Cognitive control of language production in bilinguals involves a partly independent process within the domain-general cognitive control network: evidence from task-switching and electrical brain activity

In highly proficient, early bilinguals, behavioural studies of the cost of switching language or task suggest qualitative differences between language control and domain-general cognitive control. By contrast, several neuroimaging studies have shown an overlap of the brain areas involved in language control and domain-general cognitive control. The current study measured both behavioural responses and event-related potentials (ERPs) from bilinguals who performed picture naming in single- or mixed-language contexts, as well as an alphanumeric categorisation task in single- or mixed-task context. Analysis of switch costs during the mixed-context conditions showed qualitative differences between language control and domain-general cognitive control. A 2 × 2 ANOVA of the ERPs, with domain (linguistic, alphanumeric) and context (single, mixed) as within-participant factors, revealed a significant interaction, which also suggests a partly independent language-control mechanism. Source estimations revealed the neural basis of this mechanism to be in bilateral frontal-temporal areas.     

Exploring the Phenotype of Phonological Reading Disability as a Function of the Phonological Deficit Severity: Evidence from the Error Analysis Paradigm in Arabic

The dominant error types were investigated as a function of phonological processing (PP) deficit severity in four groups of impaired readers. For this aim, an error analysis paradigm distinguishing between four error types was used. The findings revealed that the different types of impaired readers were characterized by differing predominant error types. The dysphonetic errors predominated in readers with severe PP deficit and the morphological errors predominated in those with moderate deficits. Finally, readers with attention difficulties showed a predominance of semiphonetic errors. These findings were discussed in relation to reading disability subtypes and their clinical implications.     

Predicting Reading in Vowelized and Unvowelized Arabic Script: An Investigation of Reading in First and Second Grades

This study examined the orthographic transparency of Arabic by investigating the contribution of phonological awareness (PA), vocabulary, and Rapid Automatized Naming (RAN) to reading vowelized and unvowelized words. The results from first and second grade children showed that PA contribution was similar in the vowelized and unvowelized orthographies. The RAN contribution was weak and similar in both versions. The vocabulary contribution increased with grade and was slightly higher in the unvowelized than vowelized orthography. Since orthography transparency in Arabic is determined solely by vowelization, these results are discussed in relation to its position on the transparency-depth continuum.     

Temporal dynamics of awareness for facial identity revealed with ERP

In this study, we investigated the scalp recorded event-related potential (ERP) responses related to visual awareness. A backward masking procedure was performed while high-density EEG recordings were carried out. Subjects were asked to detect a familiar face, presented at durations that varied parametrically between 16 and 266 ms. ERPs were computed and awareness was assessed using a sensitivity measure from signal detection theory (d'). Modifications in the electrical scalp topographies were found to reflect visual awareness of the stimulus. In particular, an early map topography was found to emerge progressively around 230 ms, showing a pattern of increase similar to the measure of visual awareness. This was followed by an increase in duration of a second, P300-like map. Source localisation for the early awareness-related topography revealed the activation of a distributed network of brain areas including frontal and temporo-occipital regions. Our results suggest that conscious experience emerges in parallel with the activation of a specific neural network that occurs in a time window beginning from about 200 ms.