Is there electrophysiological evidence for a bilingual advantage in neural processes related to executive functions?

Available online 3 August 2020Over the last two decades, a large number of studies have concluded that bilingualism enhances executive functions. However, other studies have reported no significant results. In addition, it is not clear how bilingualism might modulate specific executive control processes. Event-related potentials (ERP) are an excellent technique for identifying whether the neural correlates of executive control processes are strengthened by bilingualism, given their high temporal resolution. On the basis of previous research into the ERP correlates of executive functions, we hypothesize that specific ERP differences between monolinguals and bilinguals can be considered to indicate a bilingual advantage in executive functions. We then review the very limited number of studies that have investigated ERP differences between monolinguals and bilinguals during the performance of executive control tasks. Overall, we conclude that the existence of a bilingual advantage in neural processing related to executive functions remains uncertain and further studies are required. We highlight the utility of investigating several ERPs that have been ignored by previous studies.This study was funded by the Spanish government (Juan de la Cierva-Incorporación Postdoctoral Grant), European Commission (Marie Skłodowska-Curie actions 838536_BILINGUALPLAS), Basque Government (BERC 2018-2021 program), BCBL Severo Ochoa excellence accreditation SEV-2015-0490, and Grant RTI2018-093547-BI00 from the Agencia Estatal de Investigación

The Impact Of Color on Response Inhibition

Response inhibition is an important cognitive function that affects decision-making and action selection. Impairments in it occur in neurodegenerative diseases therefore, ways to support response inhibition are important for quality of life. One possibility is the use of color, as color has been shown to modulate inhibitory processes. The overall objective of this work was to determine the prefrontal networks underlying response inhibition that can be modulated through an automatic attentional process such as color. A series of three studies were performed whereby young adults performed a stop-signal task (SST) or a Go/No-go task (GNGT) with colored stimuli. In our first study, the SST, a reactive response inhibition task, was performed to determine whether the effect of color on response inhibition was due to color opponency, attentional color hierarchy, or visual associations. We found that while red stop signals produced faster response inhibition compared to green, blue and yellow stop signals did not differ from each other. This pattern of results was not consistent with color opponency or the attentional color hierarchy of red > green > yellow > blue. Therefore, red facilitating and green impairing response inhibition suggested that response inhibition was modulated by visual color associations where red means stop and green means go. In our second study, we tested if the color modulations between red and green extended beyond countermanding to more general inhibitory control by using a proactive response inhibition task, the GNGT. Indeed, participants were more successful on red in comparison to green No-go trials. Based on these results, a modified accumulator model and putative neural circuitry of color modulation response inhibition was proposed. In our third study, event-related potentials (ERPs) were recorded while participants performed a GNGT to test the putative underlying neural network. While the P300 was not modulated by color, we observed reduced N200 amplitudes and earlier N200 latencies over the prefrontal areas proposed in study 2 in response to red No-go stimuli over green, yellow, and blue. The increased accuracy was argued to be an advantage conferred by learned and evolutionary associations to the colour red. The decreased N200 amplitudes suggested reduced conflict on No-go trials with red No-go stimuli compared to other colours. These findings bring us a step closer to mapping out the differential colour modulated neural circuitry involved in response inhibition and such research will help pave the way for efficient decision-making and staving off cognitive decline

The Impact Of Color on Response Inhibition

Response inhibition is an important cognitive function that affects decision-making and action selection. Impairments in it occur in neurodegenerative diseases therefore, ways to support response inhibition are important for quality of life. One possibility is the use of color, as color has been shown to modulate inhibitory processes. The overall objective of this work was to determine the prefrontal networks underlying response inhibition that can be modulated through an automatic attentional process such as color. A series of three studies were performed whereby young adults performed a stop-signal task (SST) or a Go/No-go task (GNGT) with colored stimuli. In our first study, the SST, a reactive response inhibition task, was performed to determine whether the effect of color on response inhibition was due to color opponency, attentional color hierarchy, or visual associations. We found that while red stop signals produced faster response inhibition compared to green, blue and yellow stop signals did not differ from each other. This pattern of results was not consistent with color opponency or the attentional color hierarchy of red > green > yellow > blue. Therefore, red facilitating and green impairing response inhibition suggested that response inhibition was modulated by visual color associations where red means stop and green means go. In our second study, we tested if the color modulations between red and green extended beyond countermanding to more general inhibitory control by using a proactive response inhibition task, the GNGT. Indeed, participants were more successful on red in comparison to green No-go trials. Based on these results, a modified accumulator model and putative neural circuitry of color modulation response inhibition was proposed. In our third study, event-related potentials (ERPs) were recorded while participants performed a GNGT to test the putative underlying neural network. While the P300 was not modulated by color, we observed reduced N200 amplitudes and earlier N200 latencies over the prefrontal areas proposed in study 2 in response to red No-go stimuli over green, yellow, and blue. The increased accuracy was argued to be an advantage conferred by learned and evolutionary associations to the colour red. The decreased N200 amplitudes suggested reduced conflict on No-go trials with red No-go stimuli compared to other colours. These findings bring us a step closer to mapping out the differential colour modulated neural circuitry involved in response inhibition and such research will help pave the way for efficient decision-making and staving off cognitive decline

