Manual action re-planning interferes with the maintenance process of working memory: an ERP investigation.

The current study investigated the re-planning of the grasping movements, its functional interactions with working memory (WM), and underlying neurophysiological activity. Mainly, the current study investigated the movement re-planning interference with WM domains (verbal, visuospatial) and processes (maintenance, retrieval). We combined a cognitive-motor dual-task paradigm with an EEG setting. Thirty-six participants completed the verbal and visuospatial versions of a WM task concurrently with a manual task which required performing a grasp-and-place movement by keeping the initial movement plan (prepared movement condition) or changing it for reversing the movement direction (re-planned movement condition). ERPs were extracted for the prepared and re-planned conditions in the verbal and visuospatial tasks separately during the maintenance and retrieval processes. ERP analyses showed that during the maintenance process of both the verbal and visuospatial tasks, the re-planned movements compared to the prepared movements generated a larger positive slow wave with a centroparietal maximum between 200 and 700. We interpreted this ERP effect as a P300 component for the re-planned movements. There was no ERP difference between the planned and re-planned movements during the retrieval process. Accordingly, we suggest that re-planning the grasp-and-place movement interfered at least with the maintenance of the verbal and visuospatial domains, resulting in the re-planning costs. More generally, the current study provides the initial neurophysiological investigations of the movement re-planning-WM interactions during grasping movements, and contributes to a better understanding of the neurocognitive mechanisms underlying manual action flexibility.

Acoustic stimulation increases implicit adaptation in sensorimotor adaptation.

Sensorimotor adaptation is an important part of our ability to perform novel motor tasks (i.e., learning of motor skills). Efforts to improve adaptation in healthy and clinical patients using non-invasive brain stimulation methods have been hindered by inter-individual and intra-individual variability in brain susceptibility to stimulation. Here, we explore unpredictable loud acoustic stimulation as an alternative method of modulating brain excitability to improve sensorimotor adaptation. In two experiments, participants moved a cursor towards targets, and adapted to a 30º rotation of cursor feedback, either with or without unpredictable acoustic stimulation. Acoustic stimulation improved initial adaptation to sensory prediction errors in Study 1, and improved overnight retention of adaptation in Study 2. Unpredictable loud acoustic stimulation might thus be a potent method of modulating sensorimotor adaptation in healthy adults.

Effects of force level and task difficulty on force control performance in elderly people.

As the proportion of people over 60 years of age rises continuously in westernized societies, it becomes increasingly important to better understand aging processes and how to maintain independence in old age. Fine motor tasks are essential in daily living and, therefore, necessary to maintain. This paper extends the existing literature on fine motor control by manipulating the difficulty of a force maintenance task to characterize performance optima for elderly. Thirty-seven elderly (M = 68.00, SD = 4.65) performed a force control task at dynamically varying force levels, i.e. randomly changing every 3 s between 10%, 20%, and 30% of the individual's maximum voluntary contraction (MVC). This task was performed alone or with one or two additional tasks to increase task difficulty. The force control characteristics accuracy, variability, and complexity were analyzed. Lowest variability was observed at 20%. Accuracy and complexity increased with increasing force level. Overall, increased task difficulty had a negative impact on task performance. Results support the assumption, that attention control has a major impact on force control performance in elderly people. We assume different parameters to have their optimum at different force levels, which remain comparably stable when additional tasks are performed. The study contributes to a better understanding of how force control is affected in real-life situations when it is performed simultaneously to other cognitive and sensory active and passive tasks.

Sensorimotor Rhythm Neurofeedback Enhances Golf Putting Performance.

Sensorimotor rhythm (SMR) activity has been related to automaticity during skilled action execution. However, few studies have bridged the causal link between SMR activity and sports performance. This study investigated the effect of SMR neurofeedback training (SMR NFT) on golf putting performance. We hypothesized that preelite golfers would exhibit enhanced putting performance after SMR NFT. Sixteen preelite golfers were recruited and randomly assigned into either an SMR or a control group. Participants were asked to perform putting while electroencephalogram (EEG) was recorded, both before and after intervention. Our results showed that the SMR group performed more accurately when putting and exhibited greater SMR power than the control group after 8 intervention sessions. This study concludes that SMR NFT is effective for increasing SMR during action preparation and for enhancing golf putting performance. Moreover, greater SMR activity might be an EEG signature of improved attention processing, which induces superior putting performance.

