Neuroscience and biobehavioral reviews
July 1, 2023
Daniel Collerton, James Barnes, Nico J Diederich et al.
80 citations
Eight distinct models of complex visual hallucinations have been proposed since 2000, each based on different views of brain organization. Researchers from each model group have now agreed on an integrated Visual Hallucination Framework that aligns with current theories of both real and hallucinatory vision. The Framework identifies cognitive systems involved in hallucinations and enables systematic investigation of how hallucination experiences relate to changes in underlying cognitive structures. The episodic nature of hallucinations points to separate factors for their onset, persistence, and end, suggesting a complex relationship between temporary states and long-term traits of hallucination risk. The Framework also suggests new research directions and potential treatments for distressing hallucinations.
Molecular Psychiatry
March 31, 2015
Jordi Riba, Marta Valle, Frederic Sampedro et al.
41 citations
Chronic cannabis users, even after a period of abstinence, are more prone to false memories—mistaking events that never occurred for real ones. Using functional magnetic resonance imaging, the study found that abstinent cannabis users showed reduced brain activity in areas critical for memory processing, including the lateral and medial temporal lobe, as well as in parietal and frontal regions involved in attention and monitoring. Cannabis consumption was inversely correlated with medial temporal lobe activity, indicating a specific detriment to episodic memory. These results suggest long-lasting impairments in memory and cognitive control mechanisms that support reality monitoring.
Nature reviews. Neurology
March 1, 2024
Javier Pagonabarraga, Helena Bejr-Kasem, Saul Martinez-Horta et al.
Psychosis in Parkinson disease (PDP) includes illusions, hallucinations, and delusions that can appear even early in the disease. While once thought to be solely a side effect of dopaminergic drugs, evidence now shows PDP results from the disease's own brain changes combined with medication. Dysfunction in attentional control, sensory processing, limbic structures, the default mode network, and thalamocortical connections leads to incorrect categorization of stimuli and false percepts. This review covers recent clinical, neuroimaging, and neurochemical findings that may help identify psychotic phenomena early and guide new treatments.