Maturation of Cognitive Control: Delineating Response Inhibition and Interference Suppression

Cognitive control is integral to the ability to attend to a relevant task whilst suppressing distracting information or inhibiting prepotent responses. The current study examined the development of these two subprocesses by examining electrophysiological indices elicited during each process. Thirteen 18 year-old adults and thirteen children aged 8–11 years (mean = 9.77 years) completed a hybrid Go/Nogo flanker task while continuous EEG data were recorded. The N2 topography for both response inhibition and interference suppression changed with increasing age. The neural activation associated with response inhibition became increasingly frontally distributed with age, and showed decreases of both amplitude and peak latency from childhood to adulthood, possibly due to reduced cognitive demands and myelination respectively occurring during this period. Interestingly, a significant N2 effect was apparent in adults, but not observed in children during trials requiring interference suppression. This could be due to more diffuse activation in children, which would require smaller levels of activation over a larger region of the brain than is reported in adults. Overall, these results provide evidence of distinct maturational processes occurring throughout late childhood and adolescence, highlighting the separability of response inhibition and interference suppression.     

Dissociable components of cognitive control: an event-related potential (ERP) study of response inhibition and interference suppression

Background

Cognitive control refers to the ability to selectively attend and respond to task-relevant events while resisting interference from distracting stimuli or prepotent automatic responses. The current study aimed to determine whether interference suppression and response inhibition are separable component processes of cognitive control.

Methodology/Principal Findings

Fourteen young adults completed a hybrid Go/Nogo flanker task and continuous EEG data were recorded concurrently. The incongruous flanker condition (that required interference suppression) elicited a more centrally distributed topography with a later N2 peak than the Nogo condition (that required response inhibition).

Conclusions/Significance

These results provide evidence for the dissociability of interference suppression and response inhibition, indicating that taxonomy of inhibition is warranted with the integration of research evidence from neuroscience.     

Effects of cue information on response production and inhibition measured by event-related potentials

The aim of this study was to investigate how information carried by a cue stimulus modulate event-related potentials (ERPs) to a subsequent target stimulus which either calls for an overt response (Go stimulus) or no response (Nogo stimulus). One of the cues predicted the likely appearance of the Go stimulus (Go cue) whereas the other cue predicted the likely appearance of the Nogo stimulus (Nogo cue). Our results showed that unpredicted Nogo stimuli elicited enlarged N200 component. This finding supports the notion that Nogo N200 reflects response inhibition processes, i.e., the amplitude of the N200 is a function of the difficulty of response inhibition. In other words, increased N200 to Nogo stimuli following Go cues might be related to increased efforts in activating the response inhibition system thereby interrupting preparations to respond.     

Late ERP components in visual and auditory Go/Nogo tasks

In an audio-visual Go/Nogo paradigm we studied whether the Go/Nogo difference, usually found in the time range of the visual N2, is also present after auditory stimuli, which bears on the common response inhibition hypothesis of this N2 effect. Moreover the possible presence and variation of P300 subcomponents were studied with the goal of clarifying the reasons for the commonly observed P300 topography changes between Go and Nogo trials. To disentangle possible P300 subcomponents we applied a crossmodal divided attention (DA) condition, in which the subcomponents are known to be separated after auditory stimuli in choice tasks.An N2 effect was found after visual but not after auditory stimuli, which is evidence against the response-inhibition hypothesis. After visual stimuli a positive complex (P400) was seen, whereas after auditory stimuli two dissociated components (P400 and P507) were found instead. The P507 had a parietal maximum for both Go and Nogo trials. It was larger and it peaked later in Go than in Nogo trials. The P400 showed topographic differences between Go and Nogo trials, which could be explained by the overlap of the two subcomponents. We assume that (i) both subcomponents have a stable topography across response type, and (ii) the first subcomponent is invariant with response type, whereas the second (which overlaps the first one) is larger and peaks later on Go than on Nogo trials.     

