Elsevier

Cognition

Volume 72, Issue 1, 25 August 1999, Pages 1-44
Cognition

Default nominal inflection in Hebrew: evidence for mental variables

https://doi.org/10.1016/S0010-0277(99)00027-XGet rights and content

Abstract

According to the `word/rule' account, regular inflection is computed by a default, symbolic process, whereas irregular inflection is achieved by associative memory. Conversely, pattern-associator accounts attribute both regular and irregular inflection to an associative process. The acquisition of the default is ascribed to the asymmetry in the distribution of regular and irregular tokens. Irregular tokens tend to form tight, well-defined phonological clusters (e.g. sing-sang, ring-rang), whereas regular forms are diffusely distributed throughout the phonological space. This distributional asymmetry is necessary and sufficient for the acquisition of a regular default (Hare, M., Elman, J., Daugherty, K., 1995. Default generalization in connectionist networks. Language and Cognitive Processes 10, 601–630; Plunkett, K., Nakisa, C., 1997. A connectionist model of Arabic plural system. Language and Cognitive Processes 12, 807–836). Hebrew nominal inflection challenges this account. We demonstrate that Hebrew speakers use the regular masculine inflection as a default despite the overlap in the distribution of regular and irregular Hebrew masculine nouns. Specifically, Experiment 1 demonstrates that regular inflection is productively applied to novel nouns regardless of their similarity to existing regular nouns. In contrast, the inflection of irregular sounding nouns is strongly sensitive to their similarity to stored irregular tokens. Experiment 2 establishes the generality of the regular default for novel words that are phonologically idiosyncratic. Experiment 3 demonstrates that Hebrew speakers assign the default regular inflection to borrowings and names that are identical to existing irregular nouns. The existence of default inflection in Hebrew is incompatible with the distributional asymmetry hypothesis. Our findings also lend no support for a type-frequency account. The convergence of the circumstances triggering default inflection in Hebrew, German and English suggests that the capacity for default inflection may be general.

Introduction

The study of inflectional morphology has been the subject of a fierce controversy between symbolic and associative theories of cognition. Common to both accounts is the proposal that irregular inflection (e.g. go-went, mouse-mice) is achieved by associative memory. The center of debate concerns regular inflection (e.g. like-liked, house-houses). According to the pattern-associator hypothesis1, mental processes are fully explicable by the associations between specific tokens. Pattern-associator accounts (e.g. Rumelhart and McClelland, 1986; MacWhinney and Leinbach, 1991; Plunkett and Marchman, 1991; Daugherty and Seidenberg, 1992; Plunkett and Marchman, 1993; Hare and Elman, 1995; Hare et al., 1995), thus, attribute both regular and irregular inflection to an associative process. The representation of regular words is indistinguishable from irregular words. All words are represented solely by their phonological, semantic and orthographic features. Variables, such as noun or verb, are eliminated from mental representations. Regular inflection is thus largely explicable by the distribution of regular and irregular tokens in the language. Conversely, the `word/rule' account (Pinker, 1991; Pinker, 1994; Pinker, 1997; Pinker, 1999) views regular inflection as a symbolic process. Symbolic processes operate over variables and are blind to the contents of specific tokens (Fodor and Pylyshyn, 1988). Consequently, regular inflection applies across the board, regardless of the target's idiosyncratic features. In addition, regular inflection serves as a default: it applies to any target that fails to activate stored associations by the `elsewhere condition'. An `elsewhere condition' is the application of a general linguistic process upon the failure to trigger a more specific process (Kiparsky, 1973). The conditions for activating irregular inflection (e.g. `go' as a condition for `went') constitute a subset of the conditions for triggering regular inflection (e.g. the identification of any canonical verb stem). A failure to activate irregular inflection thus triggers the regular default.

There is substantial empirical support for the view of regular inflection as a default. For instance, regular inflection is assigned to borrowings, names and denominals, all failing to trigger stored associations due to their lack of a canonical root (Kim et al., 1991, Kim et al., 1994; Marcus et al., 1995). Likewise, regular inflection applies to non-words that are dissimilar to English verbs, hence, are unlikely to activate similar stored irregular tokens (Prasada and Pinker, 1993). In both cases, regular inflection applies generally, regardless of the similarity of the targets to stored tokens. Specifically, the assignment of regular inflection to non-words that are dissimilar to existing regular verbs does not differ from non-words that are highly similar to familiar regular verbs (Prasada and Pinker, 1993). Conversely, regular inflection is observed for borrowings, names and denominals that are highly similar, or even identical to stored irregular words (Kim et al., 1991, Kim et al., 1994; Marcus et al., 1995).

