Dec 13, 2007 - were used to produce the 32 derived words in the experimental list, it was ..... In the form untouchables, for example, the root is touch.. , A.
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Language and Cognitive Processes Publication details, including instructions for authors and subscription information: http://www.tandfonline.com/loi/plcp20
Representation and processing of derived words a
Cristina Burani & Alfonso Caramazza a
b
Istituto di Psicologia C.N.R. , Rome, Italy
b
The Johns Hopkins University , USA Published online: 13 Dec 2007.
To cite this article: Cristina Burani & Alfonso Caramazza (1987) Representation and processing of derived words, Language and Cognitive Processes, 2:3-4, 217-227, DOI: 10.1080/01690968708406932 To link to this article: http://dx.doi.org/10.1080/01690968708406932
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language and Cognitive Processes, Vol. 2, Nos.314, pp. 217-227 (1987)
0 1988 VNU Science Press.
Representation and processing of derived words CRISTINA BURANI' and ALFONSO CARAMAZZA' 'Istituto di Psicologia C.N.R., Rome, Italy and 'The Johns Hopkins University, U S A
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Received March 1987; accepted in revised form October 1987 Abstract-Two visual, lexical decision experiments with Italian derived words are reported. The issue addressed was whether or not derived words with highly productive derivational suffixes (-zione, -mento, -tore, etc.) that do not alter the orthographic/phonological characteristics of the base form, are processed/represented in a morphologically decomposed form. Experimentally, the issue investigated was whether it is the frequency of the root-morpheme of the word, the frequency of the whole word, or both that determines decision latencies and errors. Results indicate that there is an effect of both root frequency and whole-word frequency on lexical decision performance and errors to derived words. This result is interpreted within the framework of the Augmented Addressed Morphology Model of lexical access.
INTRODUCTION
An issue of current interest in research on lexical access concerns the mechanisms involved in processing morphologically complex words, that is, words made up of two or more morphemes. Two questions have been addressed by research in this area. One is related to the morphological organization of the lexicon: Are morphologically complex words represented in the lexicon as wholes, that is, does each word correspond to one lexical entry, or are these words represented in a decomposed form, with each morpheme represented as a distinct entry? The other question concerns the nature of the processes involved in lexical access of morphologically complex words, and takes the following general form: Is each morpheme in a word processed separately, or is the word processed as a whole unit, independently of its morphological structure? For purposes of discussion, it is better to keep the two questions separate. But it is to be understood that they cannot be dealt with independently, one from the other, since any theoretical account offered for one of the two sides of the problem is not without consequences for the other. Although there is a fairly large experimental data base on the role of the morphological structure of words in lexical access (see Henderson, 1985 and Taft, 1985 for reviews), these data are still insufficient to support the confident choice of any one of the proposed models over the others. And, furthermore, it is unlikely that any single experimental result will on its own resolve the general issues raised here. One approach that has been used to help distinguish among alternative modeis of lexical access of morphologically complex words is based on the well-established phenomenon of word frequency. The effect of word frequency (ie. that commonly occurring words are identified more rapidly than infrequently occurring words) is one
Address correspondence to Cristina Burani, Istituto di Psicologia, C.N.R., vide Marx 15,00156 Roma, Italy.
