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Action observation is known to enhance sensorimotor system activation, and such effect has been linked to neural priming and response facilitation mechanisms. This facilitation effect, however, has been primarily studied by focusing on high-level motor proficiency, whereas evidence on the effect of observing poorly performed actions is still lacking. We then devised a study to investigate neural correlates of the observation of suboptimal motor acts as mirrored by corticospinal activation (via transcranial magnetic stimulation (TMS), Experiment 1) and by modulation of cortical oscillatory activity (via electroencephalography (EEG), Experiment 2). 40 participants were presented with four randomly reiterated videos. Videos depicted a healthy confederate, a minimally impaired multiple sclerosis (MS) patient, a mildly impaired MS patient, or a confederate trying to simulate mild motor difficulties performing a test concerning fine motor abilities. In Experiment 1 we analyzed TMS-induced motor-evoked potentials during the observation of videos. In Experiment 2 EEG data were analyzed in the frequency-domain. Analyses highlighted both increased corticospinal excitability and desynchronized alpha-beta oscillations during the observation of poorly performed motor acts performed by the mildly impaired MS patient. Further, we observed gradually increasing beta activity across videos reiterations, specifically for the minimally impaired patient's video. Reported findings corroborate the hypotheses that the action-observation network and the motor system might be involved in processes evoked in the attempt to understand and predict observed actions which do not belong to the onlookers' motor repertoire, reflecting in an increased sensorimotor activity., (Copyright © 2018 IBRO. Published by Elsevier Ltd. All rights reserved.)

Recent studies demonstrated that beta oscillations are elicited during cognitive processes. To investigate their potential as electrophysiological markers of amnestic mild cognitive impairment (aMCI), we recorded beta EEG activity during resting and during an omitted tone task in patients and healthy elderly. Thirty participants were enrolled (15 patients, 15 healthy controls). In particular, we investigated event-related spectral perturbation and intertrial coherence indices. Analyses showed that ( a) healthy elderly presented greater beta power at rest than patients with aMCI patients; ( b) during the task, healthy elderly were more accurate than aMCI patients and presented greater beta power than aMCI patients; ( c) both groups showed qualitatively similar spectral perturbation responses during the task, but different spatiotemporal response patterns; and ( d) aMCI patients presented greater beta phase locking than healthy elderly during the task. Results indicate that beta activity in healthy elderly differs from that of patients with aMCI. Furthermore, the analysis of task-related EEG activity extends evidences obtained during resting and suggests that during the prodromal phase of Alzheimer's disease there is a reduced efficiency in information exchange by large-scale neural networks. The study for the first time shows the potential of task-related beta responses as early markers of aMCI impairments.

Executive functions tend to decrease their efficiency during the physiological aging process. Nevertheless, cognitive and brain reserves are thought to act as protective factors against cognitive decline. Then, the re-activation of cognitive and neural networks by means of non-invasive brain stimulation (NIBS) may help in maintaining those reserves and improving functional profiles. The present research investigates the effect of prefrontal NIBS in empowering executive functions and electrophysiological attention responses in healthy elderly people. Twenty-two volunteers have been assigned to a control or NIBS group. The NIBS protocol (anodal transcranial direct current stimulation) lasted eight weeks (three sessions per week), with twice-weekly administration of tasks tapping on executive functions. Participants’ cognitive and electrophysiological profiles were assessed at the beginning, after the treatment period, and after six months. Data analyses showed interesting positive modulations in post-intervention performances for the NIBS group – specifically in tests tapping on executive functions and automatic electrophysiological attention responses. Besides, participants’ subjective reports of improvement in everyday functioning, behavioral and electrophysiological evidences suggest that a moderately intensive NIBS protocol might help in empowering specific cognitive functions even in healthy aging. [ABSTRACT FROM AUTHOR]

Objective While the contribution of non-invasive brain stimulation (NIBS) in preventing cognitive decline is looked with interest, NIBS empowerment of healthy elderly is understudied. The present research aims at investigating the effect of prefrontal transcranial direct current stimulation (tDCS) in empowering executive functions and electrophysiologic attention responses in healthy aging. Methods 22 participants have been assigned to the intervention or control group and underwent a complex assessment at T0 and at T1 – after three months. The anodal tDCS protocol lasted eight weeks (three sessions per week), with twice-weekly administration of tasks tapping on executive functions. A complete set of standardized cognitive tests and an electroencephalographic recording during a challenging computerized attention task have been integrated in the assessment protocol. Results T0–T1 comparisons highlighted a significant increase in post-intervention performances for the tDCS group. Specifically, tests tapping on executive functions and automatic electrophysiologic attention responses showed positive modulations. Conclusions The consistency of behavioral and electrophysiologic findings suggests that a moderately intensive NIBS protocol might mediate the empowerment of specific cognitive functions even in healthy aging people. Key message Physiological aging is a dynamic process, where non-invasive interventions may capitalize on resources of the cognitive reserve to help improving cognitive functioning. [ABSTRACT FROM AUTHOR]