Electrophysiological indices of the violence inhibition mechanism and their associations with physical agression, callous-unemotional traits, and dietary omega-3

Each year, aggressive behaviour contributes to a substantial number of criminal offenses - resulting in severe personal, social, and financial ramifications. As such, there is importance for understanding the underlying mechanisms of aggression and how it might best be managed. The violence inhibition mechanism, thought to be dysfunctional in individuals characterised by aggressive behaviour and associated callous-unemotional traits, is used to explain how the perception of facial distress might inhibit an ongoing aggressive act. Despite a sizeable literature characterising the violence inhibition mechanism, to date, empirical research has overlooked this investigation on an electrophysiological level. This thesis developed a novel facial-affect stopping task in order to tease apart the distinct stages of face processing and distress-induced motor extinction using electroencephalography. Results suggested that whilst callous-unemotional traits, specifically uncaring traits, were associated with electrophysiological indices of structural/featural face processing (N170, P200), aggressive traits, specifically physical aggression, were associated with electrophysiological indices of distressinduced motor extinction (stop-N200, stop-P300). Furthermore, in light of a growing literature suggesting a benefit of omega-3 dietary intake for both aggressive and callous-unemotional traits, correlational analysis suggested an association between omega-3 and physical aggression/distress-induced motor extinction, but not callous-unemotional traits/face processing. These results have theoretical implications for understanding and investigating the violence inhibition mechanism on an electrophysiological level, as well as practical utility for better understanding how omega-3 might benefit aggressive traits and motor extinction. Specifically, the importance of distinguishing between both [1] aggressive and callous-unemotional traits and [2] face processing and motor extinction ability, when investigating the violence inhibition mechanism

Differential modulation of the N2 and P3 event-related potentials by response conflict and inhibition

Background: Developing reliable and specific neural markers of cognitive processes is essential to improve understanding of healthy and atypical brain function. Despite extensive research there remains uncertainty as to whether two electrophysiological markers of cognitive control, the N2 and P3, are better conceptualised as markers of response inhibition or response conflict. The present study aimed to directly compare the effects of response inhibition and response conflict on the N2 and P3 event-related potentials, within-subjects. Method: A novel hybrid go/no-go flanker task was performed by 19 healthy adults aged 18 to 25 years while EEG data were collected. The response congruence of a central target stimulus and 4 flanking stimuli was manipulated between trials to vary the degree of response conflict. Response inhibition was required on a proportion of trials. N2 amplitude was measured at two frontal electrode sites; P3 amplitude was measured at 4 midline electrode sites. Results: N2 amplitude was greater on incongruent than congruent trials but was not enhanced by response inhibition when the stimulus array was congruent. P3 amplitude was greater on trials requiring response inhibition; this effect was more pronounced at frontal electrodes. P3 amplitude was also enhanced on incongruent compared with congruent trials. Discussion: The findings support a role for N2 amplitude as a marker of response conflict and for the frontal shift of the P3 as a marker of response inhibition. This paradigm could be applied to clinical groups to help clarify the precise nature of impaired action control in disorders such as attention deficit/hyperactivity disorders (ADHD)

Cognitive and Neural Correlates of Coping and Resilience in Depression

Depression is one of the most prevalent and devastating psychological disorders, often with a chronic or remitting/reoccurring course. The inability to effectively cope with stress and negative life events has been strongly linked to the development and maintenance of depression symptoms; yet, the cognitive and biological processes underlying the complex and multidimensional behavioral construct of coping are not well understood. Using a combination of self-report measures, computerized cognitive tasks, and scalp electroencephalography (EEG) methodologies, the present study investigated associations between specific executive function abilities (i.e., inhibition and set-shifting), underlying neural activity, coping strategy and flexibility, and depression symptoms. Results did not support the primary study hypotheses predicting coping to mediate the relation between executive dysfunction and depression symptoms. Post-hoc correlational analyses elucidated relations between various components of coping strategy and depression symptomatology, and further demonstrated associations with frontocentral N200/P300 and parietal P300 peak latencies

Event-related brain potentials in the study of inhibition: cognitive control, source localization and age-related modulations