Despite the strong empirical support for the existence of a default inflection, controversy still remains regarding its source. According to the symbolic view, the wide variety of circumstances resulting in default inflection indicates that regular inflection operates over mental variables (Marcus, 1998a, Marcus, 1998b, Marcus, 1999; Pinker and Prince, 1988). Variables are abstract labels. For instance, the variable `verb stem' enumerates tokens such as like, explain, refrigerate. Variables define equivalence classes: they assign a uniform representation to all the tokens they enumerate, ignoring their individual idiosyncrasies. It is the uniform representation of all nouns (or verbs) by a single label that explains the generality of regular inflection and its insensitivity to token-specific features. Likewise, it is the representation of the grammatical category of a `root' which explains the blocking of irregular inflection for denominals, names and borrowings, despite their strong resemblance to stored irregular tokens. The appeal to variables is thus fundamental to the symbolic account. In contrast, according to the pattern-associator view, variables play no role in cognitive processes. The emergence of a regular default may be adequately explained by an associative process (e.g. Rumelhart and McClelland, 1986; Seidenberg, 1987, Seidenberg, 1997; Seidenberg and McClelland, 1989; Elman, 1993; Hare and Elman, 1995; Elman et al., 1996; Plaut et al., 1996; Rueckl et al., 1997).

The present research examines whether default inflection appeals to mental variables. We first review two associative explanations for the emergence of default inflection. We then present a new challenge to the associative account: Hebrew nominal inflection. We describe the distributional properties of Hebrew nouns and the predictions of the associative account regarding their inflection. The following experiments test these predictions.

Associative theories of cognition have proposed two accounts for the emergence of default inflection: the type frequency and the distributional asymmetry hypotheses. According to the type-frequency account (e.g. Rumelhart and McClelland, 1986; Plunkett and Marchman, 1991; Daugherty and Seidenberg, 1992; Plunkett and Marchman, 1993; Bybee, 1995), the role of regular inflection as a default is due to the ubiquity of regular types in the language. In modern English, for example, regular inflection applies to the majority of verbs in the language. Thus, the probability that a novel verb activates nodes shared with regular verbs is higher than the probability of it activating irregular verbs' nodes. The type-frequency hypothesis has been subject to theoretical and empirical challenges. On the theoretical end, it is unclear whether type frequency is sufficient for the acquisition of default inflection (see Prasada and Pinker, 1993; Marcus et al., 1995). Subsequent empirical findings indicated that type frequency is not necessary for default inflection either. Specifically, the documentation of default inflection in German (Clahsen et al., 1992; Marcus et al., 1995) and Old English (Hare et al., 1995), languages in which most types are irregular, demonstrates that default inflection may be acquired despite the minority of regular types. Thus, type frequency is neither necessary nor sufficient for default inflection.

An alternative associative account attributes the acquisition of the default to the distribution of regular and irregular tokens. Hare et al. (1995)noted a contrast in the distribution of regular and irregular tokens in Old English. Irregular tokens tend to group in phonological clusters (e.g. tiv-tav, dif-daf, dirf-darf). These clusters occupy bounded, well-defined regions of the phonological space. In contrast, regular tokens are sparsely distributed throughout the remaining space. According to the distributional asymmetry account, the acquisition of default regular inflection is due to the asymmetry in the distribution of regular and irregular tokens. Furthermore, Hare et al. (1995)demonstrated that a regular default is successfully acquired by a connectionist network trained on a corpus modeled after Old English. Hare et al. attribute the learnability of the default to the distributional properties of Old English. Specifically, they note that:

`In the current simulations, there are two conditions which together are responsible for the emergence of the default category. First, the phonologically well-defined classes occupy bounded regions in the input space....Second, the default category itself must be represented by items which are spread throughout the remaining space. It is not necessary that this space be well-populated; in the current simulations, very few exemplars were required. What is necessary is that these examples serve to isolate the regions of attraction of the non-default categories (more precisely, they establish hyperplanes around those basins). The effect of both conditions is that the network learns, through a relatively few examples, that any item which does not resemble one of the five well-defined classes is to be treated in the same way. This is the `elsewhere condition', which is often defined as the default (Hare et al., 1995, pp. 626–627).'

