Factors of influence in prisoner's dilemma task: a review of medical literature.

The Prisoner's Dilemma (PD) is one of the most popular concepts amongst the scientific literature. The task is used in order to study different types of social interactions by giving participants the choice to defect or cooperate in a specific social setting/dilemma. This review focuses on the technical characteristics of the PD task as it is used in medical literature and describes how the different PD settings could influence the players' behaviour. We identify all the studies that have used the PD task in medical research with human participants and distinguish, following a heuristic approach, seven parameters that can differentiate a PD task, namely (a) the opponent parties' composition; (b) the type of the opponent as perceived by the players; (c) the interaction flow of the game; (d) the number of rounds; (e) the instructions narrative and options that are given to players; (f) the strategy and (g) the reward matrix and payoffs of the game. We describe how each parameter could influence the final outcome of the PD task and highlight the great variability concerning the settings of these parameters in medical research. Our aim is to point out the heterogeneity of such methods in the past literature and to assist future researchers with their methodology design.

Resilience of the Hellenic navy seals assessed by heart rate variability during cognitive tasks.

OBJECTIVES: The interaction between high physical performance under extreme conditions in military and the simultaneous control of the cognitive executive functioning has been a subject of research in literature for the past few decades. Stroop test and Heart-rate variability (HRV), have been verified valuable clinical tools for the assessment of cerebral and autonomic/ cardiovascular stress responses respectively. METHODS: Thirty-four subjects were enrolled in this study. Of them, 18 were candidates under intense preparation for their enlistment in the Hellenic Navy SEALs (HN-SEALs) and 16 were healthy controls (HC). All subjects underwent stroop tasks, along with mental state and personality examination. HRV variables in time and frequency domains recordings were acquired, during each aforementioned cognitive testing procedure. RESULTS: Our results showed that HNS's performance on both cognitive and emotion stroop tasks were equivalent to controls (p≥.054); however, HNS exhibited statistically significant lower levels of HRV in different time and frequency domain variables, compared to HC (ranged from p<.01 to p<.05). Finally, in a between group comparison of the psychometric tools, HNS had significantly higher somatization, anxiety and neuroticism than HC. CONCLUSION: In conclusion, these findings indicate that HNS display flexibility in their autonomic regulation during cognitive and emotional tasks. This characteristic is closely related to problem solving or adaptability skills. Therefore, we support that HRV measurement turns out to be an invaluable tool for both scientific and clinical insights, promising to be an index regarding the psychophysiological resilience especially in the neurovisceral integration (NVI) model.

Assessment of Resilience of the Hellenic Navy Seals by Electrodermal Activity during Cognitive Tasks.

Stress resilience plays a key role in task performance during emergencies, especially in occupations like military special forces, with a routine consisting of unexpected events. Nevertheless, reliable and applicable measurements of resilience in predicting task performance in stressful conditions are still researched. This study aimed to explore the stress response in the Hellenic Navy SEALs (HN-SEALs), using a cognitive-physiological approach. Eighteen candidates under intense preparation for their enlistment in the HN-SEALs and 16 healthy controls (HCs) underwent Stroop tests, along with mental-state and personality examination. Simultaneously, electrodermal activity (EDA) was assessed during each one of cognitive testing procedures. Compared to healthy control values, multiple components of EDA values were found decreased (p < 0.05) in the HN-SEALs group. These results were associated with an increase in resilience level in the HN-SEALs group, since a restricted sympathetic reactivity according to the reduced EDA values was observed during the stressful cognitive testing. This is the first report providing physiological measurements of the sympathetic response of HN-SEALs to a stressful situation and suggests that EDA turns out to be a simple and objective tool of sympathetic activation and it may be used as a complementary index of resilience in HN-SEALs candidates.

Endocannabinoids and Heart Rate Variability Alterations after Exposure to Prolonged Intensive Physical Exercise of the Hellenic Navy SEALs.