Prosody in parsing morphologically complex words: neurophysiological evidence.

Little is known about the neurophysiological correlates of lexical prosody in the comprehension of compound words, i.e., morphologically complex words. Here, it is investigated whether lexical prosody influences the decomposition of spoken compound words. In order to explore the neurophysiological correlates (event-related potentials, ERP) of a compound prosody, German native speakers had to judge the number agreement between numerals and nouns which did or did not agree in 50% of the cases. Importantly, the nouns carried either a compound or non-compound (single noun) prosody. The compound prosody led to increased reaction times (RTs) and reduced judgement accuracy. Critically, number violations for words with a compound prosody elicited an increased ERP negativity that was delayed by about 600 ms relative to a left-anterior negativity elicited by number violations for a single noun prosody. The ERP effect for the compound prosody preceded the according behavioural response by about 200 ms and the ERP peak latency effect correlated with the RT effect. These findings suggest that the ERP effect for the compound prosody could be functionally related to the accurate judgement performance for the compound prosody. The results suggest, more generally, that prosody plays a critical role in auditory compound comprehension and morphological processing.

Athletes and novices are differently capable to recognize feint and non-feint actions.

Fast motor reactions in sports often require the ability to predict the intended action of an opponent as early as possible. Therefore, the present paper investigates whether beach volleyball athletes are able to recognize different attack hits (i.e. smash vs. poke shot) at an earlier stage of the movement than novices. Beach volleyball athletes and novices took part in a response priming experiment (Experiment 1). Participants had to decide whether a presented target picture depicts a smash or a poke shot. Importantly, the preceding prime pictures were taken from different stages of the movements varying between the jump (beginning of the movements) and the hand-ball contact (end of the movements). Diverging response congruency effects was found for athletes and novices. Athletes were able to recognize at an earlier movement stage than novices which kind of attack hit was shown at the prime picture. It is suggested that athletes might implicitly read movement-related patterns in the depicted athlete's body posture (e.g. the angle of the elbow). In contrast, novices might use information which is easier to access (e.g. hand-ball relation). In a second experiment, novice participants received a visual training to test for a potential perceptual source of the priming effects. Notably, participants did not improve their ability to differentiate the volleyball techniques, indicating that a better recognition performance in athletes is based on motor and not on perceptual expertise.

The (cognitive) future of motor control and learning.

An ongoing debate exists regarding the compatibility of dynamic systems theory (DST) and symbol processing accounts (SPA), where SPA assume abstract representations and processing. Another aspect under discussion is if either one appropriately describes and explains motor control and the modification of motor skills. Both frameworks have their strengths and weaknesses. DST provides mechanistic explanations and takes system complexity and the environment into account without reference to mental entities. System behaviour is described mathematically and considered deterministic. In contrast, SPA propose that abstract content, that is, mental representations of the (own) body, and task requirements are critically important for movement control. It is argued that neither approach nor an (unaccomplished) unification of these frameworks can achieve a comprehensive understanding of motor control and learning. In this perspective article, it is argued that further effective sources of motor learning, such as emotional support and motivational guidance, have the potential to improve and preserve motor skills indirectly and should, thus, be recognised. Qualitative approaches focussing on understanding the athlete and the situation might be appropriate for applied work.

Effects of Age and Expertise on Mental Representation of the Throwing Movement Among 6- to 16-Year-Olds.

