Biomedical subjects

José Morais

Publications and source records attributed to José Morais.

9 recordsLinked to original sources

PubMed2007

Lexical restructuring in the absence of literacy.

Vocabulary growth was suggested to prompt the implementation of increasingly finer-grained lexical representations of spoken words in children (e.g., [Metsala, J. L., & Walley, A. C. (1998). Spoken vocabulary growth and the segmental restructuring of lexical representations: precursors to phonemic awareness and early reading ability. In J. L. Metsala & L. C. Ehri (Eds.), Word recognition in beginning literacy (pp. 89-120). Hillsdale, NJ: Erlbaum.]). Although literacy was not explicitly mentioned in this lexical restructuring hypothesis, the process of learning to read and spell might also have a significant impact on the specification of lexical representations (e.g., [Carroll, J. M., & Snowling, M. J. (2001). The effects of global similarity between stimuli on children's judgments of rime and alliteration. Applied Psycholinguistics, 22, 327-342.]; [Goswami, U. (2000). Phonological representations, reading development and dyslexia: Towards a cross-linguistic theoretical framework. Dyslexia, 6, 133-151.]). This is what we checked in the present study. We manipulated word frequency and neighborhood density in a gating task (Experiment 1) and a word-identification-in-noise task (Experiment 2) presented to Portuguese literate and illiterate adults. Ex-illiterates were also tested in Experiment 2 in order to disentangle the effects of vocabulary size and literacy. There was an interaction between word frequency and neighborhood density, which was similar in the three groups. These did not differ even for the words that are supposed to undergo lexical restructuring the latest (low frequency words from sparse neighborhoods). Thus, segmental lexical representations seem to develop independently of literacy. While segmental restructuring is not affected by literacy, it constrains the development of phoneme awareness as shown by the fact that, in Experiment 3, neighborhood density modulated the phoneme deletion performance of both illiterates and ex-illiterates.

Adolescent↗

PubMed2006

Controlled processes account for age-related decrease in episodic memory.

A decrease in controlled processes has been proposed to be responsible for age-related episodic memory decline. We used the Process Dissociation Procedure, a method that attempts to estimate the contribution of controlled and automatic processes to cognitive performance, and entered both estimates in regression analyses. Results indicate that only controlled processes explained a great part of the age-related variance in a word recall task, especially when little environmental support was offered.

Adult↗

PubMed2005

Categorical perception of speech sounds in illiterate adults.

Children affected by dyslexia exhibit a deficit in the categorical perception of speech sounds, characterized by both poorer discrimination of between-category differences and by better discrimination of within-category differences, compared to normal readers. These categorical perception anomalies might be at the origin of dyslexia, by hampering the set up of grapheme-phoneme correspondences, but they might also be the consequence of poor reading skills, as literacy probably contributes to stabilizing phonological categories. The aim of the present study was to investigate this issue by comparing categorical perception performances of illiterate and literate people. Identification and discrimination responses were collected for a /ba-da/ synthetic place-of-articulation continuum and between-group differences in both categorical perception and in the precision of the categorical boundary were examined. The results showed that illiterate vs. literate people did not differ in categorical perception, thereby suggesting that the categorical perception anomalies displayed by dyslexics are indeed a cause rather than a consequence of their reading problems. However, illiterate people displayed a less precise categorical boundary and a stronger lexical bias, both also associated with dyslexia, which might, therefore, be a specific consequence of written language deprivation or impairment.

Adolescent↗

PubMed2005

Imidazolidin-4-one derivatives of primaquine as novel transmission-blocking antimalarials.

Imidazolidin-4-one derivatives of primaquine were synthesized as potential double prodrugs of the parent drug. The title compounds inhibit the development of the sporogonic cycle of Plasmodium berghei, affecting the appearance of oocysts in the midguts of the mosquitoes. The imidazolidin-4-ones are very stable, both in human plasma and in pH 7.4 buffer, indicating that they are active per se. Thus, imidazolidin-4-ones derived from 8-aminoquinolines represent a new entry in antimalarial structure-activity relationships.

Animals↗

PubMed2005

Evaluating feature-category relations using semantic fluency tasks.

The issue of the relationship between semantic features and semantic categories has been raised by Warrington and colleagues, who claimed that sensory and functional-associative features are differentially important in determining the meaning of living and nonliving things (Warrington & McCarthy, 1983, 1987; Warrington & Shallice, 1984). In the present study, the effectiveness of semantic memory search for living and nonliving things with sensory and functional-associative search cues was evaluated through eight different adaptations of the semantic fluency task. More living thing responses and clusters were generated from sensory than from functional-associative search cues, while the reverse pattern holds for nonliving things responses and clusters. The results thus provide consistent empirical support for the assumption that sensory properties are fundamental in the representation of living things, while functional-associative properties are fundamental in the semantic representation of nonliving things.

Adult↗

PubMed2005

The mental representation of living and nonliving things: differential weighting and interactivity of sensorial and non-sensorial features.