After effects of noise-induced sleep disturbances on inhibitory functions

The study focuses on possible after effects of noise-induced sleep disturbances on inhibitory brain processes reflecting in performance changes and alternations of inhibition-related components of event-related potentials (ERPs). Following a quiet night and three nights, in which railway noise was presented with different levels, twelve women and ten men (19-28 years) performed a visual Go/Nogo task that contained stimuli either compatible or incompatible with a response. Noise-induced sleep disturbances are highly evident in worsening of subjective sleep quality but did not show up in significant changes of reaction time and error rate. A smaller N2 amplitude and longer latency to incompatible than to compatible stimuli as well as an unspecific attenuation of N2 amplitude under Noise were found. The amplitude of the fronto-central P3 was reduced under Noise compared to baseline only in Nogo trials. The amplitude of the parietal P3 in Go trials was smaller to incompatible than to compatible stimuli but was not affected by Noise. Disturbed sleep was associated with a decreased blink rate during task performance. The results suggest that physiological costs to maintain performance are increased after noisy nights. Decisional processes underlying overt responses (Go-P3) are less vulnerable to noise-disturbed sleep than those related to inhibition (Nogo-N2, NoGo-P3). The deficits may have been compensated by increased on-task concentration and thereby did not become apparent in the performance data. Inhibition-related ERPs may be more sensitive indicators of moderate sleep disturbances caused by noise than performance measures.     

A pilot study of combined working memory and inhibition training for children with AD/HD

Building on recent favourable outcomes using working memory (WM) training, this study examined the behavioural and physiological effect of concurrent computer-based WM and inhibition training for children with attention-deficit hyperactivity disorder (AD/HD). Using a double-blind active-control design, 29 children with AD/HD completed a 5-week at-home training programme and pre- and post-training sessions which included the assessment of overt behaviour, resting EEG, as well as task performance, skin conductance level and event-related potentials (ERPs) during a Go/Nogo task. Results indicated that after training, children from the high-intensity training condition showed reduced frequency of inattention and hyperactivity symptoms. Although there were trends for improved Go/Nogo performance, increased arousal and specific training effects for the inhibition-related N2 ERP component, they failed to reach standard levels of statistical significance. Both the low- and high-intensity conditions showed resting EEG changes (increased delta, reduced alpha and theta activity) and improved early attention alerting to Go and Nogo stimuli, as indicated by the N1 ERP component, post-training. Despite limitations, this preliminary work indicates the potential for cognitive training that concurrently targets the interrelated processes of WM and inhibition to be used as a treatment for AD/HD.     

Skill-Specific Changes in Somatosensory Nogo Potentials in Baseball Players

Athletic training is known to induce neuroplastic alterations in specific somatosensory circuits, which are reflected by changes in somatosensory evoked potentials and event-related potentials. The aim of this study was to clarify whether specific athletic training also affects somatosensory Nogo potentials related to the inhibition of movements. The Nogo potentials were recorded at nine cortical electrode positions (Fz, Cz, Pz, F3, F4, C3, C4, P3 and P4) in 12 baseball players (baseball group) and in 12 athletes in sports, such as track and field events and swimming, that do not require response inhibition, such as batting for training or performance (sports group). The Nogo potentials and Go/Nogo reaction times (Go/Nogo RTs) were measured under a somatosensory Go/Nogo paradigm in which subjects were instructed to rapidly push a button in response to stimulus presentation. The Nogo potentials were obtained by subtracting the Go trial from the Nogo trial. The peak Nogo-N2 was significantly shorter in the baseball group than that in the sports group. In addition, the amplitude of Nogo-N2 in the frontal area was significantly larger in the baseball group than that in the sports group. There was a significant positive correlation between the latency of Nogo-N2 and Go/Nogo RT. Moreover, there were significant correlations between the Go/Nogo RT and both the amplitude of Nogo-N2 and Nogo-P3 (i.e., amplitude of the Nogo-potentials increases with shorter RT). Specific athletic training regimens may induce neuroplastic alterations in sensorimotor inhibitory processes.     

