Preparation Of Motor Response Research Articles

Imitation of Touching Dangerous Animals Triggers Motor Inhibition in a Primed Target Grasping-Categorization Task

The present study adopted a primed target grasping-categorization task and selected pictures of animals as target stimuli to investigate whether motor inhibition influences the motor interference effect of dangerous animals. The results identified more positive P2 and P3 amplitudes accompanied by larger delta event-related synchronization in the dangerous condition than in the neutral condition, suggesting that compared to neutral animal targets, dangerous animal targets attracted increased attentional resources in early processing and that subjects recruited more cognitive resources to process dangerous animal targets than neutral animal targets. Moreover, the results identified larger theta event-related synchronization (reflecting motor inhibition) in the dangerous condition than in the neutral condition. Thus, the results suggested that prepared motor responses were inhibited to avoid touching dangerous animal targets in the current task, supporting that motor inhibition influences the motor interference effect of dangerous animals based on a primed target grasping-categorization task.

Neuroelectric indices of motor response preparation are selectively associated with physical activity among adults with obesity

Previous work has demonstrated that physical activity and weight status are associated with attentional inhibition (indexed with the P3 component of event-related potentials). However, there is limited knowledge on the neural underpinnings of motor response planning and activation. This study investigated the effect of weight status on relationships between moderate-to-vigorous physical activity (MVPA) and the lateralized readiness potential (LRP), a neuroelectric index of motor response planning and activation. Adults (N = 165 [98 females]) wore ActiGraph wGT3X+ accelerometers to measure physical activity. Behavioral outcomes were recorded during the modified Eriksen Flanker task to assess attentional inhibition. EEG recordings were taken to elucidate response- (LRP-R) and stimulus-locked (LRP-S) LRPs, and P3. Participants were separated into groups based on the BMI cutoff of 30 kg/m2 (i.e., non-obese [n = 88], obese [n = 77]). Independent t-tests and ANCOVA were conducted to determine differences between groups. Regression analyses within each group were conducted to determine relationships between MVPA and LRP and P3 amplitude and latencies. There was no difference in MVPA between weight groups after adjustment for age and sex, although the non-obese group had significantly higher incongruent accuracy (p = 0.007). Only in the obese group, MVPA was positively associated with LRP-R incongruent (β = 0.014, p = 0.029) and LRP-S congruent (β = 0.013, p = 0.008) amplitude, and inversely associated with LRP-S incongruent (β = −0.488, p = 0.017) and P3 congruent (β = 0.013, p = 0.008) fractional area latency. MVPA was associated with pre-motor planning and activation only among persons with obesity. Future work should study the impact of physical activity on neuroelectric indices of motor responses in people with obesity.

Moderate-to-vigorous Physical Activity Is Related To Pre-motor Planning In Persons With Obesity

PURPOSE: Although previous work has demonstrated that physical activity and excess fat mass are associated with attentional control (indexed with the P3 component of event related potentials; ERP), there is limited knowledge on the neural underpinnings of motor response planning and activation. Accordingly, this study investigated the effect of obesity status on the relationship between moderate-to-vigorous physical activity (MVPA) and the lateralized readiness potential (LRP), a neuroelectric index of motor planning and activation. METHODS: Adults (N = 165 [98 female]; 20-45 yrs) wore hip-worn ActiGraph wGT3X+ accelerometers to measure physical activity. MVPA was defined using Troiano cut-points. Behavioral outcomes were recorded during the Eriksen Flanker task to assess attentional inhibition. EEG recordings were taken to elucidate response- and stimulus-locked LRPs at the C3 and C4 electrodes. Participants were separated into groups based on the BMI cutoff of 30 kg/m2 i.e., non-obese (n = 88) and obese (n = 77). Partial Pearson correlations controlling for age, sex, wear time, and handedness were conducted in each group to determine if MVPA was associated with the response- and stimulus-locked LRP amplitudes and latencies. RESULTS: Average MVPA was significantly different (P = 0.002) between the non-obese (41.8 + 25.0 min/day) and the obese group (31.2 + 17.7 min/day). Average congruent (P = 0.017) and incongruent (P = 0.005) accuracies were significantly different between each group. MVPA was related to incongruent accuracy (r = 0.311, P = 0.004) but not congruent (r = 0.161, P = 0.143) in the non-obese group. There were no relationships between MVPA and response- or stimulus-locked LRPs in the non-obese group. However, in participants with obesity, MVPA was associated with response-locked congruent (r = 0.251, P = 0.032) and incongruent (r = 0.260; P = 0.026) mean amplitude, and stimulus-locked congruent mean amplitude (r = 0.301, P = 0.013). CONCLUSION: MVPA was associated with pre-motor planning and activation in people with obesity. Future work should study the impact of physical activity on neuroelectric indices of motor response preparation in people with obesity. This work was funded by the Hass Avocado Board and the Kinesiology Department at the University of Illinois

