Incorrect retrievals on opaque nouns

The error analysis offers insights into what happens when GG retrieval fails at activating the expected gender, in particular in the case of opaque words. Mistakes on grammatical gender retrieval were collected and classified and it emerged that they mainly concern irregular and opaque nouns, with a higher incidence on derived ones. PADs produced 134 mistakes; of those, few concern regular nouns (n=3). The very low amount is therefore statistically different from the number of mistakes recorded on irregular (n=40) and on opaque nouns (n=91). In contrast, words in the irregular and opaque classes were equally effected in rates that, according to the statistics, are not significantly different. If we now think of the double-route to GG activation described in paragraph 3.4, namely the direct access to the gender information stored in the lexical entry and the form-based retrieval, we can actually see that the latter is well preserved and guarantees a very accurate performance, while the former shows slight signs of impairment. The two complementary routes, due to their core functional characteristics, certainly differ with respect to the kind of linguistic components they represent. Direct access is an example of declarative knowledge, while form-driven retrieval goes under the procedural system. Roughly speaking, the two components are not balanced in PADs, as the cognitive impairment affects declarative components first and to a more severe extent, while leaving procedural

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components relatively spared. This generalization holds for a variety of cognitive abilities, and linguistic competence makes no exception. The data at stake in the present chapter further support the generalization outlined above by showing that procedural retrieval of GG is well preserved and assumes the role of default strategy. Patients indeed produce mistakes on irregular or opaque words by regularizing them, rather than the contrary. We can therefore assume that PADs tend to resort to this procedure when unable to recover the target GG directly form the mental lexicon. The hypothesis is also compatible with the reverse pattern of regularization, namely the one exemplified in la

*pesta instead of la peste ('the.F pest'): in this case, correct retrieval of GG takes place and affects the opaque word by changing the final vowel -e into -a, the typical final marker for singular feminine nouns. No matter then in which direction the regularization process flows; in any case, the tendency to rely on the procedural mechanism of regularization clearly emerges in PADs.

4.4.2.1 Sensitivity to derivational morphology

If I now take a further step and have a closer look at error analysis, I can actually infer more on how over-regularization takes place and the value assigned to morphological markers. In particular, they are mistakes on opaque nouns to be informative about which factors represent a source of complexity.

First of all, the incidence of mistakes on opaque nouns is higher for derived nouns than for simple nouns, thus attesting that patients are sensitive to derivation. This agrees with previous studies on unimpaired (Meinzner et al. 2009) and on aphasic speakers.

Unimpaired speakers are indeed sensitive to the number of derivational steps involved in word formation and they differently process words depending on their level of derivational complexity (one- or two-step derivation). In particular, a higher number of derivational steps mirrors into the activation of wider brain substrates.

Although low frequency of derived nouns might have influenced the results (thus representing a confounding factor), an interesting comparison with agrammatic speakers is possible. Based on similar material, Luzzatti and De Bleser (1996) show that aphasic speakers are also sensitive to derivation and even profit from it. Their participants better retrieve GG for derived nouns than for simple ones, probably as a by-product of their capacity of cutting down words into their component morphemes and of recognizing the

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specific GG entailed in each derivational morpheme. PADs show a similar sensitivity, but in the opposite direction, in the sense that GG retrieval is more problematic for derived nouns than for simple opaque nouns, which nonetheless can be taken as a sign of sensitivity to derivation.

Moreover, the impairment at processing derived nouns and retrieving GG from the derivational suffix resembles results from a previous study conducted by Chiarelli, Manichelli and Semenza (2007) about patients’ ability to deal with compounds. Chiarelli et al. (2007) report that PADs make more errors in picture-naming with compounds rather than with simple words and, in particular, the impairment affects the second element in the compound, while the first one is more often smoothly retrieved. As a compensating strategy, PADs tend to overcome their difficulties by systematically using the most productive structure for compounds, namely Verb-Noun.

Taken together, results from the present study and from Chiarelli et al. (2007), reveal that PADs suffer from a cumulative effect and their impairment increases along with the level of internal complexity entailed in the word structure. In particular, the difficulty at retrieving GG from the derivational suffix resembles the attested difficulties at activating the second element in compounds.

4.4.2.2 Role of animacy

One more question I addressed at the beginning of the present chapter concerns the role played by natural gender. In other words, I wondered whether natural gender can facilitate GG retrieval and therefore produce an asymmetry between nouns endowed with the [+human] feature and the inanimate ones, namely artefacts or abstract nouns. Indeed, the prediction was met and the number of mistakes on inanimate nouns (n=50) significantly exceeded the number of mistakes on nouns with natural gender (n=20). I assume that this is due to the fact that PADs can resort to semantic information when direct access to GG is impaired³⁸.

That might appear to contradict the assumption that PADs are highly impaired at retrieving semantic information (Hodges et al., 1991; Almor et al., 2009), but semantics is not all equally affected by disruption. Impairments proceed from fine-grained and

38 In Chapter 3 I outlined the distinction between natural gender and grammatical gender and underlined that assignment of the latter does not depend on the former. However, NG and GG very often overlap, such that a GG retrieval strategy based on natural gender can be highly successful.

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detailed information to information that is more generic (see Chapter 2). In this view, biological gender can be considered as a macro-category from the semantic point of view, which probably holds rather spared through different stages of impairment and is available as a relevant piece of information in case the form-based procedure is not available and direct access to GG fails.

In this line of reasoning, I would also like to add one more observation, namely the fact that the asymmetry between words with natural gender and others with no natural gender might be due to an effect of concreteness, which favour the former over the latter.

Indeed, PADs have been reported to be more proficient at retrieving nouns rather than verbs (Almor et al., 2009; Bushell & Martin, 1997; Grossman et al., 1996; Robinson et al., 1996), and researchers ascribed the difference to the fact that the former is more concrete than the latter from the semantic point of view. Here I consider the hypothesis that the same difference might hold between nouns with either natural or no natural gender and that this might represent one further factor playing a role in the results.

4.4.2.3 Masculine as default grammatical gender

The third thing I can notice with respect to mistakes on opaque words is that feminine nouns are more affected by mistakes on GG retrieval than masculine nouns. In other words, cases of feminine nouns incorrectly classified as masculine, are more frequent than the opposite. This might be due to frequency asymmetries in the two classes of nouns, as it was not possible to balance feminine and masculine derived nouns for frequency. However, it could also be the case that masculine grammatical gender is regarded as a sort of default gender, to which PADs resort in case of difficulties at retrieving the proper GG for opaque words. When faced with opaque nouns, speakers can in no way retrieve the proper GG through the word form, as no morphological cue is available; direct access to the syntactic information is indeed the only possible strategy, but when PADs cannot use the latter, they must activate a last-resort strategy, which consists in assigning a default gender, namely masculine.

If the assumption is correct, we should also take into account the fact that (most probably) not all masculine nouns classified as such are the outcome of successful retrieval of GG gender from the mental lexicon. It might be the case that masculine was assigned to some items as a default value, which corresponds to the correct one just by

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accident. I intend to assume that masculine and feminine are affected by unsuccessful GG retrieval to the same extent; what changes is the fact that the use of a default gender leads to an apparent successful classification in the case of masculine nouns. In contrast, in the case of feminine nouns, default assignment causes mistakes, which are more salient.

Otherwise, we should assume a dissociation between masculine and feminine nouns, with feminine nouns evenly stored separately from masculine ones and for some reasons more affected by retrieval impairment than their counterparts are.

Unfortunately, I cannot further test the assumption with the data at hand, so that the proposal can be considered only at a pure speculative level.