Neurotransmissions presents an interdisciplinary selection of 23 essays first presented at Breaking Convention 2013, the 2nd conference on psychedelic consciousness, culture and clinical research, held at the University of Greenwich, London. It spans the sciences and humanities, from philosophy and neuroscience though to chemicals. Cross-cultural approaches explore the use of psychedelics in New Guinea, Central and South America, British free festivals, electronic music and backwards in time to the ancient civilisations of India and Rome.