Neural Evidence for Different Types of Position Coding Strategies in Spatial Working Memory.

Sustained neural activity during the delay phase of spatial working memory tasks is compelling evidence for the neural correlate of active storage and maintenance of spatial information, however, it does not provide insight into specific mechanisms of spatial coding. This activity may reflect a range of processes, such as maintenance of a stimulus position or a prepared motor response plan. The aim of our study was to examine neural evidence for the use of different coding strategies, depending on the characteristics and demands of a spatial working memory task. Thirty-one (20 women, 23 ± 5 years) and 44 (23 women, 21 ± 2 years) participants performed a spatial working memory task while we measured their brain activity using fMRI in two separate experiments. Participants were asked to remember the position of a briefly presented target stimulus and, after a delay period, to use a joystick to indicate either the position of the remembered target or an indicated non-matching location. The task was designed so that the predictability of the response could be manipulated independently of task difficulty and memory retrieval process. We were particularly interested in contrasting conditions in which participants (i) could use prospective coding of the motor response or (ii) had to rely on retrospective sensory information. Prospective motor coding was associated with activity in somatomotor, premotor, and motor cortices and increased integration of brain activity with and within the somatomotor network. In contrast, retrospective sensory coding was associated with increased activity in parietal regions and increased functional connectivity with and within secondary visual and dorsal attentional networks. The observed differences in activation levels, dynamics of differences over trial duration, and integration of information within and between brain networks provide compelling evidence for the use of complementary spatial working memory strategies optimized to meet task demands.

Retrospective composite analysis of StartReact data indicates sex differences in simple reaction time are not attributable to response preparation

Simple reaction time (RT) can vary by sex, with males generally displaying faster RTs than females. Although several explanations have been offered, the possibility that response preparation differences may underlie the effect of sex on simple RT has not yet been explored. A startling acoustic stimulus (SAS) can involuntarily trigger a prepared motor response (i.e., StartReact effect), and as such, RT latencies on SAS trials and the proportion of these trials demonstrating startle-reflex EMG in the sternocleidomastoid (SCM) muscle are used as indirect measures of response preparation. The present study employed a retrospective analysis of composite individual participant data (IPD) from 25 datasets published between 2006 and 2019 to examine sex differences in response preparation. Linear mixed effects models assessed the effect of sex on control and SAS RT as well as the proportion of SAS trials with SCM activation while controlling for study design. Results indicated significantly longer control RT in female participants as compared to males (p = .017); however, there were no significant sex differences in SAS RT (p = .441) or the proportion of trials with startle reflex activity (p = .242). These results suggest that sex differences in simple RT are not explained by variations in levels of response preparation but instead may be the result of differences in perceptual processing and/or response initiation processes.

Temporal dynamics of decision making: A synthesis of computational and neurophysiological approaches.

As interest in the temporal dynamics of decision-making has grown, researchers have increasingly turned to computational approaches such as the drift diffusion model (DDM) to identify how cognitive processes unfold during choice. At the same time, technological advances in noninvasive neurophysiological methods such as electroencephalography and magnetoencephalography now allow researchers to map the neural time course of decision making with millisecond precision. Combining these approaches can potentially yield important new insights into how choices emerge over time. Here we review recent research on the computational and neurophysiological correlates of perceptual and value-based decision making, from DDM parameters to scalp potentials and oscillatory neural activity. Starting with motor response preparation, the most well-understood aspect of the decision process, we discuss evidence that urgency signals and shifts in baseline activation, rather than shifts in the physiological value of the choice-triggering response threshold, are responsible for adjusting response times under speeded choice scenarios. Research on the neural correlates of starting point bias suggests that prestimulus activity can predict biases in motor choice behavior. Finally, studies examining the time dynamics of evidence construction and evidence accumulation have identified signals at frontocentral and centroparietal electrodes associated respectively with these processes, emerging 300-500 ms after stimulus onset. These findings can inform psychological theories of decision-making, providing empirical support for attribute weighting in value-based choice while suggesting theoretical alternatives to dual-process accounts. Further research combining computational and neurophysiological approaches holds promise for providing greater insight into the moment-by-moment evolution of the decision process. This article is categorized under: Psychology > Reasoning and Decision Making Neuroscience > Cognition Economics > Individual Decision-Making.

