Michele Miozzo

The relation between syntactic and phonological knowledge in lexical access: evidence from the 'tip-of-the-tongue' phenomenon.

The relation between access to the syntactic and to the phonological features of words in lexical access is investigated in two experiments. Italian speakers were asked to provide the gender and partial phonological information of known nouns they could not produce at that moment, words that they felt were at the tip-of-the-tongue (TOT). In both experiments, subjects were able to provide information about the word they could not produce with better-than-chance accuracy. This was true not only for phonological information such as the initial phoneme of the word but also for the words gender--a purely syntactic feature of nouns. However, analyses of the correlation between correct retrieval of the gender and the initial phoneme failed to reveal a positive relationship. This result is inconsistent with theories of lexical access the interpose two lexical nodes, lemma and lexeme nodes, between a words semantic and phonological content. A model of lexical access that does not postulate the lemma/lexeme distinction is briefly discussed.

Evidence for a cascade model of lexical access in speech production.

How word production unfolds remains controversial. Serial models posit that phonological encoding begins only after lexical node selection, whereas cascade models hold that it can occur before selection. Both models were evaluated by testing whether unselected lexical nodes influence phonological encoding in the picture-picture interference paradigm. English speakers were shown pairs of superimposed pictures and were instructed to name one picture and ignore another. Naming was faster when target pictures were paired with phonologically related (bed-bell) than with unrelated (bed-pin) distractors. This suggests that the unspoken distractors exerted a phonological influence on production. This finding is inconsistent with serial models but in line with cascade ones. The facilitation effect was not replicated in Italian with the same pictures, supporting the view that the effect found in English was caused by the phonological properties of the stimuli.

THE TWO-STAGE MODEL OF LEXICAL RETRIEVAL : EVIDENCE FROM A CASE OF ANOMIA WITH SELECTIVE PRESERVATION OF GRAMMATICAL GENDER

The two-stage theory of lexical production distinguishes the retrieval of lemmas from the subsequent retrieval of the forms of words. The information made available by lemma retrieval includes semantic and grammatical details that are specific to a particular word, but not the direct specification of its phonological or orthographic form. This theory makes very strong predictions regarding the dissociability of these information types. In this report, we present the case of an Italian anomic patient whose performance bears on these predictions. In various naming tasks this patients intact ability to identify the grammatical gender of words that he cannot produce stands in stark contrast with his inability to provide any information regarding particular lexical forms. We document the reliability of this performance pattern, and we discuss the significance of this pattern both in terms of the support it provides for the two-stage theory of lexical retrieval and in terms of the evidence it furnishes regarding the mental specification of grammatical information.

When more is less: A counterintuitive effect of distractor frequency in the picture-word interference paradigm

Pictures were shown with superimposed word distractors of high and low frequency. Low-frequency distractors produced greater interference on picture naming than did high-frequency distractors. This distractor frequency effect was not affected by manipulations that facilitated or hindered distractor recognition. Interference was reduced for distractors that were read aloud several times prior to being shown in the picture-naming task. Together these findings suggest that the distractor frequency effect has its locus at some stage of lexical access for production. Other findings further constrain hypotheses about which level of speech production is involved in the effect. The distractor frequency effect has implications for models of lexical processing in speaking as well as for accounts of picture-word interference and the frequency effect.

The Specific-Word Frequency Effect: Implications for the Representation of Homophones in Speech Production

In a series of experiments, the authors investigated whether naming latencies for homophones (e.g., /nlambdan/) are a function of specific-word frequency (i.e., the frequency of nun) or a function of cumulative-homophone frequency (i.e., the sum of the frequencies of nun and none). Specific-word but not cumulative-homophone frequency affected picture-naming latencies. This result was obtained in 2 languages (English and Chinese). An analogous finding was obtained in a translation task, where bilingual speakers produced the English names of visually presented Spanish words. Control experiments ruled out that these results are an artifact of orthographic or articulatory factors, or of visual recognition. The results argue against the hypothesis that homophones share a common word-form representation, and support instead a model in which homophones have fully independent representations.

The selection of determiners in noun phrase production.

