Use of Multichannel Near Infrared Spectroscopy to Study Relationships Between Brain Regions and Neurocognitive Tasks of Selective/Divided Attention and 2-Back Working Memory

Emergency Braking Evoked Brain Activities during Distracted Driving

Electroencephalogram (EEG) was used to analyze the mechanisms and differences in brain neural activity of drivers in visual, auditory, and cognitive distracted vs. normal driving emergency braking conditions. A pedestrian intrusion emergency braking stimulus module and three distraction subtasks were designed in a simulated experiment, and 30 subjects participated in the study. The common activated brain regions during emergency braking in different distracted driving states included the inferior temporal gyrus, associated with visual information processing and attention; the left dorsolateral superior frontal gyrus, related to cognitive decision-making; and the postcentral gyrus, supplementary motor area, and paracentral lobule associated with motor control and coordination. When performing emergency braking under different driving distraction states, the brain regions were activated in accordance with the need to process the specific distraction task. Furthermore, the extent and degree of activation of cognitive function-related prefrontal regions increased accordingly with the increasing task complexity. All distractions caused a lag in emergency braking reaction time, with 107.22, 67.15, and 126.38 ms for visual, auditory, and cognitive distractions, respectively. Auditory distraction had the least effect and cognitive distraction the greatest effect on the lag.

Self-focused attention related to social anxiety during free speaking tasks activates the right frontopolar area

Self-focused attention (SFA) and other-focused attention (OFA) are central maintenance factors of social anxiety. Tomita et al., Cognitive Therapy and Research 44:511–525, 2020 investigated brain activities when manipulating SFA and OFA during speech tasks, after controlling for social anxiety, using near-infrared spectroscopy (NIRS) and eye-tracking. Compared with the control condition, the SFA condition demonstrated greater activity in the right frontopolar area (rFPA) and right dorsolateral prefrontal cortex. In the OFA condition, relative to controls, activity was greater in the left superior temporal gyrus. We investigated whether the activity in these brain areas increased in healthy individuals in proportion to their social anxiety tendency without manipulating SFA and OFA. Thirty-nine participants performed speech tasks under a no attentional manipulation (no-instruction) condition and a control (looking at various places) condition. Brain activity was measured using NIRS (oxy-Hb responses), and eye movements were tracked. We found that higher social anxiety was associated with higher rFPA activity in the no-instruction condition compared to the control condition and that higher subjective SFA during the no-instruction condition with higher social anxiety was associated with increased rFPA between the no-instruction and control conditions. These results suggest that greater activity in the rFPA is a useful objective measure of SFA related to social anxiety during speech tasks.

Effects of the Attention Training Technique on Brain Activity in Healthy University Students Assessed by EEG Source Imaging

This study aimed to investigate the neurocognitive effects of the Attention Training Technique (ATT) on brain activity in healthy participants. The participants included 20 university students who were asked to practice ATT as a homework assignment for 20 days. The intracerebral source localization of their electroencephalogram during rest and the ATT task, which comprised selective attention, attention switching, and divided attention conditions, was evaluated by standardized low-resolution brain electromagnetic tomography. Brain activity during rest was subtracted from that during the ATT task, and that was compared before and after the homework assignment. The results for the divided attention condition indicated significantly decreased alpha 1 frequency band power in the left orbital frontal cortex (OFC) and alpha 2 power in the right inferior temporal cortex. Further, decreased alpha 1 power in the left OFC correlated with reduced subjective difficulty during the divided attention condition. One possibility is that the brain activity changed as the effect of ATT practice, although this study cannot confirm causality. Further studies are required which include a control group that would complete similar training without the ATT task.

Fusing Near-Infrared Spectroscopy with Wearable Hemodynamic Measurements Improves Classification of Mental Stress

Human-computer interaction (HCI) technology, and the automatic classification of a person's mental state, are of interest to multiple industries. In this work, the fusion of sensing modalities that monitor the oxygenation of the human prefrontal cortex (PFC) and cardiovascular physiology was evaluated to differentiate between rest, mental arithmetic and N-back memory tasks. A flexible headband to measure near-infrared spectroscopy (NIRS) for quantifying PFC oxygenation, and forehead photoplethysmography (PPG) for assessing peripheral cardiovascular activity was designed. Physiological signals such as the electrocardiogram (ECG) and seismocardiogram (SCG) were collected, along with the measurements obtained using the headband. The setup was tested and validated with a total of 16 human subjects performing a series of arithmetic and N-back memory tasks. Features extracted were related to cardiac and peripheral sympathetic activity, vasomotor tone, pulse wave propagation, and oxygenation. Machine learning techniques were utilized to classify rest, arithmetic, and N-back tasks, using leave-one-subject-out cross validation. Macro-averaged accuracy of 85%, precision of 84%, recall rate of 83%, and F1 score of 80% were obtained from the classification of the three states. Statistical analyses on the subject-based results demonstrate that the fusion of NIRS and peripheral cardiovascular sensing significantly improves the accuracy, precision, recall, and F1 scores, compared to using NIRS sensing alone. Moreover, the fusion significantly improves the precision compared to peripheral cardiovascular sensing alone. The results of this work can be used in the future to design a multi-modal wearable sensing system for classifying mental state for applications such as acute stress detection.

Relationships Between Cortically Mediated Attentional Dysfunction and Social Anxiety, Self-Focused Attention, and External Attention Bias

Social anxiety disorder is characterized by a marked fear and avoidance of social situations or a fear of being evaluated by others. Although training for top-down attentional control has been an effective treatment for social anxiety disorder, few studies have demonstrated that individuals with social anxiety have top-down attentional dysfunction. This study used dichotic listening (DL) tasks to investigate the relationship between social anxiety and top-down attentional control over relevant brain activities. We also investigated relationships between both social situation-dependent self-focused attention and external attention bias and situation-independent attentional control. Thirty-six healthy participants underwent near-infrared spectroscopy scanning while performing top-down selective and divided attention DL tasks. Then, they undertook a speech task and completed a questionnaire to assess the degrees of their self-focused attention and external attention bias. The results showed that the degree of social fear and self-focused attention during the speech task were negatively correlated with scores on the selective attention task and with the activity of the left pars opercularis during the selective DL task, which were related to each other. These results suggest that a relationship exists between social fear, self-focused attention in a social situation, and top-down selective attentional dysfunction as assessed both behaviorally and by brain activity changes.