The success of the model of Hare et al. (1995)suggests that distributional asymmetry may be sufficient for the acquisition of default inflection by a connectionist network. However, the implications of these findings to symbolic accounts are not entirely clear. The success of a connectionist network in modeling the regular default does not necessarily challenge its view as a symbolic process. Indeed, symbolic and connectionist accounts of cognition are not mutually incompatible. Multilayer networks are universal function approximators (Hornik et al., 1989; Siegelman and Sontag, 1995), hence, the potential of some connectionist device to implement symbolic functions is virtually guaranteed (for discussions, see Marcus, 1998a; Marcus, 1998b). The debate between symbolic and connectionist accounts of cognition does not concern whether connectionist networks can adequately model cognition, but instead, how they do so.

At the heart of the debate is the role of variables in mental computations: are mental computations constrained by the combinatorial structure of variables, or is cognition largely explicable by the statistical distribution of tokens? Specifically, in the case of inflectional morphology, the disagreement concerns the representation of grammatical categories (e.g. a `verb stem', `noun stem' `suffix') and rules, i.e. mental functions that are sensitive to the combinatorial structure of these categories (e.g. `copy the stem and add a suffix') (Marcus, 1998bMarcus, 1999). The successful acquisition of default inflection by a connectionist network is not incompatible with the representation of variables and rules. As pointed out by Marcus (1999), the model of Hare et al. (1995)implements rules and variables. This model includes two components: a feedforward network and an interactive-activation network that transforms the probabilistic phonological output of the feedforward network into discrete phonemes. In each of these components, there is a built-in distinction between the stem and -ed suffix. The feedforward network designates separate output units to the stem (with a further distinction between onset, nucleus and coda units) and the -ed suffix. Likewise, the clean-up network includes separate banks of units for the stem vowels and the inflected vowel and -ed suffix. This architecture implements two rules. One is `copy the stem vowel', a rule implemented by innately fixing the weights of the connections between the nuclei in the base and inflected form to one. A second rule is `add -ed if the memory trace for an irregular is weak'. The precedence of irregular over regular inflection (the `elsewhere condition') is achieved by the innate inhibitory connections between the inflected nucleus and the regular suffix. Thus, if the feedforward component of the network strongly activates an inflected nucleus, then the regular suffix is inhibited. Conversely, the failure to locate an inflected (irregular) nucleus triggers regular inflection due to innately fixed excitation of the stem and regular suffix. Because the Hare et al. (1995)model has innate rules, it does not offer an alternative to the symbolic approach, nor does it demonstrate that default inflection can be acquired in the absence of variables.

A different perspective for evaluating the distributional asymmetry hypothesis would be to test it cross linguistically. On this hypothesis, languages manifesting a regular default must exhibit a contrast in the distribution of regular and irregular tokens in the phonological space. As noted by Plunkett and Nakisa (1997), this prediction clearly contrasts with the prediction of the symbolic account:

`The symbolic default assumes that for any language there will be a type of inflection which is rule-based – that is, a phonology-independent operation on a symbolic representation of the singular. The rule-based inflection is innately specified and so is universal to all languages whatever the statistical nature of their inflectional system. A neural network can also exhibit a default-like behavior given an appropriate distribution of input forms. A distributional default develops in a network when the `default' class is distributed diffusely throughout the phonological space and the other classes are compact and separate (Plunkett and Nakisa, 1997p. 833).'

Plunkett and Nakisa (1997)further explored the predictions of the distributional asymmetry account by examining nominal inflection in Arabic. To investigate the distributional properties of nominal Arabic plurals, Plunkett and Nakisa conducted a principal component analysis of nominal Arabic plurals, assessed the coherence of plural classes and the predicability of plural forms by class membership. Their findings provided no evidence for a distinction in the phonological clustering of sound (`regular') and broken (`irregular') Arabic plurals. Plunkett and Nakisa (1997)did not examine empirical evidence for the existence of a default in Arabic. However, given the overlapping distributions of sound and broken plurals, they predicted that sound plurals in Arabic should not function as a default. Indeed, if the regular default was contingent on distributional asymmetry, then one should not expect to find a regular default in a language where the phonological properties of regular and irregular nouns or verbs are overlapping. Hebrew seems to challenge this prediction.

