Posterior brain ERP patterns related to the go/no-go task in children

Event-related potentials (ERPs) and performance correlates of inhibition of responses to no-go stimuli were investigated in 6-12-year-old children and young adults. The percent of correct responses to go stimuli was high and similar in both groups; the percent of false alarm errors to no-go was significantly higher in children. Effective inhibition of responses to no-go stimuli was elucidated by a negative component of ERPs, the frontal-central N2, with peak latency 230-430 ms after stimulus onset. In adults, N2 was larger to no-go than to go stimuli, regardless of stimulus frequency. This effect was more prominent in tasks with high (25% no-gos and 75% gos), than with low (75% no-gos and 25% gos) inhibitory demand. In children, the parietal N2 was generally larger to rare than to frequent stimuli, and it was more specifically related to inhibition. The analysis of the relationship of no-go N2 to the inhibitory content of stimuli, probability of stimuli, and the contextual task difficulty suggests that child/adult differences in behavioral responses and ERPs may be related to both the immaturity of the fronto-parietal cortical-cortical network and to different task strategies.     

Error-related negativity in children: effect of an observer

This research assessed the effect of an observer upon error-related negativity (ERN) in 20 children (ages 7-11): 9 worked alone and 11 worked under the observation of a friend of theirs (alone/audience groups). Erroneous motor responses were recorded to Go and No-Go visual stimuli (triangles in different orientations) at three brain sites (Fz, Cz, and Pz). Results for children were consistent with past adult studies in showing a significantly larger ERN only to erroneous responses in both the alone and the audience groups. Children in the audience group produced larger ERNs than those in the alone group. Furthermore, older children (ages 9-11) produced larger ERNs than younger children (ages 7-8) in both groups. These findings were discussed in the context of an action monitoring system that regulates responses, detects errors, and entrains affective responses associated with correct and incorrect responses.     

Alpha event-related desynchronization preceding a go/no-go task: a high-resolution EEG study

The authors delineated the time evolution of alpha event-related desynchronization over human frontal, parietal, and primary sensorimotor areas during the expectancy of a go/no-go task. The main issue under investigation was whether anticipatory processes impinged upon cortical areas in sequential or parallel mode. Compared with the control condition, in the experimental condition there was an Alpha 1 desynchronization over the central midline, an Alpha 2 desynchronization increasing over primary sensorimotor areas, and an Alpha 3 desynchronization increasing in parallel over bilateral primary sensorimotor areas. These processes had different temporal features. Results disclose an anticipatory activity of central midline areas and primary sensorimotor areas in both parallel and sequential modes. This reflects an adaptive, energy-consuming strategy rather than an economic waiting for the go stimulus.     

Cortical sensorimotor interactions during the expectancy of a go/no-go task: effects of painful stimuli

The intent of this electroencephalography study was to investigate the competition between cortical nociceptive and cognitive-motor processes preceding sensorimotor interactions. Sensorimotor expectancy processes to painful stimulation and motor go/no-go demands were indexed over primary sensorimotor and midline cortical areas by contingent negative variation (CNV). Before the sensorimotor interaction, CNV was observed over midline posterior and bilateral central areas. Early expectancy of painful stimulation and the go/no-go task induced an evident midline posterior CNV. During the late expectancy period. CNV extended to the right central area contralateral to the stimulation. These findings suggest a sequential activation of midline posterior and primary sensorimotor areas contralateral to the painful stimulation as a reflection of the enhanced nociceptive processes preceding painful sensorimotor interactions.     

Mismatch negativity in children and adults, and effects of an attended task

Attention has been shown to modulate the amplitude of the mismatch negativity (MMN) elicited by a small deviation in auditory stimuli in adults. The present study examined the effects of attention and deviant size on MMN amplitude in children. Children and adults were presented with sequences of tones containing standards (1000 Hz) and three deviants varying in degree of deviance from the standard (1050, 1200, and 1500 Hz). Tones were presented in three conditions: (1) while participants ignored them; (2) while participants listened to them and responded to all three deviants; and (3) while participants again ignored them. We found that the MMNs elicited by the hard deviant (1050 Hz) were larger when the children were actively discriminating the stimuli than when they were ignoring them. However, the MMNs elicited by the easy and medium deviants (1500 and 1200 Hz, respectively) in the children and by all three deviants in the adults were not affected by attention.     

