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Studies showed that introversion is the strongest personality trait related to perceived social isolation (loneliness), which can predict various complications beyond objective isolation such as living alone. Lonely individuals are more likely to resort to social media for instantaneous comfort, but it is not a perpetual solution. Largely negative implications including poorer interpersonal relationship and depression were reported due to excessive social media usage. Conversational task is an established intervention to improve verbal communication, cognitive and behavioral adaptation among lonely individuals. Despite that behavioral benefits have been reported, it is unclear if they are accompanied by objective benefits underlying physiological changes. Here, we investigate the physiological signals from 28 healthy individuals during a conversational task. Participants were ranked by trait extraversion, where greater introversion is associated with increased susceptibility to perceived social isolation as compared to participants with greater extraversion as controls. We found that introverts had a greater tendency to be neurotic, and these participants also exhibited significant differences in task-related electrodermal activity (EDA), heart rate (HR) and HR variability (HRV) as compared to controls. Notably, resting state HRV among individuals susceptible to perceived loneliness was below the healthy thresholds established in literature. Conversational task with a stranger significantly increased HRV among individuals susceptible to isolation up to levels as seen in controls. Since HRV is also elevated by physical exercise and administration of oxytocin hormone (one form of therapy for behavioral isolation), conversational therapy among introverts could potentially confer physiological benefits to ameliorate social isolation and loneliness. Our findings also suggest that although the recent pandemic has changed how people are interacting typically, we should maintain a healthy dose of social interaction innovatively.

The effect of stress on task performance is complex, too much or too little negatively affects performance; and there exists an optimal level of stress to drive optimal performance. Task difficulty and external affective factors are distinct stressors that impact cognitive performance. Neuroimaging studies showed that mood affects working memory performance and the correlates are changes in haemodynamic activity in the prefrontal cortex (PFC). We investigate the interactive effects of affective states and working memory load (WML) on working memory task performance and haemodynamic activity using functional near-infrared spectroscopy (fNIRS) neuroimaging on the PFC of healthy participants. We seek to understand if haemodynamic responses could tell apart workload related stress from situational stress arising from external affective distraction. We found that the haemodynamic changes towards affective stressor and workload related stress were more dominant in the medial and lateral PFC respectively. Our study reveals distinct affective state-dependent modulations of haemodynamic activity with increasing WML in n-back tasks, which correlate with decreasing performance. The influence of negative affect on performance is greater at higher WML, and haemodynamic activity showed evident changes in temporal, and both spatial and strength of activation differently with WML.

The effect of stress on task performance is complex, too much or too little stress negatively affects performance and there exists an optimal level of stress to drive optimal performance. Task difficulty and external affective factors are distinct stressors that impact cognitive performance. Neuroimaging studies showed that mood affects working memory performance and the correlates are changes in haemodynamic activity in the prefrontal cortex (PFC). We investigate the interactive effects of affective states and working memory load (WML) on working memory task performance and haemodynamic activity using functional near-infrared spectroscopy (fNIRS) neuroimaging on the PFC of healthy participants. We seek to understand if haemodynamic responses could tell apart workload-related stress from situational stress arising from external affective distraction. We found that the haemodynamic changes towards affective stressor- and workload-related stress were more dominant in the medial and lateral PFC, respectively. Our study reveals distinct affective state-dependent modulations of haemodynamic activity with increasing WML in n-back tasks, which correlate with decreasing performance. The influence of a negative effect on performance is greater at higher WML, and haemodynamic activity showed evident changes in temporal, and both spatial and strength of activation differently with WML.

Biosignals from psychophysiological changes can be measured as electroencephalography (EEG), heart rate, skin conductance, and respiration rate, to name a few. They have been used in many research areas including human personality. Neuroticism, one of the five major traits underlie personality, reflects stable tendency towards experiencing negative emotions. An understanding of how neuroticism influences responses to psychological distress may shed a light upon individual differences in emotion self-regulation. To study the causal relationship between neuroticism and psychophysiological signals, a selection of appropriate baseline signals as a reference signal is essential to compare to current experimental signals of interest. Thus, we present classification of neuroticism using psychophysiological signals obtained during a speaking task based on two different baseline measurements (eyes closed and eyes open). Eight healthy male participants consisting of four neurotic and four emotionally stable subjects were recruited based on Eysenck Personality Inventory (EPI) and Big Five Inventory (BFI) scoring system. Four features including mean EEG beta power, heart rate, skin conductance, and respiration rate were used for the classification using a Support Vector Machine (SVM). The results showed higher classification accuracy achieved with eyes open as the baseline (62.5%) as compared to eyes closed as the baseline (37.5%), during speaking task. This indicate the importance of selecting appropriate baseline in analysis involving EEG and physiological signals.