Hebrew plurals are produced by concatenating a suffix, either -im or -ot to the singular base. Morphological affixation often triggers also phonological changes to the base. Thus, to form the plural, speakers must determine the identity of the suffix and the phonological structure of the plural form.

The selection of the suffix is partly predicted by gender. Hebrew nouns are marked for gender, masculine or feminine. Most masculine nouns are inflected by adding the -im suffix to their base; feminine nouns are typically inflected using the -ot suffix (see Table 1). Thus, for masculine nouns, plurals taking the -im suffix are considered regular, whereas those taking the -ot suffix are irregular. Conversely, for feminine nouns, it is the -ot inflection that is regular (Aronoff, 1994). Despite the strong link between gender and inflection, this correspondence is not entirely consistent. Aronoff (1994)notes about 80 masculine nouns that are inflected by the -ot suffix, and about 30 feminine nouns inflected using the -im suffix. Furthermore, gender is not reliably inferred from the surface structure of the singular form, since some masculine-sounding nouns are feminine, taking -ot suffix. The only reliable cue for gender is syntactic agreement. In the absence of syntactic cues, the inference of gender and plural suffix is uncertain.

The inference of a noun's gender and plural suffix is somewhat easier for feminine nouns. Many singular feminine nouns are reliably marked for gender by feminine suffixes (e.g. -et: mishkéfet, molédet, zaméret; -a: yaldá, morá, piná, bniyá, bakashá). All nouns marked by these suffixes are feminine, and the majority of them take -ot as their plural suffix. In contrast, the gender of masculine nouns and their plural inflection is less obvious. The principal phonological cue for the gender of masculine nouns is the absence of a feminine suffix: most singular nouns lacking a feminine suffix are masculine. We thus refer to these nouns as `masculine sounding'. Although most masculine-sounding nouns take the regular -im suffix, neither the gender of these nouns nor their plural suffix can be reliably determined from their surface form. Some of the masculine sounding nouns are, in fact, feminine, and their inflection takes the -ot suffix (e.g.?érets-?aratsót, country). In addition, there is also a large set of masculine-sounding nouns that are indeed masculine, but their inflection is irregular, taking the -ot suffix (e.g. zug-zugót, pair). Thus, the plural suffix of masculine-sounding nouns cannot be reliably predicted from their phonological properties.

In addition to the task of selecting the plural suffix, Hebrew speakers must also determine the phonological structure of the plural. Inflection often triggers phonological changes to the singular form. Plural inflection reliably shifts the stress to the suffix. In addition, inflection often alters the stem's vowels. These phonological alternations are independent of the suffix chosen or gender (see Table 2). However, they are highly predictable by the phonological structure of the base, which, in turn, reflects its formation. Hebrew words are formed by inserting a root into a word pattern. Word patterns include place holders for the root consonants, and they provide the vowels and affixes. Nominal word patterns are called mishkalim (singular: mishkal). For instance, the words kelev (dog), sheleg (snow), and degel (flag) are formed by inserting their roots in the CeCeC mishkal. Because members of a given mishkal share their vowels and affixes, they are quite similar phonologically. The mishkal is also helpful in determining the phonological structure of the plural. All plurals generated for members of a given mishkal share the same phonological structure. For instance, all members of the CeCeC mishkal (e.g. kélev) are inflected as CCaC-suffix (e.g. klavı́m). The mishkal is thus an excellent predictor of the plural's phonological structure.

