Effects of magnesium supplementation on muscle soreness in different type of physical activities: a systematic review.

BACKGROUND: Magnesium is a micronutrient and an intracellular cation responsible for different biochemical reactions involved in energy production and storage, control of neuronal and vasomotor activity, cardiac excitability, and muscle contraction. Magnesium deficiency may result in impaired physical performance. Moreover, magnesium plays an important role on delayed onset muscle soreness after training. Thus, physically active individuals and sport specialists have to pay attention to magnesium supplementation (MgS). However, the type, timing and dosage of magnesium intake are not well elucidated yet. Hence, we aimed to systematically review the literature regarding the effects of MgS on muscle soreness in physically active individuals. We focused exclusively on MgS, excluding those studies in which magnesium was administered together with other substances. METHODS: Three electronic databases and literature sources (PUBMED, SCOPUS and Web of Sciences-Core Collection) were searched, in accordance with PRISMA guidelines. After the database search, 1254 articles were identified, and after excluding duplicates, 960 articles remained. Among these, 955 were excluded following the title and abstract screening. The remaining 5 articles were screened in full text and 4 study met the eligibility criteria. RESULTS: These studies showed that MgS reduced muscle soreness, improved performance, recovery and induced a protective effect on muscle damage. CONCLUSION: To reach these positive effects, individuals engaged in intense exercise should have a Mg requirement 10-20% higher than sedentary people, to be taken in capsules and 2 h before training. Moreover, it is suggested to maintain magnesium levels in the recommended range during the off-season. SYSTEMATIC REVIEW REGISTRATION: PROSPERO registration number: CRD42024501822.

Effects of school-based physical activity on volition in exercise, sleep quality and internet addiction in Italian adolescents.

School-settings represent ideal context to promote healthy habits as in adolescence most risk factors may occur or intensify leading to the adoption of unhealthy lifestyles. Thus, a deeper understanding of the factors promoting healthy lifestyles in adolescents is of utmost importance. This observational study aims to investigate: 1) gender-related differences in physical activity (Physical Activity Questionnaire for Adolescets - PAQ-A), sleep quality (Pittsburgh Sleep Quality Index - PSQI) and internet addiction (Internet Addiction Test - IAT) levels and Volition in Exercise (VE); 2) the relationship between PAQ-A and VE, PSQI and IAT; 3) the effects of a five-month (T0; T5) school-based physical activity (PA) intervention on the above-mentioned factors. PAQ-A,VE, PSQI and IAT were assessed before (T0) and after (T5) a school-based PA intervention. The PA intervention consisted of coordinative exercises and team sports performed for 1 h twice a week. At T0, girls showed lower PAQ-A, PSQI scores, lower volition facilitators ("self-confidence" and "coping with failure") and higher volition inhibitor ("postponing training") than boys. Significant correlations were observed for volition factors an IAT in males and volition and PSQI and IAT in females. After the PA intervention (T5), "postponing training" and "self-confidence" factors were reduced compared to T0. Exercise specialists should consider gender differences in volition in exercise factors during a school-based PA to plan and realize PA protocols aiming at maximizing exercise adherence to tackle sedentary behaviors in adolescents.

The Effects of Online Home-Based Pilates Combined with Diet on Body Composition in Women Affected by Obesity: A Preliminary Study.

Diet and exercise intervention are the first strategies to counteract obesity. An online home-based exercise program may be a feasible approach in an obese population. Therefore, this study aimed to investigate the effects of twelve weeks of online Pilates plus diet on body composition in individuals affected by obesity. Thirty-five females were randomly assigned to a home-based Pilates group (PG, n = 18) or a group without intervention (control group, CG, n = 17). All participants followed a Mediterranean diet. The PG followed a twelve-week online Pilates Matwork program (three times/week; 180 min/week), while the CG was not involved in any structured physical exercise program. Body composition and handgrip strength were evaluated at baseline (T0) and after the intervention (T1). A significant group × time interaction (p < 0.05) was found for the fat mass percentage (pFM). Specifically, the pFM was significantly lower at T1 than at T0 in the PG. Significant group × time interactions for fat-free mass (p < 0.05), appendicular skeletal muscle mass (p < 0.05), and skeletal muscle mass (p < 0.01) were found. All these variables were significantly higher at T1 than at T0 in the PG (p < 0.05). Home-based Pilates combined with diet intervention may represent an effective strategy to improve body composition in terms of fat mass reduction and muscle mass gain in adults affected by obesity.

