Preparation for action: Psychophysiological activity preceding a motor skill as a function of expertise,performance outcome,and psychological pressure

Knowledge of the psychophysiological responses that characterize optimal motor performance is required to inform biofeedback interventions. This experiment compared cortical, cardiac, muscular, and kinematic activity in 10 experts and 10 novices as they performed golf putts in low‐ and high‐pressure conditions. Results revealed that in the final seconds preceding movement, experts displayed a greater reduction in heart rate and EEG theta, high‐alpha, and beta power, when compared to novices. EEG high‐alpha power also predicted success, with participants producing less high‐alpha power in the seconds preceding putts that were holed compared to those that were missed. Increased pressure had little impact on psychophysiological activity. It was concluded that greater reductions in EEG high‐alpha power during preparation for action reflect more resources being devoted to response programming, and could underlie successful accuracy‐based performance.     

Prestimulus alpha power influences response criterion in a detection task

Recent studies have linked variability in near‐threshold stimulus detection to fluctuations in the prestimulus EEG alpha power (α, ～8–12 Hz). Typically, these studies rely on hit rate as a measure of detection performance and show that detection is enhanced when α power is low compared to when it is high. However, hit rates are determined by both sensitivity to the stimulus and the placement of the response criterion. Here, we investigated the relationships between prestimulus α power and variability in these two measures on a single‐trial basis. We confirm earlier reports that detection is inversely related to power in the individual α‐frequency band. However, our results show a stronger relationship between α power and response criterion than with sensitivity. Higher α power was related to a more conservative response criterion (i.e., more “no” responses). A response criterion that varies depending on α power might help to optimize performance in an excited state and protect against false positives in a relatively disengaged state.     

Cognitive control in the intertrial interval: Evidence from EEG alpha power

This study used electroencephalogram (EEG) power spectrum analyses to characterize neural activity during the intertrial interval, a period during which online cognitive adjustments in response to errors or conflict are thought to occur. EEG alpha power was quantified as an inverse index of cerebral activity during the period between each response and the next stimulus in a Stroop task. Alpha power was significantly reduced following error responses compared to correct responses, indicating greater cerebral activity following errors. Reduced alpha power was also observed following Stroop conflict trials compared to no‐conflict trials, suggesting that conflict engages processes of mental adjustment. Finally, hemispheric differences in alpha power during the intertrial interval supported the complementary roles of the left and right hemispheres in behavioral activation and inhibition.     

Cross‐modal distractors modulate oscillatory alpha power: the neural basis of impaired task performance

Unexpected novel sounds capture one's attention, even when irrelevant to the task pursued (e.g., playing video game). This often comes at a cost to the task (e.g., slower responding). The neural basis for this behavioral distraction effect is not well understood and is subject of this study. Our approach was motivated by findings from cuing paradigms suggesting a link between modulations in oscillatory activity and voluntary attention shifts. The current study tested whether oscillatory activity is also modulated by a task‐irrelevant auditory distractor, reflecting a neural signature of an involuntary shift of attention and accounting for the impaired task performance. We reanalyzed magnetoencephalographic data collected via an auditory‐visual distraction paradigm in which a task‐relevant visual stimulus was preceded by a task‐irrelevant sound on each trial. In 87.5% this was a regular sound (Standard); in 12.5% this was a novel sound (Distractor). We compared nonphase locked oscillatory activity in a time window prior to the visual target as a function of the experimental manipulation (Distractor, Standard). We found low power in the pretarget time window for Distractors compared to Standards in the alpha and beta frequency bands. Importantly, individual alpha power correlated with response speed on a trial‐by‐trial basis for the Distractor only. Sources were localized to the occipital cortex, and also to the parietal and supratemporal cortices. These findings support our hypothesis that the distractor‐related alpha power modulation indexes an involuntary shift of attention which accounts for the impaired task performance.     