Given that the mishkal defines a phonological cluster of singular nouns and that it also reliably predicts the phonological structure of the plural stem, one may wonder whether the mishkal can also reduce the ambiguity regarding the selection of the plural suffix. Indeed, in some languages, phonological clustering is a strong cue for inflection. For instance, English irregular verbs cluster in phonological families that may be used to predict their inflectional class (regular vs. irregular) and phonological structure. If Hebrew inflection was organized in a similar fashion, then the strong phonological clustering of Hebrew nouns could have provided a powerful clue for inflection. Specifically, if members of the mishkal shared the same inflectional suffix, then speakers could have used the phonological properties of the mishkal in order to eliminate the ambiguity regarding the plural suffix. Unfortunately, however, the mishkal provides little help in identifying the suffix of masculine sounding nouns. For instance, the CaCáC mishkal includes 48 nouns whose gender is masculine and their plural form is CCaC-suffix. Forty-three of these nouns take the -im suffix (e.g. zakan, beard; marak, soup) whereas the remaining five (e.g. zanav, tail; valad, newborn) take the -ot suffix. Likewise, the mishkal CoC (e.g. nof-, view) contains 26 nouns whose gender is masculine and their plural form is CoC-suffix. Twelve of them take the -im inflection (e.g. nof-nofim, view; xof-xofim, shore) and 14 take the -ot suffix (?or-?orot, light; sod-sodot, secret). There appears to be no feature (phonological or semantic) that can be used to determine which member of a given mishkal is regular and which one is irregular, nor is there any feature that can discriminate between regular and irregular nouns across different mishkalim. As we demonstrate in the following analyses, the lack of a correspondence between phonological clustering and inflectional classes is not unique to the two mishkalim illustrated above, but is, instead, a typical property of masculine sounding nouns in Hebrew.

The distributional-asymmetry hypothesis views default inflection as a consequence of the asymmetry in the distribution of regular and irregular nouns in the phonological space. Because of its templatic morphophonology, Hebrew is likely to exhibit phonological clusters which correspond to its nominal word patterns, the mishkalim. Members of a given mishkal share the same vowels, consonant suffixes and their arrangement relative to the root consonants. Furthermore, the mishkal is also the only predictor of the plural's phonological form. Thus, members of a given mishkal form a phonological cluster. However, the mishkal defines its members by their phonology, not their inflection. If phonology is a good predictor of inflection, then members of the phonological cluster defined by the mishkal would tend to agree in their inflection. According to the distributional-asymmetry hypothesis, Hebrew speakers could use such phonological clustering to acquire default inflection. Conversely, if the phonological clusters defined by the mishkal include both regular and irregular members, then Hebrew should not exhibit default inflection, according to the distributional hypothesis.

Our previous discussion identified two forms of regular inflection in Hebrew: the masculine regular suffix is -im and the feminine -ot. These two regular classes differ in the extent their plural members are predictable from the phonological form of the singulars. Feminine nouns are reliably marked for gender by their phonology and their inflection is highly predictable. In contrast, for masculine nouns, both gender and inflectional suffix are uncertain. If phonological form is critical for inflection, then the acquisition of the default may be quite different for each of these forms. Indeed, Plunkett and Nakisa (1997)observed a similar contrast in the phonological coherence of feminine and masculine sound plurals in Arabic, a contrast that resulted in an inferior performance on masculine nouns in their simulation. Our present investigation focuses on the default inflection of masculine-sounding nouns for two reasons. First, the classification of masculine nouns as regular or irregular is clearer than that of feminine nouns.2 Second, the inflection of masculine nouns appears to be far less predictable by their phonology. Thus, masculine-sounding nouns present a stronger test for the default inflection hypothesis.

To examine whether regular and irregular nouns contrast in their distribution in the phonological space, we examined the structure of 1971 masculine sounding nouns listed in a Hebrew grammar book (Goshen et al., 1970). Our database included 1778 masculine-sounding nouns whose plural take the -im suffix (hereafter, regular nouns) and 193 masculine-sounding nouns taking the -ot suffix (hereafter irregular nouns)3. To identify the phonological clustering of regular and irregular nouns, we classified these nouns according to their mishkalim. Any two nouns were classified as members of the same mishkal if they shared the same vowel pattern in the singular and plural form4. For instance, the nouns nof-nofim, shot-shotim fall into the CoC-CoC-suffix pattern, hence, they are assigned to the same mishkal. Conversely, the nouns dov-dubim, tof-tupim are considered a separate mishkal, since, despite sharing the singular pattern of the nof-nofim mishkal, they differ in their plural form. A mishkal is considered regular if it contains at least one regular member. Likewise, an irregular mishkal is one containing at least one irregular noun. These classifications are not mutually exclusive: any given mishkal whose inflection is not entirely consistent is considered as both regular and irregular. Following these criteria, we identified in our database a total of 91 mishkalim, 84 regular and 44 irregular. We next tested for an asymmetry in the structure of regular and irregular clusters.

