Electrophysiological correlates of dispositional mindfulness: A quantitative and complexity EEG study.

While growing evidence supports that dispositional mindfulness relates to psychological health and cognitive enhancement, to date there have been only a few attempts to characterize its neural underpinnings. In the present study, we aimed at exploring the electrophysiological (EEG) signature of dispositional mindfulness using quantitative and complexity measures of EEG during resting state and while performing a learning task. Hundred twenty participants were assessed with the Five Facet Mindfulness Questionnaire and underwent 5 min eyes-closed resting state and 5 min at task EEG recording. We hypothesized that high mindfulness individuals would show patterns of brain activity related to (a) lower involvement of the default mode network (DMN) at rest (reduced frontal gamma power) and (b) a state of 'task readiness' reflected in a more similar pattern from rest to task (reduced overall q-EEG power at rest but not at task), as compared to their low mindfulness counterparts. Dispositional mindfulness was significantly linked to reduced frontal gamma power at rest and lower overall power during rest but not at task. In addition, we found a trend towards higher entropy during task performance in mindful individuals, which has recently been reported during mindfulness meditation. Altogether, our results add to those from expert meditators to show that high (dispositional) mindfulness seems to have a specific electrophysiological pattern characteristic of less involvement of the DMN and mind-wandering processes.

Transfer effects from language processing to visual attention dynamics: The impact of orthographic transparency.

The consistency between letters and sounds varies across languages. These differences have been proposed to be associated with different reading mechanisms (lexical vs. phonological), processing grain sizes (coarse vs. fine) and attentional windows (whole words vs. individual letters). This study aimed to extend this idea to writing to dictation. For that purpose, we evaluated whether the use of different types of processing has a differential impact on local windowing attention: phonological (local) processing in a transparent language (Spanish) and lexical (global) processing of an opaque language (English). Spanish and English monolinguals (Experiment 1) and Spanish-English bilinguals (Experiment 2) performed a writing to dictation task followed by a global-local task. The first key performance showed a critical dissociation between languages: the response times (RTs) from the Spanish writing to dictation task was modulated by word length, whereas the RTs from the English writing to dictation task was modulated by word frequency and age of acquisition, as evidence that language transparency biases processing towards phonological or lexical strategies. In addition, after a Spanish task, participants more efficiently processed local information, which resulted in both the benefit of global congruent information and the reduced cost of incongruent global information. Additionally, the results showed that bilinguals adapt their attentional processing depending on the orthographic transparency.

ERP Correlates of Prospective Memory and Cue Focality in Children.

Prospective memory (PM) is essential in the everyday activities of children because it involves remembering intentions for the future, such as doing their homework or bringing written parental permissions to school. Developmental studies have shown increases in PM performance throughout childhood, but the specific processes underlying this development are still under debate. In the present study, event-related potentials were used to examine whether the focality of the PM task is related to the PM increments by testing two groups of children (first and last cycle of primary school) and assessing differences in N300 (cue detection), frontal positivity (switching), parietal positivity (retrieval of the intention) and frontal slow waves (monitoring of the retrieved intention). The results showed significant differences in focality in the group of older children but no differences in any of the components for their younger counterparts. In addition, the differences between prospective and ongoing trials were smaller for younger than older children. These findings suggest that the ability to adjust attentional strategies, monitor, switch and retrieve the intention develops across childhood and affects PM performance in attentionally demanding conditions.

Socioeconomic Status, Culture, and Reading Comprehension in Immigrant Students.

Research on reading comprehension in immigrant students is heterogeneous and conflicting. Differences in socioeconomic status and cultural origins are very likely confounds in determining whether differences to native pupils can be attributed to immigrant status. We collected data on 312 Spanish students of Native, of Hispanic origin-therefore with the same family language as native students- and Non-Hispanic origin, while controlling for socioeconomic status, non-verbal reasoning and school membership. We measured reading comprehension, knowledge of syntax, sentence comprehension monitoring, and vocabulary. Differences among groups appeared only in vocabulary and syntax (with poorer performance in the non-Hispanic group), with no differences in reading comprehension. However, regression analyses showed that most of the variability in reading comprehension was predicted by age, socioeconomic status, non-verbal reasoning, and comprehension monitoring. Group membership did not significantly contribute to explain reading comprehension variability. The present study supports the idea that socioeconomically disadvantaged students, both native and immigrants from diverse cultural backgrounds, irrespective of the language of origin, are probably equally at risk of poor reading comprehension.

Brain potentials reveal differential processing of masculine and feminine grammatical gender in native Spanish speakers.