Mindfulness‐of‐breathing exercise modulates EEG alpha activity during cognitive performance

The present study investigated whether engaging in a mindful breathing exercise would affect EEG oscillatory activity associated with self‐monitoring processes, based on the notion that mindfulness enhances attentional awareness. Participants were assigned to either an audio exercise in mindful breathing or an audio control condition, and then completed a Stroop task while EEG was recorded. The primary EEG measure of interest was error‐related alpha suppression (ERAS), an index of self‐monitoring in which alpha power is reduced, suggesting mental engagement, following errors compared to correct responses. Participants in the mindful‐breathing condition showed increased alpha power during the listening exercise and enhanced ERAS during the subsequent Stroop task. These results indicate enhanced error‐monitoring among those in the mindful‐breathing group.     

Alpha‐power modulation reflects the balancing of task requirements in a selective attention task

Recent research has related the orienting of selective attention to the lateralization of posterior EEG alpha power (∼8 to 12 Hz). Typically, alpha power decreases over the side of the head contralateral to the cued side of space. However, it is not clear how this lateralization affects behavior. We recorded EEG from 20 participants while they performed a cued visual discrimination task under three different response‐deadline conditions to investigate the effect of alpha‐power modulation on behavioral performance in more detail. Although all participants benefited from the cue behaviorally and adjusted their performance according to the response deadlines, we found the cue‐related alpha‐power modulation to depend on the general alpha‐power level at baseline: Only participants with high baseline alpha power showed significant cue‐related alpha‐power lateralization that was, however, strikingly similar across response‐deadline conditions. On the other hand, participants with low alpha power at baseline did not show any lateralization, but adjusted their alpha levels according to the response‐deadline instructions and, more importantly, showed a stronger influence of the task instructions on behavioral performance and adapted their response accuracies to the task requirements more flexibly. These findings challenge the often‐assumed role of alpha‐power lateralization for attentional deployment. While alpha power seems to be related to behavioral performance and the orienting of attention, this relationship is rather complex and, at least under the current task requirements, the general alpha‐power state seems to be more strongly related to behavioral performance (in our case, the flexible adjustment to task requirements) than the cue‐related lateralization.     

Deficient attention modulation of lateralized alpha power in schizophrenia

Modulation of 8–14 Hz (alpha) activity in posterior brain regions is associated with covert attention deployment in visuospatial tasks. Alpha power decrease contralateral to to‐be‐attended stimuli is believed to foster subsequent processing, such as retention of task‐relevant input. Degradation of this alpha‐regulation mechanism may reflect an early stage of disturbed attention regulation contributing to impaired attention and working memory commonly found in schizophrenia. The present study tested this hypothesis of early disturbed attention regulation by examining alpha power modulation in a lateralized cued delayed response task in 14 schizophrenia patients (SZ) and 25 healthy controls (HC). Participants were instructed to remember the location of a 100‐ms saccade‐target cue in the left or right visual hemifield in order to perform a delayed saccade to that location after a retention interval. As expected, alpha power decrease during the retention interval was larger in contralateral than ipsilateral posterior regions, and SZ showed less of this lateralization than did HC. In particular, SZ failed to show hemifield‐specific alpha modulation in posterior right hemisphere. Results suggest less efficient modulation of alpha oscillations that are considered critical for attention deployment and item encoding and, hence, may affect subsequent spatial working memory performance.     

Testing food‐related inhibitory control to high‐ and low‐calorie food stimuli: Electrophysiological responses to high‐calorie food stimuli predict calorie and carbohydrate intake

