Rhythmic sensory stimulation as a noninvasive tool to study plasticity mechanisms in human episodic memory

In recent years, research in animals has increasingly focused on understanding the role of precise neural timing in inducing synaptic plasticity (the strengthening or weakening of synaptic connections). Human episodic memory is thought to depend on such plasticity. Animal studies have provided valuable insights into mechanisms such as spike-timing-dependent plasticity and theta-phase-dependent plasticity, highlighting the importance of coordinated timing between neural inputs for synaptic changes to occur. Building upon these findings, recent studies employing rhythmic sensory stimulation and electromagnetic stimulation in humans have attempted to link these mechanisms to episodic memory formation. These studies have revealed that memory consolidation relies on the precise co-ordination of timing between neural inputs, particularly in the gamma and theta frequency ranges. This body of work represents a crucial bridge between our understanding of cellular-level mechanisms in animal models and the complex processes underlying human memory

The past, present, and future of the Brain Imaging Data Structure (BIDS)

The Brain Imaging Data Structure (BIDS) is a community-driven standard for the organization of data and metadata from a growing range of neuroscience modalities. This paper is meant as a history of how the standard has developed and grown over time. We outline the principles behind the project, the mechanisms by which it has been extended, and some of the challenges being addressed as it evolves. We also discuss the lessons learned through the project, with the aim of enabling researchers in other domains to learn from the success of BIDS

A TMS/EEG protocol for the causal assessment of the functions of the oscillatory brain rhythms in perceptual and cognitive processes

The combined use of transcranial magnetic stimulation (TMS), electroencephalogram (EEG), and behavioral performance allows investigation of causal relationships between neural markers and their functional relevance across a number of perceptual and cognitive processes. Here, we present a protocol for combining and applying these techniques on human subjects. We describe correlation approach and causal approach to disentangle the role of different oscillatory parameters, namely alpha frequency and amplitude that control for accuracy and metacognitive abilities, respectively, in a visual detection task. For complete details on the use and execution of this protocol, please refer to Di Gregorio et al. (2022)

Investigating visuo-tactile mirror properties in Borderline Personality Disorder: a TMS-EEG study

The present work aims at investigating the TaMS in BPD and its relationship with empathic abilities. The study will involve BPD patients and healthy controls (HCs). In both groups we will collect measures of empathic abilities, evaluated by means of self-report questionnaires, performance in a behavioral task involving TaMS activity, and connectivity indexes, obtained by TMS-EEG recording

Effect of TMS current direction and pulse waveform on cortico-cortical connectivity: A registered report TMS-EEG study - PILOT DATA and STAGE 1 RR

Transcranial magnetic stimulation (TMS)-electroencephalography coregistration (TMS-EEG) is a promising technique to measure effective connectivity, i.e., the directed transmission of physiological signals along cortico-cortical tracts. Indeed, the activation induced by the TMS pulse in the target region travels to distant connected areas along white matter tracts, generating TMS-evoked potentials (TEPs). A crucial point to be addressed for developing connectivity biomarkers from TEPs is how they are affected by changes in stimulation parameters, such as pulse waveform and the direction of the induced current. Different stimulation parameters across studies may impact latency or amplitude of responses, contributing to the general variability in TMS-EEG findings. To date, the impact of TMS parameters on responses generated in cerebral cortico-cortical pathways has been poorly investigated. To deepen this investigation, we will use as an operative model the M1-P15, an early TEP component reflecting the interhemispheric inhibition of motor areas contralateral to TMS via the corpus callosum. Assuming that the M1-P15 can be recorded regardless of TMS parameters, namely, the direction of the induced current in the brain – anterior-posterior, posterior-anterior, latero-medial – and the TMS pulse waveform – monophasic, biphasic, we will investigate whether these modulations influence M1-P15 latency and amplitude. We will also test M1-P15 reproducibility across our experimental conditions using the concordance and intraclass correlation coefficients. Finally, resting motor threshold and motor-evoked potentials will be collected in every experimental condition as control variables, allowing us to deepen the possible relationship between cortico-spinal and cortico-cortical pathways that different stimulator parameters may activate within the motor system