Neural mechanisms underlying enhanced visual search performance in action video game players

Individuals who play action video games have demonstrated faster response times on a range of cognitive tasks, but various changes across the chain of processing could contribute to the ultimate quickening in response. Some research has begun to identify neural markers associated with enhanced performance in gamers and has established that there are differences in low-level visual processing, attention allocation and visual working memory. However, gaming-related improvements could also arise from quicker preparation and execution of the motor response, and potential changes in the motor-related LRP have yet to be explored. Additionally, prior work has focused on changes in a limited number of early ERP components in isolation; therefore, further research is required to identify the relative contribution of each stage of processing to the observed behavioural changes. Using similar methodology as Clark et al. (2015), we tested action video-game players and non-video-game players and recorded EEG while participants performed a visual search ‘popout’ task. We assessed amplitudes and latencies of key ERP components, specifically, the N1 (early sensory processing), N2pc (attentional orienting to stimulus), CDA (target processing, discrimination, and manipulation of information in visual short-term memory), and both the stimulus-locked and response-locked LRPs (preparation for motor response). As expected, gamers demonstrated faster response times relative to non-gamers, and EEG analyses revealed the neural mechanisms underlying these behavioural differences. Improved performance in gamers was accompanied by changes across the processing chain from stimulus to response, evidenced by differences from the early sensory-evoked N1 component through to the later motor-related LRP component. Our findings suggest that enhanced visual search performance in action video game players is driven by differences in early sensory processing in combination with changes to later cognitive and motor processes.

T71. A DIRECT COMPARISON OF ADHD, ASD AND SCHIZOPHRENIA ON FOUR BASIC OCULAR-MOTOR TASKS: TOWARDS A MODEL OF NEURODEVELOPMENTAL CONTINUUM

BackgroundAccording to the Neurodevelopmental continuum hypothesis, neurodevelopmental disorders such as ADHD, Autism and Schizophrenia, should be conceptualised as lying on a continuum of neurodevelopmental impairment, with the individual disorders reflecting different degrees of abnormal brain development and resulting functional impairment. The model also hypothesizes that these disorders lie on a gradient of severity, suggesting that they might differ to some extent quantitatively but also qualitatively. The severity of neurodevelopmental impairment is also expressed by the severity of cognitive impairment and persistence of functional impairment. The main objective of the present study was therefore to investigate commonalities and differences among the three conditions in various cognitive subdomains using standard ocular-motor paradigms.MethodsFour groups of young adults were included: 21 with Early-Onset Schizophrenia (“SCZ”, 19.7±1.7, 15 males), 26 with Autism Spectrum Disorder (“ASD”, 19.7±1.9, 25 males), 28 with Attention-Deficit/Hyperactivity Disorder (“ADHD”, 19.9±1.4, 15 males), 29 typically developing participants (“TD”, 19.8±1.6, 12 males). Participants were matched on age and full-scale IQ. Eye movements were recorded binocularly at 1000 Hz using the Eye Link 1000+ system while four basic ocular-motor tasks (prosaccade (PRO), antisaccade (ANT), memory-guided saccade (MEM), fixation (FIX)) were administered in counterbalanced order. Eye movements were analysed with Data Viewer 3.2, SPSS 2.3 and MorePower 6.1.ResultsWith respect to standard deviation of saccadic reaction times (SRTSD), ASD and ADHD did not differ from TD for PRO, ANTI, MEM. Conversely, SCZ were significantly more variable in all tasks than TD, but not compared to ASD and ADHD. Furthermore, SCZ were significantly slower than TD and ASD, but not ADHD, in PRO and ANT. Compared to TD, increased percentage of anticipatory saccades was found for MEM in ASD and ADHD, only marginally for PRO in ASD, again for all tasks in SCZ, when compared to both TD and ASD and, in less extent, to ADHD in ANT. A significantly higher percentage of direction errors during ANT was common to all clinical groups, this inhibitory deficit being significantly more severe in SCZ than ASD, but not compared to ADHD. Increased frequency of intrusive saccades during FIX was found in SCZ and ASD, and marginally in ADHD, when compared to TD. As for microsaccades, SCZ and ASD showed a higher frequency of microsaccades for FIX (condition without distractors) and PRO (preceding correct saccades), only SCZ for ANT (both preceding correct saccades and direction errors), compared to TD.DiscussionResults suggest psychomotor slowing, unique for SCZ, as compared to ASD and ADHD, as indicated by increased mean RT in PRO. Conversely, increased anticipatory saccades and direction errors support the presence of inhibition deficits across groups, suggesting a common (pre-)frontal functional impairment. Of note, mean RT discriminates the clinical groups better than ISV, thus emerging as a trans-diagnostic process to the three conditions and, uniquely for SCZ as a deficit independent of the specific tasks administered here. Finally, atypical microsaccadic frequency might suggest common abnormalities in motor response preparation in SCZ and ASD. Across all tasks, participants with SCZ appear more impaired than those with ADHD and ASD, while the performance of ADHD was often in between SCZ and ASD, possibly in line with the idea of a continuum of neurodevelopmental impairment.