The aim of this article was to assess the development of mental representation of the overhead throwing movement as a function of age and expertise. The mental representational structure of the overhead throwing movement was measured using the Structural Dimensional Analysis-Motoric (SDA-M) method that reflects the organization of basic action concepts (BACs). BACs are fundamental building blocks of mental representations, which comprise functional, sensory, spatiotemporal, and biomechanical characteristics of a movement (Schack, 2010). In this study, novices and handball athletes (N = 199) each were grouped according to the level of development in motor ontogenesis (in childhood, pubescence, and adolescents). Male and female handball athletes played in the highest leagues of their age groups. As a result, novices of all age groups showed the same unstructured mental representation. Athletes in the earliest age band resemble all novices' groups and showed similar unstructured mental representation, whereas athletes within pubescence and adolescents showed functionally well-structured representations, which were similar to the structure of the reference group (N = 8). These results are consistent with a previous investigation of related quantitative and qualitative performance parameters of the overhead throwing movement (Gromeier et al., 2017). Without an increased training, neither the throwing performance nor the associated mental representation is unlikely to improve further by itself or automatically.

Expertise-dependent perceptual performance in chess tasks with varying complexity.

Perceptual performance, anticipating opponents' strategies, and judging chess positions especially in subliminal processing is related to expertise level and dependent on chunking processes. It becomes obvious that chess expertise is a multidimensional phenomenon related predominantly to experience. Under consideration of chess expertise categorization, we conducted two priming experiments expanding existing designs by gradually increasing the target and task complexity. The main aim was the evaluation of potential visuocognitive limitations. The results reveal experts' perceptual superiority manifested by their faster reaction times in settings with increased stimulus and task complexity. Further, experts' priming effects seem to be affected by the target content and/ or priming duration. For short prime duration, experts show priming effects only for less complex prime-target content. Interestingly, for longer prime duration and more complex prime-target content, all participants reveal priming effects. In summary, we argue that experts' visuocognitive processing (i.e., detecting or anticipating potential threats to the king) is rooted in a more efficient visuocognition due to stored chunks of checking and mating constellations. We suggest that visuocognitive limitations are related also to the prime-target complexity as well as to the task. Further investigations must be conducted in order to elucidate the factors with an increased impact on chess players' performance.

The functional neuroanatomy of morphology in language production.

The present study investigated the neural correlates of morphological priming in overt Dutch language production using a long-lag priming paradigm. Compound words were read out loud as primes that were morphologically related to picture names (e.g. the word jaszak, 'coat pocket' was used for a picture of a coat; Dutch jas), or primes were form-related, but not morphologically related monomorphemic words (e.g. jasmijn, 'jasmine'). The morphologically related compounds could be semantically transparent (e.g. eksternest, 'magpie nest') or opaque (e.g. eksteroog, lit. 'magpie eye,' 'corn,' for a picture of a magpie, Dutch ekster). These four priming conditions were complemented by two matched, unrelated conditions. The production of morphologically related, complex words but not the production of form-related words facilitated subsequent picture naming. Also, morphologically related but not form-related words led to a neural priming effect in the left inferior frontal gyrus (LIFG). The effects did not differ for transparent and opaque relations. The results point to a functional role of LIFG in morphological information processing during language production contrary to previous meta-analytic findings. Specifically, morphological priming effects in language production seem to be independent from semantic overlap. However, further research should confirm the independence of morphological and phonological factors. It is suggested that LIFG subserves word form encoding in language production.

Motor expertise modulates the unconscious processing of human body postures.

Little is known about the cognitive background of unconscious visuomotor control of complex sports movements. Therefore, we investigated the extent to which novices and skilled high-jump athletes are able to identify visually presented body postures of the high jump unconsciously. We also asked whether or not the manner of processing differs (qualitatively or quantitatively) between these groups as a function of their motor expertise. A priming experiment with not consciously perceivable stimuli was designed to determine whether subliminal priming of movement phases (same vs. different movement phases) or temporal order (i.e. natural vs. reversed movement order) affects target processing. Participants had to decide which phase of the high jump (approach vs. flight phase) a target photograph was taken from. We found a main effect of temporal order for skilled athletes, that is, faster reaction times for prime-target pairs that reflected the natural movement order as opposed to the reversed movement order. This result indicates that temporal-order information pertaining to the domain of expertise plays a critical role in athletes' perceptual capacities. For novices, data analyses revealed an interaction between temporal order and movement phases. That is, only the reversed movement order of flight-approach pictures increased processing time. Taken together, the results suggest that the structure of cognitive movement representation modulates unconscious processing of movement pictures and points to a functional role of motor representations in visual perception.

