Modulation Of Neural Processing Research Articles

Hemispheric Differences of 1 Hz rTMS over Motor and Premotor Cortex in Modulation of Neural Processing and Hand Function.

Non-invasive brain stimulation can modulate both neural processing and behavioral performance. Its effects may be influenced by the stimulated area and hemisphere. In this study (EC no. 09083), repetitive transcranial magnetic stimulation (rTMS) was applied to the primary motor cortex (M1) or dorsal premotor cortex (dPMC) of either the right or left hemisphere, while evaluating cortical neurophysiology and hand function. Fifteen healthy subjects participated in this placebo-controlled crossover study. Four sessions of real 1 Hz rTMS (110% of rMT, 900 pulses) over (i) left M1, (ii) right M1, (iii) left dPMC, (iv) right dPMC, and one session of (v) placebo 1 Hz rTMS (0% of rMT, 900 pulses) over the left M1 were applied in randomized order. Motor function of both hands (Jebsen-Taylor Hand Function Test (JTHFT)) and neural processing within both hemispheres (motor evoked potentials (MEPs), cortical silent period (CSP), and ipsilateral silent period (ISP)) were evaluated prior and after each intervention session. A lengthening of CSP and ISP durations within the right hemisphere was induced by 1 Hz rTMS over both areas and hemispheres. No such intervention-induced neurophysiological changes were detected within the left hemisphere. Regarding JTHFT and MEP, no intervention-induced changes ensued. Changes of hand function correlated with neurophysiological changes within both hemispheres, more often for the left than the right hand. Effects of 1 Hz rTMS can be better captured by neurophysiological than behavioral measures. Hemispheric differences need to be considered for this intervention.

Neurorights between ethical and legal implications

Advances in neuroimaging and brain-machine interfacing (BMI) increasingly enable the large-scale collection and further processing of neural data as well as the modulation of neural processes. In parallel, progresses in artificial intelligence (AI), especially in machine learning, create new possibilities for decoding and analysing neural data for various purposes including health monitoring, screening for disease, cognitive enhancement, and device control. This contribution discusses some major ethical, technical, and regulatory issues associated with neural data analytics and delineates a roadmap for responsible innovation in this sector. Moreover, this paper review a variety of themes including mind reading, mental privacy, cybersecurity in commercial BMI, and issues of neurotechnology governance. Finally, a framework for responsible innovation and governance is presented.

Friend versus foe: Neural correlates of prosocial decisions for liked and disliked peers

Although the majority of our social interactions are with people we know, few studies have investigated the neural correlates of sharing valuable resources with familiar others. Using an ecologically valid research paradigm, this functional magnetic resonance imaging study examined the neural correlates of prosocial and selfish behavior in interactions with real-life friends and disliked peers in young adults. Participants (N = 27) distributed coins between themselves and another person, where they could make selfish choices that maximized their own gains or prosocial choices that maximized outcomes of the other. Participants were more prosocial toward friends and more selfish toward disliked peers. Individual prosociality levels toward friends were associated negatively with supplementary motor area and anterior insula activity. Further preliminary analyses showed that prosocial decisions involving friends were associated with heightened activity in the bilateral posterior temporoparietal junction, and selfish decisions involving disliked peers were associated with heightened superior temporal sulcus activity, which are brain regions consistently shown to be involved in mentalizing and perspective taking in prior studies. Further, activation of the putamen was observed during prosocial choices involving friends and selfish choices involving disliked peers. These findings provide insights into the modulation of neural processes that underlie prosocial behavior as a function of a positive or negative relationship with the interaction partner.

Training of goal-directed attention regulation enhances control over neural processing for individuals with brain injury

Deficits in attention and executive control are some of the most common, debilitating and persistent consequences of brain injuries. Understanding neural mechanisms that support clinically significant improvements, when they do occur, may help advance treatment development. Intervening via rehabilitation provides an opportunity to probe such mechanisms. Our objective was to identify neural mechanisms that underlie improvements in attention and executive control with rehabilitation training. We tested the hypothesis that intensive training enhances modulatory control of neural processing of perceptual information in patients with acquired brain injuries. Patients (n=12) participated either in standardized training designed to target goal-directed attention regulation, or a comparison condition (brief education). Training resulted in significant improvements on behavioural measures of attention and executive control. Functional magnetic resonance imaging methods adapted for testing the effects of intervention for patients with varied injury pathology were used to index modulatory control of neural processing. Pattern classification was utilized to decode individual functional magnetic resonance imaging data acquired during a visual selective attention task. Results showed that modulation of neural processing in extrastriate cortex was significantly enhanced by attention regulation training. Neural changes in prefrontal cortex, a candidate mediator for attention regulation, appeared to depend on individual baseline state. These behavioural and neural effects did not occur with the comparison condition. These results suggest that enhanced modulatory control over visual processing and a rebalancing of prefrontal functioning may underlie improvements in attention and executive control.

The Impact of Prefrontal Cortex for Selective Attention in a Visual Working Memory Task

In this study, a variant of the n-back task was used to investigate electrophysiological correlates of top-down processes in visual-object working memory. Event-related potentials were used to replicate results concerning an attention related modulation of neural processes and to investigate the involvement of prefrontal cortex in this modulation. 16 healthy subjects executed an n-back task with sequentially presented faces and scenes. Attention was selectively directed to only one stimulus category. We found an enhancement of the N170 amplitudes for relevant stimuli compared to irrelevant or neutral stimuli. Late frontal amplitudes were stronger positive for relevant compared to neutral stimuli indicating selective attention processes of working memory. Evidence for selective inhibition was not found.

Modelling chemical modulation of neural processes

Modelling chemical modulation of neural processes

Modelling chemical modulation of neural processes

We analyse the effect of chemical neuro-modulation on collective processes in Ising spin neural networks with separable Hebbian-type synaptic interactions. Neuro-modulation is taken into account in the simplest way: a modulator-specific subset of neurons is prevented from transmitting signals. However, the presence of neuro-modulators is also taken into account during the learning stage, which leads to non-symmetric interaction matrices. The authors derive (in the limit of infinite system size) the macroscopic laws that determine the system's evolution in time at the level of order parameters. These laws are very transparent and show that, within the proposed framework, one can understand the functioning of neuro-modulators as follows: their role is to choose a particular mode of operation from a repertoire of learned behaviour. By considering specific examples of learning stages we indicate how neuro-modulation might be used by the brain as an extra degree of freedom for (a) performing selective pattern ...