The effects of pre-task music on choice visual reaction time in elite taekwondo athletes.

OBJECTIVES: The effects of music on sport performance mainly involved endurance or resistance exercises overlooking possible effects on reaction time, which is deemed essential in martial arts for a proficient performance. Therefore, the aim of this study was to investigate the effects of the exposure to pre-task music on choice visual reaction time in elite taekwondo athletes. DESIGN: Repeated measure study design. METHODS: Reaction time and mean Heart Rate (HRmean) were recorded in twenty young taekwondo athletes (17.5 ±â€¯2.5 years old) while performing a roundhouse kick in response to different visual stimuli after three warmup conditions: listening to self-selected music (SM), research-selected music (RM) or no music (CC). Moreover, Feeling Scale (FS), Felt Arousal Scale (FAS) were recorded before (T0) and after warmup (T1) in each testing session. RESULTS: SM and RM elicited significantly faster reaction times compared to CC (-3.3 % and -5.2 %, respectively). No significant difference in reaction time was observed between SM and RM. The FS and FAS scores were significantly higher at T1 compared to T0 in the SM and RM conditions, whereas no difference between T0 and T1 was observed in the CC condition. No difference was observed for HRmean between SM, RM and CC conditions. CONCLUSIONS: Listening to SM and RM during the warmup improved choice visual reaction times in elite taekwondo athletes. These results suggest the use of music as a performance-enhancing strategy prior to combat competition or training in martial arts.

Brain dynamics of visual anticipation during spatial occlusion tasks in expert tennis players.

Stimulus identification and action outcome understanding for a rapid and accurate response selection, play a fundamental role in racquet sports. Here, we investigated the neurodynamics of visual anticipation in tennis manipulating the postural and kinematic information associated with the body of opponents by means of a spatial occlusion protocol. Event Related Potentials (ERPs) were evaluated in two groups of professional tennis players (N = 37) with different levels of expertise, while they observed pictures of opponents and predicted the landing position as fast and accurately as possible. The observed action was manipulated by deleting different body districts of the opponent (legs, ball, racket and arm, trunk). Full body image (no occlusion) was used as control condition. The worst accuracy and the slowest response time were observed in the occlusion of trunk and ball. The former was associated with a reduced amplitude of the ERP components likely linked to body processing (the N1 in the right hemisphere) and visual-motor integration awareness (the pP1), as well as with an increase of the late frontal negativity (the pN2), possibly reflecting an effort by the insula to recover and/or complete the most correct sensory-motor representation. In both occlusions, a decrease in the pP2 may reflect an impairment of decisional processes upon action execution following sensory evidence accumulation. Enhanced amplitude of the P3 and the pN2 components were found in more experienced players, suggesting a greater allocation of resources in the process connecting sensory encoding and response execution, and sensory-motor representation.

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.

Does sport type matter? The effect of sport discipline on cognitive control strategies in preadolescents.

This study aimed to test the effects of specific sport practices on cognitive sensory-motor performance and underlying brain functions in children. Behavioral performance and event-related potentials (ERP) were investigated during a cognitive visuomotor task in 64 preadolescent children practicing racket (Rack) sports, martial arts (Mart), indoor climbing (Clim), or not practicing any sport (controls, Cont). At the behavioral level, response speed and accuracy were studied. At the electrophysiological level, motor, cognitive and sensory-attentional readiness, and post-perceptual attentional functions were investigated. Behavioral results showed that Mart players had the fastest response time (RT). Rack players had the most consistent RT and committed the lowest omission errors. Clim athletes were the most accurate in terms of false alarms. ERP results showed that motor readiness was largest in Mart players. The Rack group had the largest cognitive preparation and the Clim one had the largest sensory-attentional readiness activity. Rack and Mart players had the largest activity associated with post-perceptual attentional processing. This result shows that practicing specific sports may allow differential benefits on cognitive processing. Racket sports seem to stimulate action speed consistency and improve accuracy for omissions, increasing cognitive preparation, and post-perceptual attentional processing. Mart practice may allow a more speed-oriented response behavior, probably due to large motor preparation and allocation of post-perceptual attentional resources, but only when response execution is required. Indoor climbing may favor response accuracy reducing unwanted responses as indexed by an increased sensory-attentional readiness. Overall, all the considered sports disciplines may improve cognitive processing, but each one is associated with different benefits on cognitive performance by possibly stimulating separate brain processing. This kind of information could be crucial to select the more appropriate sport depending on individual demands.