Maintaining a healthy diet has important implications for physical and mental health. One factor that may influence diet and food consumption is inhibitory control—the ability to withhold a dominant response in order to correctly respond to environmental demands. We examined how N2 amplitude, an ERP that reflects inhibitory control processes, differed toward high‐ and low‐calorie food stimuli and related to food intake. A total of 159 participants (81 female; M age = 23.5 years; SD = 7.6) completed two food‐based go/no‐go tasks (one with high‐calorie and one with low‐calorie food pictures as no‐go stimuli) while N2 amplitude was recorded. Participants recorded food intake using the Automated Self‐Administered 24‐hour Dietary Recall system. Inhibiting responses toward high‐calorie stimuli elicited a larger (i.e., more negative) no‐go N2 amplitude; inhibiting responses toward low‐calorie stimuli elicited a smaller no‐go N2 amplitude. Participants were more accurate during the high‐calorie than low‐calorie task, but took longer to respond on go trials toward high‐calorie rather than low‐calorie stimuli. When controlling for age, gender, and BMI, larger high‐calorie N2 difference amplitude predicted lower caloric intake (β = 0.17); low‐calorie N2 difference amplitude was not related to caloric intake (β = −0.03). Exploratory analyses revealed larger high‐calorie N2 difference amplitude predicted carbohydrate intake (β = 0.22), but not protein (β = 0.08) or fat (β = 0.11) intake. Results suggest that withholding responses from high‐calorie foods requires increased recruitment of inhibitory control processes, which may be necessary to regulate food consumption, particularly for foods high in calories and carbohydrates.     

Golf putt outcomes are predicted by sensorimotor cerebral EEG rhythms

It is not known whether frontal cerebral rhythms of the two hemispheres are implicated in fine motor control and balance. To address this issue, electroencephalographic (EEG) and stabilometric recordings were simultaneously performed in 12 right-handed expert golfers. The subjects were asked to stand upright on a stabilometric force platform placed at a golf green simulator while playing about 100 golf putts. Balance during the putts was indexed by body sway area. Cortical activity was indexed by the power reduction in spatially enhanced alpha (8-12 Hz) and beta (13-30 Hz) rhythms during movement, referred to as the pre-movement period. It was found that the body sway area displayed similar values in the successful and unsuccessful putts. In contrast, the high-frequency alpha power (about 10-12 Hz) was smaller in amplitude in the successful than in the unsuccessful putts over the frontal midline and the arm and hand region of the right primary sensorimotor area; the stronger the reduction of the alpha power, the smaller the error of the unsuccessful putts (i.e. distance from the hole). These results indicate that high-frequency alpha rhythms over associative, premotor and non-dominant primary sensorimotor areas subserve motor control and are predictive of the golfer's performance.     

Intra-hemispheric functional coupling of alpha rhythms is related to golfer's performance: a coherence EEG study

It has been shown that frontocentral electroencephalographic (EEG) alpha rhythms (about 10-12 Hz) were higher in amplitude in expert golfers in successful than unsuccessful putts, possibly reflecting the idea that amplitude regulation of frontocentral alpha rhythms is a physiological mechanism implied in motor control and golfer's performance (Babiloni et al., 2008). Here, we tested the ancillary hypothesis that golfer's performance is also associated to an improved coordination of cortical activity, as reflected by functional coupling of alpha rhythms across cortical regions. To this aim, between-electrodes spectral coherence was computed from spatially enhanced EEG data of the mentioned study (i.e. right handed 12 expert golfers; augmented 10-20 system; surface Laplacian estimation). Low- (about 8-10 Hz) and high-frequency (about 10-12 Hz) alpha sub-bands were considered with reference to individual alpha frequency peak. Statistical results showed that intra-hemispheric low-frequency alpha coherence in bilateral parietal-frontal (P3-F3 and P4-F4 electrodes) and parietal-central (P3-C3 and P4-C4 electrodes) was higher in amplitude in successful than unsuccessful putts (p<0.004). The same was true for intra-hemispheric high-frequency alpha coherence in bilateral parietal-frontal regions (p<0.004). These findings suggest that intra-hemispheric functional coupling of cortical alpha rhythms between "visuo-spatial" parietal area and other cortical areas is implicated in fine motor control of golfer's performance.     

