Acute effects of neuromuscular electrical stimulation on cortical dynamics and reflex activation.

Superimposing neuromuscular electrical stimulation (NMES) on voluntary muscle contractions has shown the potential to improve motor performance even more than voluntary exercise alone. Nevertheless, the neurophysiological and neurocognitive mechanisms underlying this technique are still unclear. The aim of this study was to investigate the acute responses in spinal excitability and brain activity following three conditions: NMES superimposed on isometric contractions (NMES + ISO), passive NMES, and voluntary isometric contractions (ISO). Each condition involved 15 intermittent ankle plantar-flexions at submaximal level. Before and after each condition, tibial nerve stimulation was used to elicit H-reflexes, which represent a measure of spinal excitability, and somatosensory evoked potentials (SEPs), which index the activity of subcortical and cortical somatosensory areas. H-reflex amplitudes increased after NMES + ISO and decreased after passive NMES compared with baseline values, whereas they remained unaltered after ISO. Subcortical lemniscal activity remained unaltered after the three conditions. Activity in both primary and secondary somatosensory cortices (S1 and S2) increased after NMES + ISO and decreased after the ISO condition, whereas no differences emerged after NMES. At later stages of S2 processing, ISO induced no changes in cortical activity, which, conversely, increased after NMES and NMES + ISO. These findings indicate that the beneficial effects of NMES may be mediated by potentiation of the reflex pathways at the spinal level. At the brain level, peripheral input representation in the brain stem was not influenced by the experimental conditions, which, conversely, altered cortical activity by affecting synaptic efficiency through the somatosensory pathway.NEW & NOTEWORTHY Neuromuscular electrical stimulation superimposed on voluntary contractions (NMES+) is effective to improve motor performance in several populations. Here, we investigated the changes in cortical activation and reflex response following three acute conditions, including NMES+. Our results show that NMES+ has a greater excitatory effect at both spinal and cortical levels compared with passive stimulation and voluntary exercise alone. These results open up original perspectives for the implementation of NMES+ in neurorehabilitation and training environments.

Motor-cognitive exercise with variability of practice and feedback improves functional ability and cognition in older individuals.

BACKGROUND: Motor-cognitive dual-task training seems the most favorable form of exercise for functional and cognitive improvements in older individuals.  The optimal exercise regime is still uncertain, and the potential benefits of qualitative parameters of exercise prescription such as feedback provision and practice variability are mostly unknown. AIMS: To verify the effects of a motor-cognitive dual-task training with feedback provision and variability of practice for improving functional ability and cognition in older individuals. METHODS: Thirty individuals (3 men) aged over 65 years were tested on walking speed, static and dynamic balance, lower limb strength, and cognition before and after a 5-week motor-cognitive intervention. Training consisted of twice weekly, 30 min gross-motor coordination exercises with variable practice conditions combined with stimulus-response cognitive tasks generated by an interactive device. Participants were divided into an experimental group and a control group, respectively receiving and nonreceiving feedback during training. A 2 × 2 ANOVA was used to verify the effects of training. RESULTS: Both groups improved static and dynamic balance (p < 0.05), walking speeds (p < 0.05), lower limb strength (p < 0.05) and cognitive functions with greater gains observed in the experimental group (p < 0.01). DISCUSSION: Variability of practice applied to motor-cognitive dual-task training is effective for improving, in only 5 weeks, functional ability and cognitive processing in older individuals. These changes were possibly afforded through motor and cognitive enhancement induced by exercise complexity. Provision of feedback seems to particularly benefit cognitive functions. CONCLUSIONS: Brief motor-cognitive dual-task training using practice variability and feedback seems effective for counteracting the age-related cognitive and functional decline.

The Dominance of Anticipatory Prefrontal Activity in Uncued Sensory-Motor Tasks.