Motor Competence in Individuals with Down Syndrome: Is an Improvement Still Possible in Adulthood?

In children, motor competence (MC) and the amount of physical activity are tightly interconnected. In adults with Down syndrome (DS), MC has been poorly addressed, resulting in a limited understanding of the possibility to improve MC over time. Here, we aim to: (1) investigate MC in adults with DS by comparing them with a group of typically developed peers and (2) verify the effect of an adapted karate program on MC. Adults with DS (DSG; n = 57) and typically developed adults (TDG; n = 21) performed the Test of Gross Motor Development version 3 (TGMD-3). The total TGMD-3 score (TOTTGMD-3), the locomotor (LOCTGMD-3), and object control (OBJTGMD-3) scores were computed. After a 40 week adapted karate program, DSG (n = 37) underwent the post-training TGMD-3 assessment. Compared to TDG, DSG showed lower TOTTGMD-3 (DSG: 45.5 ± 17.3; TDG: 77.3 ± 9.5), LOCTGMD-3 (DSG: 22.2 ± 10.0; TDG: 36.2 ± 7.6) and OBJTGMD-3 (DSG: 23.3 ± 10.9; TDG: 41.1 ± 5.6). After the training, TOTTGMD-3, LOCTGMD-3 and OBJTGMD-3 increased by 35.6%, 30.0% and 40.7%, respectively. Our results suggest that MC acquisition does not evolve into a mature form in adulthood in individuals with DS. Moreover, a brief exposure to an adapted karate program induces an increase in motor competence in DS, even in adulthood.

Brain Plasticity Induced by Musical Expertise on Proactive and Reactive Cognitive Functions.

Proactive and reactive brain activities usually refer to processes occurring in anticipation or in response to perceptual and/or cognitive events. Previous studies found that, in auditory tasks, musical expertise improves performance mainly at the reactive stage of processing. In the present work, we aimed at acknowledging the effects of musical practice on proactive brain activities as a result of neuroplasticity processes occurring at the level of anticipatory motor/cognitive functions. Accordingly, performance and electroencephalographic recordings were compared between professional musicians and non-musicians during an auditory go/no-go task. Both proactive (pre-stimulus) and reactive (post-stimulus) event-related potentials (ERPs) were analyzed. Behavioral findings showed improved performance in musicians compared to non-musicians in terms of accuracy. For what concerns electrophysiological results, different ERP patterns of activity both before and after the presentation of the auditory stimulus emerged between groups. Specifically, musicians showed increased proactive cognitive activity in prefrontal scalp areas, previously localized in the prefrontal cortex, and reduced anticipatory excitability in frontal scalp areas, previously localized in the associative auditory cortices (reflected by the pN and aP components, respectively). In the reactive stage of processing (i.e., following stimulus presentation), musicians showed enhanced early (N1) and late (P3) components, in line with longstanding literature of enhanced auditory processing in this group. Crucially, we also found a significant correlation between the N1 component and years of musical practice. We interpreted these findings in terms of neural plasticity processes resulting from musical training, which lead musicians to high efficiency in auditory sensorial anticipation and more intense cognitive control and sound analysis.

Lower Limb Maximal Power Predicts Punching Speed in Different Static and Dynamic Attacking Techniques in Karate.

ABSTRACT: Quinzi, F, Rosellini G, and Sbriccoli, P. Lower limb maximal power predicts punching speed in different static and dynamic attacking techniques in karate. J Strength Cond Res 36(5): 1353-1359, 2022-Punching performance of karate can be predicted from lower limb maximal power. However, this relationship was observed only in single actions starting from a static position, thus calling for an investigation on the applicability of this relationship to other conditions. This study aims at investigating whether the relationship between lower limb maximal power and punch speed holds true, not only for single actions, but also for a combination of upper limb techniques in static and dynamic conditions. Ten national-level karate athletes aged 22.3 ± 1.8 years were assessed for maximal power of upper and lower limbs during a bench press and a back squat, and for punching speed during 2 punching techniques (gyaku tsuki [GT]; kizami tsuki and gyaku tsuki [KG]) starting from a static (GTS; KGS) or a dynamic (GTD; KGD) condition. Pearson's correlations were obtained between upper and lower limb maximal relative power and punch speed across tasks and conditions. Significance level was set at p < 0.05. Significant correlations were observed between lower limb maximal relative power and punch speed for all tasks and conditions (r = 0.66-0.80; p = 0.005-0.037). The present results further our knowledge on the relationship between lower limb maximal power and punch speed showing that this relationship holds true also for combinations of punching techniques performed also in dynamic conditions. This information can be useful for karate trainers to predict the punching performance of their athletes using a simple test to assess maximal lower limb power.