In the previous 15 years, a variety of experimental paradigms and methods have been employed to study inhibition. In the current review, we analyze studies that have used the high temporal resolution of the event-related potential (ERP) technique to identify the temporal course of inhibition to understand the various processes that contribute to inhibition. ERP studies with a focus on normal aging are specifically analyzed because they contribute to a deeper understanding of inhibition. Three time windows are proposed to organize the ERP data collected using inhibition paradigms: the 200 ms period following stimulus onset; the period between 200 and 400 ms after stimulus onset; and the period between 400 and 800 ms after stimulus onset. In the first 200 ms, ERP inhibition research has primarily focused on N1 and P1 as the ERP components associated with inhibition. The inhibitory processing in the second time window has been associated with the N2 and P3 ERP components. Finally, in the third time window, inhibition has primarily been associated with the N400 and N450 ERP components. Source localization studies are analyzed to examine the association between the inhibition processes that are indexed by the ERP components and their functional brain areas. Inhibition can be organized in a complex functional structure that is not constrained to a specific time point but, rather, extends its activity through different time windows. This review characterizes inhibition as a set of processes rather than a unitary process

Event-Related Potential Correlates of Performance-Monitoring in a Lateralized Time-Estimation Task

Performance-monitoring as a key function of cognitive control covers a wide range of diverse processes to enable goal directed behavior and to avoid maladjustments. Several event-related brain potentials (ERP) are associated with performance-monitoring, but their conceptual background differs. For example, the feedback-related negativity (FRN) is associated with unexpected performance feedback and might serve as a teaching signal for adaptational processes, whereas the error-related negativity (ERN) is associated with error commission and subsequent behavioral adaptation. The N2 is visible in the EEG when the participant successfully inhibits a response following a cue and thereby adapts to a given stop-signal. Here, we present an innovative paradigm to concurrently study these different performance-monitoring-related ERPs. In 24 participants a tactile time-estimation task interspersed with infrequent stop-signal trials reliably elicited all three ERPs. Sensory input and motor output were completely lateralized, in order to estimate any hemispheric processing preferences for the different aspects of performance monitoring associated with these ERPs. In accordance with the literature our data suggest augmented inhibitory capabilities in the right hemisphere given that stop-trial performance was significantly better with left- as compared to right-hand stop-signals. In line with this, the N2 scalp distribution was generally shifted to the right in addition to an ipsilateral shift in relation to the response hand. Other than that, task lateralization affected neither behavior related to error and feedback processing nor ERN or FRN. Comparing the ERP topographies using the Global Map Dissimilarity index, a large topographic overlap was found between all considered components.With an evenly distributed set of trials and a split-half reliability for all ERP components ≥.85 the task is well suited to efficiently study N2, ERN, and FRN concurrently which might prove useful for group comparisons, especially in clinical populations

Response Inhibition and Emotional Modulation Effect on Response Inhibition in Biopolar I Disorder and Schizophrenia.

Response inhibition deficits and the influence of emotion on response inhibition were investigated in patients with schizophrenia (SZ), schizoaffective disorder (SAD) and bipolar I disorder (BD) with event-related brain potentials (ERPs). Further, it was tested whether the neural deficits in response inhibition can differentiate each group by applying discriminant functional analysis. In order to fulfill the study goal, two different versions of Go/NoGo tasks were used: non-affective stimulus (alphabet letters) and the other with affective stimulus (faces with emotions).Two event-related brain potentials (ERPs), N200 and P300 components were measured for non-affective Go/NoGo task, while face-specific ERPs, N170 and N250, in addition to P300, were further obtained for emotional Go/NoGo task . With lateralized non-affective Go/NoGo task, the first study revealed that SZ showed left-lateralized response inhibition deficit over the frontal region measured by P300. SAD showed prolonged stimulus evaluation time in the early stage of response inhibition manifested by N200 latency. The second study replicated SZ’s response inhibition deficit associated with left hemisphere dysfunction. BD disorder did not show deficits in response inhibition compared to that in SZ but delayed overall cognitive stimulus evaluation was observed. When the non-affective stimuli were replaced with faces with four categories of emotions (happy, angry, sad, and neutral), emotion modulation effect (larger ERP amplitudes for faces with emotions than for neutral faces) was observed only in response execution (Go trials) not in response inhibition (NoGo trials) process in both patients and controls. Both SZ and BD showed deficits in early facial structure encoding revealed by reduced amplitude in N170 component but relatively intact in early facial affect decoding compared to healthy controls (CT). In three studies, it was replicated that P300 amplitude and N200 latency successfully discriminated SZ, SAD (study 1), BD (study 2 & 3), and CT, which implicates that distinct ERP patterns in response inhibition task can become endophenotypes of each psychiatric disorder.Ph.D.PsychologyUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/78787/1/jschun_1.pd