Recognition of Attentional States in VR Environment: An fNIRS Study.

An improvement in ecological validity is one of the significant challenges for 21st-century neuroscience. At the same time, the study of neurocognitive processes in real-life situations requires good control of all variables relevant to the results. One possible solution that combines the capability of creating realistic experimental scenarios with adequate control of the test environment is virtual reality. Our goal was to develop an integrative research workspace involving a CW-fNIRS and head-mounted-display (HMD) technology dedicated to offline and online cognitive experiments. We designed an experimental study in a repeated-measures model on a group of BCI-naïve participants to verify our assumptions. The procedure included a 3D environment-adapted variant of the classic n-back task (2-back version). Tasks were divided into offline (calibration) and online (feedback) sessions. In both sessions, the signal was recorded during the cognitive task for within-group comparisons of changes in oxy-Hb concentration in the regions of interest (the dorsolateral prefrontal cortex-DLPFC and middle frontal gyrus-MFG). In the online session, the recorded signal changes were translated into real-time feedback. We hypothesized that it would be possible to obtain significantly higher than the level-of-chance threshold classification accuracy for the enhanced attention engagement (2-back task) vs. relaxed state in both conditions. Additionally, we measured participants' subjective experiences of the BCI control in terms of satisfaction. Our results confirmed hypotheses regarding the offline condition. In accordance with the hypotheses, combining fNIRS and HMD technologies enables the effective transfer of experimental cognitive procedures to a controlled VR environment. This opens the new possibility of creating more ecologically valid studies and training procedures.

Acoustic Neurofeedback Increases Beta ERD During Mental Rotation Task.

The purpose of the present study was to identify the effect of acoustic neurofeedback on brain activity during consecutive stages of mental rotation of 3D objects. Given the fact that the process of mental rotation of objects is associated with desynchronisation of beta rhythm (beta ERD), it was expected that suppression in this band would be greater in the experimental group than in the controls. Thirty-three participants were randomly allocated to two groups performing the classic Shepard-Metzler mental rotation task (1971). The experimental group received auditory stimuli when the level of concentration fell below the threshold value determined separately for each participant based on the engagement index [ß/(α + Θ)]. The level of concentration in the control group was not stimulated. Compared to the controls, the experimental group was found with greater beta-band suppression recorded above the left parietal cortex during the early stage and above the right parietal cortex during the late stage of mental rotation task. At the late stage of mental rotation, only the experimental group was found with differences in beta ERD related to varied degrees of the rotation angle and the control condition (zero angles, no rotation) recorded above the right parietal cortex and the central area of cerebral cortex. The present findings suggest that acoustic feedback might improve the process of mental rotation.

The Impact of Different Visual Feedbacks in User Training on Motor Imagery Control in BCI.

The challenges of research into brain-computer interfaces (BCI) include significant individual differences in learning pace and in the effective operation of BCI devices. The use of neurofeedback training is a popular method of improving the effectiveness BCI operation. The purpose of the present study was to determine to what extent it is possible to improve the effectiveness of operation of sensorimotor rhythm-based brain-computer interfaces (SMR-BCI) by supplementing user training with elements modifying the characteristics of visual feedback. Four experimental groups had training designed to reinforce BCI control by: visual feedback in the form of dummy faces expressing emotions (Group 1); flashing the principal elements of visual feedback (Group 2) and giving both visual feedbacks in one condition (Group 3). The fourth group participated in training with no modifications (Group 4). Training consisted of a series of trials where the subjects directed a ball into a basket located to the right or left side of the screen. In Group 1 a schematic image a face, placed on the controlled object, showed various emotions, depending on the accuracy of control. In Group 2, the cue and targets were flashed with different frequency (4 Hz) than the remaining elements visible on the monitor. Both modifications were also used simultaneously in Group 3. SMR activity during the task was recorded before and after the training. In Group 3 there was a significant improvement in SMR control, compared to subjects in Group 2 and 4 (control). Differences between subjects in Groups 1, 2 and 4 (control) were insignificant. This means that relatively small changes in the training procedure may significantly impact the effectiveness of BCI control. Analysis of behavioural data acquired from all participants at training showed greater effectiveness in directing the object towards the right side of the screen. Subjects with the greatest improvement in SMR control showed a significantly lower difference in the accuracy of rightward and leftward movement than others.

Compensatory brain activity pattern is not present in older adults during the n-back task performance-Findings based on EEG frequency analysis.

