Psychedelic Research

Perceptual rivalry is one of the neatest ways to study the neural correlates of the contents of consciousness. If you’re not familiar with this phenomenon, you can read Olivia Carter’s online tutorial on binocular rivalry, one commonly studied type of perceptual rivalry. (There’s also some nice images in a Figure from Blake & Logothetis’ 2002 Nature Reviews Neuroscience article here).

Perceptual rivalry should fascinate anyone with an interest in consciousness research. It is also a rare area where scientific studies of consciousness and hallucinogens converge. Carter has done groundbreaking studies (links below) of how psilocybin and possibly LSD affect perceptual rivalry, including some research using the amazing phenomenon of motion-induced blindness (demo here), my favorite visual illusion. Carter’s research is consistently inspiring: She uses rigorous quantitative tools to measure the effects of pharmacological manipulations on consciousness. Her work is one reason I consider perceptual rivalry among the most interesting directions to pursue in future human hallucinogen research, even if (as Carter and Dittrich’s data suggest) hallucinogens do not affect rivalry through a 5-HT2A mechanism.

Two noteworthy developments in non-hallucinogenic rivalry research are a paper by Jakob Hohwy and colleagues giving an elegant theory for why rivalry occurs and a great paper by Joel Pearson and colleagues showing that mental imagery influences rivalry.
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How does brain activity differ when you are aware of something vs. when you are not? This brief article by Melanie Boly and colleagues reviews this question. These researchers have done some interesting work on brain activity in people in persistent vegetative states, and this paper discusses neural activity associated with self-awareness.
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