EEG correlates of cognitive load in a multiple choice reaction task

The present study aimed to examine EEG correlates of cognitive load in a task, in which multiple stimulus‑response mappings have to be maintained in working memory (WM) combined with selective inhibition of irrelevant stimulus‑response mappings on every trial. Twenty‑four healthy younger adults had to perform choice reaction tasks differed in the number of S‑R mappings and motor response requirements. Performance was lower in the high load than in the low load condition. Performance decline at higher WM loads was accompanied by an increase of EEG power in delta, theta, and beta frequency bands and by a reduction in alpha band. The effect on alpha was generalized across all the electrodes. Correlations between EEG and performance were observed in the high load condition but not in the low load condition. Theta activity negatively correlated with reaction time, whereas positive correlations between beta activity and reaction time were found. The two frequency bands negatively correlated with each other at all electrodes. The results suggest that changes in alpha and theta power may be considered as the most sensitive indicators of cognitive load. The alpha reduction may be related to activation of widespread cortical areas which were recruited for performance of complex WM tasks. The beta increase, especially in the beta‑2 range, may partly be associated with activation of motor cortex due to difficulties in preparation and execution of motor responses. Theta increases may be considered as an index of facilitation of information processing in WM and improvements in higher‑order executive control, which in turn facilitates motor processes.

Task Co-Representation in Aging: An Event-Related Potential Study

The goal of the present study was to investigate age-related changes in attentional allocation for shared task representations during joint performance; event-related potentials were recorded while participants performed a modified visual three-stimulus oddball task, both alone and together with another participant. Younger adults and older adults (14 each) participated in the study. Participants were required to identify rare target stimuli while ignoring frequent standards, as well as rare non-targets assigned to a partner’s action (i.e., no-go stimuli for one’s own task). ERP component, nogo-P3 and P3b were measured to investigate the inhibition and the attentional allocation to the partner’s stimuli. Results showed that younger adults elicited larger frontal nogo P3 and parietal P3b for non-targets in the joint than in the individual condition. Contrary to expectation, older adults induced frontal no-go P3 in the joint condition not in the individual condition. In the sharing of the task with another, the result suggested that the efficiency of matching of incoming information with the representation of the other’s task declined with age, whereas aging did not affect the suppression of incorrect preparation of motor responses instigated by this representation.

