The relation between naturalistic use of psychedelics and perception of emotional stimuli: An event-related potential study comparing non-users and experienced users of classic psychedelics

Naturalistic use of psychedelics does not modulate processing of self-related stimuli (but it might modulate attentional mechanisms): An event-related potentials study

Classic psychedelics are able to profoundly alter the state of consciousness and lead to acute experiences of ego dissolution - the blurring of the distinction between representations of self and the external world. However, whether repeated use of psychedelics is associated with more prolonged and permanent modifications to the concept of self remains to be investigated. Therefore, we conducted a preregistered, cross-sectional study in which experienced psychedelics users (15 or more lifetime experiences with psychedelics; N = 56) were compared to nonusers (N = 57) in terms of neural reactivity to a Self-name (i.e., each participant's own name) stimulus, which is known to robustly activate a representation of self. Two control stimuli were additionally used: an Other-name stimulus, as a passive control condition in which no reaction was required, and a Target-name stimulus, to which participants provided a manual response and which thus constituted an active control condition. Analysis of the amplitude of the P300 ERP component evoked by the Self- or Target-names revealed no difference between the psychedelics users and nonusers. However, psychedelic users exhibited increased P300 amplitude during perception of Other-names. In addition, in comparison to nonusers, psychedelics users exhibited a smaller increase in P300 amplitude when processing the task-relevant Target-names (in relation to both Self- and Other-names). Therefore, our data suggests that regular naturalistic use of psychedelics may not be related to long-term changes in the representation of self, but it might potentially affect the allocation of attentional resources to task-relevant stimuli.

Fatigue in taxi drivers and its relationship with traffic accident history and experiences: a cross-sectional study in the north of Iran

BACKGROUND

The monotonous nature of work, long driving duration, and working overload hours cause frequent fatigue in taxi drivers. A high prevalence of fatigue is associated with traffic accidents. However, the risk factors associated with taxi driver fatigue are unclear. Therefore, the present study aims to determine the rate of fatigue in taxi drivers and its relationship to their traffic accident experience.

METHODS

In this descriptive-analytical study, 400 taxi drivers in the city of Rasht were registered in Taxi association selected through random sampling and entered into the study based on inclusion criteria. Data was collected through a researcher-made questionnaire reliable and valid by two medical students. The statistical analysis used ordinal data and a Poisson regression model with SPSS software version 21, with a significance level set at 5%.

RESULTS

The driver fatigue self-reported was directly and significantly related to alcohol consumption (OR = 3.43, 95% CI 1.01-11.62) and had a significant and inverse relationship with smoking (OR = 0.50, 95% CI 0.32-0.76), being married (OR = 0.08, 95% CI 0.01-0.40) and driving experience there was (OR = 0.96, 95% CI 0.94-0.98). Drivers' sense of quality of life (QOL) was directly and significantly related to smoking (IRR = 1.43, 95% CI 1.28-1.59), education level under diploma (IRR = 2.41, 95% CI 1.43-4.06) diploma (IRR = 2.06, 95% CI 1.21-3.48) and bachelor (IRR = 2.42, 95% CI 1.36-4.29) and there was a significant and inverse relationship with age (IRR = 0.98, 95%CI 0.98-0.99). There was a significant relationship between the number of traffic accidents in the past year with the level of bachelor's degree (IRR = 3.10, 95% CI 1.43-6.76) and driving experience (IRR = 1.03, 95% CI 1.02-1.04 and inverse relationship between the number of traffic accidents in the past year and the QOL sense (IRR = 0.96, 95% CI 0.93-0.99) and the working hours (IRR = 0.96, 95% CI 0.94-0.99).

CONCLUSION

Legislators and policymakers should pay more attention to fatigue in single and inexperienced taxi drivers. Regarding the QOL, pay attention to drivers with high education and older. To reduce the number of crashes, pay more attention to drivers with a bachelor's degree and less driving experience and improve the feeling of QOL.