Data_Sheet_1_M1-P15 as a cortical marker for transcallosal inhibition: A preregistered TMS-EEG study.pdf

In a recently published study combining transcranial magnetic stimulation and electroencephalography (TMS-EEG), an early component of TMS-evoked potentials (TEPs), i.e., M1-P15, was proposed as a measure of transcallosal inhibition between motor cortices. Given that early TEPs are known to be highly variable, further evidence is needed before M1-P15 can be considered a reliable index of effective connectivity. Here, we conceived a new preregistered TMS-EEG study with two aims. The first aim was validating the M1-P15 as a cortical index of transcallosal inhibition by replicating previous findings on its relationship with the ipsilateral silent period (iSP) and with performance in bimanual coordination. The second aim was inducing a task-dependent modulation of transcallosal inhibition. A new sample of 32 healthy right-handed participants underwent behavioral motor tasks and TMS-EEG recording, in which left and right M1 were stimulated both during bimanual tasks and during an iSP paradigm. Hypotheses and methods were preregistered before data collection. Results show a replication of our previous findings on the positive relationship between M1-P15 amplitude and the iSP normalized area. Differently, the relationship between M1-P15 latency and bimanual coordination was not confirmed. Finally, M1-P15 amplitude was modulated by the characteristics of the bimanual task the participants were performing, and not by the contralateral hand activity during the iSP paradigm. In sum, the present results corroborate our previous findings in validating the M1-P15 as a cortical marker of transcallosal inhibition and provide novel evidence of its task-dependent modulation. Importantly, we demonstrate the feasibility of preregistration in the TMS-EEG field to increase methodological rigor and transparency.</p

Tuning alpha rhythms to shape conscious visual perception

It is commonly held that what we see and what we believe we see are overlapping phenomena. However, dissociations between sensory events and their subjective interpretation occur in the general population and in clinical disorders, raising the question as to whether perceptual accuracy and its subjective interpretation represent mechanistically dissociable events. Here, we uncover the role that alpha oscillations play in shaping these two indices of human conscious experience. We used electroencephalography (EEG) to measure occipital alpha oscillations during a visual detection task, which were then entrained using rhythmic-TMS. We found that controlling prestimulus alpha frequency by rhythmic-TMS modulated perceptual accuracy, but not subjective confidence in it, whereas controlling poststimulus (but not prestimulus) alpha amplitude modulated how well subjective confidence judgments can distinguish between correct and incorrect decision, but not accuracy. These findings provide the first causal evidence of a double dissociation between alpha speed and alpha amplitude, linking alpha frequency to spatiotemporal sampling resources and alpha amplitude to the internal, subjective representation and interpretation of sensory events

Defecography: a still needful exam for evaluation of pelvic floor diseases

The aim of this discussion is to describe what is a defecography, how we have to perform it, what can we see and to present the main physio-pathological illnesses of pelvic floor and anorectal region that can be studied with this method and its advantages over other screening techniques. Defecography is a contrastographic radiological examination that highlights structural and functional pelvic floor diseases. Upon preliminary ileum-colic opacification giving to patient radiopaque contrast, are first acquired static images (at rest, in maximum voluntary contraction of the pelvic muscles, while straining) and secondarily dynamic sequences (during evacuation), allowing a complete evaluation of the functionality of the anorectal region and the pelvic floor. Defecography is an easy procedure to perform widely available, and economic, carried out in conditions where the patient experiences symptoms, the most realistic possible. It can be still considered reliable technology and first choice in many patients in whom the clinic alone is not sufficient and it is not possible or necessary to perform a study with MRI

Angiogenic impairment of the vascular endothelium: a novel mechanism and potential therapeutic target in muscular dystrophy

Dystrophin, the missing or defective protein in Duchenne muscular dystrophy, is expressed not only in muscle cells but also in vascular endothelial cells (ECs). In this study, we assessed the effects of dystrophin deficiency on the angiogenic capacities of ECs