Anticipatory event-related potentials (ERPs) precede upcoming events such as stimuli or actions. These ERPs are usually obtained in cued sensory-motor tasks employing a warning stimulus that precedes a probe stimulus as in the contingent negative variation (CNV) paradigms. The CNV wave has been widely studied, from clinical to brain-computer interface (BCI) applications, and has been shown to emerge in medial frontoparietal areas, localized in the cingulate and supplementary motor areas. Several dated studies also suggest the existence of a prefrontal CNV, although this component was not confirmed by later studies due to the contamination of ocular artifacts. Another lesser-known anticipatory ERP is the prefrontal negativity (pN) that precedes the uncued probe stimuli in discriminative response tasks and has been localized in the inferior frontal gyrus. This study aimed to characterize the pN by comparing it with the CNV in cued and uncued tasks and test if the pN could be associated with event preparation, temporal preparation, or both. To achieve these aims, high-density electroencephalographic recording and advanced ERP analysis controlling for ocular activity were obtained in 25 volunteers who performed 4 different visuomotor tasks. Our results showed that the pN amplitude was largest in the condition requiring both time and event preparation, medium in the condition requiring event preparation only, and smallest in the condition requiring temporal preparation only. We concluded that the prefrontal CNV could be associated with the pN, and this activity emerges in complex tasks requiring the anticipation of both the category and timing of the upcoming stimulus. The proposed method can be useful in BCI studies investigating the endogenous neural signatures triggered by different sensorimotor paradigms.

Prompting future events: Effects of temporal cueing and time on task on brain preparation to action.

Prediction about event timing plays a leading role in organizing and optimizing behavior. We recorded anticipatory brain activities and evaluated whether temporal orienting processes are reflected by the novel prefrontal negative (pN) component, as already shown for the contingent negative variation (CNV). Fourteen young healthy participants underwent EEG and fMRI recordings in separate sessions; they were asked to perform a Go/No-Go task in which temporal orienting was manipulated: the external condition (a visual display indicating the time of stimulus onset) and the internal condition (time information not provided). In both conditions, the source of the pN was localized in the pars opercularis of the iFg; the source of the CNV was localized in the supplementary motor area and cingulate motor area, as expected. Anticipatory activity was also found in the occipital-parietal cortex. Time on task EEG analysis showed a marked learning effect in the internal condition, while the effect was minor in the external condition. In fMRI, the two conditions had a similar pattern; similarities and differences of results obtained with the two techniques are discussed. Overall, data are consistent with the view that the pN reflects a proactive cognitive control, including temporal orienting.

Pearl and pitfalls in brain functional analysis by event-related potentials: a narrative review by the Italian Psychophysiology and Cognitive Neuroscience Society on methodological limits and clinical reliability-part II.

This review focuses on new and/or less standardized event-related potentials methods, in order to improve their knowledge for future clinical applications. The olfactory event-related potentials (OERPs) assess the olfactory functions in time domain, with potential utility in anosmia and degenerative diseases. The transcranial magnetic stimulation-electroencephalography (TMS-EEG) could support the investigation of the intracerebral connections with very high temporal discrimination. Its application in the diagnosis of disorders of consciousness has achieved recent confirmation. Magnetoencephalography (MEG) and event-related fields (ERF) could improve spatial accuracy of scalp signals, with potential large application in pre-surgical study of epileptic patients. Although these techniques have methodological limits, such as high inter- and intraindividual variability and high costs, their diffusion among researchers and clinicians is hopeful, pending their standardization.

Pearls and pitfalls in brain functional analysis by event-related potentials: a narrative review by the Italian Psychophysiology and Cognitive Neuroscience Society on methodological limits and clinical reliability-part I.

Event-related potentials (ERPs) are obtained from the electroencephalogram (EEG) or the magnetoencephalogram (MEG, event-related fields (ERF)), extracting the activity that is time-locked to an event. Despite the potential utility of ERP/ERF in cognitive domain, the clinical standardization of their use is presently undefined for most of procedures. The aim of the present review is to establish limits and reliability of ERP medical application, summarize main methodological issues, and present evidence of clinical application and future improvement. The present section of the review focuses on well-standardized ERP methods, including P300, Contingent Negative Variation (CNV), Mismatch Negativity (MMN), and N400, with a chapter dedicated to laser-evoked potentials (LEPs). One section is dedicated to proactive preparatory brain activity as the Bereitschaftspotential and the prefrontal negativity (BP and pN). The P300 and the MMN potentials have a limited but recognized role in the diagnosis of cognitive impairment and consciousness disorders. LEPs have a well-documented usefulness in the diagnosis of neuropathic pain, with low application in clinical assessment of psychophysiological basis of pain. The other ERP components mentioned here, though largely applied in normal and pathological cases and well standardized, are still confined to the research field. CNV, BP, and pN deserve to be largely tested in movement disorders, just to explain possible functional changes in motor preparation circuits subtending different clinical pictures and responses to treatments.

