Search results for "brain activity"

Action expertise reduces brain activity for audiovisual matching actions: An fMRI study with expert drummers

2011

When we observe someone perform a familiar action, we can usually predict what kind of sound that action will produce. Musical actions are over-experienced by musicians and not by non-musicians, and thus offer a unique way to examine how action expertise affects brain processes when the predictability of the produced sound is manipulated. We used functional magnetic resonance imaging to scan 11 drummers and 11 age- and gender-matched novices who made judgments on point-light drumming movements presented with sound. In Experiment 1, sound was synchronized or desynchronized with drumming strikes, while in Experiment 2 sound was always synchronized, but the natural covariation between sound in…

A multi-sphere particle numerical model for non-invasive investigations of neuronal human brain activity

2013

In this paper, a multi-sphere particle method is built- up in order to estimate the solution of the Poisson's equation with Neumann boundary conditions describing the neuronal human brain activity. The partial difierential equations governing the relationships between neural current sources and the data produced by neuroimaging technique, are able to compute the scalp potential and magnetic fleld distributions generated by the neural activity. A numerical approach is proposed with current dipoles as current sources and going on in the computation by avoiding the mesh construction. The current dipoles are into an homogeneous spherical domain modeling the head and the computational approach i…

PCA-based source-space contrast maps reveal psychologically meaningful individual differences in continuous MEG activity

2019

AbstractWithin the field of neuroimaging, there has been an increasing trend towards studying brain activity in naturalistic conditions, and it is possible to robustly estimate networks of on-going oscillatory activity in the brain. However, not many studies have focused on differences between individuals in on-going brain activity that would be associable to psychological or behavioral characteristics. Existing standard methods can perform well at single-participant level, but generalizing the methodology across many participants is challenging due to individual differences of brains. As an example of a clinically relevant, naturalistic condition we consider here mindfulness. Trait mindful…

Emotional Responses During Music Listening

2014

The aim of this chapter is to summarize and present the current knowledge about music and emotion from a multi-disciplinary perspective. Existing emotional models and their adequacy in describing emotional responses to music are described and discussed in different applications. The underlying emotion induction mechanisms beside cognitive appraisal are presented, and their implications on the field are analyzed. Musical characteristics such as tempo, mode, loudness, and so on are inherent properties of the musical structure and have been shown to influence the emotional states during music listening. The role of each individual parameter on emotional responses as well as their interactions …

Comparison of cerebral cortex activation induced by tactile stimulation between natural teeth and implants

2020

Background The purpose of this study was to assess the cortical-level sensory differences between natural teeth with a periodontal membrane and dental implants. Material and methods We used functional near-infrared spectroscopy (fNIRS) to measure brain activity in the cerebral cortex of 12 patients who had both natural teeth and dental implants in the lower molar region. Painless vibratory tactile stimulation was performed on both the natural teeth and the dental implants. Results Activation was seen in the somatosensory cortex during stimulation of both natural teeth and dental implants. A comparison of cortical activation showed no significant differences between natural teeth and dental …

Pre- and post-ictal brain activity characterization using combined source decomposition and connectivity estimation in epileptic children

2019

In this research, the study of functional connectivity between sources of electroencephalogram (EEG) activity assessed for different classes (well before seizure, preictal and post-ictal) was performed. EEG recordings were acquired from 12 subjects with focal epilepsy. Then, ten common spatial patterns (CSP) were obtained for EEG segments describing 95% of Riemannian distance between pairs of classes, followed by estimation of multivariate autoregressive (MVAR) models’ coefficients. The MVAR models were further used to extract coherence as a functional connectivity measures. Our results show that the coherence between CSP sources differs between baseline and pre-ictal segments: it has the l…

2013

Neurovascular coupling (NVC) in the adult central nervous system (CNS) is a mechanism that provides regions of the brain with more oxygen and glucose upon increased levels of neural activation. Hemodynamic changes that go along with neural activation evoke a blood oxygen level-dependent (BOLD) signal in functional magnetic resonance imaging (fMRI) that can be used to study brain activity non-invasively. A correct correlation of the BOLD signal to neural activity is pivotal to understand this signal in neuronal development, health and disease. However, the function of NVC during development is largely unknown. The rodent whisker-to-barrel cortex is an experimentally well established model to…

Mapping Brain Response to Social Stress in Rodents With c-fos Expression: A Review

2002

Social defeat is an important event in the life of many animals, and forms part of the process of social control. Adapting to social defeat is thus an intrinsic part of social "homeostasis", and mal-adaptation may have pathological sequelae. Experimental models of social defeat (e.g. inter-male aggression) have existed for many years. However, very few studies have investigated the changes in brain activity in male animals exposed to the social stress of being defeated by another conspecific male, and in all these studies the expression of the immediate-early gene c-fos has been used as the marker of neuronal activity. In general, the results obtained inform that many areas of the brain, es…

Online Closed-Loop Real-Time tES-fMRI for Brain Modulation: Feasibility, Noise/Safety and Pilot Study

2021

AbstractRecent studies suggest that transcranial electrical stimulation (tES) can be performed during functional magnetic resonance imaging (fMRI). The novel approach of using concurrent tES-fMRI to modulate and measure targeted brain activity/connectivity may provide unique insights into the causal interactions between the brain neural responses and psychiatric/neurologic signs and symptoms, and importantly, guide the development of new treatments. However, tES stimulation parameters to optimally influence the underlying brain activity in health and disorder may vary with respect to phase, frequency, intensity and electrode’s montage. Here, we delineate how a closed-loop tES-fMRI study of …

S153. WHERE IS THE ABNORMAL BRAIN ACTIVITY IN FIRST EPISODE PSYCHOSIS?

2018

Abstract Background Recent review about functional magnetic resonance imaging (fMRI) in first episode psychosis (FEP) concluded that there is an abnormal connectivity involving the frontal temporal pathway similar to found in chronic schizophrenia (Mwansisya et al., 2017). Besides, thalamic circuits were also altered in chronic schizophrenia patients (Li et al., 2017). The present work gives a wider review of studies using functional magnetic resonance imaging techniques (fMRI) on first-episode psychotic patients, specifically focus on the main areas involved. Methods The review was made in accordance with the PRISMA guidelines (Moher et al., 2009). For each study, the following factors wer…