Event-related potentials in a Go/Nogo task of abnormal response inhibition in heroin addicts

Inhibitory control dysfunction is regarded as a core feature in addicts. The major objective of this study was to explore the time course of response inhibition in chronic heroin addicts and provide the neu-rophysiological evidence of their inhibitory control dysfunction. The amplitudes and latencies of ERP components were studied in fourteen heroin addicts (mean duration of heroin use being (13.54±5.71) years (Mean±SD), average abstinence being ((4.67±6.44) months)) and fourteen matched healthy con-trols with a visual Go/Nogo task. Our results showed that heroin addicts demonstrated significantly larger Go-N2 amplitudes which results in a decreased N2 Go/Nogo effect, but no statistically significant differences were found between heroin addicts and controls in P3. The ERP data suggest that fronto-central areas of heroin addicts were impaired during the inhibition process (200—300 ms) and over-activated to targets. The impaired early process might reflect an abnormal conflict monitoring process in heroin addicts. These results consolidate the inhibitory control dysfunction hypothesis in chronic heroin users.     

Deficits in inhibitory control in smokers during a Go/NoGo task: an investigation using event-related brain potentials

Introduction

The role of inhibitory control in addictive behaviors is highlighted in several models of addictive behaviors. Although reduced inhibitory control has been observed in addictive behaviors, it is inconclusive whether this is evident in smokers. Furthermore, it has been proposed that drug abuse individuals with poor response inhibition may experience greater difficulties not consuming substances in the presence of drug cues. The major aim of the current study was to provide electrophysiological evidence for reduced inhibitory control in smokers and to investigate whether this is more pronounced during smoking cue exposure.

Methods

Participants (19 smokers and 20 non-smoking controls) performed a smoking Go/NoGo task. Behavioral accuracy and amplitudes of the N2 and P3 event-related potential (ERP), both reflecting aspects of response inhibition, were the main variables of interest.

Results

Reduced NoGo N2 amplitudes in smokers relative to controls were accompanied by decreased task performance, whereas no differences between groups were found in P3 amplitudes. This was found to represent a general lack of inhibition in smokers, and not dependent on the presence of smoking cues.

Conclusions

The current results suggest that smokers have difficulties with response inhibition, which is an important finding that eventually can be implemented in smoking cessation programs. More research is needed to clarify the exact role of cue exposure on response inhibition.     

Proactive Control Strategies for Overt and Covert Go/NoGo Tasks: An Electrical Neuroimaging Study

Proactive and reactive inhibition are generally intended as mechanisms allowing the withholding or suppression of overt movements. Nonetheless, inhibition could also play a pivotal role during covert actions (i.e., potential motor acts not overtly performed, despite the activation of the motor system), such as Motor Imagery (MI). In a previous EEG study, we analyzed cerebral activities reactively triggered during two cued Go/NoGo tasks, requiring execution or withholding of overt or covert imagined actions, respectively. This study revealed activation of pre-supplementary motor area (pre-SMA) and right inferior frontal gyrus (rIFG), key nodes of the network underpinning reactive inhibition of overt responses in NoGo trials, also during MI enactment, enabling the covert nature of the imagined motor response. Taking into account possible proactive engagement of inhibitory mechanisms by cue signals, for an exhaustive interpretation of these previous findings in the present study we analyzed EEG activities elicited during the preparatory phase of our cued overt and covert Go/NoGo tasks. Our results demonstrate a substantial overlap of cerebral areas activated during proactive recruitment and subsequent reactive implementation of motor inhibition in both overt and covert actions; also, different involvement of pre-SMA and rIFG emerged, in accord with the intended type (covert or overt) of incoming motor responses. During preparation of the overt Go/NoGo task, the cue is encoded in a pragmatic mode, as it primes the possible overt motor response programs in motor and premotor cortex and, through preactivation of a pre-SMA-related decisional mechanism, it triggers a parallel preparation for successful response selection and/or inhibition during the response phase. Conversely, the preparatory strategy for the covert Go/NoGo task is centered on priming of an inhibitory mechanism in rIFG, tuned to the instructed covert modality of motor performance and instantiated during subsequent MI, which allows the imagined response to remain a potential motor act.     