Online Movement Correction in Response to the Unexpectedly Perturbed Initial or Final Action Goals: An ERP and sLORETA Study.

In this experiment, we explored how unexpected perturbations in the initial (grip posture) and the final action goals (target position) influence movement execution and the neural mechanisms underlying the movement corrections. Participants were instructed to grasp a handle and rotate it to a target position according to a given visual cue. After participants started their movements, a secondary cue was triggered, which indicated whether the initial or final goals had changed (or not) while the electroencephalogram (EEG) was recorded. The results showed that the perturbed initial goals significantly slowed down the reaching action, compared to the perturbed final goals. In the event-related potentials (ERPs), a larger anterior P3 and a larger central-distributed late positivity (600-700 ms) time-locked to the perturbations were found for the initial than for the final goal perturbations. Source analyses found stronger left middle frontal gyrus (MFG) activations for the perturbed initial goals than for the perturbed final goals in the P3 time window. These findings suggest that perturbations in the initial goals have stronger interferences with the execution of grasp-to-rotate movements than perturbations in the final goals. The interferences seem to be derived from both inappropriate action inhibitions and new action implementations during the movement correction.

Coordinating Initial and Final Action Goals in Planning Grasp-to-Rotate Movements: An ERP Study.

Action goals have often been investigated in previous studies within a single action. However, most of the manual actions (such as prehension) are not restricted to a single action towards the object but can involve multiple follow-up actions to achieve a further purpose. The coordination of the initial (grip posture) and final (task purpose) action goals within such complex actions is still not fully understood. In the present experiment, the neural mechanisms underlying the goal coordination were investigated with the help of event-related potentials (ERP). With the "first cue - second cue - imperative signal" design, the action goals were presented separately in different sequences (either "final-initial" or "initial-final"), and participants were instructed to plan and execute a grasp-to-rotate movement with either free-choice or specified grasping. Results revealed that shorter reaction times were needed for the final-initial than for the initial-final trials only when the movement requires a free-choice grasping. At the moment when the goal information was incomplete (at the first cue), final goals evoked a larger anterior P2 than initial goals, whereas initial goals elicited a larger anterior N2 and a more robust frontal negativity (400--550 ms) than final goals. When the goal information was complete (at the second cue), we only found a larger P2 for final goals than for initial goals in free-choice grasping. Moreover, a larger N2 was also found for the specified than for the free-choice grasping in initial-final trials. These neurophysiological results indicate that final goals are more critical than initial grip postures in planning prehensile movements. The initial and final action goals seem to be preferably coordinated in a hierarchical manner, that is, the final task purpose is processed with precedence, whereas the initial grip posture is selected depending on the final task purpose.

Physical Activity Reduces Clinical Symptoms and Restores Neuroplasticity in Major Depression.