According to the distributional-asymmetry hypothesis, default inflection requires: (a) clustering of irregular nouns in small, distinct regions of the phonological space that are primarily irregular; (b) a diffuse distribution of regular nouns in the rest of the phonological space.

Our analyses first examined whether the phonological space includes any regions that are distinctly irregular. If large phonological clusters are dominated by irregular nouns, then large mishkalim should have a lower proportion of regular nouns. Contrary to this prediction, there is a strong positive correlation between the proportion of regular members and mishkal size (r(89)=0.986, P<0.01). Large phonological clusters thus tend to include a high proportion of regular members. Consequently, phonological properties are a poor predictor of irregular inflection.

Additional tests for the phonological uniqueness of irregular clusters could be sought in their consistency (the ratio of irregular nouns to the total number of nouns in the mishkal). If Hebrew had phonological clusters that are uniquely irregular, then the mean consistency of irregular mishkalim should approach one. Furthermore, if high coherence is characteristic of irregular nouns, then the mean consistency of irregular mishkalim should be higher than that of regular mishkalim. Table 3 presents the number of regular and irregular mishkalim as a function of their consistency and the percentage of regular or irregular nouns they include. Our findings provide little support for the existence of coherent `irregular islands'. The mean consistency of irregular nouns is 0.351. Although Hebrew has one family of irregular nouns that is entirely consistent (e.g. shitafon-shitfonot, flood, including 38 nouns), most of the irregular nouns (76%) correspond to phonological clusters shared with regular nouns. Furthermore, in most of these clusters, irregular nouns are overpowered by their regular neighbors. Specifically, 57% of the irregular nouns are members of mishkalim in which the irregular nouns are a minority (less than 50% of the total number of nouns in the mishkal). In contrast, regular clusters are typically consistent. The mean consistency of regular nouns is 0.7556. Practically all (99%) of the regular nouns are members of mishkalim in which regular nouns are a majority (more than 50% of the nouns in the mishkal), and 37% of the regular nouns cluster in entirely consistent families (a total of 47 mishkalim). Our analyses thus identify numerous distinctly regular clusters. In contrast, the grand majority of irregular nouns do not group in clusters consisting entirely, or even largely, of irregular nouns.

A second condition for default inflection, according to the distributional-asymmetry hypothesis, is the density of irregular clusters: irregular clusters must exhibit not only strong coherence but also high density. Conversely, regular nouns should be diffusely distributed in the phonological space. To examine the density of regular and irregular clusters, we next sorted the regular and irregular mishkalim according to their size (i.e. the number of nouns in the mishkal). For simplicity, we collapsed our data into five categories. We then examined the number of regular and irregular mishkalim of any given size, the number of nouns in each category and its share relative to the total number of regular or irregular nouns. As evident in Table 4, most irregular nouns are clustered in the smallest mishkalim (less than 10 nouns per mishkal), whereas the majority of regular nouns are members of large size clusters. Thus, irregular clusters are more sparse than regular clusters.

In summary, the clustering of masculine sounding Hebrew nouns in the phonological space differs considerably from the requirements of the distributional-asymmetry hypothesis. According to this view, default inflection requires phonologically distinct and tight clusters of irregular nouns, and a sparse distribution of regular nouns. Hebrew violates both conditions. The phonological clusters occupied by irregular nouns are largely shared with regular nouns. Furthermore, the size of regular clusters is typically larger than that of irregular clusters. Instead of coherent irregular islands in a sea of regular nouns, the most consistent islands in the phonological space correspond to regular nouns. Irregular nouns tend to form a subset of the phonological space defined by each of these islands. Given this distributional pattern, Hebrew is unlikely to exhibit a masculine regular default.

The following experiments examine whether regular inflection constitutes a default for the inflection of masculine sounding nouns. Experiment 1 examines whether regular and irregular inflection differ in their sensitivity to similar stored tokens. Experiment 2 probes for the generality of regular inflection using targets that are phonologically idiosyncratic. Experiment 3 investigates whether Hebrew speakers use the regular inflection as a default for the inflection of names and borrowings.