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of the more stable and reliable effects in research on word recognition and lexical access (see Gordon, 1983, 1985). But, what is frequency? In early investigations of the word frequency effect (e.g., Morton, 1969), the dimension assumed to be the relevant factor responsible for the effect was whole-word frequency, i.e. the frequency of occurrence of a specific word form. More recently, it has been demonstrated that the cumulative frequency of all the words sharing the same root morpheme is an important determinant of decision latencies in lexical decision tasks. In a visual lexical decision task, Taft (1979) found that both root frequency (defined as the summed frequency of the base form and the inflected forms of a word) and whole-word frequency had an effect on reaction times. This result was replicated by Burani et al. (1984) for regular, inflected verb-forms in I taiian. This finding, revealing a complex interaction between whole-word and root frequency in determining lexical decision latencies, renders any interpretation of the frequency effect more complicated, and has important implications for hypotheses about the nature of lexical access: the root or cumulative frequency effect in lexical decision tasks could indicate that morphological structure plays a role at the access level-a role which needs to be articulated and incorporated in any serious attempt to provide an account of lexical access. The result obtained by Taft (1979) and Burani et at. (1984) for inflected words was challenged by the only published study in which the same question was addressed in relation to words with derivational suffixes (Bradley, 1979).Bradley reports that lexical decision times to derived words-suffixed by -ness, -ment, and -er-were affected by a combined frequency measure obtained by adding the frequency of the base word (and its inflections), to that of its derived forms. Bradley’s study is of special interest because she failed to find any effects of whole-word frequency in her lexical decision task. Bradley’s results have given rise to much debate and to various attempts at an interpretation (Henderson, 1982, 1985; Butterworth, 1983; Cutler, 1983; Taft, 1985). However, we know of no attempt to replicate her results. The experiments that will be reported below constitute a further investigation of lexical access of derivationally suffixed words. The derived words that were chosen for investigation differed in part from those used by Bradley (1979), and were selected on the basis of the following criteria: The root of the derived form did not differ phonologically or orthographically from the root of its base;’ the derivational suffix was highly productive; the derived word was of medium/low frequency. All the words were derived from verbal roots that were ‘regular’, i.e. the verb root did not change in any of its inflected forms (e.g., compare the past tense form of the regular verb tess-ere + tess-uto, and that of the irregular verb divid-ere -+divis-0). In Experiment 1, two sets of Italian derived words matched for whole-word frequency but differing on root frequency were compared in a lexical decision task. The issue addressed in this experiment was whether or not root frequency affected latencies and error rates for derivationally complex words-in effect we attempted to replicate Bradley’s result. In Experiment 2, two sets of Italian derived words matched for root frequency but differing on whole-word frequency were compared. The issue addressed in this experiment was whether or not the whole-word frequency of derived words influences lexical decision times and error rates.
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Experiment 1 Method Materials and design. Two sets of derived words were selected. Set A comprised 16 words derived from high-frequency verbal roots. Set B included 16 words derived from low-frequencyverbal roots. The mean whole-word frequency of the items was the same in sets A and B, and it was, of course, low. The mean root frequency in set A was 247.2; in set B it was 19.4. The mean whole-word frequency was 5.1 in set A (7.7 if root + derivational su&x frequency is considered),and 4.5 in set B (5.4 root derivational suffix frequency). The frequency counts, derived from Bortolini et al. (1971), are calculated on a word sample of 500000 occurrences. In order to increase the number of items and the variety of suffixes in each set, some derived words which did not appear in the Bortolini et al. (1971) count were included (six in set A and five in set B) and were assigned a frequency of zero. Of course, the verbs from which the selected words were derived were present in the Bortolini et al. (1971) count. The two sets of stimuli were also matched for mean word length in letters-9.8 in set A, and 9.9 in set B. The derived words were nouns and adjectives (twelve nouns and four adjectives in each set). They were all derived from regular verb roots; the verb roots in the derived words did not show any ortho/phonological differentiation from their bases. The derivational suffixes were among the most productive in Italian. They included two adjectival suffixes: -euole and -(a)/(i)bile (they approximately correspond to the English suffix -able), and four nominalizing suffixes: -zione (English: -tion), -mento (English: -merit), -tore (English: -er), and -(e)nza/-(a)nza(its approximate equivalent in English is -(a)nce/-(e)nce,but it can also correspond to -hood, -ness, -ity, -tion, -ency and so on). In general, there is only an incomplete correspondence between the Italian and the English classes of derivational suffixes, and in no case can a complete overlap be found. The same number of suffixes of each type were included in set A and set €3: two -euole, two - ( a ~ / ( ~ ~three b ~ f -mento, e, three -zione, three -tore and three -(a)/(e)nza in each set. Both singular and plural forms were included in the experimental sets. The number of plural and singular forms was the same in the two sets (two plurals and fourteen singulars in each set). The words used in each experimental list are