Impact of Active Breaks in the Classroom on Mathematical Performance and Attention in Elementary School Children.

BACKGROUND: The increasing need to face the problem of sedentarism, especially in the COVID-19 era, induced teachers and researchers to find new intervention methodologies in school context. Active breaks (ABs) include brief periods of physical activity as a part of the curriculum. This study aimed to investigate the AB acute responses on attentive skills and mathematical performance and attention in a primary school. METHODS: A total of 141 children (aged 9.61 ± 0.82), divided into six classes, participated in this study. Each class was randomly assigned to three groups on the basis of the type of protocol performed during the three ABs scheduled in a school day: fitness (FIT), creativity (CREAT), and control group (CON). At baseline and at the end of interventions, all participants underwent the Stroop Color and Word test (SCWT) and the math test (MATH) to assess the level of attention and mathematical performance, respectively. The degree of enjoyment was evaluated through the modified Physical Activity Enjoyment Scale. RESULTS: The factorial ANOVA showed significant differences between the FIT and CON in MATH test (p = 0.023) and SCWT (p = 0.034). CREAT and FIT groups showed higher degree of enjoyment than the CON (both ps < 0.001). CONCLUSIONS: This study showed a positive acute impact of AB interventions. FIT positively influenced attentive and math performances more than the CREAT, probably due to the correct work/rest ratio and executive rhythm that allowed children to reach a good level of exertion. This report showed that ABs can be a useful and productive activity to be performed between curricular lessons.

Electrophysiological Evidence of Anticipatory Cognitive Control in the Stroop Task.

The Stroop task has been largely used to explore the ability to inhibit the automatic process of reading when reporting the ink color of incongruent color-words. Given the extensive literature regarding the processes involved in task performance, here we aimed at exploring the anticipatory brain activities during the Stroop task using the event-related potential (ERP) method. To accomplish this, eighteen participants performed two different blocks where neutral words were intermixed with congruent and incongruent words, respectively. Results revealed consistent pre-stimulus activity over the frontal, premotor and parietal brain areas. The premotor and the parietal activities were also modulated by the Stroop effect, being more enhanced in the incongruent than in the congruent blocks. Present findings add on the current literature pointing at an unexplored locus of anticipatory cognitive control during task preparation, thus offering a new way to investigate top-down preparatory processes of performance control in the Stroop task.

A Single Session of Whole-Body Electromyostimulation Increases Muscle Strength, Endurance and proNGF in Early Parkinson Patients.

Parkinson's disease (PD) patients lead a sedentary lifestyle, being unable or unwilling to exercise conventionally, due to physical and mental limitations. The aim of this study was to assess the acute effects of a single session of whole-body electromyostimulation (WB-EMS) on the physical performances and serum levels of the neurotrophic factors in PD patients. Ten subjects (aged 72.60 ± 6.82) underwent 20 min of physical activity with superimposed WB-EMS and, after four weeks, the same protocol with no WB-EMS. WB-EMS was conducted with intermittent stimulation, with 4 s WB-EMS/4 s rest, at 85 Hz, 350 µs. A physical fitness assessment and blood samples collection, to evaluate neurotrophic factors' levels (BDNF, FGF21, proNGF, mNGF), were collected before and after the intervention. The RM-ANOVA showed significant improvements in sit-to-stand (p < 0.01), arm curl (p < 0.01), handgrip (p < 0.01) and soda pop test (p < 0.01) after the WB-EMS intervention. Higher proNFG serum levels were observed in the WB-EMS condition compared to the no WB-EMS after 60 min post-intervention (p = 0.0163). The effect of WB-EMS confirmed the electrostimulation ability to modulate the proNGF quantity. The positive impact of the WB-EMS protocol on physical functioning, and eye-hand coordination, makes this intervention a promising strategy to improve motor and non-motor symptoms in PD patients.

Hopping skill in individuals with Down syndrome: A qualitative and quantitative assessment.