Reduced premovement positivity during the stimulus‐response interval precedes errors: Using single‐trial and regression ERPs to understand performance deficits in ADHD

Brain mechanisms linked to incorrect response selections made under time pressure during cognitive task performance are poorly understood, particularly in adolescents with attention‐deficit hyperactivity disorder (ADHD). Using subject‐specific multimodal imaging (electroencephalogram, magnetic resonance imaging, behavior) during flanker task performance by a sample of 94 human adolescents (mean age = 15.5 years, 50% female) with varying degrees of ADHD symptomatology, we examined the degree to which amplitude features of source‐resolved event‐related potentials (ERPs) from brain‐independent component processes within a critical (but often ignored) period in the action selection process, the stimulus‐response interval, were associated with motor response errors (across trials) and error rates (across individuals). Response errors were typically preceded by two smaller peaks in both trial‐level and trial‐averaged ERP projections from posterior medial frontal cortex (pMFC): a frontocentral P3 peaking about 390 ms after stimulus onset, and a premovement positivity (PMP) peaking about 110 ms before the motor response. Separating overlapping stimulus‐locked and response‐locked ERP contributions using a “regression ERP” approach showed that trial errors and participant error rates were primarily associated with smaller PMP, and not with frontocentral P3. Moreover, smaller PMP mediated the association between larger numbers of errors and ADHD symptoms, suggesting the possible value of using PMP as an intervention target to remediate performance deficits in ADHD.     

Variations in resting frontal alpha asymmetry between high‐ and low‐neuroticism females across the menstrual cycle

Resting frontal alpha asymmetry measures the relative activation intensity across the left and right frontal regions that represent emotional experience. Here, the focus is on levels of alpha asymmetry between high‐ and low‐neuroticism females across the menstrual cycle. Resting alpha asymmetry in healthy females who scored high or low on neuroticism was assessed during the menstrual phase, the late follicular phase, and the midlate luteal phase. High‐neuroticism females exhibited lower relative left prefrontal activity than did low‐neuroticism females during the midlate luteal phase, as indexed by alpha₁ and alpha_Total asymmetry scores at the prefrontal electrode positions (FP_1/2). EEG results demonstrate that the resting frontal alpha asymmetry of high‐ and low‐neuroticism females was moderated by the menstrual cycle, and high‐neuroticism females should pay particular attention to their emotional experience during the midlate luteal phase.     

Reduction in event-related alpha attenuation during performance of an auditory oddball task in schizophrenia.

EEG frequency-domain analyses have demonstrated that cognitive performance produces a reduction in alpha activity, i.e., alpha attenuation, such as event-related desynchronization (ERD), reflecting brain activation. To examine whether schizophrenic patients have abnormalities in frequency-domain, event-related alpha attenuation, as well as in time-domain EEG phenomena, such as event-related potential, we compared alpha power change and P300 elicited simultaneously in response to the presentation of target tones in an auditory oddball paradigm between patients with schizophrenia and normal control subjects. In both patients and controls, alpha power was smaller during the time window of 512 ms following targets than following non-targets, particularly at the parietal and the posterior temporal locations (Pz, T5, and T6). The size of alpha attenuation measured as percent reduction in alpha power produced by targets relative to non-targets was smaller in patients than in controls at the posterior temporal locations. The size of alpha attenuation showed no correlation with P300 amplitude or latency in either patients or controls. Furthermore, in patients, the size of alpha attenuation showed no correlation with symptom severity, while P300 amplitude was correlated negatively with the positive subscale score of the Positive and Negative Syndrome Scale. These findings suggest that the symptom-independent reduction in event-related alpha attenuation in schizophrenia may be useful as an electrophysiological index of the impairment of neural processes distinct from that indexed by symptom-dependent P300 abnormalities.     

EEG alpha oscillations during the performance of verbal creativity tasks: differential effects of sex and verbal intelligence.