Studies of Spanish grammatical gender have shown that native speakers exploit gender cues in determiners to facilitate speech processing and are sensitive to gender mismatches. However, past research has not considered attested distributional asymmetries between masculine and feminine gender, collapsing performance on trials with one or the other gender into a single analysis. We use event-related potentials to investigate whether masculine and feminine grammatical gender elicit qualitatively different brain responses. Forty monolingual Spanish speakers read sentences that were well-formed or contained determiner-noun gender violations. Half of the nouns were masculine and the other half were feminine. Consistent with previous research, brain responses varied along a continuum between LAN- and P600-dominant effects for both gender categories. However, results showed that individuals' ERP response dominance (LAN/P600) systematically differed across the two genders: participants who showed a LAN-dominant response to masculine-noun violations were more likely to show a P600 effect in response to feminine-noun violations. Correlations with individual difference measures further revealed that responses to masculine-noun violations were modulated by performance on the AX-CPT, a measure of cognitive control, whereas responses to feminine-noun violations were modulated by lexical knowledge, as indexed by verbal fluency. Together, the results demonstrate that even when processing features of language that belong to the same "natural class," native speakers can exhibit patterns of brain activity attuned to distributional patterns of language use. The inherent variability in native speaker processing is, therefore, an important factor when explaining purported deviations from the "native norm" reported in other types of populations.

Selective directed forgetting: Eliminating output order and demand characteristics explanations.

Previous research has shown that giving an instruction to forget part of a studied list of items impairs the subsequent retrieval of these items compared with those not cued to be forgotten. This selective directed forgetting (SDF) effect has been found with slightly different procedures and in adolescents and young adults. While recent research has suggested that executive control might underlie SDF, alternative explanations that rely on procedural issues still have not been investigated. Specifically, SDF might essentially reflect output interference from the items cued to be remembered, so that the earlier recalled items interfere with the later recalled items. The effect could also result from demand characteristics: Participants might withhold the to-be-forgotten items to comply with the experimenter's implicit goals or might not be willing to engage in the effort of retrieving all studied information. The results from two experiments showed that (1) the to-be-forgotten items were less accessible and were not influenced by output interference from to-be-remembered items (Experiment 1), and (2) SDF was still present when participants were offered monetary reward for retrieving as many items as possible (Experiment 2). Hence, the findings do not provide support to explanations of SDF based on output interference and demand characteristics.

Interactional context mediates the consequences of bilingualism for language and cognition.

Proficient bilinguals use two languages actively, but the contexts in which they do so may differ dramatically. The present study asked what consequences the contexts of language use hold for the way in which cognitive resources modulate language abilities. Three groups of speakers were compared, all of whom were highly proficient Spanish-English bilinguals who differed with respect to the contexts in which they used the two languages in their everyday lives. They performed two lexical production tasks and the "AX" variant of the Continuous Performance Task (AX-CPT), a nonlinguistic measure of cognitive control. Results showed that lexical access in each language, and how it related to cognitive control ability, depended on whether bilinguals used their languages separately or interchangeably or whether they were immersed in their second language. These findings suggest that even highly proficient bilinguals who speak the same languages are not necessarily alike in the way in which they engage cognitive resources. Findings support recent proposals that being bilingual does not, in itself, identify a unique pattern of cognitive control. An important implication is that much of the controversy that currently surrounds the consequences of bilingualism may be understood, in part, as a failure to characterize the complexity associated with the context of language use. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Increased picture-word interference in chronic and recreational users of cocaine.

OBJECTIVE: The correct production of speech depends on the effective use of inhibitory control. Cocaine abuse has been linked to impaired inhibition in the verbal and nonverbal domains. The aim of this study was to evaluate the possible impairment of the inhibitory control process engaged in the production of language among chronic cocaine users, both in rehabilitation and recreational contexts. METHOD: Researchers obtained an index of semantic interference from a picture-word task performed by chronic cocaine users in rehabilitation (Experiment 1) and recreational cocaine polydrug users (Experiment 2). Cocaine users in both groups were matched for age and intelligence with cocaine-free health controls. Performance on the picture-word task was analyzed by repeated-measures analyses of variance. RESULTS: Both groups of cocaine users showed significantly more semantic interference than their respective cocaine-free control group. These results suggest a deficit in the ability to inhibit interfering information. CONCLUSIONS: The present findings suggest that cocaine use, even at recreational levels, is associated with specific impairments in the inhibitory mechanism that reduces the activation of overt competing responses in language production. This impairment results in the inefficient avoidance of irrelevant information, inducing errors and slower responses during the production of spoken language.

Correction: Genetic association study of dyslexia and ADHD candidate genes in a Spanish cohort: Implications of comorbid samples.

