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The aim of the study was to explore the effects of situational stress and anxiety in a group of healthy elderly, both in terms of psychophysiological correlates and cognitive performance. Eighteen participants (Mage = 70 ± 6.3; range 60–85) were assessed for anxiety and were instructed to perform a computerized math task, under both a stressful and a control condition, while near-infrared spectroscopy (NIRS) signal and electrocardiography (ECG) were recorded. NIRS results evidenced an increased activation of right PFC during the entire procedure, even if effect sizes between left and right channels were larger during the experimental condition. The amount of right activation during the stressful condition was positively correlated with anxiety. Response times (RTs) were slower in more anxious than in less anxious individuals, both during the control and stressful conditions. Accuracy was lower in more anxious than in less anxious individuals, only during the stressful condition. Moreover, heart rate (HR) was not modulated by situational stress, nor by anxiety. Overall, the present study suggests that in healthy elderly, anxiety level has a significant impact on cerebral responses, and both on the amount of cognitive resources and the quality of performance in stressful situations.

Emotions characterized by opposite valences (positive vs. negative) seem to lead to specific patterns of autonomic and cortical activity. For example, according to valence or approach-withdrawal hypotheses, specific emotions lead to an asymmetrical activation of left or right prefrontal cortex (PFC). The aim of the present study was to explore the psychophysiological underpinnings of emotion experiencing using a paradigm with higher ecological validity than is typically accomplished in neuroimaging research. A total of 28 healthy participants were instructed to recall personally-relevant situations from the past that caused positive (happiness) or negative (anger) emotions, during a 2 min silent preparatory phase and a subsequent 3 min verbal phase. A wearable electrocardiographic (ECG) recording system and a portable 2-channel near-infrared spectroscopy (NIRS) device were used to collect heart rate (HR), high frequencies of heart rate variability (HF-HRV), and the hemodynamic responses of prefrontal cortex during the entire procedure. Results showed that during both anger and happiness recall tasks, HR increased and high frequencies of HRV decreased with respect to the baseline. HR and HF-HRV reached, respectively, their highest and lowest points during the verbal phase of anger recall task. NIRS data evidenced a bilateral increase of oxyhemoglobin concentration changes during both anger and happiness recall tasks, which was highest during the verbal phases. However, no lateralization patterns were found. Overall, present results suggest that the experience of negative emotions, if compared with positive ones, is characterized by a combination of reduced parasympathetic activation and/or increased sympathetic activation. Thus, cardiological data provided partial support to autonomic specificity of emotions. However, the recall paradigm did not evidence an asymmetry of PFC activity during the experience of emotions with opposite valences, probably due to the high nu

Stress responses are mediated by complex patterns of cortical and autonomic activity. Earlier studies showed increased recruitment of the right prefrontal cortex (PFC) and parasympathetic withdrawal during a stress task; however, it remains unclear whether these responses change in relation to different levels of psychopathological symptoms, such as trait anxiety. The present study examines the effect of a mathematical task (with a control condition and a stressful/experimental condition) on the PFC and autonomic activity, using a two-channel near infrared spectroscopy (NIRS) and an ECG monitoring system. After a preliminary screening of 65 subjects, a sample of 12 individuals (6 with the highest and 6 with the lowest scores on an anxiety questionnaire, i.e. the STAI trait) was selected. The two groups were similar regarding demographic variables (age, sex, body mass index) and baseline STAI-state scores. Repeated measures ANOVAs were used to compare changes from baseline in oxyhemoglobin (oxy-Hb), heart rate (HR) and root mean square of successive differences (RMSSD) between the two groups. Individuals affected by high levels of trait anxiety showed a reduced bilateral PFC activity during the entire experimental procedure compared to those with low anxiety. No differences in NIRS channels were found between the two groups. During both conditions, RMSSD was lower among individuals affected by high levels of anxious symptoms. Finally, throughout the procedure, changes in HR were higher in the anxious group. Overall, these findings suggest a reduced PFC activity and a larger parasympathetic withdrawal during a stress task in individuals with high levels of trait anxiety compared to those with low anxiety. These results could represent a starting point for future NIRS and ECG studies on the relationship between mental disorders and acute stress responses.

Aging is associated with changes in biological functions, such as reduced cardiovascular responses to stressful tasks. However, less is known about the influence of age on the reactivity of the prefrontal cortex (PFC) to acute stressors. Therefore, this study aimed to investigate the effects of a computerized-controlled stress task on the PFC and autonomic system activity in a sample of older and younger adults. We recruited a total of 55 healthy, right-handed persons (26 older adults with mean age 69.5, SD 5.8 years; and 29 younger adults with mean age 23.8, SD 3.3 years); groups were balanced for sex. Tasks included a control and an experimental condition: during both tasks individuals had to solve simple mental arithmetic problems. For the experimental condition, all participants were faced with a time limit that induced significant stress. Physiological indexes were collected continuously during the entire procedure using a 2-channel near infrared spectroscopy (NIRS) and an ECG monitoring system. Repeated measures ANOVA were used to assess changes in hemoglobin concentrations, and changes in both heart rate and performance outcomes. NIRS, ECG and performance data showed a significant interaction between the group and condition. Post-hoc analyses evidenced a significant increase in heart rate and Oxy-Hb concentration in the bilateral PFC between the control and experimental condition only in the younger group. Post-hoc analyses of behavioral data showed lower percentages of correct responses and higher response times in the older group. In summary, these results suggested that cardiovascular and cortical reactivity to stress tasks are a function of age. Older individuals seem to be characterized by blunted physiological reactivity, suggestive of impaired adaptive responses to acute stressors. Therefore, future studies should investigate the underlying physiological mechanisms of prefrontal and cardiovascular changes related to aging.

The purpose of this study was to assess the interrelation between cortical, cardiovascular, behavioural, and psychological responses to acute stressors in a large sample of healthy individuals. To date, there are only preliminary evidences for a significant association among these psychophysiological indexes during a stress task. 65 participants completed psychological questionnaires (Beck Depression Inventory and State-Trait Anxiety Inventory) and underwent a psychosocial math stress task, consisting of a control and an experimental (i.e. stressful) condition. Prefrontal and autonomic activities were recorded using respectively a 2-channel near-infrared spectroscopy (NIRS) device and a portable ECG monitoring system. Results evidenced an increased activation of both frontal areas assessed by NIRS, and a positive association between the right NIRS channel and heart rate changes from baseline, during both control and experimental conditions. Subjective stress increased during the procedure, reaching its maximum during the experimental condition. Behavioural performances during the task (e.g. response time) did not correlate with anxiety or depression. Autonomic data evidenced, as expected, an overall reduction of vagal tone during the experimental condition. Finally, severity of depressive and anxious symptoms predicted an increase in parasympathetic activity both at rest and during the task, even when controlling for respiration rate. Results support the hypothesis of an integration between right sectors of frontopolar or dorsolateral PFC and cardiac regulation. Trait anxiety and depression predicted an increase in vagal tone during the entire procedure. The implication of these findings is discussed.