INTRODUCTION: Individuals with Down syndrome (DS) show a delayed acquisition of gross motor skills. Among gross motor skills, hopping is a particular form of jumping that can be performed using one leg. Despite its large use during play and physical activity, this skill in adults with DS has not received much attention so far. Here, we aim at investigating hopping skill in adults with DS both from a quantitative and qualitative point of view. METHODS: Center of mass and dominant leg kinematics during hopping over distance were recorded from 24 adult individuals with DS and from 21 typically developed adults (TD) using two inertial measurement units positioned on the posterior aspect of the lower back and on the lateral malleolus of the hopping leg. From linear acceleration and angular velocity signals, hopping frequency (HF), cycle, stance and flight duration (CD, SD, FD), vertical stiffness (KV) and peak to peak linear acceleration and angular velocities about the cranio-caudal, antero-posterior and medio-lateral axes were extracted. A qualitative process assessment of the hopping skill was carried out using the performance criteria of the test for gross motor development (TGMD-3). The extracted parameters were submitted to analysis of covariance, with stature as a covariate to rule-out possible confounding effects. RESULTS: The qualitative assessment highlighted a poorer hopping performance in the DS group compared to the TD group. DS participants showed higher HF and KV, shorter CD, SD, FD and lower angular velocity about the cranio-caudal axis compared to the TD group. Significant correlations between the temporal parameters of the quantitative assessment and the results of the qualitative assessment were observed. DISCUSSION: The poorer motor competence in hopping in individuals with DS compared to TD peers may be related to the shorter flight time and higher vertical stiffness observed in TD peers. The adopted instrumental approach, overcoming the limitations of subjective evaluations, represents a promising opportunity to quantify motor competence in hopping.

Anodal tDCS over the dorsolateral prefrontal cortex reduces Stroop errors. A comparison of different tasks and designs.

In the present work, we evaluated the possibility to induce changes in the inhibitory control through non-invasive excitatory stimulation of the prefrontal cortex (PFC). To this aim, different montages of the transcranial direct current stimulation (tDCS) were adopted in three separate experiments, wherein different cognitive tasks were performed before and after the stimulation. In the first experiment, participants performed a visual Go/no-go task, and a bilateral anodic or sham stimulation was provided over the scalp area corresponding to the inferior frontal gyrus (IFG). In the second experiment, the IFG was stimulated unilaterally over the right hemisphere, and participants performed a Stroop task combined with a concurrent n-back task, which was aimed at overloading PFC activity. Since no behavioral effects of tDCS were observed in both experiments, we conducted a third experiment with different montage and paradigm. Stimulation was provided bilaterally over the dorsolateral PFC (DLPFC) in the context of a classic Stroop task: results indicated that anodal stimulation favored a reduction of errors. Present findings suggest that the bihemispheric stimulation of the DLPFC might be effective to increase inhibition in healthy subjects, and that this effect might be mediated by the implementation of sustained attention, as predicted by the attentional account of the inhibitory control.

Sustained visuospatial attention enhances lateralized anticipatory ERP activity in sensory areas.

The existence of neural correlates of spatial attention is not limited to the reactive stage of stimulus processing: neural activities subtending spatial attention are deployed well ahead of stimulus onset. ERP evidence supporting this proactive (top-down) attentional control is based on trial-by-trial S1-S2 paradigms, where the onset of a directional cue (S1) indicates on which side attention must be directed to respond to an upcoming target stimulus (S2). Crucially, S1 onset trigger both attention and motor preparation, therefore, these paradigms are not ideal to demonstrate the effect of attention at preparatory stage of processing. To isolate top-down anticipatory attention, the present study used a sustained attention paradigm based on a steady cue that indicates the attended side constantly throughout an entire block of trials, without any onset of an attentional cue. The main result consists in the description of the attention effect on the visual negativity (vN) component, a growing neural activity starting before stimulus presentation in extrastriate visual areas. The vN was consistently lateralized in the hemisphere contralateral to the attended side, regardless of the hand to be used. At the opposite, the lateralized motor activity emerged long after, confirming that the hand-selection process followed the spatial attention orientation process. The present study confirms the anticipatory nature of the vN component and corroborate its role in terms of preparatory visuospatial attention.

The Role of Task Complexity on Frontal Event-related Potentials and Evidence in Favour of the Epiphenomenal Interpretation of the Go/No-Go N2 Effect.