How Does Emotional Context Modulate Response Inhibition in Alexithymia: Electrophysiological Evidence from an ERP Study

Background

Alexithymia, characterized by difficulties in identifying and describing feelings, is highly indicative of a broad range of psychiatric disorders. Several studies have also discovered the response inhibition ability impairment in alexithymia. However, few studies on alexithymic individuals have specifically examined how emotional context modulates response inhibition procedure. In order to investigate emotion cognition interaction in alexithymia, we analyzed the spatiao-temporal features of such emotional response inhibition by the approaches of event-related potentials and neural source-localization.

Method

The study participants included 15 subjects with high alexithymia scores on the 20-item Toronto Alexithymia Scale (alexithymic group) and 15 matched subjects with low alexithymia scores (control group). Subjects were instructed to perform a modified emotional Go/Nogo task while their continuous electroencephalography activities were synchronously recorded. The task includes 3 categories of emotional contexts (positive, negative and neutral) and 2 letters (“M” and “W”) centered in the screen. Participants were told to complete go and nogo actions based on the letters. We tested the influence of alexithymia in this emotional Go/Nogo task both in behavioral level and related neural activities of N2 and P3 ERP components.

Results

We found that negatively valenced context elicited larger central P3 amplitudes of the Nogo–Go difference wave in the alexithymic group than in the control group. Furthermore, source-localization analyses implicated the anterior cingulate cortex (ACC) as the neural generator of the Nogo-P3.

Conclusion

These findings suggest that difficulties in identifying feelings, particularly in negative emotions, is a major feature of alexithymia, and the ACC plays a critical role in emotion-modulated response inhibition related to alexithymia.     

Neural Manifestations of Implicit Self-Esteem: An ERP Study

Behavioral research has established that humans implicitly tend to hold a positive view toward themselves. In this study, we employed the event-related potential (ERP) technique to explore neural manifestations of positive implicit self-esteem using the Go/Nogo association task (GNAT). Participants generated a response (Go) or withheld a response (Nogo) to self or others words and good or bad attributes. Behavioral data showed that participants responded faster to the self paired with good than the self paired with bad, whereas the opposite proved true for others, reflecting the positive nature of implicit self-esteem. ERP results showed an augmented N200 over the frontal areas in Nogo responses relative to Go responses. Moreover, the positive implicit self-positivity bias delayed the onset time of the N200 wave difference between Nogo and Go trials, suggesting that positive implicit self-esteem is manifested on neural activity about 270 ms after the presentation of self-relevant stimuli. These findings provide neural evidence for the positivity and automaticity of implicit self-esteem.     

Mapping P300 waves onto inhibition: Go/NoGo discrimination

Subjects viewed letters presented at 2 sec intervals and prepared a fast button press whenever an “O” appeared. If the next letter was an “X” the button press was executed (Go signal), but if the letter was a non-X character (T, H, Z) suppression of the response was required (NoGo cue). NoGo signals elicited a P300-like wave that was larger at central and frontal scalp sites contralateral to the prepared movement, compared to P300s elicited by Go cues which were symmetric about the sagittal midline and dominant at parietal sites. Subtraction of preparatory CNVs from the NoGo P300 did not remove differences in scalp topography, or reduce the amplitude of the NoGo P300 to that seen following control letters that required perceptual identification but did not call for suppression of prepared motor responses. Principal components analysis identified a middle positive wave following X-alone control stimuli whose topography resembled the NoGo P300. These findings suggest that the source of augmented NoGo P300s is a generator involved with sensorimotor inhibition. We discuss the mechanism of P300 waves and evidence linking these waves with inhibition in other task arrangements.     

Immature frontal lobe contributions to cognitive control in children: evidence from fMRI.

