Increased Entropic Brain Dynamics during DeepDream-Induced Altered Perceptual Phenomenology

Abstract

In recent years, the use of psychedelic drugs to study brain dynamics has flourished due to the unique opportunity they offer to investigate the neural mechanisms of conscious perception. Unfortunately, there are many difficulties to conduct experiments on pharmacologically-induced hallucinations, especially regarding ethical and legal issues. In addition, it is difficult to isolate the neural effects of psychedelic states from other physiological effects elicited by the drug ingestion. Here, we used the DeepDream algorithm to create visual stimuli that mimic the perception of hallucinatory states. Participants were first exposed to a regular video, followed by its modified version, while recording electroencephalography (EEG). Results showed that the frontal region’s activity was characterized by a higher entropy and lower complexity during the modified video, with respect to the regular one, at different time scales. Moreover, we found an increased undirected connectivity and a greater level of entropy in functional connectivity networks elicited by the modified video. These findings suggest that DeepDream and psychedelic drugs induced similar altered brain patterns and demonstrate the potential of adopting this method to study altered perceptual phenomenology in neuroimaging research.

Simulated visual hallucinations in virtual reality enhance cognitive flexibility

“…Crucially, these results seem to corroborate at the behavioral level the findings from Greco et al 37 , in which they observed a general increased entropic brain dynamics due to DeepDream exposure. Therefore, it seems reasonable to interpret these mouse trajectories findings in light of the entropic brain hypothesis 32 , 35 , according to which, during psychedelic experiences, the brain is supposed to operate at a criticality state, where it has access to a larger repertoire of physical states and therefore has a more chaotic dynamics.…”

“…DeepDream is a computational procedure that alters images relying on a pre-trained deep convolutional neural network (CNN), a process also referred to as “algorithmic pareidolia” 37 . The algorithm starts by passing an input image with width ( ) and height ( ) through the CNN up to a selected layer .…”

“…Using behavioral measures, they found that this simulation induced visual perceptual phenomenology qualitatively similar to psychedelics, directly comparing the effects of psilocybin and perceptual experiences induced by this Hallucination Machine 36 . Moreover, Greco et al 37 found similar brain patterns between psychedelic drugs and the artificially-induced altered perceptual phenomenology, with an increased entropic brain dynamics and global functional connectivity. These findings further support such methodology the study of the phenomenological aspects of the psychedelic experience.…”

“…Despite earlier scientific studies demonstrating a beneficial effect of psychedelics on CF, experimental evidence is lacking whether the Hallucination Machine might modulate CF similarly to the actual psychedelic experience. Since DeepDream altered perceptual phenomenology in VR appears to be qualitatively comparable to psychedelic experience 36 , 37 , and the latter seems to modulate CF 21 – 24 , 33 , it is noteworthy to examine the effects of DeepDream altered perceptual phenomenology in VR on CF. Importantly, if artificially-induced perceptual phenomenology is able to mediate changes in CF, it could be used as a potentially novel, ecological, and controlled tool to investigate CF, as well as the underlying neural mechanisms.…”

Psychedelic replications in virtual reality and their potential as a therapeutic instrument: an open-label feasibility study

“…Recent developments in VR technology suggest that it could be possible to induce mystical experiences 52,53 and imitate parts of the phenomenology of the psychedelic state 54 . Also, some recent studies have suggested that using psychedelic phenomenology in VR can lead to similar cognitive 55 and neural 56 effects as seen under psychedelic substances. Thus, these recent works raise the intriguing possibility that perhaps the implementation of such phenomenology in VR could be used to confer similar therapeutic benefits to psychedelicaugmented therapy.…”