Manuel Gimenes

Purpose This study investigates the effects of different levels of acute normobaric hypoxia on cognitive function and cerebral oxygenation in healthy young adults. Methods Twenty-four participants aged 18–30 years were exposed to hypoxia with an inspired oxygen fraction (FiO₂) equivalent to 20.9%, 17.44%, 14.5% and 12.7%. They performed different cognitive tasks, including the Stroop test, Corsi blocks (forward and backward), the n-Back task (1-Back and 2-Back), and the Go/No-Go task. Cerebral oxygenation was measured using the near-infrared spectroscopy (NIRS) during each cognitive task. Results In this study, we did not observe any effect of hypoxia on cognitive performance. However, perceived difficulty increased with increasing hypoxia, especially for the Stroop task (p = 0.003, Kendall’s W = 0.208) and Corsi (p = 0.018, Kendall’s W = 0.152). NIRS results showed a progressive increase in deoxyhemoglobin (ΔHHb) and a progressive decrease in oxyhemoglobin (ΔO₂Hb) with increasing hypoxia for all cognitive tasks. There was no effect on total hemoglobin (ΔtHb). Finally, positive correlations were found between pulse oxygen saturation (SpO₂) and ΔTSI% and between SpO₂ and ΔO₂Hb for all tasks, while a negative correlation was observed between SpO₂ and ΔHHb. No correlation was found between SpO₂ or TSI% and cognitive performance. Conclusion In conclusion, cognitive function appears to be unaffected by acute exposure to acute normobaric hypoxia at FiO₂ above 12.7%. These results suggest a complete compensation of oxygenation of the prefrontal cortex region in young healthy subjects.

We present VOC-ADO, a database of the written vocabulary of French adolescents between the ages of 11 and 15 (French secondary school students). VOC-ADO pr

Line bisection is one of the most commonly used tasks to assess spatial neglect. More recently, line bisection has been recommended as a task to monitor for spatial neglect during awake brain tumor surgery, but the operative constraints hamper the normal test conditions. We developed and validated in 118 healthy participants the BLOC test, a computerized version of line bisection, suppressing the motor component, in both sitting and lying positions. The results showed that the computerized line bisection task is strictly comparable to manual bisection and that it can be used in the sitting or lying position with the same significance threshold. The BLOC test therefore represents a relevant tool for clinical practice in a variety of contexts.

Several nonlanguage factors influence literacy development, and motor skills are among those most studied. Despite the publication of several studies that have supported the existence of this relationship, the type of influence and underlying mechanisms have been little explored. Herein, we propose modeling the relationship between motor skills and literacy through structural equation modeling, testing the contribution of executive functions and handwriting skills as the possible mediators of this relationship. In a study of 278 third-grade children, we used a wide range of measures related to written language (reading, spelling, reading comprehension, and written production), fine motor skills (dominant hand, nondominant hand, and bimanual dexterity), executive functions (verbal and visuospatial working memory, inhibition, and shifting), and handwriting. Structural equation modeling of the relationship between these different variables indicated that in the third grade, the influence of fine motor skills on literacy is fully mediated by both executive functions and handwriting skills. These motor skills effects are observed for both low levels of processing (reading, spelling) and high levels of processing (reading comprehension, written production). The results are discussed in terms of the potential mechanisms underlying different literacy skills and their implications for pedagogical programs.

Psycholinguistic research has shown that both the regularity and consistency of the grapheme-phoneme and phoneme-grapheme correspondences impact word proce

Lexical frequency is one of the strongest predictors of word processing time. The frequencies are often calculated from book-based corpora, or more recently from subtitle-based corpora. We present new frequencies based on Twitter, blog posts, or newspapers for 66 languages. We show that these frequencies predict lexical decision reaction times similar to the already existing frequencies, or even better than them. These new frequencies are freely available and may be downloaded from http://​worldlex.​lexique.​org .

Double centre-embedded structures such as “the rat the cat the boy chased ate was brown” seem ungrammatical to many human subjects. Using an offline complexity judgement task, Gibson and Thomas (1999) demonstrated that people found such sentences no more difficult to understand when the second verb phrase (VP) was omitted, relative to a condition where all the required VPs were present. According to the Syntactic Prediction Locality Theory (SPLT; Gibson, 1998), this syntactic illusion is determined by the high working memory cost associated with the integration of the second VP. This cost could be reduced by replacing the third noun phrase (the boy) by a pronoun, making the reader more sensitive to the omission of the second VP. This hypothesis was tested in two experiments using French sentences. Both experiments confirmed the syntactic illusion when the second VP was not a pronoun. The second experiment measured the reading times of the VPs and showed that the pronoun induced a longer reading time of the final VP when the second VP was omitted. The overall results indicate a condition under which human subjects could process the most complex part of a sentence with more than one embedded relative clause. The overall results are consistent with most of the hypotheses derived from the SPLT although offline complexity judgements could not be the most sensitive measure to test some of these hypotheses.