Neuroelectric evidences of top-down hypnotic modulation associated with somatosensory processing of sensory and limbic regions.

A large literature indicated hypnosis as a useful tool to reduce pain perception, especially in high susceptible individuals. However, due to different methodological aspects, it was still not clear whether hypnosis modulates the early sensory processing of the stimuli or if it affects only the later stages of affective processing. In the present study, we measured the EEG activity of subjects with a medium level of hypnotizability while receiving electrical non-painful stimuli on the median nerve in the conditions of awake and hypnosis with suggestions of hypoesthesia. Subjective reports indicated that hypnosis reduced both the sensory and the affective perception of the stimuli. ERP data revealed that hypnosis reduced the activity of both the early (N20) and the late (P100, P150, P250) SEP components. Neuroelectric source imaging further confirmed the top-down hypnotic modulation of a network of brain areas including the SI (N20), SII (P100), right anterior insula (P150) and cingulate cortex (P150/P250). The present study provides neurophysiological evidence to the hypnotic regulation of somatosensory inputs outside of pain, that is since the earliest stage of thalamocortical processing. Also, because present subjects were selected regardless of the level of hypnotizability, inferences from the present study are more generalizable than investigations restricted to high-hypnotizable individuals.

Immediate cortical adaptation in visual and non-visual areas functions induced by monovision.

KEY POINTS: Monovision is an optical correction for presbyopes that consists of correcting one eye for far distance and the other for near distance, creating a superimposition of an in-focus with a blurred image. Brain adaptation to monovision was studied in unexperienced observers by measuring visual evoked potentials from 64-channels. The first clear effect of monovision on visual evoked potentials was the C1 amplitude reduction, indicating that the unilateral blurring induced by monovision reduces feed-forward activity in primary visual area. Monovision led also to an increased amplitude of the P1 and pP1 components, with the latter originating in prefrontal regions. This effect probably works as an attentional compensatory activity used to compensate for the degraded V1 signal. ABSTRACT: A common and often successful option to correct presbyopia with contact lenses is monovision. This is an unbalanced correction across the two eyes where one eye is corrected for far vision and the other eye is corrected for near vision. Monovision is therefore a form of acquired anisometropia that causes a superimposition of an in-focus image with a blurred image. In spite of this visual anisometropia, monovision has been successfully used for many decadesl however the brain mechanism supporting monovision is not well understood. The present study aimed to measure the visual evoked potentials with a high-density electrode array (64-channel) in a group of presbyopes and to provide a detailed spatiotemporal analysis of the cortical activity after a short period of adaptation to monovision with contact lenses. When compared with a balanced eye near correction, monovision produced both a clear reduction of the earliest visual evoked potential components, the C1 and the N1, and an amplitude increase of the P1 and pP1. These results indicate that the unilateral blurring induced by wearing monovision contact lenses reduces feed-forward activity in the primary visual area and feedback activity in extrastriate areas (C1 and N1 reduction). Interestingly, other brain activities in both extrastriate visual areas (the P1 component) and in the anterior insula (the pP1 component) appear to compensate for this dysfunction, increasing their activity during monovision. These changes confirm the presence of fluid brain adaptation in visual and non-visual areas during monocular interferences.

Detailed spatiotemporal brain mapping of chromatic vision combining high-resolution VEP with fMRI and retinotopy.

