Filter bank common spatial patterns in mental workload estimation.

EEG-based workload estimation technology provides a real time means of assessing mental workload. Such technology can effectively enhance the performance of the human-machine interaction and the learning process. When designing workload estimation algorithms, a crucial signal processing component is the feature extraction step. Despite several studies on this field, the spatial properties of the EEG signals were mostly neglected. Since EEG inherently has a poor spacial resolution, features extracted individually from each EEG channel may not be sufficiently efficient. This problem becomes more pronounced when we use low-cost but convenient EEG sensors with limited stability which is the case in practical scenarios. To address this issue, in this paper, we introduce a filter bank common spatial patterns algorithm combined with a feature selection method to extract spatio-spectral features discriminating different mental workload levels. To evaluate the proposed algorithm, we carry out a comparative analysis between two representative types of working memory tasks using data recorded from an Emotiv EPOC headset which is a mobile low-cost EEG recording device. The experimental results showed that the proposed spatial filtering algorithm outperformed the state-of-the algorithms in terms of the classification accuracy

Improving memory performance using a wearable BCI

Human ability to encode and memorize information fluctuates from moment to moment. Several studies have reported differences in electroencephalography (EEG) signals recorded during memorization of items that were forgotten at a later point of time compared to those that were remembered. Given these observations the question then arises whether or not a wearable BCI system can be designed to identify poorly encoded items. Such a device could be used to provide feedback to the user so as to improve the memory encoding process. This paper reports on an experimental study designed to assess this possibility

Narrowband Searches for Continuous and Long-duration Transient Gravitational Waves from Known Pulsars in the LIGO-Virgo Third Observing Run

Isolated neutron stars that are asymmetric with respect to their spin axis are possible sources of detectable continuous gravitational waves. This paper presents a fully coherent search for such signals from eighteen pulsars in data from LIGO and Virgo's third observing run (O3). For known pulsars, efficient and sensitive matched-filter searches can be carried out if one assumes the gravitational radiation is phase-locked to the electromagnetic emission. In the search presented here, we relax this assumption and allow both the frequency and the time derivative of the frequency of the gravitational waves to vary in a small range around those inferred from electromagnetic observations. We find no evidence for continuous gravitational waves, and set upper limits on the strain amplitude for each target. These limits are more constraining for seven of the targets than the spin-down limit defined by ascribing all rotational energy loss to gravitational radiation. In an additional search, we look in O3 data for long-duration (hours-months) transient gravitational waves in the aftermath of pulsar glitches for six targets with a total of nine glitches. We report two marginal outliers from this search, but find no clear evidence for such emission either. The resulting duration-dependent strain upper limits do not surpass indirect energy constraints for any of these targets. © 2022. The Author(s). Published by the American Astronomical Society

Studying space representation within a neuropsychological perspective

This special issue is in honour of Luigi (better known as Gino) Pizzamiglio, who devoted his long and productive scientific career to neuropsychological research and made significant contributions in areas ranging from phonology and language to space perception and human navigation. His approach is characterized by a highly innovative combination of experimental methods deriving from psychology, phonology, and cognitive neuroscience to study the disorders of individuals with circumscribed cerebral lesions and particular genetic profiles. With the advent of neuroimaging techniques, Gino began to use these methods to make further important contributions in the areas of neglect, human navigation, and representation of action. This all took place in parallel with his enduring interest in using experimental paradigms to study recovery and rehabilitation following brain damage

The effects of visuomotor feedback training on the recovery of hemispatial neglect symptoms: assessment of a 2-week and follow-up intervention

In patients suffering from left unilateral neglect, their right-biased attention to the phenomenal world can be ameliorated, short-term, by making motor responses to left–right extended objects (rods) that immediately reveal to them that their phenomenal world is in fact skewed. In this study the extent to which more intensive experiences of this type produced enduring and useful improvements in neglect, was assessed by first examining the effect of a 3-day experimenter-administered practice of rod lifting, then by examining the effects of a self-administered practice for a further 2-week period and a further 1 month post-training. Despite the fact that by the time the patients were able to undergo the intervention they had progressed to the chronic neglect stage, significant improvements of the intervention over the control group were found for a third of the tests given after the 3-day practice. Additionally, at the 1-month follow-up the intervention group again showed significantly better results in 46% of the direct neglect tests. As far as we are aware this is the first time that significant long-term improvements have been shown in a rehabilitation approach with neglect patients with a mean time of more than 12 months post-stroke and visuomotor feedback training can thus be seen as a most encouraging paradigm for future attempts