Task-related power changes in the EEG alpha band were analyzed in 31 participants (17 males and 14 females) during performance of two verbal creativity tasks. Participants were confronted with verbal problems that are in need of explanation (insight problems) and utopian situations that will actually never happen. In both tasks they were instructed to generate as many but also as unusual, unique or original ideas as possible. To assess brain responses that come along with highly original ideas, individual responses were divided into more and less original ideas (within each participant). Creative problem solving was generally accompanied by lower levels of cortical arousal (i.e., increases in alpha power from a pre-stimulus reference to an activation interval). Additionally, more original (vs. less original) responses were associated with a stronger task-related alpha synchronization in posterior (particularly centroparietal) cortices. Task-related alpha power changes during creative problem solving were also moderated by verbal IQ and sex.     

Sleep deprivation compromises resting‐state emotional regulatory processes: An EEG study

Resting‐state spontaneous neural activities consume far more biological energy than stimulus‐induced activities, suggesting their significance. However, existing studies of sleep loss and emotional functioning have focused on how sleep deprivation modulates stimulus‐induced emotional neural activities. The current study aimed to investigate the impacts of sleep deprivation on the brain network of emotional functioning using electroencephalogram during a resting state. Two established resting‐state electroencephalogram indexes (i.e. frontal alpha asymmetry and frontal theta/beta ratio) were used to reflect the functioning of the emotion regulatory neural network. Participants completed an 8‐min resting‐state electroencephalogram recording after a well‐rested night or 24 hr sleep deprivation. The Sleep Deprivation group had a heightened ratio of the power density in theta band to beta band (theta/beta ratio) in the frontal area than the Sleep Control group, suggesting an affective approach with reduced frontal cortical regulation of subcortical drive after sleep deprivation. There was also marginally more left‐lateralized frontal alpha power (left frontal alpha asymmetry) in the Sleep Deprivation group compared with the Sleep Control group. Besides, higher theta/beta ratio and more left alpha lateralization were correlated with higher sleepiness and lower vigilance. The results converged in suggesting compromised emotional regulatory processes during resting state after sleep deprivation. Our work provided the first resting‐state neural evidence for compromised emotional functioning after sleep loss, highlighting the significance of examining resting‐state neural activities within the affective brain network as a default functional mode in investigating the sleep–emotion relationship.     

The power of frontal midline theta and post‐error slowing to predict performance recovery: Evidence for compensatory mechanisms

Past studies utilizing cognitive control tasks have noted that trials following errors are characterized by slowed reaction time. Despite the assumption long held by researchers that this slowing is compensatory (in the service of post‐error performance recovery), studies consistently show that post‐error trials are no more accurate than post‐correct trials. As a result, it has recently been proposed that post‐error slowing (PES) is merely part of an orienting response that serves no task‐relevant cognitive control purpose. Frontal midline theta (FMθ) oscillations represent another potential compensatory mechanism serving cognitive control processes, yet past studies relying on ERPs have failed to find an association between FMθ and post‐error accuracy. The present study investigated the potentially adaptive role of PES and FMθ oscillations during a flanker task using trial‐by‐trial comparisons. Results indicated that error‐related FMθ oscillations signal the need for enhanced top‐down cognitive control and that PES supports cognitive control by providing the added time needed to achieve greater confidence in judgment. Overall, findings provide convergent evidence that both error‐related FMθ and PES predict performance recovery following errors.     

Theta‐ and alpha‐power enhancements in the electroencephalogram as an auditory delayed match‐to‐sample task becomes impossibly difficult