Introduction: Cognitive ability is one of the most important enablers for successful aging. At the same time, cognitive decline is a well-documented phenomenon accompanying the aging process. Nevertheless, it is acknowledged that aging can also be related to positive processes that allow one to compensate for the decline. These processes include the compensatory brain activity of older adults primarily investigated using fMRI and PET. To strengthen the cognitive interpretation of compensatory brain activity in older adults, we searched for its indicators in brain activity measured by EEG. Methods: The study sample comprised 110 volunteers, including 50 older adults (60-75 years old) and 60 young adults (20-35 years old) who performed 1-back, 2-back, and 3-back tasks while recording the EEG signal. The study analyzed (1) the level of cognitive performance, including sensitivity index, the percentage of correct answers to the target, and the percentage of false alarm errors; (2) theta and alpha power for electrodes located in the frontal-midline (Fz, AF3, AF4, F3, F4, FC1, and FC2) and the centro-parietal (CP1, CP2, P3, P4, and Pz) areas. Results: Cognitive performance was worse in older adults than in young adults, which manifested in a significantly lower sensitivity index and a significantly higher false alarm error rate at all levels of the n-back task difficulty. Simultaneously, performance worsened with increasing task difficulty regardless of age. Significantly lower theta power in the older participants was observed at all difficulty levels, even at the lowest one, where compensatory activity was expected. At the same time, at this difficulty level, cognitive performance was worse in older adults than in young adults, which could reduce the chances of observing compensatory brain activity. The significant decrease in theta power observed in both age groups with rising task difficulty can reflect a declining capacity for efficient cognitive functioning under increasing demands rather than adapting to this increase. Moreover, in young adults, alpha power decreased to some extent with increasing cognitive demand, reflecting adaptation to them, while in older adults, no analogous pattern was observed. Discussion: In conclusion, based on the results of the current study, the presence of compensatory activity in older adults cannot be inferred.

Brief Visual Deprivation Effects on Brain Oscillations During Kinesthetic and Visual-motor Imagery.

It is widely recognized that opening and closing the eyes can direct attention to external or internal stimuli processing. This has been confirmed by studies showing the effects of changes in visual stimulation changes on cerebral activity during different tasks, e.g., motor imagery and execution. However, an essential aspect of creating a mental representation of motion, such as imagery perspective, has not yet been investigated in the present context. Our study aimed to verify the effect of brief visual deprivation (under eyes open [EO] and eyes closed [EC] conditions) on brain wave oscillations and behavioral performance during kinesthetic imagery (KMI) and visual-motor imagery (VMI) tasks. We focused on the alpha and beta rhythms from visual- and motor-related EEG activity sources. Additionally, we used machine learning algorithms to establish whether the registered differences in brain oscillations might affect motor imagery brain-computer interface (MI-BCI) performance. The results showed that the occipital areas in the EC condition presented significantly stronger desynchronization during VMI tasks, which is typical for enhanced visual stimuli processing. Furthermore, the stronger desynchronization of alpha rhythms from motor areas in the EO, than EC condition confirmed previous effects obtained during real movements. It was also found that simulating movement under EC/EO conditions affected signal classification accuracy, which has practical implications for MI-BCI effectiveness. These findings suggest that shifting processing toward external or internal stimuli modulates brain rhythm oscillations associated with different perspectives on the mental representation of movement.

Self-concept clarity and processing self-relevant information: An event-related potential study.

Self-concept clarity (SCC) refers to the extent to which self-beliefs are clearly and confidently defined, internally consistent, and stable. While there is an abundance of research showing an association between SCC, well-being, and effective self-regulation, there is little knowledge about how SCC relates to basic cognitive processes such as attention and memory. Drawing on the attentional function theory of cognitive control, we hypothesized that low SCC is associated with greater attentional control during a trait assessment task. We also expected that low SCC individuals retrieve self-related information from semantic memory less efficiently compared to high SCC individuals. Fifty participants took part in the ERP study. The P300 and N400 components were measured as electrophysiological indices of attentional and semantic processing. The results showed that individuals with low SCC had larger P300 amplitude in response to positive versus negative words, and marginally larger P300 amplitude in response to positive words compared to high SCC individuals. These results suggest greater attentional involvement in the processing of positive self-related information in people with low SCC. There were no significant differences between groups in N400 amplitude. The results are discussed in the context of the relationship of SCC to self-esteem and self-motive theory.

