A growing proportion of the population is engaging in recreational psychedelic use. Psychedelics are uniquely capable of reliably occasioning mystical experiences in ordinary humans without contemplative or religious backgrounds. While clinical research has made efforts to characterize psychedelic experiences, comparably little is understood about how humans naturalistically engage with psychedelics. The present study employs a mixed-methods approach to examine the content and implications of psychedelic and mystical experiences, occurring outside of laboratory settings. We use text mining analyses to arrive at a qualitative description of psychedelic experiential content by abstracting from over two-thousand written reports of first-person psychedelic experiences. Following up, we conducted quantitative analyses on psychometric data from a large survey (N = 1424) to reveal associations between psychedelic use practices, complete mystical experiences, and psychological wellbeing. Topic-modelling and sentiment analyses present a bottom-up description of human interactions with psychedelic compounds and the content of such experiences. Psychometric results suggest psychedelic users encounter complete mystical experiences in high proportions, dependent on factors such as drug type and dose-response effects. Furthermore, a salient association was established between diverse metrics of wellbeing and those with complete mystical experiences. Our results paint a new picture of the growing relationships between humans and psychedelic experiences in the real-world use context. Ordinary humans appear to encounter complete mystical experiences via recreational psychedelic use, and such experiences are strongly associated with improved psychological wellbeing.

Rationale: Both psychedelics and mindfulness are a recently emerging topic of interest in academia and popular culture alike. Personal meditation practices and recreational psychedelic use have consistently increased in the past decade. While clinical work has shown both to improve long-term wellbeing, the data on naturalistic applications of psychedelics and mindfulness is rather lacking.Objective: The current study aims to examine the relationship between psychedelic use, mindfulness, and multi-faceted wellbeing as an outcome. Hierarchical regression was used to quantify these associations on a large sample of people (N = 1219), who engage in both meditation practices and psychedelic use.Results: These results show that both mindfulness and mystical experiences each predict substantial increases in wellbeing. Psychedelics were found to be an important moderator of mystical experience to explain improvements in wellbeing.Conclusions: These data are among the first to establish a strong relationship between personal mindfulness practice, recreational psychedelic use, and overall psychological wellbeing in a naturalistic framework.

Prototype, exemplar, and boundary models compete to explain representational-level abstractions during human category learning. Vast majority of previous work use linear categories structures to evaluate learning. We present the development of a novel, circular category structure and leverage it to explore limitations of prototype, exemplar and boundary models. We find that circular categories are readily learned by human participants, and the induced representation is most likely a quadratic boundary. We deductively eliminate prototype theories as an explanation of these circular categories and show that exemplar models, though viable, provide a weaker explanation than boundary models which are best fitted to the present data. These circular category structures offer a promising new technique to studying implicit category learning.

The dual-process theory of thinking defines a heuristic-based System I which trades-off precision and accuracy in favour of speed. It is prone to consistent range of error modes formalized as cognitive biases. In contrast, System II is slower, requires deliberate engagement but can work through complex problems with lower error. Mindfulness research points to positive improvements in higher-cognition processes with specific emphasis on attention and an attitude of non-judgement; both are thought to underlie successful recruitment of System II. We hypothesized that individuals with higher mindfulness would be less susceptible to common cognitive biases. We evaluate two constructs of mindfulness. Trait mindfulness: a long-term dispositional mindfulness with can enhanced via deliberate training but otherwise remains consistent across an individual’s lifetime. State mindfulness: refers to a short-term experience of mindfulness which is subject to experimental manipulation. The present study consists of two-arms. The first arm (N = 391) was administered completely online and evaluates trait mindfulness. The second arm (N =191) was conducted in-lab and randomized participants into one of two conditions: mindfulness induction or a sham control condition. Participants from both arms underwent performance assessment on a battery of common cognitive bias tasks. We found that trait mindfulness was associated with reduced susceptibility to specific biases: anchoring, resistance to sunk costs, availability, and logical fallacies. Contrary to expectations, experimental manipulation of state mindfulness did not influence susceptibility to cognitive biases when compared to the sham control. These findings suggest trait, but not state mindfulness may improve resistance to cognitive biases.