Neuroimaging studies have identified so far, several color-sensitive visual areas in the human brain, and the temporal dynamics of these activities have been separately investigated using the visual-evoked potentials (VEPs). In the present study, we combined electrophysiological and neuroimaging methods to determine a detailed spatiotemporal profile of chromatic VEP and to localize its neural generators. The accuracy of the present co-registration study was obtained by combining standard fMRI data with retinotopic and motion mapping data at the individual level. We found a sequence of occipito activities more complex than that typically reported for chromatic VEPs, including feed-forward and reentrant feedback. Results showed that chromatic human perception arises by the combined activity of at the least five parieto-occipital areas including V1, LOC, V8/VO, and the motion-sensitive dorsal region MT+. However, the contribution of V1 and V8/VO seems dominant because the re-entrant activity in these areas was present more than once (twice in V8/VO and thrice in V1). This feedforward and feedback chromatic processing appears delayed compared with the luminance processing. Associating VEPs and neuroimaging measures, we showed for the first time a complex spatiotemporal pattern of activity, confirming that chromatic stimuli produce intricate interactions of many different brain dorsal and ventral areas.

Hemispheric asymmetries in the transition from action preparation to execution.

Flexible and adaptive behavior requires the ability to contextually stop inappropriate actions and select the right one as quickly as possible. Recently, it has been proposed that three brain regions, i.e., the inferior frontal gyrus (iFg), the anterior insula (aIns), and the anterior intraparietal sulcus (aIPs), play an important role in several processing phases of perceptual decision tasks, especially in the preparation, perception and action phases, respectively. However, little is known about hemispheric differences in the activation of these three areas during the transition from perception to action. Many studies have examined how people prepare to stop upcoming responses through both proactive and reactive inhibitory control. Although inhibitory control has been associated with activity in the right prefrontal cortex (PFC), we have previously reported that, during a discriminative response task performed with the right hand, we observed: 1) a bilateral activity in the iFg during the preparation phase, and 2) a left dominant activity in the aIns and aIPs during the transition from perception to action, i.e., the so-called stimulus-response mapping. To clarify the hemispheric dominance of these processes, we combined the high temporal resolution of event-related potentials (ERPs) with the high spatial resolution of event-related functional magnetic resonance imaging (fMRI) while participants performed a discriminative response task (DRT) and a simple response task (SRT) using their non-dominant left hand. We confirmed that proactive inhibitory control originates in the iFg: its activity started one second before the stimulus onset and was released concomitantly to the stimulus appearance. Most importantly, we confirmed the presence of a bilateral iFg activity that seems to reflect a bilateral proactive control rather than a right-hemisphere dominance or a stronger control of the hemisphere contralateral to the responding hand. Further, we observed a stronger activation of the left aIns and a right-lateralized activation of the aIPs reflecting left-hemisphere dominance for stimulus-response mapping finalized to response execution and a contralateral-hand parietal premotor activity, respectively.

Missing the Target: the Neural Processing Underlying the Omission Error.

The omissions are infrequent errors consisting in missing responses to the target stimuli. This is the first study aimed at investigating the brain activities associated with omissions in a decision-making task. We recorded event-related potentials (ERPs) in 12 subjects which reported a suitable number of omissions in a visual go/no-go task. We investigated both the pre- and post-stimulus brain activities associated with correct and omitted trials. The electrical neuroimaging technique (BESA) was adopted to extract the anterior insula (aIns) activity associated with the prefrontal P2 component (pP2) peaking about 300 ms after the stimulus and reflecting the stimulus-response mapping process. We found that omissions were predicted by a delayed onset (about half a second) of two pre-stimulus components, i.e. the prefrontal negativity (pN) and the Bereitschaftspotential (BP) associated with the top-down control and the motor preparation, respectively. Further, at the post-stimulus stage the omission trials were characterized by the suppression of the pP2 (and the aIns activity as measured by BESA). No differences between omission and correct trials were detected at the level of the P1 and N1 visual components, as well as the P3. These findings would suggest that omissions are attentional lapsebased errors, as indicated by the delayed brain preparation before the stimulus onset. The reduced cortical activity during the preparation phase did not affect the visual processing; in contrast the stimulus categorization process at the level of the anterior insula did not start at all, resulting in the inability to reach a decision.

