Age-related changes in cortical connectivity influence the neuromodulatory effects of transcranial electrical stimulation.

Transcranial electrical stimulation (tES) is a potentially viable tool for boosting cognitive performance in aging. However, most knowledge on tES effects is based on studies involving young adults. Here, we applied tES (transcranial random noise stimulation [tRNS] as an effective stimulation and anodal transcranial direct current stimulation [atDCS] as a "control" stimulation) to the visual cortex during visual perceptual learning (VPL) in healthy young and older individuals.

The mismatch negativity as an index of cognitive decline for the early detection of Alzheimer's disease.

Evidence suggests that Alzheimer's disease (AD) is part of a continuum, characterized by long preclinical phases before the onset of clinical symptoms. In several cases, this continuum starts with a syndrome, defined as mild cognitive impairment (MCI), in which daily activities are preserved despite the presence of cognitive decline. The possibility of having a reliable and sensitive neurophysiological marker that can be used for early detection of AD is extremely valuable because of the incidence of this type of dementia.

Is neural hyperpolarization by cathodal stimulation always detrimental at the behavioral level?

Cathodal transcranial direct current stimulation (c-tDCS) is usually considered an inhibitory stimulation. From a physiological perspective, c-tDCS induces hyperpolarization at the neural level. However, from a behavioral perspective, c-tDCS application does not always result in performance deterioration.

Vegetative versus minimally conscious states: a study using TMS-EEG, sensory and event-related potentials.

Differential diagnoses between vegetative and minimally conscious states (VS and MCS, respectively) are frequently incorrect. Hence, further research is necessary to improve the diagnostic accuracy at the bedside. The main neuropathological feature of VS is the diffuse damage of cortical and subcortical connections.

The role of timing in the induction of neuromodulation in perceptual learning by transcranial electric stimulation.

Background: Transcranial electric stimulation (tES) protocols are able to induce neuromodulation, offering important insights to focus and constrain theories of the relationship between brain and behavior. Previous studies have shown that different types of tES (i.e.

Random noise stimulation improves neuroplasticity in perceptual learning.

Perceptual learning is considered a manifestation of neural plasticity in the human brain. We investigated brain plasticity mechanisms in a learning task using noninvasive transcranial electrical stimulation (tES). We hypothesized that different types of tES would have varying actions on the nervous system, which would result in different efficacies of neural plasticity modulation.

The neural basis of the Enigma illusion: a transcranial magnetic stimulation study.

The aim of this study was to test the role of the visual primary (V1) and the middle temporal area (V5/MT) in the illusory motion perception evoked by the Enigma figure. The Enigma figure induces a visual illusion that is characterized by apparent rotatory motion in the presence of a static figure. By means of repetitive transcranial magnetic stimulation (rTMS) we show that V5/MT is causally linked to the illusory perception of motion.

Sensory memory during physiological aging indexed by mismatch negativity (MMN).

Physiological aging affects early sensory-perceptual processes. The aim of this experiment was to evaluate changes in auditory sensory memory in physiological aging using the Mismatch Negativity (MMN) paradigm as index. The MMN is a marker recorded through the electroencephalogram and is used to evaluate the integrity of the memory system.

Heritability of intracortical inhibition and facilitation.

The present twin study investigates heritability of motor cortex excitability, measured by the paired pulse transcranial magnetic stimulation technique. Specifically, intracortical facilitation (ICF) and inhibition (ICI) and corticospinal excitability were tested in monozygotic (MZ), dizygotic (DZ), and unrelated pairs (UP). Robust ICF and ICI effects were found, with a higher similarity of MZ than DZ and UP pairs.

Cortical plasticity induced by transcranial magnetic stimulation during wakefulness affects electroencephalogram activity during sleep.

Background: Sleep electroencephalogram (EEG) brain oscillations in the low-frequency range show local signs of homeostatic regulation after learning. Such increases and decreases of slow wave activity are limited to the cortical regions involved in specific task performance during wakefulness. Here, we test the hypothesis that reorganization of motor cortex produced by long-term potentiation (LTP) affects EEG activity of this brain area during subsequent sleep.