New evidence of animal consciousness

Abstract

This paper reviews evidence that increases the probability that many animals experience at least simple levels of consciousness. First, the search for neural correlates of consciousness has not found any consciousness-producing structure or process that is limited to human brains. Second, appropriate responses to novel challenges for which the animal has not been prepared by genetic programming or previous experience provide suggestive evidence of animal consciousness because such versatility is most effectively organized by conscious thinking. For example, certain types of classical conditioning require awareness of the learned contingency in human subjects, suggesting comparable awareness in similarly conditioned animals. Other significant examples of versatile behavior suggestive of conscious thinking are scrub jays that exhibit all the objective attributes of episodic memory, evidence that monkeys sometimes know what they know, creative tool-making by crows, and recent interpretation of goal-directed behavior of rats as requiring simple nonreflexive consciousness. Third, animal communication often reports subjective experiences. Apes have demonstrated increased ability to use gestures or keyboard symbols to make requests and answer questions; and parrots have refined their ability to use the imitation of human words to ask for things they want and answer moderately complex questions. New data have demonstrated increased flexibility in the gestural communication of swarming honey bees that leads to vitally important group decisions as to which cavity a swarm should select as its new home. Although no single piece of evidence provides absolute proof of consciousness, this accumulation of strongly suggestive evidence increases significantly the likelihood that some animals experience at least simple conscious thoughts and feelings. The next challenge for cognitive ethologists is to investigate for particular animals the content of their awareness and what life is actually like, for them.

On the evolution of conscious attention

“…Even if one thinks that cognitive function could explain the emergence of consciousness, attention and consciousness would still be dissociated since the lower-level forms of attention have evolved in organisms that do not seem to have conscious awareness (see Griffin & Speck, 2004). This is not to deny that there may be phenomenal consciousness in animalssome animals with central nervous systems may experience pain or color in ways that resemble human experiences.…”

“…As described above, there are forms of attention that are related to more primitive brain regions that operate in a bottom-up and automatic manner. These brain regions emerged early in evolution and include invertebrates, which are animals that usually would not be considered to have consciousness (Griffin & Speck, 2004).…”

“…These higher-level cognitive processes require a voluntary, sustained form of attention, as well as interactions with other cognitive processes, such as working memory and long-term memory. Animals exhibiting such higher-level behaviors include blue jays, crows, parrots, macaque monkeys, and chimpanzees, as they show signs of tool manipulation or rudimentary language abilities (Griffin & Speck, 2004). Having a self-awareness, however, seems to be a more complex attribute of voluntary attention than mere sustained attention.…”

“…Whether or not animals possess selfawareness remains debatable, but some have proposed ways in which basic consciousness might be identified in animals (see Griffin & Speck, 2004;Seth, Dienes, Cleeremans, Overgaard, & Pessoa, 2008). For example, Bayne's (2007) theory of "creature consciousness", which specifies whether or not an organism can be said to be phenomenally conscious, requires mechanisms that generate the "phenomenal field" (related to activity in the thalamus), and neural inputs from the different cortical areas responsible for processing sensory and memory-related information.…”

“…Only after integrative processes occur can consciousness be considered present in animals, but such claims require empirical support. Currently, problem-solving behaviors (e.g., tool usage) in animals provide the best examples of the possible presence of conscious attention in animals (for a review on animal consciousness, see Griffin & Speck, 2004). Various brain regions, considered to be more evolutionarily advanced, have been identified to support voluntary top-down attention.…”