Neural mechanisms of response-preparation and inhibition in bilingual and monolingual children: Lateralized Readiness Potentials (LRPs) during a nonverbal Stroop task

Inhibitory control is a core executive function (EF) skill, thought to involve cognitive ‘interference suppression’ and motor ‘response inhibition’ sub-processes. A few studies have shown that early bilingualism shapes interference suppression but not response inhibition skills, however current behavioral measures do not fully allow us to disentangle these subcomponents. Lateralized Readiness Potentials (LRPs) are centroparietal event-related potentials (ERPs) that track motor response-preparations between stimulus-presentation and behavioral responses. We examine LRPs elicited during successful inhibitory control on a nonverbal Stroop task, in 6–8 year-old bilingual (n = 44) and monolingual (n = 48) children from comparable socio-economic backgrounds. Relative to monolinguals, bilinguals showed longer and stronger incorrect-response preparations, and a more mature pattern of correct-response preparation (shorter peak-latencies), underlying correct responses on Stroop-interference trials. Neural markers of response-inhibition were comparable between groups and no behavioral differences were found between-groups on the Stroop task. Results suggest group differences in underlying mechanisms of centroparietal motor-response preparation mechanisms in this age group, contrary to what has been shown using behavioral tasks previously. We discuss neural results in the context of speed-accuracy trade-offs. This is the first study to examine neural markers of motor-responses in bilingual children.

Adiposity is related to neuroelectric indices of motor response preparation in preadolescent children

ObjectiveEvent-related brain potentials (ERPs) have been utilized to study the cognitive implications of health-related behaviors, although many questions remain regarding the neural correlates underlying the cognition and adiposity relationship in childhood. Specifically, it is unknown whether excess fat mass is associated with the neural correlates of motor preparation and activation. The present work examined interrelationships between adiposity and ERPs that index inhibition, stimulus evaluation, and motor planning. MethodTo further elucidate the neural components of inhibitory control that are sensitive to adiposity, N2, P3, and response- and stimulus-locked Lateralized Readiness Potential (LRPs) were measured while preadolescent children completed an attentional inhibition task. Whole body percent adiposity was measured via dual-energy x-ray absorptiometry (DXA). ResultsAdiposity was related to the response-locked LRP amplitudes and marginally to P3 amplitude during the incongruent trials, such that participants with less adiposity elicited larger LRP and P3 components. Furthermore, P3 was strongly related to participant reaction times, suggesting that while LRP is strongly associated with adiposity, P3 has a more direct relationship to behavioral task performance. ConclusionsThe results suggest that while different cognitive functions may be affected by health-related characteristics, stimulus evaluation and motor activation may be particularly sensitive to excess adiposity in children. These findings extend previous work implicating adiposity in cognitive health in the pediatric population. Study importance1.What is already known about this subject?a.Excess adiposity is inversely associated with cognitive function in children.b.Adiposity has been associated with several event-related brain potentials, such that smaller P3 components, which index stimulus evaluation, and N2 components, which index attentional inhibition, are related to greater adiposity in children.c.The neural correlates underlying the cognition-adiposity relationship are under specified, and additional ERP components should be studied; one such component is the LRP, which underlies motor planning and activation.2.What does your study add?a.Our results show that adiposity was related to the P3 and the response-locked LRP components such that children with less adiposity showed larger P3 and LRP waveforms.b.These findings suggest that two separable, though related, processes may be affected by adiposity in childhood: One involving the evaluation of a stimulus, represented by the P3, and one involving the activation of motor control, represented by the response-locked LRP.Clinical Registry Number: NCT02630667 at https://clinicaltrials.gov.

Oscillatory brain dynamics supporting impaired Stroop task performance in schizophrenia-spectrum disorder

The Stroop color-word interference task, prompting slower response to color-incongruent than to congruent items, is often used to study neural mechanisms of inhibitory control and dysfunction in schizophrenia-spectrum disorders. Inconsistent findings of an augmented Stroop effect limit identification of relevant dysfunctional mechanism(s) in schizophrenia. The present study sought to advance understanding of normal and impaired neural oscillatory dynamics by distinguishing interference detection and response preparation during the Stroop task in schizophrenia-spectrum disorders via analysis of behavioral performance and 4–7 Hz (theta) and 10–30 Hz (alpha/beta) EEG oscillations in 40 patients (SZ) and 27 healthy comparison participants (HC). SZ responded more slowly and showed less dorsal anterior cingulate (dACC) theta enhancement during INC trials, less enhancement of dACC-sensorimotor cortex connectivity (theta phase synchrony) during INC trials, more alpha/beta suppression though less enhancement of that suppression during INC trials, and slower post-response alpha/beta rebound than did HC. Reaction time distributions showed larger group and Stroop effects during the 25% of trials with the slowest responses. Poorer theta phase coherence in patients indicates impaired communication between regions associated with interference processing (dACC) and response preparation (sensorimotor cortex). Results suggest a failure cascade in which compromised behavioral Stroop effects are driven at least in part by dysfunctional interference processing (less theta power increase) prompting dysfunctional motor response preparation (less alpha/beta power suppression). Inconsistent Stroop effects in past studies of schizophrenia may result from differing task parameters sampling different degrees of Stroop task difficulty.

