A single low oral dose of the synthetic cannabinoid nabilone (1-2 mg) impaired both verbal and spatial working memory in healthy adults, with a stronger effect in people who used cannabis less frequently. Spatial working memory was more affected than verbal working memory. The drug did not significantly change psychosis-like experiences (schizotypy scores). However, higher schizotypy scores were linked to worse working memory under placebo, and more frequent cannabis use was associated with better overall working memory across drug conditions, suggesting tolerance to the memory-impairing effects of cannabinoids.
A single-blind, placebo-controlled crossover study tested whether a synthetic THC analogue, Nabilone (1-2 mg), alters the sense of agency and body ownership in 32 healthy volunteers, comparing effects to those previously seen in schizophrenia. The study found that Nabilone had multimodal and bidirectional effects on the projected hand illusion, widening the spatio-temporal binding window in some participants and narrowing it in others, depending on spatial and temporal conditions. Evidence supported a unitary spatio-temporal binding window rather than separate spatial and temporal windows. No significant associations were found between agency and embodiment measures, and a large proportion of participants did not experience the illusion.
Large-scale brain networks function near a critical state, and partial phase locking—a network science concept—shapes the characteristic functional connectivity and asymmetric anterior-posterior phase lag entropy (PLE) topography at this critical state, with low PLE for high-degree nodes and high PLE for low-degree nodes. Comparing PLE topography at criticality with electroencephalogram data from baseline consciousness, isoflurane anesthesia, ketamine anesthesia, vegetative state/unresponsive wakefulness syndrome, and minimally conscious state shows that topographical similarity and strength of PLE differentiate these pharmacologic and pathologic states of consciousness. This provides a theory-based metric to quantify how far a perturbed brain network deviates from criticality, rather than merely determining critical or non-critical state.
A practical method estimates integrated information (Φ), a measure proposed by integrated information theory to be related to consciousness, from 128-channel EEG. The method alone cannot distinguish certain anesthetic states, but combining Φ with four EEG connectivity parameters—power, frequency, functional connectivity, and modularity—differentiates all states of consciousness. The association of Φ with EEG connectivity during anesthesia offers a new approach to applying the theory, potentially useful for characterizing consciousness in sleep, anesthesia, and coma.