Event-related fMRI was employed to characterize differences in brain activation between children ages 8-12 and adults related to two forms of cognitive control: interference suppression and response inhibition. Children were more susceptible to interference and less able to inhibit inappropriate responses than were adults. Effective interference suppression in children was associated with prefrontal activation in the opposite hemisphere relative to adults. In contrast, effective response inhibition in children was associated with activation of posterior, but not prefrontal, regions activated by adults. Children failed to activate a region in right ventrolateral prefrontal cortex that was recruited for both types of cognitive control by adults. Thus, children exhibited immature prefrontal activation that varied according to the type of cognitive control required.     

ERP Correlates of Proactive and Reactive Cognitive Control in Treatment-Na?ve Adult ADHD

This study investigated whether treatment naïve adults with Attention Deficit Hyperactivity Disorder (ADHD; n = 33; 19 female) differed from healthy controls (n = 31; 17 female) in behavioral performance, event-related potential (ERP) indices of preparatory attention (CueP3 and late CNV), and reactive response control (Go P3, NoGo N2, and NoGo P3) derived from a visual cued Go/NoGo task. On several critical measures, Cue P3, late CNV, and NoGo N2, there were no significant differences between the groups. This indicated normal preparatory processes and conflict monitoring in ADHD patients. However, the patients had attenuated Go P3 and NoGoP3 amplitudes relative to controls, suggesting reduced allocation of attentional resources to processes involved in response control. The patients also had a higher rate of Go signal omission errors, but no other performance decrements compared with controls. Reduced Go P3 and NoGo P3 amplitudes were associated with poorer task performance, particularly in the ADHD group. Notably, the ERPs were not associated with self-reported mood or anxiety. The results provide electrophysiological evidence for reduced effortful engagement of attentional resources to both Go and NoGo signals when reactive response control is needed. The absence of group differences in ERP components indexing proactive control points to impairments in specific aspects of cognitive processes in an untreated adult ADHD cohort. The associations between ERPs and task performance provided additional support for the altered electrophysiological responses.     

Electrophysiological Evidence for Domain-General Inhibitory Control during Bilingual Language Switching

This paper presents an experiment that explored the role of domain–general inhibitory control on language switching. Reaction times (RTs) and event–related brain potentials (ERPs) were recorded when low–proficient bilinguals with high and low inhibitory control (IC) switched between overt picture naming in both their L1 and L2. Results showed that the language switch costs of bilinguals with high–IC were symmetrical, while that of bilinguals with low–IC were not. The N2 component failed to show a significant interaction between group, language and task, indicating that inhibition may not comes into play during the language task schema competition phase. The late positive component (LPC), however, showed larger amplitudes for L2 repeat and switch trials than for L1 trials in the high–IC group, indicating that inhibition may play a key role during the lexical response selection phase. These findings suggest that domain–general inhibitory control plays an important role in modulating language switch costs and its influence can be specified in lexical selection phase.     

Differential but competitive binding of Nogo protein and class i major histocompatibility complex (MHCI) to the PIR-B ectodomain provides an inhibition of cells

Binding of class I MHC molecules (MHCI) to an inhibitory receptor, PIR-B, expressed on B cells and myeloid cells provides constitutive cellular inhibition, thus ensuring peripheral tolerance. Recent unexpected findings pointed to a novel inhibitory role of PIR-B in neurite regeneration through binding to three axonal outgrowth inhibitors of myelin, including Nogo. Thus, it becomes interesting to determine whether the actions of the inhibitory myelin proteins and MHCI could coexist independently or be mutually exclusive as to the PIR-B-mediated immune and neural cell inhibition. Here, we present data supporting the competition of Nogo- and MHCI-mediated inhibition where they coexist. Kinetic analyses of Nogo and MHCI binding to the whole or a part of the recombinant PIR-B ectodomain revealed that PIR-B binds with higher affinity to Nogo than MHCI and that the MHCI binding only occurred with the N-terminal domains of PIR-B, whereas Nogo binding occurred with either the N- or C-terminal ectodomains. Importantly, kinetic tests indicated that the binding to PIR-B of Nogo and MHCI was competitive. Both endogenous and exogenous Nogo intensified the PIR-B-mediated suppression of interleukin-6 release from lipopolysaccharide-stimulated wild-type, but not PIR-B-deficient, cultured mast cells, indicating that PIR-B mediates Nogo-induced inhibition. Thus, we propose a novel mechanism by which PIR-B-mediated regulation is achieved differentially but competitively via MHCI and Nogo in cells of the immune system.     