The Scope of Planning Serial Actions during Typing.

Human activities consisting of multiple component actions require the generation of ordered sequences. This study investigated the scope of response planning in highly serial task, typing, by means of ERPs indexing motor response preparation. Specifically, we compared motor-related ERPs yielded by words typed using a single hand against words that had all keystrokes typed with a single hand, except for a deviant one, typed with the opposite hand. The deviant keystroke occurred either early in the typed sequence, corresponding to the second or third letters, or late, corresponding to the penultimate or last letter. Motor-related ERPs detected before response onset were affected only by deviant keystrokes located at the beginning of the sequence, whereas deviant keystrokes located at the end yielded ERPs that were undistinguishable from unimanual responses. These results impose some constraints on the notion of parallel processing of component actions.

Influence of pain on motor preparation in the human brain.

The protective function of pain depends on appropriate motor responses to avoid injury and promote recovery. The preparation and execution of motor responses is thus an essential part of pain. However, it is not yet fully understood how pain and motor processes interact in the brain. Here we used electroencephalography to investigate the effects of pain on motor preparation in the human brain. Twenty healthy human participants performed a motor task in which they performed button presses to stop increasingly painful thermal stimuli when they became intolerable. In another condition, participants performed button presses without concurrent stimulation. The results show that the amplitudes of preparatory event-related desynchronizations at alpha and beta frequencies did not differ between conditions. In contrast, the amplitude of the preparatory readiness potential was reduced when a button press was performed to stop a painful stimulus compared with a button press without concomitant pain. A control experiment with nonpainful thermal stimuli showed a similar reduction of the readiness potential when a button press was performed to stop a nonpainful thermal stimulus. Together, these findings indicate that painful and nonpainful thermal stimuli can similarly influence motor preparation in the human brain. Pain-specific effects on motor preparation in the human brain remain to be demonstrated.NEW & NOTEWORTHY Pain is inherently linked to motor processes, but the interactions between pain and motor processes in the human brain are not yet fully understood. Using electroencephalography, we show that pain reduces movement-preparatory brain activity. Further results indicate that this effect is not pain specific but independent of the modality of stimulation.

Concealed Around-the-Ear EEG Captures Cognitive Processing in a Visual Simon Task.

In theory, miniaturized systems such as the around-the-ear electrode arrays (cEEGrids) enable mobile monitoring of the electroencephalogram (EEG) in a variety of real life situations without interfering with the natural setting. However, the research benefit of such cEEGrid recordings critically depends on their validity. To investigate whether visual and motor processing are reflected in the cEEGrid-EEG, a direct comparison of EEG that was concurrently recorded with the cEEGrids and with a high-density cap setup was conducted. Thirteen participants performed a classic Simon task in which letters were presented laterally and a lateralized choice response was executed. N1, P1 and P300 event-related potential (ERP) waveforms were extracted from cEEGrid-EEG: they were found to be strongly correlated with corresponding waveforms extracted from cap-EEG but with lower signal strength and lower signal-to-noise-ratio (SNR). Event-related lateralizations (ERLs) recorded at posterior scalp sites were well reflected in middle cEEGrid pairs. Moreover, the effect size of the Simon correspondence effect on the extracted ERLs was similar between the two systems. However, lateralizations at central cap sites were less well reflected in the cEEGrid-EEG indicating a difficulty in capturing motor response preparation and execution. These results show that well-described visual and cognitive ERPs and ERLs can be measured using the cEEGrids, while motor-related cortical potentials are not well captured. This study further demonstrates the potential and possible limitations of unobtrusive cEEGrid-EEG recordings.

