Behavioral and neurophysiological modulation of error-related processes

The term brain modulation refers to a wide range of interventions that allow modifying the central nervous system. The general purpose of this dissertation will regard the investigation and modulation of error-related processes through the use of behavioral interventions and noninvasive brain stimulation (NIBS). In order to accomplish this aim, three studies were conducted. Study 1 investigated the motivation-cognition interaction. In particular, this study aimed to increase error awareness by using rewards in a group of healthy older adults, compared to younger adults. Results showed a reduction of error awareness when participants were rewarded, both older and younger adults. This detrimental effect of rewards suggests more attention in planning motivational interventions with the aim to modulate error awareness. Study 2 aimed to investigate the neural bases of error awareness and modulate error awareness by using on-line transcranial magnetic stimulation (TMS). Results revealed an implication of the dorsolateral prefrontal cortex (DLPFC) in error awareness. However, this modulation was specifically induced by a single-pulse TMS paradigm, compared to a paired-pulse TMS paradigm that did not produce a modulation of the process. These results highlight how subtle variations of the TMS paradigm can differently affect error awareness. Study 3 investigated the behavioral and neurophysiological modulation of error-related processes induced by a low-frequency repetitive TMS paradigm. Results showed a reduction of the error positivity (Pe), an electrophysiological component associated with error awareness, only when the left DLPFC was stimulated, compared to the homologous right DLPFC and the Vertex. This result contributes to provide new knowledge about error-related processes, in particular about the neural bases of the Pe. Finally, a critical review of these studies will provide general insights for the design of future modulatory interventions

"Delirium Day": A nationwide point prevalence study of delirium in older hospitalized patients using an easy standardized diagnostic tool

Background: To date, delirium prevalence in adult acute hospital populations has been estimated generally from pooled findings of single-center studies and/or among specific patient populations. Furthermore, the number of participants in these studies has not exceeded a few hundred. To overcome these limitations, we have determined, in a multicenter study, the prevalence of delirium over a single day among a large population of patients admitted to acute and rehabilitation hospital wards in Italy. Methods: This is a point prevalence study (called "Delirium Day") including 1867 older patients (aged 65 years or more) across 108 acute and 12 rehabilitation wards in Italian hospitals. Delirium was assessed on the same day in all patients using the 4AT, a validated and briefly administered tool which does not require training. We also collected data regarding motoric subtypes of delirium, functional and nutritional status, dementia, comorbidity, medications, feeding tubes, peripheral venous and urinary catheters, and physical restraints. Results: The mean sample age was 82.0 \ub1 7.5 years (58 % female). Overall, 429 patients (22.9 %) had delirium. Hypoactive was the commonest subtype (132/344 patients, 38.5 %), followed by mixed, hyperactive, and nonmotoric delirium. The prevalence was highest in Neurology (28.5 %) and Geriatrics (24.7 %), lowest in Rehabilitation (14.0 %), and intermediate in Orthopedic (20.6 %) and Internal Medicine wards (21.4 %). In a multivariable logistic regression, age (odds ratio [OR] 1.03, 95 % confidence interval [CI] 1.01-1.05), Activities of Daily Living dependence (OR 1.19, 95 % CI 1.12-1.27), dementia (OR 3.25, 95 % CI 2.41-4.38), malnutrition (OR 2.01, 95 % CI 1.29-3.14), and use of antipsychotics (OR 2.03, 95 % CI 1.45-2.82), feeding tubes (OR 2.51, 95 % CI 1.11-5.66), peripheral venous catheters (OR 1.41, 95 % CI 1.06-1.87), urinary catheters (OR 1.73, 95 % CI 1.30-2.29), and physical restraints (OR 1.84, 95 % CI 1.40-2.40) were associated with delirium. Admission to Neurology wards was also associated with delirium (OR 2.00, 95 % CI 1.29-3.14), while admission to other settings was not. Conclusions: Delirium occurred in more than one out of five patients in acute and rehabilitation hospital wards. Prevalence was highest in Neurology and lowest in Rehabilitation divisions. The "Delirium Day" project might become a useful method to assess delirium across hospital settings and a benchmarking platform for future surveys