Major depressive disorder (MDD) is the most common mental disorder and deficits in neuroplasticity are discussed as one pathophysiological mechanism. Physical activity (PA) enhances neuroplasticity in healthy subjects and improves clinical symptoms of MDD. However, it is unclear whether this clinical effect of PA is due to restoring deficient neuroplasticity in MDD. We investigated the effect of a 3-week PA program applied on clinical symptoms, motor excitability and plasticity, and on cognition in patients with MDD (N = 23), in comparison to a control intervention (CI; N = 18). Before and after the interventions, the clinical symptom severity was tested using self- (BDI-II) and investigator- (HAMD-17) rated scales, transcranial magnetic stimulation (TMS) protocols were used to test motor excitability and paired-associative stimulation (PAS) to test long-term-potentiation (LTP)-like plasticity. Additionally, cognitive functions such as attention, working memory and executive functions were tested. After the interventions, the BDI-II and HAMD-17 decreased significantly in both groups, but the decrease in HAMD-17 was significantly stronger in the PA group. Cognition did not change notably in either group. Motor excitability did not differ between the groups and remained unchanged by either intervention. Baseline levels of LTP-like plasticity in the motor cortex were low in both groups (PA: 113.40 ± 2.55%; CI: 116.83 ± 3.70%) and increased significantly after PA (155.06 ± 10.48%) but not after CI (122.01 ± 4.1%). Higher baseline BDI-II scores were correlated with lower levels of neuroplasticity. Importantly, the more the BDI-II score decreased during the interventions, the stronger did neuroplasticity increase. The latter effect was particularly strong after PA (r = -0.835; p < 0.001). The level of neuroplasticity related specifically to the psychological/affective items, which are tested predominantly in the BDI-II. However, the significant clinical difference in the intervention effects was shown in the HAMD-17 which focuses more on somatic/neurovegetative items known to improve earlier in the course of MDD. In summary, PA improved symptoms of MDD and restored the deficient neuroplasticity. Importantly, both changes were strongly related on the individual patients' level, highlighting the key role of neuroplasticity in the pathophysiology and the clinical relevance of neuroplasticity-enhancing interventions for the treatment of MDD.

Cognitive Interaction Technology in Sport-Improving Performance by Individualized Diagnostics and Error Prediction.

The interdisciplinary research area Cognitive Interaction Technology (CIT) aims to understand and support interactions between human users and other elements of socio-technical systems. Important reasons for the new interest in understanding CIT in sport psychology are the impressive development of cognitive robotics and advanced technologies such as virtual or augmented reality systems, cognitive glasses or neurotechnology settings. The present article outlines this area of research, addresses ethical issues, and presents an empirical study in the context of a new measurement and assessment system for training in karate. Recent advances in the field of cognitive assistance systems enabled largely automatized assessments of individual mental representation structures for action sequences, such as choreographed movement patterns in dance or martial arts. Empirical investigations with karate practitioners of different skill levels demonstrate that advanced software-based survey and algorithmic analysis procedures based on cognitive models generate individualized performance predictions for a movement sequence from the Kanku-dai kata (a pre-defined karate movement sequence), which correlated significantly not only with formal expertise (kyu/dan rank) but also with the actual likelihood of mistakes in action execution. This information could prospectively be used to define individual training goals for deliberate practice and incorporated into cognitive interaction technology to provide appropriate feedback. We argue that the development of cognitive interaction systems for sport should explicitly take ethical issues into consideration and present a particular developed engineering approach. The potential benefits of such an assistance system for intermediate and advanced practitioners include more effective and flexible practice, as well as supportive effects, and more flexible training schedules. Furthermore, we argue that researchers from the field of sport psychology can benefit from advances in technological systems that enhance the understanding of mental and motor control in skilled voluntary action.

Social cues can impact complex behavior unconsciously.

In three experiments, we investigated the effect of unconscious social priming on human behavior in a choice reaction time task. Photographs of a basketball player passing a ball to the left/right were used as target stimuli. Participants had to respond to the pass direction either by a whole-body (complex) response or a button-press (simple) response. Visually masked stimuli, showing both a task-relevant cue (pass direction) and a task-irrelevant, social cue (gaze direction), were used as primes. Subliminal social priming was found for kinematic (center of pressure) and chronometric measures (response times): gaze direction in the primes affected responses to the pass direction in the targets. The social priming effect diminished when gaze information was unhelpful or even detrimental to the task. Social priming of a complex behavior does not require awareness or intentionality, indicating automatic processing. Nevertheless, it can be controlled by top-down, strategic processes.

Event-related brain potentials during the monitoring of speech errors.