reported in Appendix A. It was considered important to avoid list effects that could arise if a subject saw too many instances of a particular suffix. Therefore, consideringthat 6 derivational suffixes were used to produce the 32 derived words in the experimental list, it was decided to split each set of derived words into two sets of 16 items each, balanced for length, frequency and suffix type. Each subject was tested with a list of 130 words: 114 fillers and 16 derived words, 8 from set A and 8 from set B (the eight words from set A were also balanced with the eight from set B so that each subject saw an analogous variety of derivational suffixes). The 114 filler-wordswere of various lengths (from 5 to 13 letters),and were selected from various frequency ranges and from all grammatical classes. There were 34 verbs, 56 nouns, 17 adjectives and 9 function-words. The relative proportion of items in each class was intended to roughly reflect that in the Italian language. All the verbs, nouns and adjectives are inflected in Italian. Thus, we chose verbal forms of different
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conjugations, tenses, persons and numbers; nouns and adjectives were singular or plural. A few filler words (10) had other derivational suffixes. No root of filler verbs also appeared as part of an experimental word; no root was repeated twice in the list, One hundred and thirty nonwords were constructed by changing either one or two letters in a word. The 130 words from which the nonwords were constructed were matched for length, frequency and form class with the 130 words in the list. The letter change occurred 1/3 of the time in the initial, 1/3 in the medial and 1/3 in the final part of the word. In this way we made sure that the nonwords had a mean length that was equal to that of the words, and that both their endings and initial parts closely respected the distribution of suffixes and root morphemes in the word set. Thus, some nonwords had real roots, some had derivational and some had inflectional suffixes. In short, each subject saw a total of 260 stimuli, 130 words and 130 nonwords. The 130 nonwords and the 114 filler words were the same for each subject, but the 16 derived words varied: Subject l a saw 8 words from each of sets A and B, and subject 1b saw the other 8 words from each of sets A and B. Subject l a and subject l b (subjects assigned to two complementary subsets of derived words) constituted ‘subject’ 1 (experimental subject), for a total of 13 experimental subjects. There were two orders of randomization for each experimental list, for a total of four random orders, and each subject was alternatively assigned to one of the four randomized lists. The following constraints on randomization were respected: No more than four words and four nonwords appeared in sequence; a derivational suffx could not appear very close to another derivational suffix, and, since the 260 experimental stimuli were presented in blocks, approximately the same number of words with derivational suffixes appeared in each block. Procedure. Stimuli were displayed in upper case letters on a black and white monitor controlled by an Apple 111computer. A subject’s task was to press one button if the letter string presented was a word and another button if it was a nonword. The subjects gave the YES response with their preferred hand. Both reaction time and type of response were recorded. The subjects were given written instructions and they were told to respond as accurately and as quickly as possible. Each subject was given two blocks of 40 practice trials before being tested with the test items. Following the two blocks of practice trials, four blocks of test trials were presented. Each block had 65 items. Each trial started with a warning signal, followed after 600 ms by the presentation of a fixation point at the center of the screen. The fixation point remained on for 400 ms after which letter-string (word or nonword) was displayed at the center of the screen. The display of the letter-string was terminated either by the subject’s response or after 1000ms had elapsed. Response time feedback was shown on the screen for 1500ms if the subject responded correctly, otherwise an error signal appeared on the screen. A constant interstimulus interval of 1000ms was programmed between the letter-string display and the start of the next trial. There was a one minute rest between blocks followed by a signal that the subject could continue the experiment by a button press when ready. The experiment was conducted in a single session that lasted about 40min. Subjects. Twenty-six native Italian speakers participated as subjects in the experiment, for a total of thirteen experimental subjects. The subjects were students at
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Table 1. Mean reaction times (in ms) and percent errors for derived words with high-frequency roots (A) and with low-frequency roots (B). Experiment 1. (A) 578 (2.4)
(B) 608 (14.0)
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the University of Rome and were paid for their participation in the experiment. No subject participated in more than one of the present experiments. Results In this, and the following experiment, extreme values (2 SD above and below the mean by subjects and by items) were excluded from analysis. Analyses of variance with both subject and item means as units were computed. MinF statistics were calculated, and are reported when they were significant; otherwise, the significant F statistics for the subjects analysis is reported. The above procedure was used for each of the experiments reported in this paper. The mean latencies and error rates for each test condition are shown in Table 1. It can be seen that derived words from high-frequency verbal roots (A) produced both lower latencies and a lower error rate than words derived from low-frequency verbal roots (B): There was a significant effect of word type in the subject analysis, F( 1,24) = 14.2228, p < 0.001, for reaction times and a significant effect of word type, minF’ (1,52) = 6.29, p 0.025, for errors.