Behavioral and neurophysiological modulation of error-related processes

The term brain modulation refers to a wide range of interventions that allow modifying the central nervous system. The general purpose of this dissertation will regard the investigation and modulation of error-related processes through the use of behavioral interventions and noninvasive brain stimulation (NIBS). In order to accomplish this aim, three studies were conducted. Study 1 investigated the motivation-cognition interaction. In particular, this study aimed to increase error awareness by using rewards in a group of healthy older adults, compared to younger adults. Results showed a reduction of error awareness when participants were rewarded, both older and younger adults. This detrimental effect of rewards suggests more attention in planning motivational interventions with the aim to modulate error awareness. Study 2 aimed to investigate the neural bases of error awareness and modulate error awareness by using on-line transcranial magnetic stimulation (TMS). Results revealed an implication of the dorsolateral prefrontal cortex (DLPFC) in error awareness. However, this modulation was specifically induced by a single-pulse TMS paradigm, compared to a paired-pulse TMS paradigm that did not produce a modulation of the process. These results highlight how subtle variations of the TMS paradigm can differently affect error awareness. Study 3 investigated the behavioral and neurophysiological modulation of error-related processes induced by a low-frequency repetitive TMS paradigm. Results showed a reduction of the error positivity (Pe), an electrophysiological component associated with error awareness, only when the left DLPFC was stimulated, compared to the homologous right DLPFC and the Vertex. This result contributes to provide new knowledge about error-related processes, in particular about the neural bases of the Pe. Finally, a critical review of these studies will provide general insights for the design of future modulatory interventions

Intra-individual variability of error awareness and post-error slowing in three different age-groups

none3nononeMasina, Fabio*; Di Rosa, Elisa; Mapelli, DanielaMasina, Fabio; Di Rosa, Elisa; Mapelli, Daniel

Repetitive TMS over the left dorsolateral prefrontal cortex modulates the error positivity: An ERP study.

Error processing is a critical step towards an efficient adaptation of our behavior to achieve a goal. Little research has been devoted to investigate the contribution of the dorsolateral prefrontal cortex (DLPFC) in supporting error processing. In this study, the causal relationship of the DLPFC in error commission was examined by means of a repetitive transcranial magnetic stimulation protocol (rTMS). Specifically, the effects of an inhibitory protocol were assessed by examining the electroencephalographic signal recorded during the execution of a Go/No-Go task. To this aim, a group of 15 healthy young participants performed a three-session study. At each session, either the right DLPFC, the left DLPFC, or the Vertex (control site) were stimulated, for 20\u202fmin at 1\u202fHz. Immediately after the stimulation, participants performed the task. Although no behavioral effects of rTMS emerged, the analysis of event-related electric potentials (ERPs) revealed that the amplitude of a positive potential evoked by error commission, the error positivity (Pe), was reduced after the stimulation of the left DLPFC. On the contrary, the earlier error-related negativity component (ERN) was not affected. These results revealed that the left DLPFC intervenes at later stages of error-related processes. We could speculate that its role is specifically linked to error awareness

Dataset related to article "State-dependent tDCS modulation of the somatomotor network: A MEG study"

Il dataset può essere visualizzato mediante il software R Studio, importandolo come file di testo. Il dataset è così suddiviso: colonna 1: nessuna informazione colonna 2: region of interest colonna 3: power del segnale EEG colonna 4: ID del partecipante (tutti soggetti sani) colonna 5: momento in cui è avvenuta la registrazione EEG (prima vs. dopo la stimolazione) colonna 6: condizione di stimolazione tDCS (reale vs. sham/placebo) colonna 7: frequenza del segnale EEG colonna 8-12: info sul network

Intra-Individual Variability of Error Awareness and Post-error Slowing in Three Different Age-Groups

Background: Error awareness (EA) and post-error slowing (PES) are two crucial components of an adequate performance monitoring because, respectively, they allow being aware of an error and triggering performance adjustments following unexpected events.Objective: The purpose of the present study was to investigate the ontogenetic trajectories of EA and PES, as well as to examine how EA and PES interact with each other.Methods: The performance of three groups of participants (children, younger, and older adults) in a modified version of the Error Awareness task (EAT; Hester et al., 2005) was compared. In particular, in this study not only variations of the average performance were examined, but also intra-individual variability (IIV), considered in terms of variations of SD and ex-Gaussian parameters (mu, sigma, and tau).Results: Two distinct ontogenetic trajectories of EA and PES were observed. Regarding EA, we observe a U-shaped curve that describes an increase of the process from childhood to early adulthood and a progressive reduction advancing age in late adulthood. Furthermore, a greater IIV in older adults indicated a susceptibility of EA to the aging process. The ontogenetic trajectory of PES seems substantially different from the trajectory that describes EA since in PES we do not observe age-related differences.Conclusion: These results suggest that EA and PES are two independent processes. Furthermore, it appears that EA and PES are differently prone to short-term fluctuations in performance across the lifespan. While EA presents an increase in IIV in aging, PES seems to be immune to these changes