Effect of variability of sequence length of go trials preceding a stop trial on ability of response inhibition in stop-signal task

Abstract

This study investigated whether the variability of the sequence length of the go trials preceding a stop trial enhanced or interfered with inhibitory control. The hypotheses tested were either inhibitory control improves when the sequence length of the go trials varies as a consequence of increased preparatory effort or it degrades as a consequence of the switching cost from the go trial to the stop trial. The right-handed participants abducted the left or right index finger in response to a go cue during the go trials. A stop cue was given at 50, 90, or 130?ms after the go cue, with 0.25 probability in the stop trial. In the less variable session, a stop trial was presented after two, three, or four consecutive go trials. In the variable session, a stop trial was presented after one, two, three, four, or five consecutive go trials. The reaction time and stop-signal reaction time were not significantly different between the sessions and between the response sides. Nevertheless, the probability of successful inhibition of the right-hand response in the variable session was higher than that in the less variable session when the stop cue was given 50?ms after a go cue. This finding supports the view that preparatory effort due to less predictability of the chance of a forthcoming response inhibition enhances the ability of the right-hand response inhibition when the stop process begins earlier.     

Rule-Based Category Learning in Children: The Role of Age and Executive Functioning

Rule-based category learning was examined in 4–11 year-olds and adults. Participants were asked to learn a set of novel perceptual categories in a classification learning task. Categorization performance improved with age, with younger children showing the strongest rule-based deficit relative to older children and adults. Model-based analyses provided insight regarding the type of strategy being used to solve the categorization task, demonstrating that the use of the task appropriate strategy increased with age. When children and adults who identified the correct categorization rule were compared, the performance deficit was no longer evident. Executive functions were also measured. While both working memory and inhibitory control were related to rule-based categorization and improved with age, working memory specifically was found to marginally mediate the age-related improvements in categorization. When analyses focused only on the sample of children, results showed that working memory ability and inhibitory control were associated with categorization performance and strategy use. The current findings track changes in categorization performance across childhood, demonstrating at which points performance begins to mature and resemble that of adults. Additionally, findings highlight the potential role that working memory and inhibitory control may play in rule-based category learning.     

The Effects of Foreknowledge and Task-Set Shifting as Mirrored in Cue- and Target-Locked Event-Related Potentials

The present study examined the use of foreknowledge in a task-cueing protocol while manipulating sensory updating and executive control in both, informatively and non-informatively pre-cued trials. Foreknowledge, sensory updating (cue switch effects) and task-switching were orthogonally manipulated in order to address the question of whether, and to which extent, the sensory processing of cue changes can partly or totally explain the final task switch costs. Participants responded faster when they could prepare for the upcoming task and if no task-set updating was necessary. Sensory cue switches influenced cue-locked ERPs only when they contained conceptual information about the upcoming task: frontal P2 amplitudes were modulated by task-relevant cue changes, mid-parietal P3 amplitudes by the anticipatory updating of stimulus-response mappings, and P3 peak latencies were modulated by task switching. Task preparation was advantageous for efficient stimulus-response re-mapping at target-onset as mirrored in target N2 amplitudes. However, N2 peak latencies indicate that this process is faster for all repeat trials. The results provide evidence to support a very fast detection of task-relevance in sensory (cue) changes and argue against the view of task repetition benefits as secondary to purely perceptual repetition priming. Advanced preparation may have a stronger influence on behavioral performance and target-locked brain activity than the local effect of repeating or switching the task-set in the current trial.