International Journal of Clinical and Experimental Hypnosis
March 24, 2012
Quinton Deeley, David A. Oakley, Brian Toone et al.
149 citations
Hypnosis reduces activity in the default mode network (DMN), a set of brain regions active during rest and linked to self-awareness and task-independent thinking, while increasing activity in prefrontal attentional systems. Using brain imaging and subjective measures during passive visual stimulation, the authors found that the state of attentional absorption after a hypnotic induction was associated with these neural changes. Hypnosis and spontaneous conceptual thought at rest were both subjectively and neurally distinct, offering insight into the hypnotic state and its neural basis.
Schizophrenia Bulletin Open
January 1, 2020
M. Sami, R. Mccutcheon, U. Ettinger et al.
Both chronic cannabis use and psychotic disorders are linked to abnormalities in how the brain processes visual attention. Using resting-state fMRI, connectivity was measured in the visual and dorsal attention networks of people with early psychosis who did or did not use cannabis, and healthy controls who did or did not use cannabis. Patients with a history of cannabis use showed increased connectivity in the dorsal attention network (134%) and between the visual and dorsal attention networks (285%) compared to non-using controls. In patients who used cannabis, connectivity in these networks correlated with visual hallucinations and with severity of cannabis dependence. The findings suggest that disrupted connectivity in these networks may play different roles depending on cannabis use.
European Neuropsychopharmacology
July 1, 2018
M. Colizzi, P. McGuire, V. Giampietro et al.
Modest previous cannabis use blunts the acute behavioral and neurophysiological effects of ∆9-THC, the main psychoactive ingredient in cannabis. In a double-blind, placebo-controlled challenge, abstinent modest users (average 24.5 lifetime joints) showed worse cognitive performance and stronger right hemispheric brain activation than non-users, regardless of whether they received ∆9-THC or placebo. Acute ∆9-THC caused transient anxiety and psychosis-like symptoms in all participants, with stronger effects in non-users. Non-users under placebo activated specific brain areas for tasks while deactivating others, an opposite pattern to that seen in non-users under ∆9-THC and in cannabis users under placebo. Among non-users, more severe drug-induced symptoms and cognitive impairments correlated with greater neurophysiological changes.