Does the emotional go/no-go task really measure behavioral inhibition?: Convergence with measures on a non-emotional analog

This study tested the convergence of behavioral inhibition measures across emotional and non-emotional versions of the same go/no-go task in 85 college students. The two tasks differed only in the stimuli used for trial cues (i.e., circles versus facial expressions). Moderate correlations (r=.51-.56) between commission errors across the emotional and non-emotional tasks support the construct validity of behavioral inhibition. Further, parametric manipulation of preceding context had comparable effects on performance on the two tasks. Responses were slower and more variable, commission errors were more numerous, and perceptual sensitivity was lower on the emotional than the non-emotional task. A bias for happy faces on the emotional task resulted in faster responses and more commission errors for happy than sad faces despite marginally greater sensitivity for the latter. These results suggest that the basic neuropsychological constructs of the original go/no-go task were preserved in the emotional adaptation.     

Wulst lesions in pigeons disrupt go/no-go reversal

Pigeons with lesions of either the Wulst or ectostriatum were compared to controls on reversal of a go/no-go pattern discrimination. The Wulst-lesioned animals were slower to acquire the response to the new S+ but were not different from the other groups on extinction of response to the old S+. The ectostriatum-lesioned group was not different from controls. The results extend the range of situations in which Wulst-lesioned pigeons have been found to show a reversal deficit and are consistent with the notion that Wulst lesions may disrupt learning.     

Performance and ERP components in the equiprobable go/no‐go task: Inhibition in children

The equiprobable go/no‐go task lacks the dominant go imperative found in the usual go/no‐go task, and hence we previously regarded it as involving little inhibition. However, children have relative difficulty with this task, and demonstrate large frontal no‐go N2s. We investigated whether this child N2 plays an inhibitory role, using performance measures to illuminate the link between N2 and inhibition. Forty children aged 8 to 13 were presented with four stimulus blocks each containing 75 go and 75 no‐go tone stimuli in random order. A temporal PCA with unrestricted varimax rotation quantified the mean go and no‐go ERP component amplitudes. Most identified components were differentially enhanced to go or no‐go as in adults, supporting a previously proposed differential processing schema. Between subjects, larger frontocentral no‐go N2bs were associated with fewer commission errors. Hence, the no‐go N2b in this paradigm can be interpreted as an individual marker of inhibition in children.     

ERP components and behavior in the auditory equiprobable go/no‐go task: Inhibition in young adults

Previous research suggests that young adults do not need active and effortful inhibition to successfully complete the auditory equiprobable go/no‐go task, a view that was incorporated into Barry and De Blasio's sequential processing schema for this task. However, recent evidence in children suggests that view could be incorrect. The present research aims to clarify the functionality of the N2 and P3 subcomponents within the proposed schema, assessing the role of inhibition in this task. To optimize the quantification of the N2 and P3 subcomponents, separate temporal PCAs were applied to the go/no‐go ERP data from 40 young adults. Correlations were then used to link subcomponent amplitudes with performance outcomes, informing a functional interpretation of each subcomponent. Larger N2b and P3a amplitudes were each linked to fewer commission errors. N2c amplitude also increased with intraindividual reaction time variability, but no performance outcomes were associated with P3b. These findings link the young adult N2b and P3a with inhibition in the auditory equiprobable task, confirming the importance of control for successful nontarget processing in that paradigm. The functionality of N2c and P3b remain unclear from our results. However, these outcomes improve our understanding of cognitive processing in equiprobable tasks, and contribute to an improved conceptualization of the sequential processing schema.     

Spatial selectivity of go/no-go neurons in monkey prefrontal cortex

We examined single-unit activity in the inferior prefrontal cortex during a visual go/no-go discrimination task under maintained visual fixation. The monkeys had to base their response on either the color, shape, or position of a discriminative cue, and the relevant task condition was indicated by the color of the fixation spot. We analyzed the spatial selectivity of 128 go/no-go neurons showing a marked differential cue-period activity that depended on whether the stimulus signaled a go or no-go response. Most of these neurons (n = 106, 83%) showed asymmetry between their responses to stimuli in the contralateral and ipsilateral visual fields. Seventy-seven of these neurons had a contralateral preferential field, and 29 had an ipsilateral preferential field. These results show that in many inferior prefrontal neurons a degree of differentiation in their responses to go and no-go stimuli depends on the cue positions, and that the coding of behavioral meaning is carried out mainly in the contralateral hemisphere.     