Spatiotemporal brain mapping during preparation, perception, and action.

Deciding whether to act or not to act is a fundamental cognitive function. To avoid incorrect responses, both reactive and proactive modes of control have been postulated. Little is known, however, regarding the brain implementation of proactive mechanisms, which are deployed prior to an actual need to inhibit a response. Via a combination of electrophysiological and neuroimaging measures (recorded in 21 and 16 participants, respectively), we describe the brain localization and timing of neural activity that underlies the anticipatory proactive mechanism. From these results, we conclude that proactive control originates in the inferior Frontal gyrus, is established well before stimulus perception, and is released concomitantly with stimulus appearance. Stimulus perception triggers early activity in the anterior insula and intraparietal cortex contralateral to the responding hand; these areas likely mediate the transition from perception to action. The neural activities leading to the decision to act or not to act are described in the framework of a three-stage model that includes perception, action, and anticipatory functions taking place well before stimulus onset.

Short-term monocular deprivation alters early components of visual evoked potentials.

KEY POINTS: Short-term monocular deprivation in adult humans produces a perceptual boost of the deprived eye reflecting homeostatic plasticity. Visual evoked potentials (VEPs) to transient stimuli change after 150 min of monocular deprivation in adult humans. The amplitude of the C1 component of the VEP at a latency of about 100 ms increases for the deprived eye and decreases for the non-deprived eye after deprivation, the two effects being highly negatively correlated. Similarly, the evoked alpha rhythm increases after deprivation for the deprived eye and decreases for the non-deprived eye. The data demonstrate that primary visual cortex excitability is altered by a short period of monocular deprivation, reflecting homeostatic plasticity. ABSTRACT: Very little is known about plasticity in the adult visual cortex. In recent years psychophysical studies have shown that short-term monocular deprivation alters visual perception in adult humans. Specifically, after 150 min of monocular deprivation the deprived eye strongly dominates the dynamics of binocular rivalry, reflecting homeostatic plasticity. Here we investigate the neural mechanisms underlying this form of short-term visual cortical plasticity by measuring visual evoked potentials (VEPs) on the scalp of adult humans during monocular stimulation before and after 150 min of monocular deprivation. We found that monocular deprivation had opposite effects on the amplitude of the earliest component of the VEP (C1) for the deprived and non-deprived eye stimulation. C1 amplitude increased (+66%) for the deprived eye, while it decreased (-29%) for the non-deprived eye. Source localization analysis confirmed that the C1 originates in the primary visual cortex. We further report that following monocular deprivation, the amplitude of the peak of the evoked alpha spectrum increased on average by 23% for the deprived eye and decreased on average by 10% for the non-deprived eye, indicating a change in cortical excitability. These results indicate that a brief period of monocular deprivation alters interocular balance in the primary visual cortex of adult humans by both boosting the activity of the deprived eye and reducing the activity of the non-deprived eye. This indicates a high level of residual homeostatic plasticity in the adult human primary visual cortex, probably mediated by a change in cortical excitability.

Why do we make mistakes? Neurocognitive processes during the preparation-perception-action cycle and error-detection.

The event-related potential (ERP) literature described two error-related brain activities: the error-related negativity (Ne/ERN) and the error positivity (Pe), peaking immediately after the erroneous response. ERP studies on error processing adopted a response-locked approach, thus, the question about the activities preceding the error is still open. In the present study, we tested the hypothesis that the activities preceding the false alarms (FA) are different from those occurring in the correct (responded or inhibited) trials. To this aim, we studied a sample of 36 Go/No-go performers, adopting a stimulus-locked segmentation also including the pre-motor brain activities. Present results showed that neither pre-stimulus nor perceptual activities explain why we commit FA. In contrast, we observed condition-related differences in two pre-response components: the fronto-central N2 and the prefrontal positivity (pP), respectively peaking at 250 ms and 310 ms after the stimulus onset. The N2 amplitude of FA was identical to that recorded in No-go trials, and larger than Hits. Because the new findings challenge the previous interpretations on the N2, a new perspective is discussed. On the other hand, the pP in the FA trials was larger than No-go and smaller than Go, suggesting an erroneous processing at the stimulus-response mapping level: because this stage triggers the response execution, we concluded that the neural processes underlying the pP were mainly responsible for the subsequent error commission. Finally, sLORETA source analyses of the post-error potentials extended previous findings indicating, for the first time in the ERP literature, the right anterior insula as Pe generator.