-=
EXPERIMENT 2
Method Materials and design. Two sets of derived words (10 in set A and 10 in set B) were used in this experiment. The words in the two sets had the same mean verbal root frequency (65.7 in set A, and 66.8 in set B), but differed in mean whole-word frequency. Words in set A had higher mean whole-word frequency (40, and 49.4 if root + derivational suffixfrequency was considered) than words in set B (4.3 whole-word frequency, 4.8 if root + derivational suffix frequency is considered). The words in the two sets were otherwise alike on all relevant factors: they had the same mean letter length, 10.5 in set A and 10.7 in set B; there were nine nouns and one adjective in each set; they were all derived from regular verb roots; and the verbal root that appeared in the derived word did not show any ortho/phonological differentiation from the base. The derivational suffixesselected were some of the productive suffixes already used in Experiment 1. There were: five -zione, three -(a)/(e)nza, one -mento and one -evole, in each set. Only singular forms were included in the experimental lists. The words in each experimental set are reported in Appendix B. Since the total number of derived words was only 20, it was not considered necessary to split them into subsets and use the procedure followed in Experiment 1; however, the number of fillers was slightly increased.
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Cristina Burani and Alfonso Caramazza Table 2. Mean reaction times (in ms) and percent errors for derived words of high whole-word frequency (A) and low whole-word frequency (B). Experiment 2.
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(A) 542 (3.3)
(B) 578 (6.6)
There were 130filler-words, from various frequency ranges and of various lengths (513 letters). There were 40 verbs, 55 nouns, 20 adjectives and 15 functors. Verbs were of various conjugations, tense, person and number; nouns and adjectives were singular or plural. No root was used twice in the list. One hundred and fifty nonwords were constructed, using the same procedure described in Experiment 1. As a result of this procedure, some nonwords had real derivational suffixes, some had inflectional suffixes and some had real word roots. Each subject saw a total of 300 stimuli, 150 words and 150 nonwords. Each list had four random orders, and each subject was alternatively assigned to one of the four randomized lists. The constraints on the randomizations were those followed in Experiment 1. Procedure. The same procedure as that used in Experiment 1 was used in Experiment 2. The list was divided into five blocks of 60 items each. The experimental blocks were preceded by two blocks of 30 practice trials each. The experiment was conducted in a single session that lasted about 45 min. Subjects. Twenty-four students from the University of Rome participated as subjects in the experiment, and were paid for their participation. They were all native Italian speakers; none had participated in the preceding experiment. Results The mean latencies and error rates for the two test conditions with derived words are reported in Table 2. As can be seen, faster response times and lower error rates were obtained for derived words of higher whole-word frequency (A), than for words with lower whole-word frequency (B): A significant effect of word type was obtained, minF’ (1,62) = 4.54, p < 0.05,for reaction times. No reliable effect was found for errors. However, error rates displayed the same tendency shown by latencies. DISCUSSION
Our results only partially match Bradley’s (1979). In Experiment 1 we found, like Bradley, an effect of root frequency on derived words whose root do not show any ortho/phonological differentiation from their base. Bradley had found root-frequency effects with words formed by the neutral affixes -merit, -er and -ness that do not affect pronunciation of the root morphemes to which they are attached. She failed to find the root frequency effect with derived words formed by the non-neutral affix -ion that affects the root morpheme’s pronunciation (e.g., prevent *prevention), sometimes stress
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placement (e.g., discriminate 4discrimination), and in most cases also the root morpheme’s spelling (e.g., divide +division). The contrasting pattern of results obtained for different types of derived words was taken by Bradley as evidence for a difference in the lexical representation of derived words. According to Bradley, words in -merit, -er and -ness share a representation in the lexicon with their base forms, while words in -ion do not.2 The interesting difference between Bradley’s (1979) and our results was found in Experiment 2. While Bradley failed to show an effect of whole-word frequency for derived words (and this not only for words suffixed by -ment, -er and -ness, but also for words suffixed by -ion!),we found a clear effect of whole-word frequency for derived words. Bradley’s result may be due to a methodological artifact. Consider in this regard her experiment with -ness nominals, the experiment for which the author gives clear information about the experimental method used in the reported research. In this experiment, the