Takuto Hayashi

Beta Activities in EEG Associated with Emotional Stress

Abstract The aim of this paper is to assess whether objective time-course physiological responses from electroencephalogram (EEG) and electrocardiogram (ECG) can quantify stress level or not. Physi...

Emotion Regulation of Neuroticism: Emotional Information Processing Related to Psychosomatic State Evaluated by Electroencephalography and Exact Low-Resolution Brain Electromagnetic Tomography

Emotion regulation is the process that adjusts the type or amount of emotion when we experience an emotional situation. The aim of this study was to reveal quantitative changes in brain activity during emotional information processing related to psychosomatic states and to determine electrophysiological features of neuroticism. Twenty-two healthy subjects (mean age 25 years, 14 males and 8 females) were registered. Electroencephalography (EEG) was measured during an emotional audiovisual memory task under three conditions (neutral, pleasant and unpleasant sessions). We divided the subjects into two groups using the Cornell Medical Index (CMI): (CMI-I: control group, n = 10: CMI-II, III or IV: neuroticism group, n = 12). We analyzed the digital EEG data using exact low-resolution brain electromagnetic tomography (eLORETA) current source density (CSD) and functional connectivity analysis in several frequency bands (δ, θ, α, β, γ and whole band). In all subjects, bilateral frontal α CSD in the unpleasant session increased compared to the pleasant session, especially in the control group (p < 0.05). CSD of the neuroticism group was significantly higher than that of the control group in the full band at the amygdala and inferior temporal gyrus, and in the α band at the right temporal lobe (p < 0.05). Additionally, we found an increase in functional connectivity between the left insular cortex and right superior temporal gyrus in all subjects during the unpleasant session compared to the pleasant session (p < 0.05). In this study, using EEG analysis, we could find a novel cortical network related to brain mechanisms underlying emotion regulation. Overall findings indicate that it is possible to characterize neuroticism electrophysiologically, which may serve as a neurophysiological marker of this personality trait.

Comparison of EEG propagation speeds under emotional stimuli on smartphone between the different anxiety states

The current study evaluated the effect of different anxiety states on information processing as measured by an electroencephalography (EEG) using emotional stimuli on a smartphone. Twenty-three healthy subjects were assessed for their anxiety states using The State Trait Anxiety Inventory (STAI) and divided into two groups: low anxiety (I, II) or high anxiety (III and IV, V). An EEG was performed while the participant was presented with emotionally laden audiovisual stimuli (resting, pleasant, and unpleasant sessions) and emotionally laden sentence stimuli (pleasant sentence, unpleasant sentence sessions) and EEG data was analyzed using propagation speed analysis. The propagation speed of the low anxiety group at the medial coronal for resting stimuli for all time segments was higher than those of high anxiety group. The low anxiety group propagation speeds at the medial sagittal for unpleasant stimuli in the 0–30 and 60–150 s time frames were higher than those of high anxiety group. The propagation speeds at 150 s for all stimuli in the low anxiety group were significantly higher than the correspondent propagation speeds of the high anxiety group. These events suggest that neural information processes concerning emotional stimuli differ based on current anxiety state.

Measurement of Personality Stability in Infants and Young Adults Under Emotional Stimuli Using a Brain Functional Reaction Method

Objective: We abstracted the relationship between parents′ nurturing attitudes toward their children and the child’s personality stability in a psychological way, and evaluated and quantified the relationship between the intensity degrees of brain functional responses to emotional stimuli and the mental stabilities of infants and young adults in a physiological way. Methods: Children’s personality stability and parents’ nurturing attitudes were measured using psychological methods, and brain functions of the children were measured using EEG and MEG under resting and under emotional stimuli. Results: Our results in the psychological findings showed that nurturing attitudes influenced the personality stability of the infant, but personality stability in adolescence was no longer affected by the parent’s nurturing attitudes. Our results in physiological findings showed that the brain fimctional activity on the occipital area under pleasant stimuli was provoked if the personality of the young adult were...

27. Evaluation of the autonomic nervous function using photoplethysmography under the emotional stress stimuli on a smartphone

The aim of this study is to confirm a feasibility of the identification of a phoneme in a single trial for an electrocorticographic brainmachine interface. We obtained electrocorticogram in 5 patients with brain tumor, intractable epilepsy, or intractable pain, who were implanted subdural electrodes covering the inferior part of precentral gyrus (IPrG) and/or the inferior frontal gyrus (IFG). The subjects voluntarily pronounced 5 Japanese vowels (‘a’, ‘i’, ‘u’, ‘e’, and ‘o’) repeatedly. The pronounced phonemes were separately inferred from the obtained potentials through a support vector machine. We used a sliding period of interest with a width of 200 ms in a step of 50 ms and calculated decoding accuracies. The average of the best accuracy rate in each subject was 54.9% (S.D. 10.9) for 3 phonemes, 32.3% (S.D. 8.0) for 5 phonemes, which were above the chance levels. Accuracies increased before the pronunciation and peaked just after the pronunciation. The electrodes of substantial contribution toward decoding were located over the IPrG, the IFG and also dorsolateral prefrontal cortex. We showed the feasibility of identification of a phoneme in a single trial for an electrocorticographic brain-machine interface. Our findings may also contribute to clarifying neural processes of pronouncing phonemes.