Handedness effects on motor imagery during kinesthetic and visual-motor conditions.

Recent studies show that during a simple movement imagery task, the power of sensorimotor rhythms differs according to handedness. However, the effects of motor imagery perspectives on these differences have not been investigated yet. Our study aimed to check how handedness impacts the activity of alpha (8-13 Hz) and beta (15-30 Hz) oscillations during creating a kinesthetic (KMI) or visual-motor (VMI) representation of movement. Forty subjects (20 right-handed and 20 left-handed) who participated in the experiment were tasked with imagining sequential finger movement from a visual or kinesthetic perspective. Both the electroencephalographic (EEG) activity and behavioral correctness of the imagery task performance were measured. After the registration, we used independent component analysis (ICA) on EEG data to localize visual- and motor-related EEG sources of activity shared by both motor imagery conditions. Significant differences were obtained in the visual cortex (the occipital ICs cluster) and the right motor-related area (right parietal ICs cluster). In comparison to right-handers who, regardless of the task, demonstrated the same pattern in the visual area, left-handers obtained higher power in the alpha waves in the VMI task and better performance in this condition. On the other hand, only the right-handed showed different patterns in the alpha waves in the right motor cortex during the KMI condition. The results indicate that left-handers imagine movement differently than right-handers, focusing on visual experience. This provides new empirical evidence on the influence of movement preferences on imagery processes and has possible future implications for research in the area of neurorehabilitation and motor imagery-based brain-computer interfaces (MI-BCIs).

The Role of Motor Imagery in Predicting Motor Skills in Young Male Soccer Players.

The study aimed to find out whether the imagery ability within the two subcomponents of motor imagery (visual and kinesthetic) allows predicting the results in simple response time task and eye-hand coordination task in a group of young male soccer players (9-15 years old). Non-specific simple response time and eye-hand coordination play a key role in predicting specific sports performance level. Participants performed Reaction Time Task, Eye-Hand Coordination Task, and completed Motor Imagery Questionnaire-Revised. Data were submitted to the structural equations analysis based on the maximum likelihood method in order to estimate a structural model of relationship between variables. Results indicate visual rather than kinesthetic motor imagery is associated with non-specific motor skills. Higher scores on the visual motor imagery scale were observed to correlate with faster reaction times and better coordination in the study group. This supports the idea that during learning a new perceptual-motor-task the visual control is required. Results provide the evidence for the specific role of the third-person perspective imagery in young athletes playing soccer.

A Functional Model for Unifying Brain Computer Interface Terminology.

Brain Computer Interface (BCI) technology is a critical area both for researchers and clinical practitioners. The IEEE P2731 working group is developing a comprehensive BCI lexicography and a functional model of BCI. The glossary and the functional model are inextricably intertwined. The functional model guides the development of the glossary. Terminology is developed from the basis of a BCI functional model. This paper provides the current status of the P2731 working group's progress towards developing a BCI terminology standard and functional model for the IEEE.

The effects of handedness on sensorimotor rhythm desynchronization and motor-imagery BCI control.

Brain-computer interfaces (BCIs) allow control of various applications or external devices solely by brain activity, e.g., measured by electroencephalography during motor imagery. Many users are unable to modulate their brain activity sufficiently in order to control a BCI. Most of the studies have been focusing on improving the accuracy of BCI control through advances in signal processing and BCI protocol modification. However, some research suggests that motor skills and physiological factors may affect BCI performance as well. Previous studies have indicated that there is differential lateralization of hand movements' neural representation in right- and left-handed individuals. However, the effects of handedness on sensorimotor rhythm (SMR) distribution and BCI control have not been investigated in detail yet. Our study aims to fill this gap, by comparing the SMR patterns during motor imagery and real-feedback BCI control in right- (N = 20) and left-handers (N = 20). The results of our study show that the lateralization of SMR during a motor imagery task differs according to handedness. Left-handers present lower accuracy during BCI performance (single session) and weaker SMR suppression in the alpha band (8-13 Hz) during mental simulation of left-hand movements. Consequently, to improve BCI control, the user's training should take into account individual differences in hand dominance.

Problematic Video Gaming and Problematic Internet Use Among Polish Young Adults.

