 A more recent review concluded in 1985 that "the best approach is to use experiment (especially psychophysics) and observation to trace the dawning and ontogeny of self-consciousness, perception, communication, intention, beliefs, and reflection in normal human fetuses, infants, and children".In 2012, a group of neuroscientists signed the "Cambridge Declaration on Consciousness", which "unequivocally" asserted that "humans are not unique in possessing the neurological substrates that generate consciousness.Non-human animals, including all mammals and birds, and many other creatures, including octopuses, also possess these neural substrates."