Interhemispheric fusion

Psychointegrators: Multidisciplinary Perspectives on the Therapeutic Effects of Hallucinogens

Vision-inducing plants ("hallucinogens") are important in many societies, evoking powerful emotional, psychological, cognitive, religious, spiritual, therapeutic and political reactions. These substances' psychophysiological properties shape cross- cultural similarities in patterns of use and experiences, while political factors shape their cultural desirability. Neurological studies illustrate that common effects are based in intervention in serotonergic neurotransmission. Effects upon neural, sensory, emotional, and cognitive processes stimulate integrative information processing, justifying a new term-"psychointegrators." Psychointegrators disin hibit sensory and emotional processes. They stimulate systemic integration of brain information-processing functions, enhancing integration of limbic system self and emotional dynamics with neocortical processes. Their therapeutic applications are reviewed from perspectives of cross-cultural and clinical studies.

Effects of the Amazonian psychoactive beverage Ayahuasca on binocular rivalry: interhemispheric switching or interhemispheric fusion?

An early theoretical analysis supposed changes in hemispheric integration as the basis of altered state of consciousness induced by psychoactive drugs. Brain imaging studies revealed right cortical activation after administration of hallucinogens. Recent studies on binocular rivalry suggest that interhemispheric switching is the neural substrate of the perceptual oscillations observed during dichoptic stimulus presentation. The current study tested perceptual alternation in ceremonial participants, who ingested the South American hallucinogenic beverage ayahuasca, to examine the claim that there might be changes in interhemispheric function under the influence of hallucinogens. Ingestion of ayahuasca resulted in a decrease of rivalry alternation rates, increased length of one percept and there was evidence of phenomenal fusion. The findings are in line with results of brain activation studies and support the concept of interhemispheric fusion in altered states of consciousness.