vent ) take longer to classify when the bound form is more frequent than the free form. Finally, prefixed nonwords took longer to classify when they contained a real stem (e.g., dejuvenate ), compared with control items which did not (e.g., depertoire ). A general model of word recognition is presented which incorporates the process of morphological decomposition.

Recognition of affixed words and the word frequency effect.

Three experiments are reported in which the word frequency effect is used as a diagnostic for determining whether affixed words coming from the same stem are stored together or separately in the lexicon. Prefixed words are examined in the first experiment, inflected words in the second and third. In the first two experiments, two types of word are compared where the words in each condition are matched on surface or presented frequency but are varied on the frequency of their stems or base frequency. It is found that lexical decision times are influenced by base frequency, thus indicating that words related by affixation are stored together in the lexicon. The third experiment, however, demonstrates that when base frequency is held constant and surface frequency is varied, lexical decision times are influenced by surface frequency. The results are accounted for by a model of word recognition whereby frequency has its effect at two different stages of the recognition process.

Lexical storage and retrieval of polymorphemic and polysyllabic words.

Abstract Five experiments are deseribed which examine how polysyllabic words (e.g., DAY-DREAM, ATHLETE) are stored and retrieved from lexical memory. The first four experiments look at interference effects caused by the accessing of inappropriate lexical entries. It is found that compound nonwords whose first constituent is a word (e.g., DUSTWORTH, FOOTMILGE) take longer to classify as nonwords than compound nonwords whose first constituent is not a word (e.g., TROWBREAK, MOWDFLISK). Moreover, the presence of a word in the second constituent position appears to be irrelevant. These effects hold even when the boundary between constituents is unclear on an orthographic basis (e.g., TRUCERIN). It is also argued that first syllables, as opposed to last syllables, have independent status in the lexicon since nonword first syllables (e.g., ATH) show interference effects, while last syllables (e.g., CULE) do not. The fifth experiment reveals that the frequency of the first constituent of a compound word influences classification times. The results point to the conclusion that polysyllabic words, regardless of whether they are polymorphemic or monomorphemic, are accessed via their first syllable.

Interactive-activation as a framework for understanding morphological processing

Abstract A description is given of the main experiments that have been taken as support for the view that, in reading, a prefixed word is stripped of its prefix and lexically accessed on the basis of its stem. Since one of the most important of those experiments had been poorly executed, a new version of the same study is presented with results that are entirely consistent with the previous one. However, logical problems exist with the view that says that stems act as access codes used to gain access to the lexicon, the main ones having to do with the fact that a prefix store is required. As a result, an alternative model is favoured, namely, an interactive-activation model. Prefixed words are represented in decomposed form in this model, but no prelexical prefix-stripping is required. A detailed examination is made of the manner in which this framework is able to incorporate the previous empirical results, as well as other aspects of morphological processing.

Lexical Access Via an Orthographic Code: The Basic Orthographic Syllabic Structure (BOSS).

Five experiments are described which detail both the structure of lexical representations accessed in visual word recognition and the method of parsing words in order to access these representations. All experiments employ the lexical decision task. The first three experiments provide support for the view that the lexical representation of a word is a representation termed here the Basic Orthographic Syllabic Structure (or BOSS) of that word rather than any articulatorily defined structure. The principle for determining the BOSS is based on both orthographic and morphological factors. Experiments 1 and 2 demonstrate that words are disrupted more when a division is made in the word according to its pronunciation than when it is made according to its BOSS. It is shown in Experiment 3 that final silent Es are not a part of the lexical representations of words and this is predicted by the BOSS principle. The last two experiments provide evidence for a parsing procedure for retrieval that is a reiterative left-to-right technique whereby lexical searches are made for combinations of letters that begin with the initial letter of the word. The results, in all, support a system of lexical access that is not mediated by phonological encoding.

