Ultra-low Noise EEG at LSBB: New results

Abstract

Abstract. In this study, we investigate functional correlates of gamma band oscillations in low-noise EEG signals acquired in the LSBB shielded capsule and compare them to signals acquired in a typical hospital environment. Using a research-grade EEG acquisition system, we acquired 64-channel EEG recordings from three volunteers performing several cognitive, sensory, and motor tasks in both LSBB and hospital settings. Time-frequency analysis on the signals acquired in both environments reveals that the task-induced increase in gamma band (>30 Hz) energy relative to the resting state EEG is more prominent in signals acquired at LSBB, suggesting that task-specific changes in EEG are better reflected and more readily detected in signals acquired at LSBB. These results further demonstrate the potential value of low-noise settings such as the LSBB for conducting challenging highfrequency EEG studies.

Ultra-low Noise EEG at LSBB: Effective Connectivity Analysis

“…Interestingly, we also observe that for a specific subject, more significant connections are present in recordings at LSBB than their counterparts at the hospital environment. This is a direct consequence of low-noise conditions, and is in accordance with our findings in [2], as task-specific effective connectivity is another gamma band correlate which is enhanced and better detected in the low-noise environment. Another property deducible from Figure 9 is laterality and the amount of inter and intrahemispheric connections.…”

“…Brain connectivity structure comprises networks of different brain sites connected by anatomical, functional, or causal (effective) associations. In this paper, we extended the segregated analysis of [2] to search for the presence and direction of task-specific gamma band connectivity links in our EEG dataset during motor tasks.…”

“…However, in recent years, the gamma band has received greater scrutiny within the research community. In [1], and in particular in [2] the use of time-frequency analysis revealed that the task-induced increase in gamma band (>30 Hz) energy relative to the resting state EEG is more prominent in signals acquired at LSBB than in a typical hospital environment, suggesting that task-specific changes in EEG are better reflected and more readily detected in signals acquired at LSBB. In this report we go further by analyzing the connectivity in the gamma band of EEG acquired during motor tasks.…”

“…In two previous studies [1], [2] we have demonstrated the potential of the ultra-low noise shielded capsule at the heart of LSBB is an ideal environment for acquiring ultra-high, wideband electroencephalographic (EEG) signals without the need of filtering. The EEG has proven to be a useful information source in the analysis of brain activity, neural plasticity, and the diagnosis of various neurological disorders, as well as the development of intelligent brain-computer interfaces (BCIs).…”