Awareness
The Cambridge Declaration on Consciousness
On this day of July 7, 2012, a prominent international
group of cognitive neuroscientists, neuropharmacologists,
neurophysiologists, neuroanatomists and computational neuroscientists
gathered at The University of Cambridge to reassess the neurobiological
substrates of conscious experience and related behaviors in human and
non-human animals. While comparative research on this topic is naturally
hampered by the inability of non-human animals, and often humans, to
clearly and readily communicate about their internal states, the
following observations can be stated unequivocally:
- The field of Consciousness research is rapidly evolving. Abundant
new techniques and strategies for human and non-human animal research
have been developed. Consequently, more data is becoming readily
available, and this calls for a periodic reevaluation of previously held
preconceptions in this field. Studies of non-human animals have shown
that homologous brain circuits correlated with conscious experience and
perception can be selectively facilitated and disrupted to assess
whether they are in fact necessary for those experiences. Moreover, in
humans, new non-invasive techniques are readily available to survey the
correlates of consciousness.
- The neural substrates of emotions do not appear to be confined to
cortical structures. In fact, subcortical neural networks aroused during
affective states in humans are also critically important for generating
emotional behaviors in animals. Artificial arousal of the same brain
regions generates corresponding behavior and feeling states in both
humans and non-human animals. Wherever in the brain one evokes
instinctual emotional behaviors in non-human animals, many of the
ensuing behaviors are consistent with experienced feeling states,
including those internal states that are rewarding and punishing. Deep
brain stimulation of these systems in humans can also generate similar
affective states. Systems associated with affect are concentrated in
subcortical regions where neural homologies abound. Young human and
nonhuman animals without neocortices retain these brain-mind functions.
Furthermore, neural circuits supporting behavioral/electrophysiological
states of attentiveness, sleep and decision making appear to have arisen
in evolution as early as the invertebrate radiation, being evident in
insects and cephalopod mollusks (e.g., octopus).
- Birds appear to offer, in their behavior, neurophysiology, and
neuroanatomy a striking case of parallel evolution of consciousness.
Evidence of near human-like levels of consciousness has been most
dramatically observed in African grey parrots. Mammalian and avian
emotional networks and cognitive microcircuitries appear to be far more
homologous than previously thought. Moreover, certain species of birds
have been found to exhibit neural sleep patterns similar to those of
mammals, including REM sleep and, as was demonstrated in zebra finches,
neurophysiological patterns, previously thought to require a mammalian
neocortex. Magpies in particular have been shown to exhibit striking
similarities to humans, great apes, dolphins, and elephants in studies
of mirror self-recognition.
- In humans, the effect of certain hallucinogens appears to be
associated with a disruption in cortical feedforward and feedback
processing. Pharmacological interventions in non-human animals with
compounds known to affect conscious behavior in humans can lead to
similar perturbations in behavior in non-human animals. In humans, there
is evidence to suggest that awareness is correlated with cortical
activity, which does not exclude possible contributions by subcortical
or early cortical processing, as in visual awareness. Evidence that
human and nonhuman animal emotional feelings arise from homologous
subcortical brain networks provide compelling evidence for
evolutionarily shared primal affective qualia.
We declare the following: “The absence of a neocortex does not appear
to preclude an organism from experiencing affective states. Convergent
evidence indicates that non-human animals have the neuroanatomical,
neurochemical, and neurophysiological substrates of conscious states
along with the capacity to exhibit intentional behaviors. Consequently,
the weight of evidence indicates that humans are not unique in
possessing the neurological substrates that generate consciousness.
Nonhuman animals, including all mammals and birds, and many other
creatures, including octopuses, also possess these neurological
substrates.”
* The Cambridge Declaration on Consciousness was written by
Philip Low and edited by Jaak Panksepp, Diana Reiss, David Edelman,
Bruno Van Swinderen, Philip Low and Christof Koch. The Declaration was
publicly proclaimed in Cambridge, UK, on July 7, 2012, at the Francis
Crick Memorial Conference on Consciousness in Human and non-Human
Animals, at Churchill College, University of Cambridge, by Low, Edelman
and Koch. The Declaration was signed by the conference participants that
very evening, in the presence of Stephen Hawking, in the Balfour Room
at the Hotel du Vin in Cambridge, UK. The signing ceremony was
memorialized by CBS 60 Minutes. [10]
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