Technological advancements, on the one hand, facilitate everyday activities and, on the other hand, may lead to problematic behavior. These include problematic video gaming (PVG) and problematic Internet use. The purpose of this article is to present the specificity of these behavioral addictions in a group of Polish young adults and to determine their predictors and interrelatedness. The study involved a group of 1,493 young adults, aged from 18 to 30. The intensity of problematic Internet use was measured with the Problematic Internet Use Test (the Polish version of Internet Addiction Test developed by Kimberly Young), and intensity of PVG was measured with the Problem Video Game Playing Questionnaire. Based on the results, it can be shown that in the group of Polish young adults participating in the study, 0.3 percent of the individuals present very high problematic Internet use. On the contrary, 3.6 percent of the gamers show signs of PVG. Furthermore, analysis of structural equations showed that only the model assuming a correlation between the two types of behavioral addiction correctly fits the data set. Based on the developed model, it was established that the duration of social network usage is probably a predictor of problematic Internet use, while predictors of PVG include the amount of time dedicated to playing video games as well as engagement in action games. The present findings enable better understanding of the relationship between PVG and problematic Internet use among young adults. They also support other studies which suggest that, despite similarities between them, various types of behavioral addictions may be predicted by different factors.

Most Popular Signal Processing Methods in Motor-Imagery BCI: A Review and Meta-Analysis.

Brain-Computer Interfaces (BCI) constitute an alternative channel of communication between humans and environment. There are a number of different technologies which enable the recording of brain activity. One of these is electroencephalography (EEG). The most common EEG methods include interfaces whose operation is based on changes in the activity of Sensorimotor Rhythms (SMR) during imagery movement, so-called Motor Imagery BCI (MIBCI).The present article is a review of 131 articles published from 1997 to 2017 discussing various procedures of data processing in MIBCI. The experiments described in these publications have been compared in terms of the methods used for data registration and analysis. Some of the studies (76 reports) were subjected to meta-analysis which showed corrected average classification accuracy achieved in these studies at the level of 51.96%, a high degree of heterogeneity of results (Q = 1806577.61; df = 486; p < 0.001; I 2 = 99.97%), as well as significant effects of number of channels, number of mental images, and method of spatial filtering. On the other hand the meta-regression failed to provide evidence that there was an increase in the effectiveness of the solutions proposed in the articles published in recent years. The authors have proposed a newly developed standard for presenting results acquired during MIBCI experiments, which is designed to facilitate communication and comparison of essential information regarding the effects observed. Also, based on the findings of descriptive analysis and meta-analysis, the authors formulated recommendations regarding practices applied in research on signal processing in MIBCIs.

Effects of harmonics on aesthetic judgments of music: an ERP study involving laypersons and experts.

The purpose of the study was to test whether aesthetic judgments of music are affected by expertise or harmonic violation of musical sequences. The participants were 14 musical experts and 13 laypersons; they were asked to judge the beauty and correctness of extracts from J. S. Bach's chorales. Experts and laypersons showed different late positive potential (LPP) responses to the appraisal of correctness. LPP also proved to be sensitive to the extent to which the extracts violated harmonic expectations. The relationship between the early right anterior negativity potential (ERAN) and the harmonic correctness of chords was similar in laypersons and experts.

Short-term kinesthetic training for sensorimotor rhythms: effects in experts and amateurs.

The authors' aim was to examine whether short-term kinesthetic training affects the level of sensorimotor rhythm (SMR) in different frequency band: alpha (8-12 Hz), lower beta (12.5-16 Hz) and beta (16.5-20 Hz) during the execution of a motor imagery task of closing and opening the right and the left hand by experts (jugglers, practicing similar exercises on an everyday basis) and amateurs (individuals not practicing any sports). It was found that the performance of short kinesthetic training increases the power of alpha rhythm when executing imagery tasks only in the group of amateurs. Therefore, kinesthetic training may be successfully used as a method increasing the vividness of motor imagery, for example, in tasks involving the control of brain-computer interfaces based on SMR.

The suppression of the µ rhythm during the creation of imagery representation of movement.

The aim of this study was to answer the following question: are there differences between the attenuation of µ rhythms, recorded with EEG in the parietal area during observation of movement and the creation of its imaginative representation? In addition, we checked the extent to which the µ rhythm suppression depends on whether the observed and the imagined movement is performed by a human or is artificial. As a result of the experiment a significant difference in µ rhythm suppression between the conditions "Observation," "Imagery," and "White noise" was recorded. It did not matter whether the motion was carried out by a human being or performed by a machine. The results are discussed in the light of findings which relate to the mirror neuron system.