Picture-word interference experiments conducted with Italian speakers investigated how determiners are selected in noun phrase (NP) production. Determiner production involves the selection of a nouns syntactic features (mass or count, gender), which specify the type of determiner to be selected, and the subsequent selection of a particular phonological form (e.g., the/a in English). The research focused on the syntactic feature of gender. Results repeatedly failed to replicate the gender-congruity effect in NP production reported with Dutch speakers (longer latencies for target-distractor noun pairs with contrasting as opposed to the same gender). It is proposed that the discrepant results reflect processing differences in lexical access in Italian and Dutch: The selection of determiners in Italian, but not in Dutch, depends on phonological properties of the word that follows it in the NP. Evidence consistent with this explanation was obtained in an experiment in which determiner selection in NP production was hindered by conflicting phonological information in the NP.

Varieties of pure alexia : The case of failure to access graphemic representations

We document the case of a patient (GV) w ho, following a left posterior brain lesion, showed a selective and severe deficit in naming visual objects and in reading letters, words, and numerals. Three sets of findings are critical for the interpretation of the patients alexia. First, despite intact visual processing abilities and preserved ability to recognise the shape and orientation of letters, GV could not determ ine whether a pair of letters had the same name. Second, she should not access the orthographic structure and meaning of visually presented words, although she could access meaning from orally spelled words and she could access orthographic structure from m eaning in w ritten words. Third, GV could access partial semantic information from pictures and Arabic num erals. Based on this pattern of results, we conclude that the form of alexia manifested by our patient results from failure to access the graphemic representations of letters and w ords from normally processed visual input. The findings further suggest that access to letter forms and grapheme representations are sequentially ordered stages of processing in word recognition. The results also suggest that graphemic processing may be a distinct property of the left hemisphere.

Pupillary Stroop effects

We recorded the pupil diameters of participants performing the words’ color-naming Stroop task (i.e., naming the color of a word that names a color). Non-color words were used as baseline to firmly establish the effects of semantic relatedness induced by color word distractors. We replicated the classic Stroop effects of color congruency and color incongruency with pupillary diameter recordings: relative to non-color words, pupil diameters increased for color distractors that differed from color responses, while they reduced for color distractors that were identical to color responses. Analyses of the time courses of pupil responses revealed further differences between color-congruent and color-incongruent distractors, with the latter inducing a steep increase of pupil size and the former a relatively lower increase. Consistent with previous findings that have demonstrated that pupil size increases as task demands rise, the present results indicate that pupillometry is a robust measure of Stroop interference, and it represents a valuable addition to the cognitive scientist’s toolbox.

Which Words Are Activated during Bilingual Word Production

Whether words are or are not activated within the lexicon of the nonused language is an important question for accounts of bilingual word production. Prior studies have not led to conclusive results, either because alternative accounts could be proposed for their findings or because activation could have been artificially induced by the experimental paradigms. Moreover, previous data only involved target translations, and nothing is known about the activation of nontarget words in the nonused language. The picture-picture interference paradigm was used here, since it allowed the activation of nontarget words to be determined without showing stimuli that could artificially activate the nonused language. Proficient Spanish-Catalan speakers were presented with pairs of partially overlapping colored pictures and were instructed to name the green picture and ignore the red picture. In Experiment 1, distractor pictures with cognate names interfered more than distractor pictures with noncognate names. In Experiment 2, facilitation was observed when the names of the distractor pictures in the nonused language were phonologically related to the names of the target pictures. Overall, these results indicate that nontarget words are activated in the nonused language, at least in the case of proficient bilingual speakers. These results help researchers to constrain theories of bilingual lexical access. (PsycINFO Database Record (c) 2009 APA, all rights reserved).

Early Parallel Activation of Semantics and Phonology in Picture Naming: Evidence from a Multiple Linear Regression MEG Study

The time course of brain activation during word production has become an area of increasingly intense investigation in cognitive neuroscience. The predominant view has been that semantic and phonological processes are activated sequentially, at about 150 and 200–400 ms after picture onset. Although evidence from prior studies has been interpreted as supporting this view, these studies were arguably not ideally suited to detect early brain activation of semantic and phonological processes. We here used a multiple linear regression approach to magnetoencephalography (MEG) analysis of picture naming in order to investigate early effects of variables specifically related to visual, semantic, and phonological processing. This was combined with distributed minimum-norm source estimation and region-of-interest analysis. Brain activation associated with visual image complexity appeared in occipital cortex at about 100 ms after picture presentation onset. At about 150 ms, semantic variables became physiologically manifest in left frontotemporal regions. In the same latency range, we found an effect of phonological variables in the left middle temporal gyrus. Our results demonstrate that multiple linear regression analysis is sensitive to early effects of multiple psycholinguistic variables in picture naming. Crucially, our results suggest that access to phonological information might begin in parallel with semantic processing around 150 ms after picture onset.