Section snippets

Experiment 1

Experiment 1 examines two questions: (a) Does the similarity of a novel Hebrew word to an existing noun affect its inflection; and (b) Are similarity effects modulated by the regularity of these nouns. To address these questions, we employed a method previously used by Bybee and Moder (1983)and Prasada and Pinker (1993)in their investigation of similarity effects in the inflection of English past tense verbs. We constructed a set of novel words that systematically differ in their similarity to

Participants

Twenty-one native Hebrew speakers served as participants. They were all students in the school of education at the University of Haifa. The experiment was administered as part of a course lecture. The participants received no compensation for their participation.

Materials

The materials consisted of 48 trios of words constructed by analogy to 24 pairs of existing Hebrew nouns (base nouns, see Appendix A). These base nouns serve only as models for the construction of the experimental target words, and they

Experiment 2

The broad application of regular inflection for targets that are dissimilar from their regular base and its selective insensitivity to similarity and neighborhood size suggests that regular inflection may be general. Regular inflection seems to apply to any target, regardless of its phonological characteristics. This conclusion, however, is qualified by the structure of the materials used in Experiment 1. In this experiment, regular targets defined as highly dissimilar to their base did not

Experiment 3

The broad application of regular inflection to targets that are phonologically distant from existing words and to idiosyncratic words indicates that the similarity between a target word and a stored token is not necessary for its regular inflection. This finding agrees with the view of regular inflection as a symbolic process, triggered by the `elsewhere condition'. Experiment 3 examines a second prediction of the `word/rule' account concerning the inflection of irregular words. Our findings so

General discussion

This research examines the inflection of masculine sounding Hebrew nouns. Our investigation addresses two questions: (1) Does the regular -im inflection constitute a default for the inflection of masculine sounding nouns? (2) Is default inflection achieved by a symbolic process? In discussing these questions, we first review our evidence for the presence of default inflection in Hebrew. We next examine its computation. Finally, we briefly address the implications of our findings to online

Acknowledgements

This research was supported by NIH FIRST award 1R29 DC03277-017 and NIH HD 18381 grants.

References (52)

  • S Pinker et al.

    On language and connectionism: analysis of parallel distributed processing model of language acquisition

    Cognition

    (1988)
  • J Rueckl et al.

    Morphological priming, fragment completion, and connectionist networks

    Journal of Memory and Language

    (1997)
  • Aronoff, M., 1994. Morphology By Itself. MIT Press, Cambridge,...
  • S Bentin et al.

    The contribution of morphological and semantic relatedness in visual word recognition: evidence from Hebrew

    Quarterly Journal of Experimental Psychology

    (1990)
  • Berent, I., Everett, D., Shimron, J., 1998. Do phonological representations specify variables? Evidence from the...
  • C Burani et al.

    Morphological structure and lexical access

    Visible Language

    (1984)
  • J Bybee

    Regular morphology and the lexicon

    Language and Cognitive Processes

    (1995)
  • L Bybee et al.

    Morphological classes as natural categories

    Language

    (1983)
  • Daugherty, K., Seidenberg, M., 1992. Rules or connections? The past tense revisited. Proceedings of the 14th Annual...
  • Elman, J., Bates, E., Johnson, M., Karmiloff-Smith, A., Parisi, D., Plunkett, K., 1996. Rethinking Innateness: a...
  • L.B Feldman et al.

    Morphological analysis of disrupted morphemes: evidence from Hebrew

    Quarterly Journal of Experimental Psychology

    (1994)
  • L.B Feldman et al.

    Decomposing words into their constituent morphemes: evidence from English and Hebrew. Journal of Experimental Psychology: Learning

    Memory and Cognition

    (1995)
  • Frost, R., Forster, K., Deutsch, A., 1997. What can we learn from the morphology of Hebrew? A masked-priming...
  • Goshen, M., Livne, Z., Shafan, S., 1970. Hadikduk ha'Ivri hashimushi. (Hebrew Grammar). Shocken,...
  • M Hare et al.

    Default generalization in connectionist networks

    Language and Cognitive Processes

    (1995)
  • Harris, C., 1992. Understanding English past tense formation: the shared meaning hypothesis. Proceedings of the 14th...
  • Cited by (0)

    View full text