BACKGROUND: Recent research indicates that both endocannabinoids (eCB) and heart rate variability (HRV) are associated with stress-induced experiences. However, these underlying mechanisms are not elucidated. The present study aims to investigate whether exposure to acute and chronic stress conditions can give rise to measurable changes, both to the peripheral eCB ligands and HRV. METHODS: Thirteen candidates under intense preparation for their enlistment in the Hellenic Navy SEALs (HNS) participated in the study. All subjects underwent mental state examination, while HRV variables in time and frequency domain recordings were acquired. Furthermore, at baseline and 30 days after prolonged and intensive physical exercise, hair was collected to measure eCB ligands, such as anandamide (AEA), 2-arachidonoylglycerol (2-AG), and the N-acyl ethanolamine (NAE) molecules: palmitoylethanolamide (PEA) and oleoylethanolamide (OEA). RESULTS: Comparing basal hair concentrations of eCB ligands before and after intense physical exercise, we found that AEA, PEA, and OEA were notably increased, whereas no differences were observed regarding the ligand 2-AG. Furthermore, there were observed associations between the concentrations of peripheral eCB ligands, both at baseline and after the prolonged physical exercise and the time and frequency domains of HRV. CONCLUSIONS: These findings suggest that endocannabinoid-HRV interrelations might share a short-term, and long-term adaptability of the changes in self-regulation associated with stress. Further studies will be required to determine the validity of peripheral eCB signaling and HRV as a biomarker for different aspects of the stress response.

Lifetime co-occurring psychiatric disorders in newly diagnosed adults with attention deficit hyperactivity disorder (ADHD) or/and autism spectrum disorder (ASD).

BACKGROUND: Co-occurring psychiatric disorders in adults with Attention Deficit Hyperactivity Disorder (ADHD) and/or Autism Spectrum Disorder (ASD) contribute to the burden of the healthcare and possibly to the delay of diagnosis. Aim of the study was to clinically assess the prevalence and compare lifetime co-occurring psychopathology in a sample of newly diagnosed ADHD and/or ASD adults and discuss the diagnostic challenges they pose. METHODS: The lifetime prevalence rates of ten of the most frequently co-occurring psychiatric diagnoses was registered in 336 adults of normal intelligence who underwent a thorough clinical evaluation for the diagnosis of ADHD and/or ASD for the first time in their lives. Four study groups were formed: the ADHD (n = 151), the ASD (n = 58), the ADHD+ASD (n = 28) and the nonADHD/nonASD (NN) (n = 88) group. RESULTS: At least one co-occurring psychopathology was found in 72.8% of the ADHD group, in 50% of the ASD group, in 72.4% of the ADHD+ASD group and in 76.1% of the NN group (p = 0.004). In all groups the most frequent psychiatric disorder was depressive disorder. The only significant difference regarding the patterns of psychiatric co-occurrence between the ADHD and the nonADHD groups (ASD and NN groups) was found for SUD (p = 0.001). Also, the proportion of subjects with Bipolar Disorder was significantly greater in the NN group as compared to those with ASD (p = 0.025). CONCLUSIONS: Our results support the high prevalence of co-occurring psychiatric disorders in adults with ADHD and/or ASD with the ASD group presenting the lowest rate. The most marked difference between the ADHD and the nonADHD groups was found for SUD. Moreover, our findings highlight the need for a thorough clinical assessment of all referred patients both in the presence and absence of ADHD and/or ASD.

Long survival in a 69,XXX triploid infant in Greece.

The live birth of a triploidy infant is a very rare event and death usually occurs within the first hours of life. Triploid cases with a survival of more than two months are infrequent. We report on an infant with a 69,XXX chromosome constitution who survived 164 days. Chromosomal analysis demonstrated a 69,XXX karyotype with no evidence of mosaicism. This is the longest survival reported for this condition to date in Greece and the fourth longest worldwide. The infant was admitted to our clinic several times due to respiratory problems, and supplementary oxygen was required. The improved survival of our case was possibly due to better management of respiratory illness and prematurity, and these are essential factors that physicians should consider carefully with such rare cases.