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Electroencephalography (EEG) is a crucial tool in cognitive neuroscience, enabling the study of neurophysiological function by measuring the brain's electrical activity. Its applications include perception, learning, memory, language, decision making and neural network mapping. Recently, interest has surged in extending EEG measurements to domestic environments. However, the high costs associated with traditional laboratory EEG systems have hindered accessibility for many individuals and researchers in education, research, and medicine. To tackle this, a mobile-EEG device named "DreamMachine" was developed. A more affordable alternative to both lab-based EEG systems and existing mobile-EEG devices. This system boasts 24 channels, 24-bit resolution, up to 6 h of battery life, portability, and a low price. Our open-source and open-hardware approach empowers cognitive neuroscience, especially in education, learning, and research, opening doors to more accessibility. This paper introduces the DreamMachine's design and compares it with the lab-based EEG system "asalabTM" in an eyes-open and eyes-closed experiment. The Alpha band exhibited higher power in the power spectrum during eyes-closed conditions, whereas the eyes-open condition showed increased power specifically within the Delta frequency range. Our analysis confirms that the DreamMachine accurately records brain activity, meeting the necessary standards when compared to the asalabTM system. [ABSTRACT FROM AUTHOR]

Structural and functional neuroimaging studies have shown that brain areas associated with fear and anxiety (defensive system areas) are modulated by individual differences in sensitivity to punishment (SP). However, little is known about how SP is related to brain functional connectivity and the factors that modulate this relationship. In this study, we investigated whether a simple methodological manipulation, such as performing a resting state with eyes open or eyes closed, can modulate the manifestation of individual differences in SP. To this end, we performed an exploratory fMRI resting state study in which a group of participants (n = 88) performed a resting state with eyes closed and another group (n = 56) performed a resting state with eyes open. All participants completed the Sensitivity to Punishment and Sensitivity to Reward Questionnaire. Seed-based functional connectivity analyses were performed in the amygdala, hippocampus, and periaqueductal gray (PAG). Our results showed that the relationship between SP and left amygdala-precuneus and left hippocampus-precuneus functional connectivity was modulated by eye state. Moreover, in the eyes open group, SP was negatively related to the functional connectivity between the PAG and amygdala and between the PAG and left hippocampus, and it was positively related to the functional connectivity between the amygdala and hippocampus. Together, our results may suggest underlying differences in the connectivity between anxiety-related areas based on eye state, which in turn would affect the manifestation of individual differences in SP. [ABSTRACT FROM AUTHOR]

The motor evoked potentials (MEPs) elicited by single-pulse transcranial magnetic stimulation (TMS) vary considerably at rest, but the mechanism underlying this amplitude variation is largely unknown. We hypothesized that prestimulus EEG oscillations modulate the subsequent MEPs in a state-dependent manner. We studied the relationship between prestimulus alpha/beta oscillations and MEPs during eyes open (EO)/closed (EC) conditions, and then modulated TMS intensity in the EO condition. Furthermore, we developed an EEG-triggered TMS system ("informed open-loop") to verify our hypothesis. TMS was applied to the left motor cortex. We first compared EEG power differences between high- and low-amplitude MEP epochs in the EO and EC conditions when using a high TMS intensity. Next, we evaluated the effects of varying TMS intensities (high vs. low) on the EEG–MEP relationship. Finally, we used EEG-triggered TMS to determine whether prestimulus EEG oscillations predicted MEP amplitudes. Prestimulus higher-power alpha/low-beta bands produced larger MEPs only in the high-intensity EO condition. A positive relationship between EEG power and MEP amplitude was observed at C3 and left frontal electrodes. This relationship was obscured when using the lower TMS intensity but was observed in the high-intensity condition at the C3 electrode. EEG-triggered TMS demonstrated that higher alpha power predicted higher MEP amplitudes, but beta power at around 20 Hz did not. A causal relationship between alpha/low-beta oscillations and MEP amplitudes at rest requires high TMS intensity delivered when eyes are open. This association may allow us to develop a new informed open-loop TMS protocol. • We studied the relationship between prestimulus EEG oscillations and MEPs. • High prestimulus alpha/low-beta (10–15 Hz) power induced high MEP amplitudes. • This relationship was weaker in the eyes-closed state or if TMS intensity was low. • EEG-triggered TMS suggested the importance of alpha power. • The EEG–MEP relationship was modulated in a state-dependent manner. [ABSTRACT FROM AUTHOR]