When we perceive speech, our goal is to extract the meaning of the verbal message which includes semantic processing. However, how deeply do we process speech in different situations? In two experiments, native Dutch participants heard spoken sentences describing simultaneously presented pictures. Sentences either correctly described the pictures or contained an anomalous final word (i.e. a semantically or phonologically incongruent word). In the first experiment, spoken sentences were task-irrelevant and both anomalous conditions elicited similar centro-parietal N400s that were larger in amplitude than the N400 for the correct condition. In the second experiment, we ensured that participants processed the same stimuli semantically. In an early time window, we found similar phonological mismatch negativities for both anomalous conditions compared to the correct condition. These negativities were followed by an N400 that was larger for semantic than phonological errors. Together, these data suggest that we process speech semantically, even if the speech is task-irrelevant. Once listeners allocate more cognitive resources to the processing of speech, we suggest that they make predictions for upcoming words, presumably by means of the production system and an internal monitoring loop, to facilitate lexical processing of the perceived speech.

The Cognitive Structure of the Basketball Free Throw in Adolescent Physical Education Students.

In adult performers, research suggests that mental representations (MRs) mediate performance of skilled movement. During adolescence, cortical brain areas responsible for generating MRs develop rapidly along with limb size, which, together, may affect movement and movement representations. The aim of this study was to examine the relationship between adolescent MRs and free-throw shooting expertise. Using structural dimensional analysis of MRs, skilled (n = 11) and less skilled (n = 11) participants sorted free-throw submovements according to their relatedness in movement execution. Data were analyzed using a hierarchical cluster analysis, factor analysis, and invariance test to examine between-group cluster comparisons. Cluster solutions for the skilled and less skilled participants were significantly variant (λ = 0.56). This method of measuring MRs distinguished expertise-related differences in MRs in an adolescent population. Findings may influence methods in which practitioners detect motor-planning faults, track development, and provide feedback to trainees.

Morphological priming in overt language production: electrophysiological evidence from Dutch.

The present study investigated morphological priming in Dutch and its time course in overt speech production using a long-lag priming paradigm. Prime words were compounds that were morphologically related to a picture name (e.g. the word jaszak, 'coat pocket' was used for a picture of a coat; Dutch jas) or form-related monomorphemic words (e.g. jasmijn, 'jasmine'). The morphologically related compounds could be semantically transparent (e.g. eksternest, 'magpie nest') or opaque (e.g. eksteroog, lit. 'magpie eye', 'corn', for a picture of a magpie, Dutch ekster). Behavioral and event-related potential (ERP) data were collected in two sessions. The production of morphologically related and complex words facilitated subsequent picture naming and elicited a reduced N400 compared with unrelated prime words. The effects did not differ for transparent and opaque relations. Mere form overlap between a prime word and a target picture name did not affect picture naming. These results extend previous findings from German to another language and demonstrate the feasibility of measuring cognitive ERP components during overt speech. Furthermore, the results suggest that morphological priming in language production cannot be reduced to semantic and phonological processing. The time course of these priming effects as reflected in the ERP measure is in accordance with a meta-analytic temporal estimate of morphological encoding in speaking [Indefrey, P., & Levelt, W.J.M. (2004). The spatial and temporal signatures of word production components. Cognition, 92, 101-144.] suggesting that morphological relations are encoded at the word form level.

Capturing regularities in event sequences: evidence for two mechanisms.

The processing of regular event sequences was investigated by presenting categorical visual events in sequences that followed a rule system and a category restriction. Participants' task was to detect deviations of the rule or category restriction (single deviants) or both (double deviants). In Experiment 1, participants detected double deviants faster and more accurately than single deviants. This result is compatible with statistical facilitation, i.e. with distinct information processing in two channels. Experiment 2 used the same paradigm but did not require an immediate behavioural response to deviants. Here, event-related brain potentials revealed a redundant deviance effect in the P3 component (i.e. shorter latency and larger amplitude for double deviants compared with either single deviant). Category restriction deviants additionally led to an increased P2 amplitude. It is suggested that rule and category restriction information is processed separately at central levels, and that two central stages can be distinguished in the processing of categorical visual sequence events that make different use of short-term and long-term memory resources.