Modulation of ERP components by task instructions in a cued go/no‐go task

The present study investigated how components of ERPs are modulated when participants optimize speed versus accuracy in a cued go/no‐go task. Using a crossover design, 35 participants received instructions to complete the task prioritizing response speed in half of the task, and accurate responding in the other half of the task. Analysis was performed on the contingent negative variation (CNV), P3go, and P3no‐go and the corresponding independent components (IC), as identified by group independent component analysis. After speed instructions, the IC CNV_late, P3go_anterior, P3no‐go_early, and P3no‐go_late all had larger amplitudes than after accuracy instructions. Furthermore, both the IC P3go_posterior and IC P3go_anterior had shorter latencies after speed than after accuracy instructions. The results demonstrate that components derived from the CNV and P3 components are facilitated when participants optimize response speed. These findings indicate that these ERP components reflect executive processes enabling adjustment of behavior to changing demands.     

Error-related negativity in individuals with obsessive-compulsive symptoms: toward an understanding of hoarding behaviors

The error-related negativity (ERN), an event-related potential component elicited by error responses in cognitive tasks, has been shown to be abnormal in most, but not all, studies of obsessive-compulsive disorder or obsessive-compulsive symptoms (OCD/S); these inconsistencies may be due to task selection, symptom subtype, or both. We used meta-analysis to further characterize the ERN in OCD/S, and pooled data across studies to examine the ERN in OCD/S with hoarding. We found an enhanced ERN in OCD/S relative to controls, as well as heterogeneity across tasks. When stratified, OCD/S showed a significantly enhanced ERN only in response conflict tasks. However, OCD/S + hoarding showed a marginally larger ERN than OCD/S-hoarding, but only for probabilistic learning tasks. These results suggest that abnormal ERN in OCD/S is task-dependent, and that OCD/S + hoarding show different ERN activity from OCD/S − hoarding perhaps suggesting different pathophysiological mechanisms of error monitoring.     

Rat behavior in go/no-go and two-alternative choice odor discrimination: differences and similarities

To elucidate the cognitive structures of animals, neuroscientists use several behavioral tasks. Therefore, it is imperative to have a firm understanding of each task's behavioral parameters in order to parse out possible task effects. We compare two operant discrimination tasks (Go/No-Go: GNG; Two-Alternative Choice: TAC) that are commonly used in olfactory research. Past research has suggested that solving the two tasks requires divergent cognitive strategies. One hypothesis is that the two tasks differ in how an animal optimizes reward rate by means of a speed-accuracy trade-off (SAT). If this is true, then changing tasks could give researchers an additional tool to understand animal cognition. However, no study has systematically analyzed the two tasks in parallel using odor stimuli. Using standardized training protocols, we test GNG and TAC in parallel. Our protocols allow us to isolate the stimulus sampling period from a general reaction time period. We find that the two tasks do not differ with regard to the stimulus sampling period and conclude that the two tasks do not differ in the amount of time it takes an animal to perform a discrimination. Instead, tasks differ in the time it takes to make an overt behavioral response, with GNG showing shorter periods than TAC. We also find no evidence of rats using either task-specific or intertrial interval-dependent SAT schema in order to optimize reward rate. We show that similarities between dependent variables, with the possible exception of response delay, appear to be under experimenter control.     

Monitoring force errors: medial-frontal negativity in a unimanual force-production task

The effects of force production on medial-frontal negativity (MFN), reflecting the activity of an internal action-monitoring system, were investigated in a force-production task. A precue indicated a low or high force before a stimulus signaled the execution of the same or opposite force. An incorrectly exerted force was assumed to involve an error of force selection if the opposite force was required (invalid precue), and an error of force execution if the same force was required (valid precue). The task was repeated to examine any improvements in monitoring sensitivity. No force-related effects were observed on MFN amplitude. Although performance improved, there was no evidence of a force-error sensitive monitoring system. As the MFN and motor activity were affected by the precue invalidity regardless of the response outcome, the MFN might reflect the activity of a general action-evaluation system that is indirectly related to motor activation.     

