A passive brain–computer interface based upon functional near-infrared spectroscopy brain signals is used for earlier detection of human drowsiness during driving tasks. This BCI modality acquired hemodynamic signals of 13 healthy subjects from the right dorsolateral prefrontal cortex of the brain. Drowsiness activity is recorded using a continuous-wave fNIRS system and eight channels over the right DPFC. During the experiment, sleep-deprived subjects drove a vehicle in a driving simulator while their cerebral oxygen regulation state was continuously measured. Vector phase analysis (...) was used as a classifier to detect drowsiness state along with sleep stage-based threshold criteria. Extensive training and testing with various feature sets and classifiers are done to justify the adaptation of threshold criteria for any subject without requiring recalibration. Three statistical features along with six VPA features were used. The average accuracies for the five classifiers are 90.9% for discriminant analysis, 92.5% for support vector machines, 92.3% for nearest neighbors, 92.4% for both decision trees, and ensembles over all subjects’ data. Trajectory slopes of CORE vector magnitude and angle: m and m are the best-performing features, along with ensemble classifier with the highest accuracy of 95.3% and minimum computation time of 40 ms. The statistical significance of the results is validated with a p-value of less than 0.05. The proposed passive BCI scheme demonstrates a promising technique for online drowsiness detection using VPA along with sleep stage classification. (shrink)

There is growing interest for implementing tools to monitor cognitive performance in naturalistic work and everyday life settings. The emerging field of research, known as neuroergonomics, promotes the use of wearable and portable brain monitoring sensors such as functional near infrared spectroscopy (fNIRS) to investigate cortical activity in a variety of human tasks out of the laboratory. The objective of this study was to implement an on-line passive fNIRS-based brain computer interface to discriminate two levels of working memory load during (...) highly ecological aircraft piloting tasks. Twenty eight recruited pilots were equally split into two groups (flight simulator vs. real aircraft). In both cases, identical approaches and experimental stimuli were used (serial memorization task, consisting in repeating series of pre-recorded air traffic control instructions, easy vs. hard). The results show pilots in the real flight condition committed more errors and had higher anterior prefrontal cortex activation than pilots in the simulator, when completing cognitively demanding tasks. Nevertheless, evaluation of single trial working memory load classification showed high accuracy (>76%) across both experimental conditions. The contributions here are two-fold. First, we demonstrate the feasibility of passively monitoring cognitive load in a realistic and complex situation (live piloting of an aircraft). In addition, the differences in performance and brain activity between the two experimental conditions underscore the need for ecologically-valid investigations. (shrink)

Hyperscanning studies using functional Near-Infrared Spectroscopy have been performed to understand the neural mechanisms underlying human-human interactions. In this study, we propose a novel methodological approach that is developed for fNIRS multi-brain analysis. Our method uses support vector regression to predict one brain activity time series using another as the predictor. We applied the proposed methodology to explore the teacher-student interaction, which plays a critical role in the formal learning process. In an illustrative application, we collected fNIRS data of the (...) teacher and preschoolers’ dyads performing an interaction task. The teacher explained to the child how to add two numbers in the context of a game. The Prefrontal cortex and temporal-parietal junction of both teacher and student were recorded. A multivariate regression model was built for each channel in each dyad, with the student’s signal as the response variable and the teacher’s ones as the predictors. We compared the predictions of SVR with the conventional ordinary least square predictor. The results predicted by the SVR model were statistically significantly correlated with the actual test data at least one channel-pair for all dyads. Overall, 29/90 channel-pairs across the five dyads presented significant signal predictions withthe SVR approach. The conventional OLS resulted in only 4 out of 90 valid predictions. These results demonstrated that the SVR could be used to perform channel-wise predictions across individuals, and the teachers’ cortical activity can be used to predict the student brain hemodynamic response. (shrink)

According to foundationalism, some beliefs are justified but do not depend for their justification on any other beliefs. According to access internalism, a subject is justified in believing some proposition only if that subject is aware of or has access to some reason to think that the proposition is true or probable. In this paper I discusses a fundamental challenge to internalist foundationalism often referred to as the Sellarsian dilemma. I consider three attempts to respond to the dilemma – phenomenal (...) conservatism, BonJour’s classical foundationalism, and Fumerton’s classical foundationalism. I argue that, of these three, only the last seems to avoid getting impaled on one or the other horn of the dilemma. I end by responding to some concerns with Fumerton’s account. (shrink)

It is commonly thought that we depend fundamentally on the “evidence of the senses” for our empicial beliefs, including and most directly, our beliefs about our local environment, the spatial world around us. The ultimate evidence we have for our perceptual beliefs is provided in some way by perception or perceptual experience. But what is this evidence? There seem to be three main options: external factualism allows that the evidence include facts about the external world; internal factualism takes facts that (...) involve only the internal, mental world—like facts about one’s perceptual experiences or appearances—to count as one’s perceptual evidence; and non-factualism takes propositions, including false ones, to count as evidence—for example, propositional contents of appearances or seemings. We shall see that all these options face significant challenges. Some might conclude that perceptual beliefs can be justified without depending on evidence. Others might choose to accept skepticism: our perceptual beliefs are not justified. I shall end, however, by tentatively suggesting that there is a sort of internal fact that is a plausible candidate for perceptual evidence that has been overlooked. (shrink)

Codes of ethics in journalism in the light of Koran and Hadith (Islamic traditions).