experimental list consisted of 120 words and 60 nonwords. Of the 120 words, 60 (the critical items) were sdixed by -ness, while 60 were non-derived (e.g., magazine, wizard). Of the 60 nonwords, an unspecified number were suffixed by -ness (e.g., tabidness, lealness). Clearly, the list composition was very far from respecting the relative proportion of types of words in the language, and it goes without saying that derived words (always in -ness!)were overrepresented in the list. In addition, the suffix -ness was also present in a number of nonwords. This list composition, where almost half of the items had a constant terminal part (-ness),could induce an artifactual decomposition strategy-in most cases a decision could be taken relying just on the first part of the item, without whole-word processing. This could have had the consequence of reducing the wholeword frequency effect for suffixed words. The more balanced proportion of items with derivational suffixes (of different types) in our experimentallists (in Experiment 2 there were 28 derived words, of which 8 were fillers, out of 150 words in total), makes much less likely an artifactual list effect, and permits the whole-word frequency effect to manifest i t ~ e l f . ~ The methodological inadequacy in Bradley’s experiments could have produced another consequence-that of inflating the root frequency effect. However, since this effectwas replicated with a more balanced experimentallist in our Experiment 1 (where we had 26 derived words, 16 experimental words and 10 fillers, out of a total of 130 words), it suggests that the effect is a robust and reliable one. Our results demonstrate that both root frequency and whole-word frequency affect lexical decision performance for (at least our class of) derived words. How are these effects to be interpreted within a processing model of lexical access? The reported results are compatible with different interpretations. If taken in isolation, the data do not enable us to opt for one of the proposed models of lexical access over the others. Neither do they permit us to unequivocally identify the locus (or loci) of the reported frequency effects; that is, the component(s) of the lexical access process that is(are)responsible for the effects. In particular, the root frequency effect is compatible both with models that assume morphological decomposition at some level of lexical access and models that do not assume morphological decomposition. For models ofthis latter type, the root frequency effect may reflect the facilitatory activation of all the members of independently represented but morphologically related lexical representations. However, when the reported results are interpreted in the broader
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context of the now relatively extensive data base on the role of morphological structure in lexical access, the range of plausible interpretations is radically reduced. The interpretation we will offer of the reported data is in terms of the Augmented Addressed Morphology (AAM) model proposed by Caramazza et al. (1985, in press; see also, Burani et al., 1984; Laudanna and Burani, 1985). Briefly, this model assumes that while lexical representations in the orthographic (input) lexicon are morphologically decomposed-i.e. roots or stems are represented independently of inflectional affixes and, possibly, derivational affixes-the access procedure operates with both whole-word and morpheme access units. Previously experienced words activate wholeword access units while the recognition of novel words occurs through the activation of morpheme access units. Thus, for example, if the stimulus word arnaua (shelhe loved) were to be a familiar word, it would activate in the access system a unit corresponding to the whole-word amava, which, in turn, would serve to activate the two entries A M (corresponding to the verb root) and - A V A (corresponding to the third person past inflectional suffix) in the orthographic lexicon. By contrast, if the stimulus word arnaua were to be an unfamiliar word it would only activate the morpheme access units amand - m a which would, in turn, activate their corresponding lexical representations in the orthographic lexicon. For present purposes, we will focus on lexical access for. familiar words. To account for both whole-word and root frequency effects, we must detail some of the processing assumptions made by the AAM model. One of the major assumptions is that access units are activated in a parallel, passive, logogen-like fashion (e.g., Morton, 1979). As in Morton’s model, access units vary in terms of their activation threshold values; an access unit’s threshold is assumed to be a function of the number of times that the unit has been activated-the more frequently an access unit is activated, the lower its threshold value. This model can account for the whole-word frequency effect on lexical decision times. Those whole-word access units that have been frequently activated (i.e. whose corresponding stimulus words were frequently seen, or recognized) will have lower threshold values, and consequently will lead to quicker lexical decision times. But how can the model explain the root frequency effect? The