[This corrects the article DOI: 10.1371/journal.pone.0206431.].

Genetic association study of dyslexia and ADHD candidate genes in a Spanish cohort: Implications of comorbid samples.

Dyslexia and attention deficit hyperactivity disorder (ADHD) are two complex neuro-behaviorally disorders that co-occur more often than expected, so that reading disability has been linked to inattention symptoms. We examined 4 SNPs located on genes previously associated to dyslexia (KIAA0319, DCDC2, DYX1C1 and FOXP2) and 3 SNPs within genes related to ADHD (COMT, MAOA and DBH) in a cohort of Spanish children (N = 2078) that met the criteria of having one, both or none of these disorders (dyslexia and ADHD). We used a case-control approach comparing different groups of samples based on each individual diagnosis. In addition, we also performed a quantitative trait analysis with psychometric measures on the general population (N = 3357). The results indicated that the significance values for some markers change depending on the phenotypic groups compared and/or when considering pair-wise marker interactions. Furthermore, our quantitative trait study showed significant genetic associations with specific cognitive processes. These outcomes advocate the importance of establishing rigorous and homogeneous criteria for the diagnosis of cognitive disorders, as well as the relevance of considering cognitive endophenotypes.

The modulating effect of education on semantic interference during healthy aging.

Aging has traditionally been related to impairments in name retrieval. These impairments have usually been explained by a phonological transmission deficit hypothesis or by an inhibitory deficit hypothesis. This decline can, however, be modulated by the educational level of the sample. This study analyzed the possible role of these approaches in explaining both object and face naming impairments during aging. Older adults with low and high educational level and young adults with high educational level were asked to repeatedly name objects or famous people using the semantic-blocking paradigm. We compared naming when exemplars were presented in a semantically homogeneous or in a semantically heterogeneous context. Results revealed significantly slower rates of both face and object naming in the homogeneous context (i.e., semantic interference), with a stronger effect for face naming. Interestingly, the group of older adults with a lower educational level showed an increased semantic interference effect during face naming. These findings suggest the joint work of the two mechanisms proposed to explain age-related naming difficulties, i.e., the inhibitory deficit and the transmission deficit hypothesis. Therefore, the stronger vulnerability to semantic interference in the lower educated older adult sample would possibly point to a failure in the inhibitory mechanisms in charge of interference resolution, as proposed by the inhibitory deficit hypothesis. In addition, the fact that this interference effect was mainly restricted to face naming and not to object naming would be consistent with the increased age-related difficulties during proper name retrieval, as suggested by the transmission deficit hypothesis.

The gender congruency effect during bilingual spoken-word recognition.

We investigate the 'gender-congruency' effect during a spoken-word recognition task using the visual world paradigm. Eye movements of Italian-Spanish bilinguals and Spanish monolinguals were monitored while they viewed a pair of objects on a computer screen. Participants listened to instructions in Spanish (encuentra la bufanda / 'find the scarf') and clicked on the object named in the instruction. Grammatical gender of the objects' name was manipulated so that pairs of objects had the same (congruent) or different (incongruent) gender in Italian, but gender in Spanish was always congruent. Results showed that bilinguals, but not monolinguals, looked at target objects less when they were incongruent in gender, suggesting a between-language gender competition effect. In addition, bilinguals looked at target objects more when the definite article in the spoken instructions provided a valid cue to anticipate its selection (different-gender condition). The temporal dynamics of gender processing and cross-language activation in bilinguals are discussed.

Directed forgetting of memories in cocaine users.

Memory retrieval requires an effective recruitment of inhibitory control to successfully reject unnecessary memories. The use of cocaine is associated with poor cognitive control processes, but little is known about the impact of chronic and recreational use of cocaine on inhibitory control during intentional forgetting. We studied whether chronic and recreational users of cocaine show impairments on the mechanism responsible for intentional forgetting of memories. Two experiments were carried out on chronic cocaine users in rehabilitation (Experiment 1) and recreational cocaine polydrug users (Experiment 2) performing a directed forgetting (DF) task, an index of memory suppression. Participants were matched for sex, age, and intelligence (Raven's standard progressive matrices) with cocaine-free controls and compared on their performance on a DF procedure. Chronic cocaine users in rehabilitation and recreational cocaine polydrug users, as compared with controls, were not able to intentionally suppress the required information and they did not show a reliable DF effect. The consumption of cocaine appears to alter the control processes implicated in intentional suppression of nonrelevant memories in episodic memory. The use of cocaine, even for recreational purposes, seems to be associated with poor performance in effectively triggering this control mechanism. The inability to suppress interference in declarative memory may have repercussion for daily activities. (PsycINFO Database Record

Inhibitory effects of thought substitution in the think/no-think task: evidence from independent cues.

