In 2002, James Rose (University of Wyoming) and more recently Brian Key (University of Queensland) published reviews arguing that fish (and presumably crustaceans) cannot feel pain because they lack a neocortex in the brain and therefore do not have consciousness. This has been robustly contested. Animal behaviouralist, Temple Grandin, (Colorado State University) argues that animals could still have consciousness without a neocortex because "different species can use different brain structures and systems to handle the same functions." Lynne Sneddon (University of Liverpool) proposes that to suggest a function suddenly arises without a primitive form defies the laws of evolution. Other researchers also believe that animal consciousness does not require a neocortex, but can arise from homologous subcortical brain networks.