model may account for this effect in one of two ways, depending on where we assume a word’s frequency to have its effect on lexical decision performance; that is, whether we assume that the frequency effect results at the level of activation of access units or whether we assume the effect to result at the level of activation of lexical representations in the orthographic lexicon (see Caramazza et al., in press, for detailed discussion of the distinction drawn here). If the frequency effect were only to reflect differential activation rates at the access unit level we would have to make the following assumption. Each time a specific wholeword access unit is activated and, in turn, activates its corresponding root entry in the orthographic lexicon, the activation of the root propagates to all the whole-word access units that share this root morpheme. Thus, the activation of the access unit for the word arnaua (shelhe loved), leads to the activation of the units corresponding to amo ( I love), amavi (You loved), amato (loved),amare (to love), and so on, including the derived form amabile (lovable),with the consequence that the activation thresholds of the access units for these words will be permanently lowered. One of the consequences of this process is that an infrequently activated access unit (e.g., amabile) which belongs to a set that includes very frequently activated units
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(amaua, amo, ama, amare) benefits by the repeated activation of the latter units: Its threshold level will become permanently lower than the threshold level of a unit corresponding to a word with analogous whole-word frequency but lower root morpheme frequency. Alternatively, we could assume that frequency effects reflect processing differences both at the level of the access system and the orthographic lexicon. On this view, a final positive decision about whether or not a letter string forms a word is taken only when a full lexical entry is activated in the orthographic lexicon. And, if we were to assume that the activation of morpheme representations in the orthographic lexicon is frequency sensitive, just as we have assumed for the access units, we would be able to account for the root morpheme frequency effect. Thus, to return to our example of the stimulus amaua, presentation of this stimuIus will activate the whole-word access unit amaua which activates the morphemes A M - and - A V A . If we were to assume that the threshold values of activation of the morpheme A M - is a function of the frequency with which that partial representation has been activated, then, the decision latency to recognize arnaoa would be affected by the frequency of the root morpheme am-. At present we are unable to choose between the alternative accounts of the locus of the frequency effect offered here. The account we have given of the frequency effects found for derived words is based on the assumption that derived words of the type we have considered are represented in the orthographic lexicon in decomposed form, as root and suffix, analogously to inflected forms. Many questions about the representation of morphologically complex words are still open. For example, the representation of derivational affixes is still unexplored. Can some form of organization be hypothesized within the system of derivational affixes as has been done for inflectional suffixes (Caramazza et a/., in press)? Is the class of derivational affixes a unitary system, or are there different subsystems for different types of affixes? Some organizational principles suggest themselves but none has been explored experimentally. Thus, for example, we might suppose that in spite of their greater heterogeneity (there is no ‘paradigm’ for derivational suffixes as there is for inflections),derivational suffixes could be organized in the lexicon along the dimension of productivity, or of grammatical class, but these questions await experimental evaluation. We should emphasize that the representational solution we have adopted for derived words (root and derivational affixes are represented separately) may only apply to derived words of the kind investigated in this report, i.e. to medium-low frequency derived forms whose root does not show any ortho/phonological differentiation from the base verb, and whose derivational suffx is productive (e.g., see Bybee, 1985). A question in need of further investigation is how other types of derived words are represented in the lexicon. It could be that for derived words with different characteristics, the root morpheme may not be the best candidates as the unit of representation. For instance, the proper representational form for high-frequency derived words could be the stem, intended as the root in combination with the derivational suffix (Bybee, 1985).Similarly, derived forms in which the combination of the root with the derivational suffix has given rise to a form with orthographic and phonological characteristics different from those of the base might also be represented by their stem (see Caramazza et al., in press), as is probably the case for semantically opaque, derived words. Answers to these questions must await further experimental investigations.
