Browsing by Subject "ASYMMETRY"
Now showing items 1-7 of 7
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(2020)Objectives Teaching involves multiple performance situations, potentially causing psychosocial stress. Since the theater-based improvisation method is associated with diminished social stress, we investigated whether improvisation lessened student teachers’ stress responses using the Trier Social Stress Test (TSST; preparatory phase, public speech, and math task). Moreover, we studied the influence of interpersonal confidence (IC) – the belief regarding one’s capability related to effective social interactions – on stress responses. Methods The intervention group (n = 19) received a 7-week (17.5 h) improvisation training, preceded and followed by the TSST. We evaluated experienced stress using a self-report scale, while physiological stress was assessed before (silent 30-s waiting period) and during the TSST tasks using cardiovascular measures (heart rate, heart rate variability [HRV]), electrodermal activation, facial electromyography (f-EMG), and EEG asymmetry. Hypothalamus-pituitary-adrenal (HPA-axis) reactivity was assessed through repeated salivary cortisol sampling. Results Compared to the control group (n = 16), the intervention group exhibited less f-EMG activity before a public speech and higher HRV before the math task. The low IC intervention subgroup reported significantly less stress during the math task. The controls showed a decreased heart rate before the math task, and controls with a low IC exhibited higher HRV during the speech. Self-reported stress and cortisol levels were positively correlated during the post-TSST preparatory phase. Conclusions These findings suggest that improvisation training might diminish stress levels, specifically before a performance. In addition, interpersonal confidence appears to reduce stress responses. The decreased stress responses in the control group suggest adaptation through repetition. Keywords: Improvisation; Anticipatory anxiety; Interpersonal confidence; Psychophysiology; Teacher education; Trier Social Stress Test
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(2022)With the advent of consumer grade virtual reality (VR) headsets and physiological measurement devices, new possibilities for mediated social interaction emerge enabling the immersion to environments where the visual features react to the users' physiological activation. In this study, we investigated whether and how individual and interpersonally shared biofeedback (visualised respiration rate and frontal asymmetry of electroencephalography, EEG) enhance synchrony between the users' physiological activity and perceived empathy towards the other during a compassion meditation exercise carried out in a social VR setting. The study was conducted as a laboratory experiment (N = 72) employing a Unity3D-based Dynecom immersive social meditation environment and two amplifiers to collect the psychophysiological signals for the biofeedback. The biofeedback on empathy-related EEG frontal asymmetry evoked higher self-reported empathy towards the other user than the biofeedback on respiratory activation, but the perceived empathy was highest when both feedbacks were simultaneously presented. In addition, the participants reported more empathy when there was stronger EEG frontal asymmetry synchronization between the users. The presented results inform the field of affective computing on the possibilities that VR offers for different applications of empathic technologies.
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(2018)High-speed videoendoscopy, glottal inverse filtering, and physical modeling can be used to obtain complementary information about speech production. In this study, the three methodologies are combined to pursue a better understanding of the relationship between the glottal air flow and glottal area. Simultaneously acquired high-speed video and glottal inverse filtering data from three male and three female speakers were used. Significant correlations were found between the quasi-open and quasi-speed quotients of the glottal area (extracted from the high-speed videos) and glottal flow (estimated using glottal inverse filtering), but only the quasi-open quotient relationship could be represented as a linear model. A simple physical glottal flow model with three different glottal geometries was optimized to match the data. The results indicate that glottal flow skewing can be modeled using an inertial vocal/subglottal tract load and that estimated inertia within the glottis is sensitive to the quality of the data. Parameter optimisation also appears to favour combining the simplest glottal geometry with viscous losses and the more complex glottal geometries with entrance/exit effects in the glottis.
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(2018)Corticokinematic coherence (CKC) between limb kinematics and magnetoencephalographic (MEG) signals reflects cortical processing of proprioceptive afference. However, it is unclear whether strength of CKC is reproducible across measurement sessions. We thus examined reproducibility of CKC in a follow-up study. Thirteen healthy right-handed volunteers (7 females, 21.7 +/- 4.3 yrs) were measured using MEG in two separate sessions 12.6 +/- 1.3 months apart. The participant was seated and relaxed while his/her dominant or non-dominant index finger was continuously moved at 3 Hz (4 min for each hand) using a pneumatic movement actuator. Finger kinematics were recorded with a 3-axis accelerometer. Coherence was computed between finger acceleration and MEG signals. CKC strength was defined as the peak coherence value at 3 Hz form a single sensor among 40 pre-selected Rolandic gradiometers contralateral to the movement. Pneumatic movement actuator provided stable proprioceptive stimuli and significant CKC responses peaking at the contralateral Rolandic sensors. In the group level, CKC strength did not differ between the sessions in dominant (Day-1 0.40 +/- 0.19 vs. Day-2 0.41 +/- 0.17) or non-dominant (0.35 +/- 0.16 vs. 0.36 +/- 0.17) hand, nor between the hands. Intraclass-correlation coefficient (ICC) values indicated excellent inter-session reproducibility for CKC strength for both dominant (0.86) and non-dominant (0.97) hand. However, some participants showed pronounced inter-session variability in CKC strength, but only for the dominant hand. CKC is a promising tool to study proprioception in long-term longitudinal studies in the group level to follow, e.g., integrity of cortical proprioceptive processing with motor functions after stroke.
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(2021)Seipin is a disk-like oligomeric endoplasmic reticulum (ER) protein important for lipid droplet (LD) biogenesis and triacylglycerol (TAG) delivery to growing LDs. Here we show through biomolecular simulations bridged to experiments that seipin can trap TAGs in the ER bilayer via the luminal hydrophobic helices of the protomers delineating the inner opening of the seipin disk. This promotes the nanoscale sequestration of TAGs at a concentration that by itself is insufficient to induce TAG clustering in a lipid membrane. We identify Ser166 in the alpha 3 helix as a favored TAG occupancy site and show that mutating it compromises the ability of seipin complexes to sequester TAG in silico and to promote TAG transfer to LDs in cells. While the S166D-seipin mutant colocalizes poorly with promethin, the association of nascent wild-type seipin complexes with promethin is promoted by TAGs. Together, these results suggest that seipin traps TAGs via its luminal hydrophobic helices, serving as a catalyst for seeding the TAG cluster from dissolved monomers inside the seipin ring, thereby generating a favorable promethin binding interface.
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(2022)Space, time and number are key dimensions that underlie how we perceive, identify and act within the environment. They are interconnected in our behaviour and brain. In this study, we examined interdependencies between these dimensions. To this end, left- and right-handed participants performed an object collision task that required space–time processing and arithmetic tests that involved number processing. Handedness of the participants influenced collision detection with left-handers being more accurate than right-handers, which is in line with the premise that hand preference guides individual differences as a result of sensorimotor experiences and distinct interhemispheric integration patterns. The data further showed that successful collision detection was a predictor for arithmetic achievement, at least in right-handers. These findings suggest that handedness plays a mediating role in binding information processing across domains, likely due to selective connectivity properties within the sensorimotor system that is guided by hemispheric lateralisation patterns.