Morphological decomposition and the reverse base frequency effect

If recognition of a polymorphemic word always takes place via its decomposition into stem and affix, then the higher the frequency of its stem (i.e., base frequency) the easier the lexical decision response should be when frequency of the word itself (i.e., surface frequency) is controlled. Past experiments have demonstrated such a base frequency effect, but not under all circumstances. Thus, a dual pathway notion has become dominant as an account of morphological processing whereby both decomposition and whole–word access is possible. Two experiments are reported here that demonstrate how an obligatory decomposition account can handle the absence of base frequency effects. In particular, it is shown that the later stage of recombining the stem and affix is harder for high base frequency words than for lower base frequency words when matched on surface frequency, and that this can counterbalance the advantage of easier access to the higher frequency stem. When the combination stage is crucial for discriminating the word items from the nonword items, a reverse base frequency effect emerges, revealing the disadvantage at this stage for high base frequency words. Such an effect is hard for the dual–pathway account to explain, but follows naturally from the idea of obligatory decomposition.

Submorphemic processing in reading Chinese

Three experiments are reported here to address the question of whether submorphemic information is involved in the recognition of Chinese characters. A character decision task was used in which frequency characteristics of the radicals within a character and radical status of the components within a noncharacter were manipulated. The frexlueney of the fight-hand radical affected responses to 2-radical characters, whereas the radical status of both left and right components affected noncharaeter responses. Furthermore, the impact of radical frequency was shown to be sensitive to radical position. For 3-radical characters, it appeared that the frequency of a compound radical (composed of 2 subradicals) had no effect on responses, whereas the frequency of the subradicals did. It is concluded that all simple radicals are independently activated in the process of character recognition. Compound radicals are not activated in this way despite their common occurrence. The results are considered within a multilevel interactive-activation framework incorporating position sensitivity.

Prefix stripping revisited

Rubin, Becker, and Freeman ( Journal of Verbal Learning and Verbal Behavior , 1979, 18, 757–767) have recently claimed that prefixed words are only recognized via a prefix-stripping procedure in certain experiment-specific circumstances. The experiments reported in the present study, however, provide evidence for the prefix-stripping procedure when no strategies are likely. Explanations for the discrepancy between the present results and those of Rubin et al. are discussed.

Syllables and morphemes: contrasting frequency effects in Spanish.

Three types of sublexical units were studied in Spanish visual word recognition: the syllable, the basic orthographic syllabic structure (BOSS), and the root morpheme. In Experiment 1, using a lexical-decision task, a typical inhibitory effect of the first-syllable frequency was found (while keeping constant the BOSS frequency) as well as the word-frequency effect. Experiment 2 examined the role of both the BOSS frequency and the word frequency, also in a lexical-decision task. Syllable frequency was controlled. Both the BOSS frequency and the word frequency showed facilitatory effects. However, in Experiments 3A and 3B, a facilitatory effect of the root frequency (when controlling for BOSS frequency) and a null effect of BOSS frequency (when controlling for root frequency) were found, suggesting that the BOSS effect is in fact reflecting a morpheme effect. A review of the current models shows that it is difficult to integrate syllables and morphemes in a unique model.

The Efficiency of Attentional Networks in Early and Late Bilinguals: The Role of Age of Acquisition

Previous studies have demonstrated a bilingual advantage in the efficiency of executive attention. A question remains, however, about the impact of the age of L2 acquisition and relative balance of the two languages on the enhancement of executive functions in bilinguals, and whether this is modulated by the similarity of the bilinguals two languages. The present study explores these issues by comparing the efficiency of attentional networks amongst three groups of young adults living in Australia: English monolinguals and early and late Chinese–English bilinguals. We also address the impact of bilingualism on hemispheric lateralization of cognitive functions, which is of interest since a recent study on early bilinguals revealed reduced hemispheric asymmetry in attentional functioning. In the present study, participants performed a modified version of the lateralized attention network test. Both early and late bilinguals were found to have more efficient executive network than monolinguals. The late bilinguals, who were also reported to be more balanced in the proficiency and usage of their two languages, showed the greatest advantage in conflict resolution, whereas early bilinguals seemed to show enhanced monitoring processes. These group differences were observed when controlling for non-verbal intelligence and socioeconomic status. Such results suggest that specific factors of language experience may differentially influence the mechanisms of cognitive control. Since the bilinguals had distinct language sets, it seems that the influence of bilingualism on executive functions is present regardless of the similarity between the two languages. As for hemispheric lateralization, although the results were not clear-cut, they suggest the reduced lateralization in early bilinguals.