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Acknowledgements The research reported here was supported by a grant from the Consiglio Nazionale delle ricerche, Rome and by NIH Grant NS23836 to The Johns Hopkins University. We would like to thank Bill Badecker, Alessandro Laudanna, and Domenico Parisi for their comments on an earlier version of this paper, and Cristina Delogu for her help in testing subjects. We also thank Kathy Yantis for her help in the preparation of this manuscript. Please address requests for reprints to Dr. Cristina Burani or Alfonso Caramazza.
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NOTES 1. Two terms (root and stem) are used in the literature to designate that part ofa word that remains when all aflixes have been removed. Following some recent attempts to distinguish between them, we have opted for the term root. A clear distinction between root and stem is made for instances by Bauer (1983):"...A root is a form which is not further analysable, either in terms of derivational or inflectional morphology. It is that part of a word-form that remains when all inflectional and derivational affixes have been removed. A root is the basic part always present in a lexeme. In the form untouchables, for example, the root is touch.. , A stem.. .may be-but need not be-complex, either in that it contains derivational affixes (as does gouern.ment) or in that it contains more than one root (as does redskin). Inflectional (but not derivational) affixes are added to it: It is the part of the word-form which remains when all the inflectional affixes have been removed. In the form untouchables the stem is untouchable.. ." (Bauer, 1983; p. 20). 2. Recently, it has been argued(Downey et al., 1985; Fowler et al., 1985)that both neutral and non-neutral suffixed derivations share a lexical entry with their base. This conclusion was supported by obtaining full repetition priming effects on morphologically related words by both types of derived words, with n o loss in priming when the orthographic or phonological shapes of suflixed primes and morphologically related targets did not fully overlap. However, as has been argued by Henderson (1985) and Monsell (1985). the relevance of repetition priming data for issues oflexical representation needs to be further investigated, as it is not clear what components of the lexical access process are responsible for this effect. 3. Cole et at. (1986) studied the effects of a set induction technique on the access of prefixed and suffixed words. They demonstrated that the access of suffixed words (but not of prefixed words) was affected by the morphological properties of items in the list. Derived test words in a context list composed of words sharing the property of being suffixed showed significantly shorter reaction times in this context set than in a context set of unsufixed words. The same did not apply for prefixed words when they were part ofa context list composed of other prefixed words.
REFERENCES Bauer, L. (1983). English Word Formation. University Press, Cambridge. Bortolini, U., Tagliavini, C. and Zampolli, A. (197I). Lessico di Frequenza della Lingua Italiana Conternporanea. Garzanti, Milano. Bradley, D. (1979). Lexical representation of derivational relation. In: M. Aronoffand M. L. Kean (Eds.), Juncture. MIT Press, Cambridge, Mass. Burani, C., Salmaso, D. and Cararnazza, A. (1984). Morphological structure and lexical access. Visible Language 4, 348-358. Butterworth, B. (1983). Lexical representation. In: B. Butterworth (Ed.), Language Production 2. Academic Press, London. Bybee, J. L. (1985).Morphology: A Study of the Relation between Meaning and Form. Benjamins, Amsterdam. Caramazza, A., Laudanna, A. and Romani, C. (in press). Lexical access and inflectional morphology. Cognition. Caramaua, A,, Miceli, G., Silveri, M. C. and Laudanna, A. (1985).Reading mechanisms and the organization of the lexicon: Evidence from acquired dyslexia. Cognitioe Neuropsychology 2, 8 1- 114. Cole, P., Beauvillain, C., Pavard, B. and Segui, J. (1986).Organisation morphologique et access au lexique. LAnnee Psychologique 86, 349-365. Cutler, A. (1983). Lexical complexity and sentence processing. In: G. B. Flores d'Arcais and R. J. Jarvella (Eds.), The Process of Language Understanding. Wiley, New York. Downey, R., Milech, D. and Kirsner, K. (1985). Unit definition in the mental lexicon. Australian Journal of Psychology 37, 141-155. Fowler, C. A., Napps, S. E. and Feldman, L. (1985).Relations among regular and irregular morphologically related words in the lexicon as revealed by repetition priming. Memory and Cognition 13, 241-255.
