The effects of microdose LSD on time perception: a randomised, double-blind, placebo-controlled trial

Rationale: Previous research demonstrating that lysergic acid diethylamide (LSD) produces alterations in time perception has implications for its impact on conscious states and a range of psychological functions that necessitate precise interval timing. However, interpretation of this research is hindered by methodological limitations and an inability to dissociate direct neurochemical effects on interval timing from indirect effects attributable to altered states of consciousness. Methods: We conducted a randomised, double-blind, placebo-controlled study contrasting oral administration of placebo with three microdoses of LSD (5, 10, and 20 μg) in older adults. Subjective drug effects were regularly recorded and interval timing was assessed using a temporal reproduction task spanning subsecond and suprasecond intervals. Results: LSD conditions were not associated with any robust changes in self-report indices of perception, mentation, or concentration. LSD reliably produced over-reproduction of temporal intervals of 2000 ms and longer with these effects most pronounced in the 10 μg dose condition. Hierarchical regression analyses indicated that LSD-mediated over-reproduction was independent of marginal differences in self-reported drug effects across conditions. Conclusions: These results suggest that microdose LSD produces temporal dilation of suprasecond intervals in the absence of subjective alterations of consciousness

Correction to: The effects of microdose LSD on time perception: a randomised, double-blind, placebo-controlled trial

n/

L'analyse cognitive des expressions composées (le cas des verbes composés en persan)

Il existe un phénomène linguistique étonnant dans la langue persane. La grande majorité des verbes se présentent comme des formes composées à partir d'un verbe support (VS), et d'un autre élément lexical, appelé préverbe (PV). Chaque VS se combine avec une grande variété de PV pour former des constructions à verbe-support (CVS) différentes avec une grande variété de sens. En raison du caractère quasi-compositionnel de ces formes, les CVS persanes présentent une ouverture intéressante sur le processus de construction de sens. Dans cette thèse, j'étudie le problème de la construction du sens d'un énoncé composé, afin d'examiner des propriétés fondamentales des langues humaines : la productivité linguistique, la compositionalité, la polysémie, et la construction des expressions composées. Cette thèse propose que l'espace sémantique des constructions verbales persanes est organisés en ilôts notionels représentés par des constructions exprimant des propriétés linguistiques et cognitifs.Persian has a deceptively small repertoire of about 160 single word verbs wich belies an intricate system of light verb constructions (LVC). A sophisticated verbal system results from this small set of light verb construction (LVC). A sophisticated verbal system results from this small set of light verbs. The LVs combine with an open set of preverbs (PV) to produce new verbal expressions. The meaning of the whole is more than the sum of the meaning of its parts. The objective of the current study is to investigate the mechanisms that regulate the meaning of LVCs. We introduce the idea of islands, where a cluster a LVCs express similar verbal notions using the same LV and a strict class of PVs. This study sheds light on the organization of highly structured verbal semantic space of Persian and opens a window from wich we can study fundamental properties of human languages and conceptual systems : productivity, compositionality, polysemy, and the construction of composite expressions.PARIS3-BU (751052102) / SudocPARIS-Fondation MSH (751062301) / SudocSudocFranceF

Evidence for a constituent order boost in structural priming

The study investigates the role of constituent order in structural priming. We report the results from a PO/DO priming experiment in German, in which we experimentally manipulated verb position in primes and targets. Significant structural priming effects occurred irrespective of whether verb position was the same in prime and target or not. However, additional similarity in constituent order was able to boost structural priming effects, with significantly stronger priming when the verb occurred in the same position in prime and target. We argue that existing one-stage and two-stage accounts of formulation struggle to account for the entire data pattern and propose an alternative account of formulation which can explain our results

Evidence for a constituent order boost in structural priming

The study investigates the role of constituent order in structural priming. We report the results from a PO/DO priming experiment in German, in which we experimentally manipulated verb position in primes and targets. Significant structural priming effects occurred irrespective of whether verb position was the same in prime and target or not. However, additional similarity in constituent order was able to boost structural priming effects, with significantly stronger priming when the verb occurred in the same position in prime and target. We argue that both one-stage and two-stage accounts of formulation struggle to account for the entire data pattern, and propose an alternative account of formulation which can explain our results

Perceptions of safety, subjective effects, and beliefs about the clinical utility of lysergic acid diethylamide (LSD) in healthy participants within a novel intervention paradigm: Qualitative results from a proof-of-concept study.

Background: Classic psychedelics show promise in the treatment of mental health conditions; however, more scalable intervention protocols are needed to maximize access to these novel therapeutics. In this proof-of-concept study, perceptions of safety, subjective effects, and beliefs about the clinical utility of lysergic acid diethylamide (LSD) were evaluated among healthy participants (N = 31) administered 50 to 100 µg LSD in a treatment paradigm conceptualized as more scalable than traditional approaches to administering classic psychedelics. Methods: Semi-structured interviews assessed participants’ expectations, experience, and thoughts on the safety and efficacy of the study design. These interviews were transcribed for thematic analysis relating to perceptions of safety, subjective effects, and beliefs about the clinical utility of LSD. Results: Most participants felt safe throughout the study, with a minority reporting concerns related to having a challenging experience that diminished over time. Participants attributed their feelings of safety to the study structure and support of their attendants, which allowed them to “let go” and immerse themselves in the experience without pre-occupation. Furthermore, participants reported transcendent, mystical-type experiences characteristic of classic psychedelics, with almost half highlighting the prominent role played by music during the acute period of drug action. Finally, participants endorsed support for the clinical utility of LSD in controlled environments, expressing the belief that LSD is safe and has the potential to help others. Conclusion: Findings provide preliminary support for the feasibility of this scalable interventional paradigm and set the stage for future critical research with clinical populations