The effects of AMPA receptor blockade on resting magnetoencephalography recordings

The ionotropic N-methyl-D-aspartate and α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors of the glutamatergic neurotransmitter system are of fundamental importance to healthy brain function. Neuroimaging studies in humans have previously been conducted using various drugs that interact with N-methyl-D-aspartate glutamate receptors, but no such studies have investigated AMPA receptor signalling. The recent approval of perampanel (Fycompa) for use in humans provides a means to specifically study the role of AMPA receptors in the pharmacological basis of neuroimaging signals. Twenty male subjects participated in this placebo-controlled crossover study that consisted of two study days separated by a minimum two-week washout period. On one occasion participants ingested a 6 mg dose of perampanel, and on the other a placebo. Ten minutes of wakeful rest was recorded before and after each dose using magnetoencephalography. Subjective ratings of intoxication were significantly higher following drug than placebo. Cluster-based randomisation testing of sensor-level magnetoencephalography data showed significant drug-induced increases in low frequency power (1–4 Hz, 4–8 Hz, 8–13 Hz, 13–30 Hz), along with a significant decrease in the high gamma range (50–90 Hz). We also observed selective increases in functional connectivity in the alpha and beta bands. The findings are consistent with preclinical work and are similar to the spectral profile of other anti-epileptic drugs

MODMA dataset: a Multi-modal Open Dataset for Mental-disorder Analysis

According to the World Health Organization, the number of mental disorder patients, especially depression patients, has grown rapidly and become a leading contributor to the global burden of disease. However, the present common practice of depression diagnosis is based on interviews and clinical scales carried out by doctors, which is not only labor-consuming but also time-consuming. One important reason is due to the lack of physiological indicators for mental disorders. With the rising of tools such as data mining and artificial intelligence, using physiological data to explore new possible physiological indicators of mental disorder and creating new applications for mental disorder diagnosis has become a new research hot topic. However, good quality physiological data for mental disorder patients are hard to acquire. We present a multi-modal open dataset for mental-disorder analysis. The dataset includes EEG and audio data from clinically depressed patients and matching normal controls. All our patients were carefully diagnosed and selected by professional psychiatrists in hospitals. The EEG dataset includes not only data collected using traditional 128-electrodes mounted elastic cap, but also a novel wearable 3-electrode EEG collector for pervasive applications. The 128-electrodes EEG signals of 53 subjects were recorded as both in resting state and under stimulation; the 3-electrode EEG signals of 55 subjects were recorded in resting state; the audio data of 52 subjects were recorded during interviewing, reading, and picture description. We encourage other researchers in the field to use it for testing their methods of mental-disorder analysis

Guidelines for the recording and evaluation of pharmaco-EEG data in man: the International Pharmaco-EEG Society (IPEG)

The International Pharmaco-EEG Society (IPEG) presents updated guidelines summarising the requirements for the recording and computerised evaluation of pharmaco-EEG data in man. Since the publication of the first pharmaco-EEG guidelines in 1982, technical and data processing methods have advanced steadily, thus enhancing data quality and expanding the palette of tools available to investigate the action of drugs on the central nervous system (CNS), determine the pharmacokinetic and pharmacodynamic properties of novel therapeutics and evaluate the CNS penetration or toxicity of compounds. However, a review of the literature reveals inconsistent operating procedures from one study to another. While this fact does not invalidate results per se, the lack of standardisation constitutes a regrettable shortcoming, especially in the context of drug development programmes. Moreover, this shortcoming hampers reliable comparisons between outcomes of studies from different laboratories and hence also prevents pooling of data which is a requirement for sufficiently powering the validation of novel analytical algorithms and EEG-based biomarkers. The present updated guidelines reflect the consensus of a global panel of EEG experts and are intended to assist investigators using pharmaco-EEG in clinical research, by providing clear and concise recommendations and thereby enabling standardisation of methodology and facilitating comparability of data across laboratories

Perfiles de actividad magnética cerebral de jóvenes con consumo intensivo de alcohol

Tesis inédita de la Universidad Complutense de Madrid, Facultad de Psicología, leída el 24-01-2017El patrón de consumo de alcohol binge drinking se caracteriza por la ingesta intermitente de grandes cantidades del alcohol en un corto espacio de tiempo alternándose con periodos de abstinencia. En España, este tipo de consumo de alcohol se asocia al conocido efecto botellón en el que los jóvenes se reúnen en espacios públicos, principalmente los fines de semana, teniendo el alcohol como protagonista. La adolescencia, edad en la que se inicia este tipo de consumo, es considerada un periodo crítico de desarrollo en el que el cerebro experimenta grandes cambios madurativos, fundamentalmente en los lóbulos frontales. Dada su inmadurez, el cerebro adolescente muestra mayor vulnerabilidad ante el efecto neurotóxico del alcohol que el cerebro adulto. Debido a la alta prevalencia que este tipo de consumo presenta entre los jóvenes, la comunidad científica ha mostrado interés en las últimas décadas por estudiar las posibles consecuencias que puede tener en la estructura y funcionamiento del cerebro de jóvenes que beben de este modo. Sin embargo, hasta el momento no existían estudios que evaluasen el efecto del binge drinking en la actividad magnética cerebral. La Magnetoencefalografía es una técnica no invasiva que mide las corrientes magnéticas generadas por las pequeñas corrientes neurales que producen las neuronas. La presente tesis ha utilizado esta técnica a lo largo de los tres experimentos en los que se estudió: 1) la actividad magnética cerebral en el espacio de los sensores asociada del estado de reposo de jóvenes universitarios de 18-19 años con el patrón binge drinking y un grupo control, 2) la actividad magnética cerebral en espacio de las fuentes del estado de reposo y la conectividad estructural de los mismos jóvenes dos años más tarde, con 20-21 años; y 3) la actividad magnética cerebral en espacio de las fuentes asociada a una tarea Go/NoGo de los mismos jóvenes durante la primera fase del estudio, cuando tenían 18-19 años...The alcohol consumption binge drinking pattern is characterized by intermittent intake of large amounts of alcohol in a short space of time, alternated with periods of abstinence. In Spain, this type of alcohol consumption is associated with the well-known “efecto botellón” where young people gather in public spaces, especially on weekends, having the alcohol as the protagonist. Adolescence, the age in which this type of consumption begins, is considered a critical period of neural development in which the brain undergoes maturational changes, mainly in the frontal lobes. Given its immaturity, adolescent brain is more vulnerable to the neurotoxic effects of alcohol than the adult brain. Because of its high prevalence among young adolescents, since last decades the scientific community has shown increasing interest to study the possible consequences that binge drinking may have on the structure and functioning of the brain. However, so far there are no studies assessing the effect of binge drinking with Magnetoencephalography. Magnetoencephalography is a noninvasive technique that measures the magnetic currents generated by neural currents produced by pyramidal neurons. The present dissertation has used this technique over the three experiments, studying: 1) brain magnetic activity in the sensor space associated to resting state of university students of aged 18-19 years old with alcohol binge drinking pattern and also a control group, 2) brain magnetic activity in the source space also associated to resting state and structural connectivity of the same young students two years later, with 20-21 years old; and finally, 3) the brain magnetic activity in source space associated with a Go/NoGo task in the first phase of the study, when the participants were 18-19...Fac. de PsicologíaTRUEunpu