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Gordon, B. ( 1983). Lexical access and lexical decision: Mechanisms of frequency sensitivity.Journal of Verbal Learning and Verbal Behavior 22, 146-160. Gordon, B. (1985). Subjective frequency and the lexical decision latency function: Implications for mechanisms of lexical access. Journal of Memory and Language 24,631-645. Henderson, L. (1 982). Orthography and Word Recognition in Reading. Academic Press, London. Henderson, L. (1985).Towards a psychology of morphemes. In: A. W. Ellis (Ed.), Advances in the Psychology of Language 1 . LEA, London. Laudanna, A. and Burani, C. (1985). Address mechanisms to decomposed lexical entries. Linguistics 23, 775-792. Monsell, S . (1985). Repetition and the lexicon. In: A. W. Ellis (Ed.), Advances in the Psychology ofLanguage I . LEA, London. Morton, J. (1969). The interaction of information in word recognition. Psychological Review 76, 165-178. Morton, J. (1979).Word recognition. In: J. Morton and I. Marshall (Eds.),Psycholinguistics 2: Structures and Processes. MIT Press, Cambridge, MA. Taft, M. (1979). Recognition of aflixed words and the word frequency enect. Memory and Cognition 7, 263-272. Taft, M. (1985). The decoding of words in lexical access: A review of the morphographic approach. In: D. Besner, T. G . W a l k and G. E. Mackinnon (Eds.), Reading Research 5 . Academic Press, London. APPENDIX A
Experimental words in Set A (derived forms w i t h high-frequency r o o t ) and in Set B ( d e r i v e d forms with low-frequency root). E x p e r i m e n t I . Set A osservazione continuazione abitazione pagament o cambiamento trattamento parlatore portatore vincitori conoscenze esistenza dimenticanza amabile passabile piacevole girevole
(observation) (continuation) (dwelling) (payment) (change) (treatment) (speaker) (carrier) (winners) (knowledge) (existence) (forgetting) (lovable) (acceptable) (likeable) (turnable)
Set B illustrazione dominazione applicazione mutamento ammonimento ornament0 traditore narratore fornitore esigenze somiglianza sorveglianza digeribili guaribile gradevole cedevole
(illustration) (domination) (application) (mutation) (warning) (ornament) (betrayer) (narrator) (supplier) (demands) (resemblance) (surveillance) (digestible) (healable) (pleasant) (yielding)
APPENDIX B
E x p e r i m e n t a l words in S e t A ( d e r i v e d f o r m s with higher w h o l e - w o r d f r e q u e n c y ) a n d i n S e t
B (derived forms with lower whole-word frequency). Experiment 2. Set A situazione comunicazione dichiarazione costruzione produzione allevamento conseguenza irnportanza mancanza notevole
(situation) (communication) (declaration) (construction) (production) (breeding) (consequence) (importance) (lack) (remarkable)
Set B negazione continuazione abitazione proibizione estrazione cambiamento assistenza somiglianza sorveglianza ammirevole
(negation) (continuation) (dwelling) (prohibition) (extraction) (change) (assistance) (resemblance) (surveillance) (admirable)