Illusory and veridical mapping of tactile objects in the primary somatosensory and posterior parietal cortex.

While several behavioral and neuroscience studies have explored visual, auditory, and cross-modal illusions, information about the phenomenology and neural correlates of somatosensory illusions is meager. By combining psychophysics and somatosensory evoked potentials, we explored in healthy humans the neural correlates of 2 compelling tactuo-proprioceptive illusions, namely Aristotle (1 object touching the contact area between 2 crossed fingers is perceived as 2 lateral objects) and Reverse illusions (2 lateral objects are perceived as 1 between crossed-fingers object). These illusions likely occur because of the tactuo-proprioceptive conflict induced by fingers being crossed in a non-natural posture. We found that different regions in the somatosensory stream exhibit different proneness to the illusions. Early electroencephalographic somatosensory activity (at 20 ms) originating in the primary somatosensory cortex (S1) reflects the phenomenal rather than the physical properties of the stimuli. Notably, later activity (around 200 ms) originating in the posterior parietal cortex is higher when subjects resist the illusions. Thus, while S1 activity is related to illusory perception, PPC acts as a conflict resolver that recodes tactile events from somatotopic to spatiotopic frames of reference and ultimately enables veridical perception.

The motor preparation of directionally incompatible movements.

This work explores, for the first time, the electro-cortical activity related to the preparation of bimanual incompatible actions. To accomplish this aim, we recorded motor-related cortical potentials (MRCPs) in 16 healthy subjects, who were asked to draw lines and/or circles during three experimental conditions: Unimanual, Bimanually Compatible (either lines or circles with both hands) and Bimanually Incompatible (a line with one hand and a circle with the other hand). We show that the electro-cortical activity recorded during the preparation of the bimanually incompatible actions included a central positivity (CP) that began approximately 2.5s before movement onset and was localized in medial frontal areas. We then recorded a later (ca. 700ms before movement onset) negative activity in the supplementary motor area (consistent with Bereitschaftspotential). Finally, a strong frontal lateral positivity (FLP) emerged ca. 1.8s before the initiation of drawing that was localized in the dorsolateral prefrontal cortex. All components were bilateral. The CP component has not been described before. These data are discussed with regard to the "interference network" theory.

Bayesian interpretation of the prefrontal P2 ERP component based on stimulus/response mapping uncertainty.

The brain can be seen as a predictive system continuously computing prior information to guess posterior probabilities minimizing sources of uncertainty. To test this Bayesian view of the brain, event-related potentials (ERP) methods have been used focusing on the well-known P3 component, traditionally associated with decision-making processes and sources of uncertainty regarding target probability. Another ERP component linked with decision-making is the prefrontal P2 (pP2) component, which has never been considered within the Bayesian framework. To test which source of uncertainty could be associated with the pP2, uncertainty induced by target probability and stimulus-response (S/R) mapping were modulated in three visuomotor tasks. Results showed that the pP2 had the largest amplitude in the task with the largest uncertainty regarding the S/R mapping and degraded as the S/R mapping became more predictable. The P3 was maximal in the tasks with larger uncertainty regarding the target probability. While we confirmed the P3 association with target probability, we extended our knowledge on the pP2 associating it with S/R mapping uncertainty. This component, which has been previously localized within the anterior insular cortex, may minimize S/R mapping uncertainty allowing response-related evidence accumulation and comparing current events with internal representations to extract action-related probabilities.

Effect of anticipatory multisensory integration on sensory-motor performance.