Neuroticism is correlated with negative emotion such as anxiety, fear, depressed mood and loneliness which could be measured using physiological signals such as skin conductance, heart rate, and respiration rates. In this paper, we aim to investigate the correlation between neuroticism and physiological changes during speaking tasks. Eight healthy male subjects were selected including four subjects with high level of neuroticism (neurotic) and four emotionally stable subjects evaluated by Eysenck Personality Inventory (EPI) and Big Five Inventory (BFI) tools. The physiological responses were recorded during baseline measurements (eyes closed and eyes open) and during speaking tasks by using the FlexComp Infiniti encoder with Biograph Infiniti software by Thought Technology Ltd. The results showed that the skin conductance and the heart rate of neurotic subjects were higher than that of the stable subjects during baseline measurements and speaking tasks. In comparison to the baseline, lower respiration rate was exhibited in both stable and neurotic subjects during speaking tasks. However, the neurotic subjects exhibited slight increase in their respiration rates compared to the stable subjects. This paper provides preliminary evidence for physiological responses associated with neuroticism that can shed some light in social interaction studies, stress reduction studies based on mindfulness or emotion regulation to name a few.

Neuroimaging studies show that mood affects working memory performance (WMP) through changes in haemodynamic activity (HA) in the prefrontal cortex (PFC). However, it is unknown how WMP and HA is modulated by increasing working memory load (WML) under different mood states. We investigate the interactive effects of mood state (psychological factor) and WML (difficulty factor) on WMP and HA with N-back task using functional near-infrared spectroscopy (fNIRS) neuroimaging of the PFC in 31 healthy subjects (HS). Our study reveals distinct mood-dependent modulations of HA with increasing WML which correlate with decreasing WMP. The influence of mood on performance is greatest at high WML.

The chapter aims at analyzing the impact of induced-mood states on working-memory functions of the prefrontal cortex. We would like to propose functional near-infrared spectroscopy (fNIRS) as alternative neuroimaging modality for functional magnetic resonance imaging to allow a more naturalistic settings. fNIRS allows the subject to sit comfortably (neuroergonomics) and therefore it is less likely to randomly modulate the subject's emotion, suitable for study related to psychology. 31 participants were chosen to undergo the n-back task paradigm and the results were recorded.

Cognitive brain functions such as language, comprehension, planning and reasoning require working memory (WM), a temporary storage which holds a limited information for instant manipulation. It is hypothesized that WM performance play an important role in altering the brain activity on the prefrontal cortex (PFC) region. Here, Optical Topography Functional Near Infrared Spectroscopy (OT-fNIRS) was used to measure the haemodynamic responses on the PFC during n-back tasks with incremental WM loads (N= 0, 1, 2). Behavioural and functional data were acquired from 14 male university student volunteers to examine the effects of n-back WM task performance. Subjects were categorized as high performance (>90% accuracy for all tasks) and normal groups for further analysis. Behavioural results showed that the normal group responded slower, regardless of the given WM load. During 2-back task, subjects in normal group performed significantly poor (low accuracy, p

Neuroimaging studies have shown that negative mood states will impair the working memory (WM) functions that affect haemodynamic conditions at the prefrontal cortex (PFC) region. Compared to other neuroimaging tools, haemodynamic responses in surrounding brain surfaces can be assessed feasibly and with less constrained using Optical Topography (OT). This paper presents near infrared spectroscopy (NIRS) signal analysis technique and OT brain haemodynamic assessment methods to investigate sensorimotor and working memory tasks, without biasing of mood. The continuous OT measurements for finger-tapping task and N-back tasks should result in significant task activation on the lateral motor cortex region and PFC region respectively. Findings from the first study confirmed the phenomena of contralateral motor cortex activation. In the second study, it is found that larger haemodynamic responses are associated with N-back WM task with higher difficulty.