Warrington and colleagues (Warrington & McCarthy, 1983, 1987; Warrington & Shallice, 1984) claimed that sensorial and functional-associative (FA) features are differentially important in determining the meaning of living things (LT) and nonliving things (NLT). The first aim of the present study was to evaluate this hypothesis through two different access tasks: feature generation (Experiment 1) and cued recall (Experiment 2). The results of both experiments provided consistent empirical support for Warrington and colleagues' assumption. The second aim of the present study was to test a new differential interactivity hypothesis that combines Warrington and colleagueS' assumption with the notion of a higher number of intercorrelations and hence of a stronger connectivity between sensorial and non-sensorial features for LTs than for NLTs. This hypothesis was motivated by previoUs reports of an uncrossed interaction between domain (LTs vs NLTs) and attribute type (sensorial vs FA) in, for example, a feature verification task (Laws, Humber, Ramsey, & McCarthy, 1995): while FA attributes are verified faster than sensorial attributes for NLTs, no difference is observed for LTs. We replicated and generalised this finding using several feature verification tasks on both written words and pictures (Experiment 3), including in conditions aimed at minimising the intervention of priming biases and strategic or mnemonic processes (Experiment 4). The whole set of results suggests that both privileged relations between features and categories, and the differential importance of intercorrelations between features as a function of category, modulate access to semantic features.

Analysis of Variance↗

PubMed2004

Comprehension, encoding, and monitoring in the production of confabulation in memory: a study with schizophrenic patients.

INTRODUCTION: The aim of the present study was to test the hypotheses proposed by Nathaniel-James and collaborators (Nathaniel-James & Frith, 1996; Nathaniel-James, Foong, & Frith, 1996) to account for the cognitive deficits involved in the production of confabulations in schizophrenic patients: impairments in comprehension, memory encoding, and memory monitoring. METHOD: Five patients were investigated in this multiple single-case study. Comprehension abilities were investigated in several tests in which a memory bias was avoided. The encoding deficit hypothesis was tested by manipulating cues at encoding and/or retrieval. "Memory monitoring" abilities were examined in two tasks: the Hayling test for all patients and an AB-AC word pairs learning task for two patients. RESULTS: Four of the patients produced an abnormal level of confabulations in story and fable learning tests. All patients exhibited encoding deficits and specific comprehension difficulties. However, some demonstrated preserved memory monitoring abilities. Across different tests, it was observed that the more the confabulations occurred, the more severe were the comprehension difficulties. CONCLUSION: The results are in favour of the hypothesis that verbal comprehension difficulties lead to the production of confabulation. They are inconsistent with the idea that memory monitoring impairment is necessarily involved.

Journal Article↗

PubMed2002

Is there an association between edentulism and nutritional state?

Edentulous people have difficulty chewing foods that are hard or tough in texture, even when wearing well-made dentures. These individuals typically modify their diets to compensate for loss of oral function. This practice leads to the question of whether the diet of edentulous individuals is adequate to maintain good general health. This overview summarizes articles that describe the changes in diet associated with edentulism. Such changes include reductions in fruits, vegetables, meats and other hard-to-chew foods and are associated with compromised nutrition. The evidence suggests that edentulous individuals lack specific nutrients and, as a result, may be at risk for various health disorders. The authors have recently shown that mandibular prostheses supported by only 2 implants may significantly improve nutritional status in edentulous patients.

Aged↗

PubMed2002

Evaluation of aortic stenosis severity: role of contrast echocardiography in comparison with conventional echocardiography and cardiac catheterization.

OBJECTIVES: To evaluate the role of contrast Doppler echocardiography in the assessment of aortic stenosis severity, in comparison with the conventional method and using the catheterization study as the gold standard. STUDY DESIGN: Prospective comparative study. SETTING: Echocardiography Laboratory of Cardiology Department. POPULATION: We included 36 consecutive patients, 20 male, aged 67 +/- 11 years, referred for catheterization study to evaluate aortic stenosis severity. METHODS: All patients underwent conventional and contrast Doppler echocardiography and catheterization study. For contrast Doppler, we used Levovist (300 mg/ml infusion). We analyzed the following echocardiographic parameters: a) left ventricle dimensions, wall thickness and function; b) aortic valve morphology; c) post-stenotic aortic valve flow--peak velocity, velocity-time integral, peak gradient, mean gradient; d) left ventricle outflow tract flow--peak velocity, velocity-time integral; e) aortic valve functional area; f) acquisition time and Doppler signal intensity for post-stenotic aortic valve flow. Catheterization parameters analyzed: a) peak aortic valve gradient; b) mean aortic valve gradient. RESULTS: Contrast Doppler yielded higher peak gradients than conventional Doppler (85.6 +/- 30.2 vs 72.6 +/- 26.1 mmHg, p < 0.001), as well as higher mean gradients (51.4 +/- 19.0 vs 44.2 +/- 15.9 mmHg, p < 0.001). Peak gradients obtained with contrast Doppler correlated with those obtained invasively (r = 0.88, p < 0.001), although the values were higher (85.6 +/- 30.2 vs 73.6 +/- 32.0 mmHg, p < 0.001). There was no difference between mean contrast Doppler gradients and mean catheterization gradients, which showed a high correlation (r = 0.89, p < 0.001). There was no difference between peak and mean gradients obtained by conventional Doppler and invasively, which yielded correlations of 0.73 and 0.75, respectively (p < 0.001). The sensitivity of contrast Doppler for detection of severe aortic stenosis was 100% for peak gradient and 84% for mean gradient, while for conventional Doppler it was 68% and 58%. The specificity of contrast Doppler was 65% for peak gradient and 88% for mean gradient, while for conventional Doppler it was, respectively, 58% and 88%. Acquisition time for aortic flow visualization was lower (p < 0.001) and flow intensity higher for contrast Doppler, in comparison with conventional Doppler. CONCLUSIONS: In this study, contrast Doppler yielded high correlations with invasive data and higher sensitivity and specificity for detection of severe aortic stenosis than conventional Doppler. It is a useful method for evaluation of aortic stenosis severity.

Adult↗