O-3-32. Relationship between brain activity and mental state during emotional olfactory stimulation

The aim of this study was to investigate the relationship between mental state and brain activity in response to odors in the environment. The mental state of 20 healthy adults was estimated using the Profile of Mood States (POMS) scale. The subjects were placed in a room, which was individually filled with vanillin, Mainichi-Koh (Japanese incense), skatol, and distilled water (control) odors, and their electroencephalograms (EEGs) were recorded while performing an auditory oddball task in the room. Both phase-locked and non-phase-locked event-related desynchronization/synchronization (ERD/ERS) of theta frequency EEG activity (4–8 Hz) were averaged for the time interval 0–500 ms. Statistical analysis was performed using multiple ANOVA, with cluster, odor, and group divided by score on the POMS subscale. The ERS activity in response to vanillin was significantly higher in the phase-locked component in the lower group of the POMS depression subscale and in the non-phase-locked component in the lower group of the POMS tension-anxiety subscale compared with both the control odor and the higher group of each POMS subscale. These results suggest that biological reactions related to odor stimulus were associated with moderately depressed and anxious mental states in healthy people.

Psychosomatic state in each region affects EEG propogating speeds for emotional stimuli on smartphones

To investigate the performance of propagation speed analysis of EEG under the emotional stimuli using smartphone. Twenty-three healthy subjects were assessed for their anxiety states using CMI and divided to two groups: low CMI score (I) or high CMI score (II, III and IV) group. EEG was measured under emotionally stimuli (relaxed and pleasant, unpleasant and unpleasant sentence sessions) stimuli and analyzed using propagation speed analysis. The propagation speed for all session in the high CMI score group had a significantly region at left and right temporal and occipital regions. And the propagation speed for all session in the low CMI score group had a significantly region at frontal region. Especially, all stimuli of the low CMI score group were propagated in a longitudinal direction. The propagation speed for all session in the low CMI score group had a significantly higher than propagation speed in the high CMI score group. These processes in the brain would affect the event that stresses on human relationships that often cause people to suffer from mental disorders.

Evaluation of phase-locked and non-phase-locked MEG activities under emotional stimuli

The present study investigates phase-locked and non-phase-locked brain responses in theta and alpha frequency bands. A 122-ch whole-head magnetoencephalogram (MEG) was recorded continuously during emotional audio-visual stimuli. The results showed that emotional stimuli induced increased theta band phase-locked activity at 200-400 ms and non-phase-locked activity at 100-600 ms. These activities were stronger with pleasant stimuli over all areas compared with the baseline period. In addition, decreased alpha1 band non-phase-locked activity was shown at 600-1000 ms in the pleasant and around 800-1000 ms in the unpleasant stimuli over the occipital cluster. These results indicate that emotional processing induces increased brain activity in the theta frequency band soon after the onset of the stimuli.

Response of the autonomic nervous system to emotional email on a smartphone

The objective of this research was to evaluate autonomic nervous function by photoplethysmography (PS) during emotional stimuli delivered via a smartphone. The mental and physical status of 24 healthy subjects were assessed using The Cornell Medical Index (CMI), The State Trait Anxiety Inventory (STAI), and The Stress Check Inventory (SCI). The subjects were divided into two groups, those who were psychosomatically stable and unstable. PS was measured during emotional (relaxed, pleasant, and unpleasant) audio-visual stimuli and in response to emotional written stimuli (pleasant and unpleasant stimuli) on a smartphone. PS pulse wave amplitude and length were evaluated. The mean pulse wave amplitudes among stimuli, between “task” (during stimuli) and “recall” (after stimuli), and between groups were compared. Parasympathetic nerve activity in peripheral and central areas was higher during recall than during task of emotional audio-visual stimuli in both groups. In the psychosomatically stable group, peripheral sympathetic nerve activity during recall of emotional written stimuli was higher than during task. In both groups, there were no differences between task and recall in central areas of the body. These events suggest that receiving an email message could activate the sympathetic nerve even after replying to the message and while waiting for a response.

P2-20. Quantitative evaluation of EEG using sLORETA during emotional information processing related to psychosomatic state

In order to quantitatively evaluate EEG using sLORETA during the emotional information processing related to psychosomatic states, 22 healthy subjects (mean age 25.0, male/female 14/8) were enrolled and were classified into 2 groups by Cornell Medical Index (CMI): 10 subjects with CMI-I (healthy group) and 12 subjects with CMI-II, III or IV (neurotic tendency group). EEG was measured under three emotional audiovisual recollection tasks (neutral, pleasant, and unpleasant sessions). Current source density (CSD) analysis and functional connectivity analysis were performed using sLORETA in several frequency bands. In whole subjects, we found a bilateral increase in frontal alpha CSD in unpleasant session compared with pleasant session, especially in healthy group. Compared with healthy group, the neurotic tendency group exhibited significantly higher CSD in whole band at amygdala and the inferior temporal gyrus, and in alpha band at right temporal lobe. Whole subjects showed increased functional connectivity between left insular cortex and right superior temporal gyrus in unpleasant session compared with pleasant session. Our findings suggest that induced frontal alpha CSD might show some neural activity during emotional information processing and that higher CSD in the neurotic tendency group might reflect the different emotional processing in this group.