It is well established that task complexity can affect both performance and brain processing. Event-related potentials (ERPs) studies have shown modulation of the well-known N2 and P3 components. However, limited information is available on the recently described frontal components associated with processing within the anterior insular cortex. This work aims to shed light on the effect of task complexity on the insular ERP components associated with perceptual (pN1) and sensory-motor awareness (pP1), as well as with stimulus-response mapping (the pP2). Moreover, this comparison of tasks with different complexity was expected to provide a new point of view on the debate on inhibitory or conflict monitoring role of the N2 component. Thirty-two participants were assigned to two groups: one performed an easy response task (with only a target and a non-target stimulus), the other one performed a complex response task (with two target and two non-target stimuli). The task comparison revealed enhanced pP1 and pP2 components but a reduced N2 component in the complex paradigm. These results suggest that task complexity may entail greater processing strength in the anterior insula functions associated with endogenous perceptual processing. Also, findings on the N2 activity provide evidence against both the inhibitory and conflict interpretation of this component, as the N2 amplitude was reduced in the complex task.

Preparatory ERPs in visual, auditory, and somatosensory discriminative motor tasks.

Previous event-related potential (ERP) studies mainly from the present research group showed a novel component, that is, the prefrontal negativity (pN), recorded in visual-motor discriminative tasks during the pre-stimulus phase. This component is concomitant to activity related to motor preparation, that is, the Bereitschaftspotential (BP). The pN component has been reported in experiments based on the visual modality only; for other modalities (acoustic and/or somatosensory) the presence of the pN warrants further investigation. This study represents a first step toward this direction; indeed, we aimed at describing the pN and the BP components in discriminative response tasks (DRTs) for three sensory modalities. In experiment 1 ERPs were recorded in 29 adults in visual and auditory DRT; an additional group of 15 adults participated to a somatosensory DRT (experiment 2). In line with previous results both the pN and the BP were clearly detectable in the visual modality. In the auditory modality the prefrontal pN was not detectable directly; however, the pN could be derived by subtraction of separate EEG traces recorded in a "passive" version of the same auditory task, in which motor responses were not required. In the somatosensory modality both the pN and the BP were detectable, although with lower amplitudes with respect to other two sensory modalities. Overall, regardless of the sensory modality, anticipatory task-related pN and BP components could be detected (or derived by subtraction) over both the prefrontal and motor cortices. These results support the view that anticipatory processes share common components among sensory modalities.

Cerebral mechanisms of hypnotic hypoesthesia. An ERP investigation on the expectancy stage of perception.

The present study aims at identifying reliable markers of neural preparatory processes during hypnosis. To this goal, we recorded the electroencephalographic activity of 23 volunteers regardless of their hypnotizability score. Somatosensory evoked potentials (SEPs) were elicited while participants received non-painful electrical stimuli on the left median nerve in the conditions of relaxation and hypnosis with suggestions of reduced sensation. SEPs analysis was focused on the pre-stimulus activity and revealed two main components: the prefrontal negativity (pN) and the somatosensory negativity (sN) over the frontal and parietal areas of the scalp, respectively. Results showed reduced amplitudes for both components under hypnosis, mostly for the pN, suggesting a change of top-down control of parietal and prefrontal areas. Furthermore, the sLORETA source imaging showed a deactivation of the lateral and anterior portions of the prefrontal cortex (PFC) during the hypnotic state. The present study highlights the downregulation of the PFC as a core aspect of the adopted hypnotic task and confirms the ability of hypnosis to modulate the activity of frontal executive functions. Further, since the majority of participants fell into the medium range of hypnotizability, the present findings could reflect the hypnosis effects in most of the population.

The role of cognitive reserve on prefrontal and premotor cortical activity in visuo-motor response tasks in healthy old adults.

Cognitive reserve (CR) is a key factor to mitigate the cognitive decline during the aging process. Here, we used event-related potentials to target the preparatory brain activities associated with different levels of CR during visuo-motor simple response tasks (SRTs) and discriminative response tasks (DRTs). EEG was recorded from 28 healthy old (Age: 72.2 ± 4.7 years) and 14 young (Age: 22.2 ± 2.4 years) individuals during an SRT and a DRT. Depending on the CR median score, old participants were divided into either a high (High-CR) or a low CR (Low-CR) group. Behavioral performance and electrophysiological data were compared across the 3 groups. Compared with the Low-CR, the High-CR group showed larger prestimulus prefrontal (prefrontal negativity) and premotor activity (Bereitschaftspotential-BP), in the SRT, and increased premotor readiness (BP), in the DRT. The High-CR was faster and more accurate than the Low-CR group in the DRT and SRT, respectively. The High-CR group revealed enhanced brain preparatory activities that, paralleled to their behavioral performance, might reflect neural compensation and maintenance effects possibly counteracting the age-related decline in cognitive functioning.