Multisensory integration (MSI) is a phenomenon that occurs in sensory areas after the presentation of multimodal stimuli. Nowadays, little is known about the anticipatory top-down processes taking place in the preparation stage of processing before the stimulus onset. Considering that the top-down modulation of modality-specific inputs might affect the MSI process, this study attempts to understand whether the direct modulation of the MSI process, beyond the well-known sensory effects, may lead to additional changes in multisensory processing also in non-sensory areas (i.e., those related to task preparation and anticipation). To this aim, event-related potentials (ERPs) were analyzed both before and after auditory and visual unisensory and multisensory stimuli during a discriminative response task (Go/No-go type). Results showed that MSI did not affect motor preparation in premotor areas, while cognitive preparation in the prefrontal cortex was increased and correlated with response accuracy. Early post-stimulus ERP activities were also affected by MSI and correlated with response time. Collectively, the present results point to the plasticity accommodating nature of the MSI processes, which are not limited to perception and extend to anticipatory cognitive preparation for task execution. Further, the enhanced cognitive control emerging during MSI is discussed in the context of Bayesian accounts of augmented predictive processing related to increased perceptual uncertainty.

Effects of a Virtual Reality Reaction Training Protocol on Physical and Cognitive Skills of Young Adults and Their Neural Correlates: A Randomized Controlled Trial Study.

Increasing evidence shows that virtual reality (VR) training is highly effective in cognitive and motor rehabilitation. Another modern form of training is cognitive-motor dual-task training (CMDT), which has been demonstrated to rapidly improve physical and cognitive functions in real environments. This study aims to test whether a VR-based CMDT protocol can be used for motor and cognitive skill enhancement in young, healthy subjects. For this aim, 24 university students participated in a randomized control trial. The experimental group participated in a 5-week virtual reality reaction training (VRRT), performing 30 min sessions once a week. The control group did not receive any training but was tested twice with the same measures and temporal distance as the experimental group. Before and after the intervention, motor, cognitive, and electrophysiological measures were assessed. The results showed that following VRRT, the response time for both physical and cognitive tests was improved by about 14% and 12%, respectively, while the control group did not show significant changes. Moreover, electrophysiological data revealed a significant increase in anticipatory motor readiness in premotor brain areas in the experimental group only; however, cognitive top-down control tended to be increased in prefrontal areas after VRRT. This training protocol in a VR modality seems to be as effective as other CMDT methodologies carried out in a real modality. Still, it has the advantages of being more flexible and more user-friendly compared to standard training. The VRRT's efficacy on physical and cognitive functions indicates that virtual reality applications can be used by the young population, not only for entertainment purposes but also in the form of cognitive-motor training.

A Nonpharmacologic Treatment for Anxiety in Older Adults Based on Cognitive-Motor Training With Response-Generated Feedback.

OBJECTIVES: Simultaneous combinations of cognitive and physical exercises (cognitive-motor dual-task training [CMDT]) are more effective than physical and cognitive training alone in counteracting the decline of older adults and promoting physical and psychological well-being. The CMDT can be particularly effective in improving cognitive and functional abilities. Here, we validated an innovative nonpharmacologic intervention for anxiety and general well-being in older people by combining CMDT and response-generated feedback (RGF) principles. As outcomes, anxiety, cognitive functions, and functional mobility were evaluated. In addition, electroencephalographic methods were employed to investigate the neural basis of the possible intervention effects. METHODS: Thirty older adults were divided into an experimental group trained using a CMDT + RGF protocol and a control group using the CMDT only. The CMDT + RGF consisted of the simultaneous execution of whole-body exercises, cognitive tasks that were realized using interactive devices, and continuous feedback on every response. RESULTS: Results showed decreased anxiety and increased response speed in the experimental group, and both groups improved their functional ability and response accuracy after the intervention. According to electroencephalographic results, both groups showed an increase in the bilateral prefrontal cortex anticipatory activity, but the experimental group also showed a further increase in the left prefrontal cortex and in the premotor areas anticipatory functions. DISCUSSION: This study confirms the effectiveness of the proposed intervention on anxiety by adopting a nonpharmacology treatment that could affect public and individual health costs by proposing an alternative approach to expensive medications and psychotherapy and could significantly improve older adults' quality of life.