When people try not to think about a certain item, they can accomplish this goal by using a thought substitution strategy and think about something else. Research conducted with the think/no-think (TNT) paradigm indicates that such strategy leads subsequently to forgetting the information participants tried not to think about. The present study pursued two goals. First, it investigated the mechanism of forgetting due to thought substitution, contrasting the hypothesis by which forgetting is due to blocking caused by substitutes with the hypothesis that forgetting is due to inhibition (using an independent cue methodology). Second, a boundary condition for forgetting due to thought substitution was examined by creating conditions under which the generation of appropriate substitutes would be impaired. In two experiments, participants completed a TNT task under thought substitution instructions in which either words or pseudo-words were used as original cues and memory was assessed with original and independent cues. The results revealed forgetting in both original and independent cue tests, supporting the inhibitory account of thought substitution, but only when cues were words, and not when they were non-words, pointing to the ineffectiveness of a thought substitution strategy when original cues lack semantic content.

Chronic and recreational use of cocaine is associated with a vulnerability to semantic interference.

RATIONALE: Language production requires that speakers effectively recruit inhibitory control to successfully produce speech. The use of cocaine is associated with impairments in cognitive control processes in the non-verbal domain, but the impact of chronic and recreational use of cocaine on these processes during language production remains undetermined. OBJECTIVES: This study aims to observe the possible impairment of inhibitory control in language production among chronic and recreational cocaine polydrug users. METHOD: Two experiments were carried out on chronic (experiment 1) and recreational (experiment 2) cocaine polydrug users performing a blocked-cycled naming task, yielding an index of semantic interference. Participants were matched for sex, age, and intelligence (Raven's Standard Progressive Matrices) with cocaine-free controls, and their performance was compared on the blocked-cycled naming task. RESULTS: Chronic and recreational users showed significantly larger semantic interference effects than cocaine-free controls, thereby indicating a deficit in the ability to inhibit interfering information. CONCLUSION: Evidence indicates a relationship between the consumption of cocaine, even at recreational levels, and the inhibitory processes that suppress the overactive lexical representations in the semantic context. This deficit may be critical in adapting and responding to many real-life situations where an efficient self-monitoring system is necessary for the prevention of errors.

Long-term effects of chronic khat use: impaired inhibitory control.

So far no studies have systematically looked into the cognitive consequences of khat use. This study compared the ability to inhibit and execute behavioral responses in adult khat users and khat-free controls, matched in terms of age, race, gender distribution, level of intelligence, alcohol and cannabis consumption. Response inhibition and response execution were measured by a stop-signal paradigm. Results show that users and non-users are comparable in terms of response execution but users need significantly more time to inhibit responses to stop signals than non-users.

How does bilingualism improve executive control? A comparison of active and reactive inhibition mechanisms.

It has been claimed that bilingualism enhances inhibitory control, but the available evidence is equivocal. The authors evaluated several possible versions of the inhibition hypothesis by comparing monolinguals and bilinguals with regard to stop signal performance, inhibition of return, and the attentional blink. These three phenomena, it can be argued, tap into different aspects of inhibition. Monolinguals and bilinguals did not differ in stop signal reaction time and thus were comparable in terms of active-inhibitory efficiency. However, bilinguals showed no facilitation from spatial cues, showed a strong inhibition of return effect, and exhibited a more pronounced attentional blink. These results suggest that bilinguals do not differ from monolinguals in terms of active inhibition but have acquired a better ability to maintain action goals and to use them to bias goal-related information. Under some circumstances, this ability may indirectly lead to more pronounced reactive inhibition of irrelevant information.

Age differences in memory control: evidence from updating and retrieval-practice tasks.

Some contemporary approaches suggest that inhibitory mechanisms play an important role in cognitive development. In addition, several authors distinguish between intentional and unintentional inhibitory processes in cognition. We report two experiments aimed at exploring possible developmental changes in these two types of inhibitory mechanisms. In Experiment 1, an updating task was used. This task requires that participants intentionally suppress irrelevant information from working memory. In Experiment 2, the retrieval-practice task was used. Retrieval practice of a subset of studied items is thought to involve unintentional inhibitory processes to overcome interference from competing memories. As a result, suppressed items become forgotten in a later memory test. Results of the experiments indicated that younger children (8) were less efficient than older children (12) and adults at intentionally suppressing information (updating task). However, when the task required unintentional inhibition of competing items (retrieval-practice task), this developmental trend was not found and children and adults showed similar levels of retrieval-induced forgetting. The results are discussed in terms of the development of efficient inhibition and the distinction between intentional and unintentional inhibitions.