Applications of brain imaging methods in driving behaviour research

Applications of neuroimaging methods have substantially contributed to the scientific understanding of human factors during driving by providing a deeper insight into the neuro-cognitive aspects of driver brain. This has been achieved by conducting simulated (and occasionally, field) driving experiments while collecting driver brain signals of certain types. Here, this sector of studies is comprehensively reviewed at both macro and micro scales. Different themes of neuroimaging driving behaviour research are identified and the findings within each theme are synthesised. The surveyed literature has reported on applications of four major brain imaging methods. These include Functional Magnetic Resonance Imaging (fMRI), Electroencephalography (EEG), Functional Near-Infrared Spectroscopy (fNIRS) and Magnetoencephalography (MEG), with the first two being the most common methods in this domain. While collecting driver fMRI signal has been particularly instrumental in studying neural correlates of intoxicated driving (e.g. alcohol or cannabis) or distracted driving, the EEG method has been predominantly utilised in relation to the efforts aiming at development of automatic fatigue/drowsiness detection systems, a topic to which the literature on neuro-ergonomics of driving particularly has shown a spike of interest within the last few years. The survey also reveals that topics such as driver brain activity in semi-automated settings or the brain activity of drivers with brain injuries or chronic neurological conditions have by contrast been investigated to a very limited extent. Further, potential topics in relation to driving behaviour are identified that could benefit from the adoption of neuroimaging methods in future studies

Altered Alpha Oscillatory Power Dynamics Underlie Difficulties with Cognitive Flexibility

Cognitive flexibility is an important mental faculty, but there are certain populations that experience reduced flexibility, which may be associated with altered neural activity. Rumination is when an individual becomes mentally stuck on a thought, and they experience difficulty shifting their attention away from the ruminative thought demonstrating reduced cognitive flexibility. In a similar manner, individuals diagnosed with substance use disorder show varying degrees of attentional bias towards drug related stimuli. The drug cues capture attention, and it is difficult for these individuals to shift attention away from thoughts related to drug cues. Both populations experience difficulty shifting attention when they experience highly salient thoughts (high automatic constraints). Here we suggest and demonstrate that reduced cognitive flexibility in these populations is associated with altered activity of alpha oscillations, as alpha oscillations play an important role in supporting cognitive flexibility. In our first study, we assess the relationship between trait tendency to ruminate and resting state alpha power in left frontal and parietal located electrodes. Individuals higher in trait rumination exhibit higher alpha power in left frontal located electrodes. This finding suggests that higher alpha power may contribute to mental inflexibility associated with rumination. In our second study, we assess the relationship between attentional bias towards drug cues and alpha power while automatic constraints on thought are high during an emotional version of the Stroop task and when drug cues are not present and therefore automatic constraints are low, but flexibility is required during a probabilistic reversal learning task. The emotional version of the Stroop task includes traditional congruent and incongruent word meanings as well as drug related and neutral word meanings. Participants in this study were long-term nicotine smokers, therefore the emotional stimuli were smoking related. The probabilistic reversal learning task instructs participants to choose one of two presented stimuli on each trial. The stimuli have different probabilities of reward or punishment. If the participant chooses the stimulus with the higher probability of reward several trials in a row, the reward probabilities reverse, and the participant must adapt to the new reward contingencies. Participants demonstrate the traditional Stroop effect of lower accuracy and slower reaction time during incongruent trials compared to congruent trials. Additionally, participants show a slowed reaction time during drug trials compared to neutral trials suggesting attentional bias during drug trials. Greater attentional bias is associated with higher alpha power in left frontal electrodes during drug trials. No significant relationship between attentional bias and alpha power during the probabilistic reversal learning task was revealed. Together, these results suggest higher alpha power in left frontal regions may contribute to mental inflexibility prompted by attentional bias when automatic constraints are high, but when automatic constraints are low, flexibility may not be reduced. All together these results reveal a relationship between reduced cognitive flexibility when salient stimuli or thoughts are present and altered alpha power dynamics, which may offer new avenues for behavioral intervention to improve cognitive flexibility