Word production and the picture-word interference paradigm: the role of learning.

Psycholinguistic experiments conducted with the picture-word interference paradigm are typically preceded by a phase during which participants learn the words they will have to produce in the experiment. In Experiment 1, the pictures (e.g., a frog) were to be named and were presented with a categorically related (e.g., cat) or unrelated distracter (e.g., pen). In the related condition responses were slower relative to the unrelated condition for the participants who had gone through the learning phase. In contrast, participants who had not been previously familiarized with the materials showed facilitation. In Experiment 2 one group of participants, as usual, learned to produce the targets upon presentation of the corresponding pictures (e.g., a frog). The other group learned to produce the same targets upon presentation of unrelated pictures (e.g., a clock). They showed very similar semantic effects. The implications of the findings in the study of word production are discussed.

Argument structure and morphological factors in noun and verb processing: an fMRI study.

In a functional MRI (fMRI) study, we have investigated the grammatical categories of object noun, event noun and verb in order to assess the cortical regions of activation supporting their processing. Twelve Italian healthy participants performed a lexical decision task. They had to decide whether a string was an Italian word or not. Words could be objects like medaglia (medal), or events like the noun pianto (cry); or the verb dormire (to sleep). Noun and verb comparison shows differences in regions of activation in the left Inferior Frontal cortex and in the extent of the same areas. We have found specific areas of activation for object noun, and similarities in the pattern of activation for event noun and verb. The activations induced by pseudowords highly resembled the areas activated by the corresponding word category. The implications of the results are discussed in light of the recent debate on the role of grammatical category in the brain.

Descriptive norms for 245 Italian idiomatic expressions.

The present study reports descriptive normative measures for 245 Italian verbal idiomatic expressions. For each of the idiomatic expressions the following variables are reported: Length, Knowledge, Familiarity, Age of Acquisition, Predictability, Syntactic flexibility, Literality and Compositionality. Syntactic flexibility was assessed using five syntactic operations: adverb insertion, adjective insertion, left dislocation, passive and movement. The psycholinguistic relevance of each dimension, their measures and the correlations among them are provided and discussed. The databases are freely available for down-loading from the Psychonomic Society Web archive at www.psychonomic.org/archive/.

Speaking of events: the case of C.M.

C.M. is an agrammatic patient who on assessment tests shows a disproportionate difficulty when producing verbs compared with nouns. In three experiments, we investigated whether C.M. also has difficulties with nouns referring to events and whether event nouns and verbs show similar patterns of disruption. Experiment 1 suggested that she is sensitive to argument structure complexity and has a greater impairment in the production of event nouns and verbs than object nouns. Experiment 2 revealed that C.M. finds derivationally complex words, such as event nouns, difficult to produce. However, morphological complexity does not completely explain C.M.'s problems with event nouns. In Experiment 3, an assessment of C.M.'s ability to use different aspects of semantic and syntactic knowledge relative to event nouns and verbs showed an almost identical performance with the two types of words. The relevance of the findings with respect to models of word production is considered.

Why are idioms recognized fast?

It is an established fact that idiomatic expressions are fast to process. However, the explanation of the phenomenon is controversial. Using a semantic judgment paradigm, where people decide whether a string is meaningful or not, the present experiment tested the predictions deriving from the three main theories of idiom recognition-the lexical representation hypothesis, the idiom decomposition hypothesis, and the configuration hypothesis. Participants were faster at judging decomposable idioms, nondecomposable idioms, and clichés than at judging their matched controls. The effect was comparable for all conventional expressions. The results were interpreted as suggesting that, as posited by the configuration hypothesis, the fact that they are known expressions, rather than idiomaticity, explains their fast recognition.

Phonotactic regularities in the segmentation of spoken Italian.

Five word-spotting experiments explored the role of consonantal and vocalic phonotactic cues in the segmentation of spoken Italian. The first set of experiments tested listeners' sensitivity to phonotactic constraints cueing syllable boundaries. Participants were slower in spotting words in nonsense strings when target onsets were misaligned (e.g., lago in ri.blago) than when they were aligned (e.g., lago in rin.lago) with phonotactically determined syllabic boundaries. This effect held also for sequences that occur only word-medially (e.g., /tl/ in ri.tlago), and competition effects could not account for the disadvantage in the misaligned condition. Similarly, target detections were slower when their offsets were misaligned (e.g., cittá in cittáu.ba) than when they were aligned (e.g., cittá in cittá.oba) with a phonotactic syllabic boundary. The second set of experiments tested listeners' sensitivity to phonotactic cues, which specifically signal lexical (and not just syllable) boundaries. Results corroborate the role of syllabic information in speech segmentation and suggest that Italian listeners make little use of additional phonotactic information that specifically cues word boundaries.

Processing idiomatic expressions: effects of semantic compositionality.

Three experiments tested the main claims of the idiom decomposition hypothesis: People have clear intuitions on the semantic compositionality of idiomatic expressions, which determines the syntactic behavior of these expressions and how they are recognized. Experiment 1 showed that intuitions are clear only for a very restricted number of expressions, but for the majority of idioms, they are not consistent across speakers. Experiment 2 failed to support the claim that semantic compositionality influences the syntactic flexibility of idioms. Finally, Experiment 3 showed that idioms are more quickly recognized than their literal counterparts, regardless of compositionality and syntactic flexibility. All of the findings were at odds with the tenets of the idiom decomposition hypothesis. The theoretical implications of the results with respect to idiom processing and the notion of compositionality are discussed.

Spoken idiom recognition: meaning retrieval and word expectancy.

This study investigates recognition of spoken idioms occurring in neutral contexts. Experiment 1 showed that both predictable and non-predictable idiom meanings are available at string offset. Yet, only predictable idiom meanings are active halfway through a string and remain active after the string's literal conclusion. Experiment 2 showed that the initial fragment of a predictable idiom inhibits recognition of a word providing a congruous, but literal, conclusion to the expression. No comparable effects were obtained with non-predictable idioms. These findings are consistent with the view that spoken idiom identification differs from word recognition and occurs word-by-word, just as with other familiar, multi-lexical phrases.

Idiom comprehension in aphasic patients.

Idiom comprehension was assessed in 10 aphasic patients with semantic deficits by means of a string-to-picture matching task. Patients were also submitted to an oral explanation of the same idioms, and to a word comprehension task. The stimuli of this last task were the words following the verb in the idioms. Idiom comprehension was severely impaired, with a bias toward the literal interpretation. Very few errors were produced with words, making impossible to establish a correlation between comprehension of idioms and of individual words. The difficulties in idiom comprehension seemed to be due to the fact that patients rely on a literal-first strategy, accessing a figurative interpretation only when the linguistic analysis fails to yield acceptable results.