Deficits in Go and NoGo P3 potentials in patients with schizophrenia

Cognitive control processes elicited during a cued continuous performance test were evaluated using event-related potentials in 46 patients who were within the first 5 years of diagnosis of schizophrenia, and 29 healthy controls. Patients had longer reaction times, lower hit rates, and higher false alarm rates compared with controls. Patients had an overall P3 amplitude reduction that was more prominent on NoGo compared with Go trials. This greater P3 reduction on NoGo trials was present in central and parietal regions, but was absent in the frontal region, where the P3 reduction was comparable on NoGo and Go trials. Our findings suggest that the neural activity contributing to Go and NoGo P3s are both deteriorated in schizophrenia, but those contributing to central and parietal NoGo P3s are the most severely affected ones. We conclude that the cognitive control processes engaged during execution, and particularly during inhibition of a prepared motor response were disturbed in the early course of schizophrenia. Our findings might be related to our sample being in relatively early stages of schizophrenia and/or related to the use of atypical antipsychotics by most of our patients.

Enhanced action tendencies in obsessive-compulsive disorder: An ERP study

Obsessive-compulsive disorder (OCD) is characterized by repeated thoughts and behaviors. This study explored the stages of motor response preparation that precede action performance or inhibition: We investigated whether OCD is related to enhanced action tendencies in response to external stimuli. Response preparation processes were assessed using the event-related potential (ERP) component of the readiness potential (RP). ERPs were recorded while 15 participants with OCD and 16 healthy controls performed a variation of the go/no-go task and the stop-signal task using schematic faces (angry and neutral). The OCD group presented with a greater RP slope gradient and amplitude over bilateral frontoparietal areas corresponding to the motor cortex. The amplitude effect was further enhanced under negative valence, compared to the neutral condition. Results support the hypothesis that stronger readiness for action might characterize OCD, especially in the presence of threatening stimuli. These findings – specifically correlated with OCD and not with anxiety and depression symptoms – may underlie habitual behavior and embodiment tendencies in OCD. This study suggests that early stages of motor preparation might be important to the etiology and maintenance of OCD.

On the functional relationship between language and motor processing in typewriting: an EEG study

ABSTRACTThe functional relationship between language and motor processing was investigated to elucidate whether it is better described in terms of a discrete or a continuous account of information flow. To this end, we recorded event-related potentials during a typewriting task that combined a semantic priming paradigm with a manipulation of response side (response initiated with right vs. left hand), and focused on the lateralised potentials indexing motor-response activation and inhibition. The critical issue was to assess whether, in the semantically related condition, the increased evidence for the target representation at the conceptual-lexical levels percolates into motor-response preparation, thus triggering an enhanced activation of the corresponding response hand, or whether lexical-semantic and motor-preparation processes unfold independently. Despite effective priming on response times, no selective influence of semantic relatedness was observed on motor-preparation potentials. These results are more compatible with a discrete account.

Actions speak louder than words: Enhanced action tendencies in obsessive-compulsive disorder: An ERP study

Obsessive-compulsive disorder (OCD) is characterized by repeated thoughts and behaviors. Several studies have detected deficient response inhibition ability in individuals with OCD, leading researchers to suggest this deficit as an endophenotype of OCD. However, other researchers maintain that the effect size of this deficit is modest and that it lacks clinical significance. The current investigation examines a potential alternative explanation for difficulties in response inhibition, namely enhanced action tendencies in response to stimuli. Therefore, early processes of motor response preparation preceding action performance (or inhibition) were studied with the event-related potential (ERP) component of readiness potential (RP). RP measures brain reactions related to motor activity in response to external stimuli. ERPs were recorded while 15 participants with OCD and 16 healthy controls performed a variation of a go/no-go task and a stop-signal task using schematic faces (angry and neutral). The OCD group presented with a greater RP slope gradient and amplitude over bilateral parietal areas corresponding to the motor cortex. The amplitude effect was further enhanced under negative valence, compared with the neutral condition. Differences in RP between the OCD and control groups remained significant when controlling for levels of trait anxiety. Results support the hypothesis that a stronger readiness for action might characterize OCD, especially in the presence of threatening stimuli. This finding, specific to OCD and not to anxiety symptoms, may underlie habitual tendencies in OCD. This study suggests that early-stages of motor preparation might be important to the etiology and maintenance of OCD.Disclosure of interestThe authors have not supplied their declaration of competing interest.