Recent studies have related enhancements of theta‐ (∼4–8 Hz) and alpha‐power (∼8–13 Hz) to listening effort based on parallels between enhancement and task difficulty. In contrast, nonauditory works demonstrate that, although increases in difficulty are initially accompanied by increases in effort, effort decreases when a task becomes so difficult as to exceed one's ability. Given the latter, we examined whether theta‐ and alpha‐power enhancements thought to reflect effortful listening show a quadratic trend across levels of listening difficulty from impossible to easy. Listeners (n = 14) performed an auditory delayed match‐to‐sample task with frequency‐modulated tonal sweeps under impossible, difficult (at ∼70.7% correct threshold), and easy (well above threshold) conditions. Frontal midline theta‐power and posterior alpha‐power enhancements were observed during the retention interval, with greatest enhancement in the difficult condition. Independent component‐based analyses of data suggest that theta‐power enhancements stemmed from medial frontal sources at or near the anterior cingulate cortex, whereas alpha‐power effects stemmed from occipital cortices. Results support the notion that theta‐ and alpha‐power enhancements reflect effortful cognitive processes during listening, related to auditory working memory and the inhibition of task‐irrelevant cortical processing regions, respectively. Theta‐ and alpha‐power dynamics can be used to characterize the cognitive processes that make up effortful listening, including qualitatively different types of listening effort.     

Alpha power is influenced by performance errors

Error commission evokes changes in event-related potentials, autonomic nervous system activity, and behavior, presumably reflecting the operation of a cognitive control network. Here we test the hypothesis that errors lead to increased cortical arousal, measurable as changes in electroencephalogram (EEG) alpha band power. Participants performed a Stroop task while EEG was recorded. Following correct responses, alpha power increased and then decreased in a quadratic pattern, implying transient mental disengagement during the intertrial interval. This trend was absent following errors, which elicited significantly less alpha power than correct trials. Moreover, post-error alpha power was a better predictor of individual differences in post-error slowing than the error-related negativity (ERN), whereas the ERN was a better predictor of post-error accuracy than alpha power. These findings imply that changes in cortical arousal play a unique role in modulating post-error behavior.     

Using trial‐level data and multilevel modeling to investigate within‐task change in event‐related potentials

EEG data, and specifically the ERP, provide psychologists with the power to examine quickly occurring cognitive processes at the native temporal resolution at which they occur. Despite the advantages conferred by ERPs to examine processes at different points in time, ERP researchers commonly ignore the trial‐to‐trial temporal dimension by collapsing across trials of similar types (i.e., the signal averaging approach) because of constraints imposed by repeated measures ANOVA. Here, we present the advantages of using multilevel modeling (MLM) to examine trial‐level data to investigate change in neurocognitive processes across the course of an experiment. Two examples are presented to illustrate the usefulness of this technique. The first demonstrates decreasing differentiation in N170 amplitude to faces of different races across the course of a race categorization task. The second demonstrates attenuation of the ERN as participants commit more errors within a task designed to measure implicit racial bias. Although the examples presented here are within the realm of social psychology, the use of MLM to analyze trial‐level EEG data has the potential to contribute to a number of different theoretical domains within psychology.     

Don’t look,don’t think,just do it! Toward an understanding of alpha gating in a discrete aiming task

Prior to and during movement, oscillatory alpha activity gates cognitive resources toward motor areas of the cortex by inhibiting neuronal excitability in nonmotor areas. The present study examined the effect of manipulating target variability on this alpha gating phenomenon. Using a baseline‐test‐retention design, we measured EEG alpha power, performance accuracy, and task difficulty in 32 recreational golfers as they putted golf balls (20 per target) to one central target (baseline, retention) and four targets of different directions and extents (manipulation). For participants in the random group (n = 16), target location varied with each repetition in a random fashion, whereas for participants in the blocked group (n = 16), it was kept constant within blocks. Regional analyses revealed a focal pattern of lower central alpha and higher occipital and temporal alpha. This topography was specific to preparation for movement and was associated with performance: smallest performance errors were preceded by decreased central combined with increased occipital alpha. The random group performed worse than the blocked group and found the task more difficult. Importantly, left temporal alpha prior to movement onset was lower for the random group than the blocked group. No group differences were found at baseline or retention. Our study proved that alpha gating can be altered by manipulating intertrial variability and thereby demonstrated the utility of the alpha gating model. Our findings underscore the importance of inhibiting occipital and left temporal areas when performing movements and provide further evidence that alpha gating reflects neural efficiency during motor tasks.