Recently, psychotherapeutic medical trials have been performed in Switzerland using LSD to rehabilitate patients suffering from various ailments. In response to this, I have felt compelled to consider where the intersection exists between cognitive processing and psychedelic experiences. As the stimulation of both consciousness and sensory actions occur in this altered state of mind, psychedelic synesthesia comes to mind as a junction.

         Psychedelic synesthesia can be described as the connection between multisensory perception and an altered state of consciousness induced by a psychedelic substance. Synesthesia, from a contemporary neurological viewpoint, is a condition where one sensory pathway invokes involuntary experiences in a secondary sensory pathway (Cytowic, 2002).  Classical synesthesia is exhibited in those who, for example, see numbers or letters in colours; i.e. the number 2 is considered yellow, or the word Tuesday is perceived as Blue. Ordinal Linguistic Personification (OLP) involves number forms being associated with personality or gender, such 1981 being a female or Sunday being regarded as kind and gentle (Simner & Holenstein, 2007). One of the more recent discoveries, and a reported experience in psychedelic activated synesthesia, is known as Visually Induced Auditory Synesthesia. Within this form, synesthetes(those who experience synesthesia) are able to hear sounds as a response to visual motion (Saenz & Koch, 2008).

         Yet perhaps better known within psychedelic subculture, is the inverse in which auditory processing induces visual synesthesia. To exemplify, I turn to an account of auditory induced visual synesthesia as a result of lysergic acid diethylamide (LSD) ingestion.

          “As I sit in my chair with The Beatles playing loudly over the speakers behind me, I observe a lamppost in front of me. As I listen to the initiation of a brush hitting the symbol, the lamppost appeared normal and fully intact as it should. As the rhythm progressed through the brushing sound, the lamppost disintegrated into little droplets, suspending into the air, and collapsing back into normal in time to repeat the motion for the next hit of the symbol” (Anonymous., 2011).

         This experience shows a full blown hallucination that is creatively fabricated by the mind and is realistically impossible. However, many synesthetes experiences auditory or visual hallucinations which are entirely relevant to their environment. For example, a subject who sees a child playing outside may also hear laughter since the two are often observed together in this familiar setting.

           While less is known about psychedelic-induced synesthesia, studying naturally occurring auditory-motion synesthesia could greatly contribute to understanding auditory and visual interactions in the brain. Experiments by Saenz & Koch involving induced visual synesthesia via auditory rhythmic sequences suggested “thatthe brain may normally translate the temporal structure of visual information into an auditory representation in order to improve temporal judgments of visual input” (2013, p. 650). Further research could confirm this and additionally contribute a better understanding of the relationship between synesthesia occurrence and the auditory and visual systems of the brain.

References:

Anonymous. 2011. Experience reports. The vaults of erowid: Psychoactive vaults. [Internet] [Cited 2011, February] Available from: http://www.erowid.org

Cytowic, R., E. (2002). Synesthesia: A Union of the Senses (2nd edition). Cambridge, Massachusetts: MIT Press.

Saenz, M. & Koch, C. (2008). The sound of change: visually induced auditory synesthesia. Biology 18(15):p.650

Simner, J. & Holenstein, E. (2007). Ordinal Linguistic Personification as a Variant of Synesthesia. Journal of Cognitive Neuroscience 19(4):694-703