Benzodiazepines impair the acquisition and reversal of olfactory go/no-go discriminations in rats

The present study assessed whether benzodiazepines impair the acquisition, performance, and reversal of olfactory and auditory go/no-go discriminations in rats. Experiment 1 showed that midazolam (0.5-2 mg/kg sc) did not affect the performance of a well-learned two-odor olfactory discrimination and moderately facilitated performance of a go/no-go auditory discrimination. Experiment 2 found that midazolam (1 mg/kg) increased the number of errors made in the acquisition of a novel go/no-go olfactory discrimination task and in the reversal of a previously well-learned olfactory discrimination. However, midazolam did not affect the acquisition and reversal of an equivalent auditory discrimination task. Experiment 3 showed that diazepam (1 mg/kg) also impaired the acquisition and reversal of a novel olfactory discrimination task. Taken together, these results indicate that benzodiazepines cause a selective impairment of olfactory discrimination learning. This may reflect an effect of benzodiazepines in the glomerular circuitry of the olfactory bulb and at downstream olfactory processing sites such as the piriform cortex and orbitofrontal cortex.     

Frontal and central oscillatory changes related to different aspects of the motor process: a study in go/no-go paradigms

We studied alpha and beta EEG oscillatory changes in healthy volunteers during two different auditory go/no-go paradigms, in order to investigate their relationship with different components of the motor process. In the first paradigm (S2-centered), the initial tone (S1) was constant (warning), and the second tone (S2) indicated the subject whether to move or not. In the second paradigm (S1-centered), S1 indicated whether to move or not, while S2 just indicated the timing of the movement. A medial frontal beta energy increase was found in all conditions after the stimulus that forces the subject to decide whether to move or not (S1 or S2 depending on the paradigm). In both go conditions, a central alpha and beta energy decrease began after the go decision, reaching minimum values during the movement; it was followed by a beta post-movement increase, limited to the central contralateral area. In the no-go conditions, a marked fronto-central beta synchronization appeared after the decision not to move. In conclusion, our study was able to dissociate the beta oscillatory changes related to movement preparation and execution (central decrease/increase) from those associated with decision-making (medial frontal increase) and motor inhibition (fronto-central increase).     

Effects of a startle stimulus on response speed and inhibition in a go/no‐go task

Two studies examined the interaction of an acoustic startle stimulus and visual go/no‐go task stimuli on startle reactivity and task performance. In the first study, an acoustic stimulus (50 ms, 100 dB noise) was presented alone or with a green (go) or red (no‐go) circle; in the second study, a prepulse (50 ms, 75 dB noise) was presented alone or 120 ms before the startle stimulus or circle. The startle stimulus speeded responses to the go stimuli and increased the covert false alarm rate in the no‐go condition (measured by EMG activity in the hand), although very few overt errors were made in the no‐go condition. Startle response magnitude was increased by a circle but decreased by a prepulse. The speeding of go responses caused by a startle stimulus was attenuated by the occurrence of a startle response, suggesting that an intense accessory stimulus can facilitate responding to an imperative stimulus, and that the startle response to that intense stimulus can interfere with that facilitation.     

Slow brain potentials in a visual monitoring task.

The purpose of this study was to analyse slow brain potentials (SPs) during visual monitoring, needed to perform the clock-monitoring task (CMT). This task was successfully applied in behavioural studies, in which attention capabilities were investigated in dependence on individual factors. Clearly pronounced preparatory SPs were observed during the CMT reflecting a high level of preparation and attention, necessary for achieving high performance accuracy. The well-known influence of task repetition on SPs and the relation between SP and behaviour were confirmed. The practicability of the CMT, the clear and easily detectable SP components and the sensitivity of the present approach makes it recommendable for further applications, e.g. for the evaluation of the effects of occupational/environmental exposures on processes of information processing.     

Frontal negativity of pattern-reversal visual evoked potentials in humans.

We investigated the nature of negative potential in the frontal region with an approximate latency of 100 ms ('frontal negativity') as a component of pattern-reversal visual evoked potential (PVEP) in healthy human subjects. It was recorded by stimulation of one-half of the visual field, with different reference electrodes and with experimental manipulations of the stimulating visual field ('central scotomata' and 'peripheral constriction'). A negative potential field was demonstrated to be localized in the frontal region, and its physiological properties detected by the visual field manipulations were shown to be different from those of the occipital positive (P100) and negative (N105) components of PVEP. We conclude, therefore, that frontal negativity of PVEP is an actual electrical event generated in the frontal region, independent of P100 and N105.