Cambridge scientist argues consciousness rooted in ancient brain regions, not cortex

A Cambridge neuroscientist has published a sweeping review arguing that consciousness may originate in the brain’s oldest structures rather than the cortex. Dr. Peter Coppola synthesizes stimulation studies, animal experiments, and neurological case reports spanning more than a century to contend that basic conscious experience could be generated by subcortical and hindbrain regions.

In a piece published for The Conversation, Coppola notes that the accumulating evidence points to a provocative conclusion: the oldest parts of the brain may be enough for basic consciousness, with the cortex adding refinement rather than serving as the sole source. If confirmed, the claim could reshape how scientists think about patient care after brain injuries and how society weighs questions of animal consciousness and rights.

The brain is often described as a nesting doll: the outer cortex handles complex tasks such as memory, thinking, and problem-solving, while the deeper subcortical structures form an ancient core that has changed little in hundreds of millions of years of evolution. The outer layer, known as the cortex, sits atop a more primitive inner region that researchers often call the subcortex or hindbrain. Those older regions regulate basic impulses and sensations such as hunger, thirst, pain, pleasure, and fear. Coppola argues that scientists have underestimated the role of these deepest parts in producing conscious experience.

Historically, experiments that interrupted or disturbed brain activity showed that interfering with the cortex could alter perception, memory, and judgment, leading many to conclude that consciousness arose from the neocortex. Coppola contends that when researchers looked more closely at deep-brain activity, the effects on consciousness could be even more striking. Stimulation or disruption of subcortical areas sometimes produced profound changes in awareness, and in some cases could even resemble waking from anesthesia or altering the sense of self. While these findings do not prove that the lizard brain alone creates consciousness, they do suggest that the deeper regions play a central, perhaps foundational, role.

Coppola points to cases where parts of the brain are damaged or missing. In certain rare instances, children born with hydranencephaly lack most of their cortex yet have been observed to feel upset, respond to music, recognize people, or show enjoyment of interactions. Medical textbooks have long described these patients as vegetative, but real-world observations appear to reveal a more nuanced picture of conscious experience sustained by older brain structures.

Similarly, some animal studies reported after removing the neocortex from rats, cats, and even monkeys show preserved emotional behavior, grooming, parenting, and learning. These findings suggest that the subcortex can support a basic level of conscious experience even when the cortex is absent. Coppola stresses that these results do not diminish the cortex’s role in human consciousness; rather, they suggest the newer brain regions—and the cerebellum—tend to expand and refine a foundational awareness into the richer human experience marked by language, self-awareness, and creativity.

The central takeaway, Coppola writes, is not that the cortex is irrelevant but that our understanding of consciousness should start from the brain’s most ancient components. If the oldest regions can support basic conscious experience, then consciousness may be more widespread across species than previously assumed, with meaningful implications for clinical care and ethics.

To ground the discussion, Coppola examines how scientists study brain activity. Functional magnetic resonance imaging (fMRI) is one of the most widely used tools for probing consciousness in living subjects. fMRI measures metabolic changes in the brain, such as shifts in blood flow, to infer which regions are engaged during perception, memory, and attention. Unlike a standard MRI, which images brain structure, fMRI helps researchers infer functional activity and track how different areas coordinate during tasks. The technology, along with other imaging and stimulation techniques, forms the evidentiary backbone for arguments about where conscious experience arises and how it might be distributed across brain networks.

The potential implications of Coppola’s review are broad. If basic consciousness can originate in the subcortex, this could influence how clinicians respond to patients with deep brain injuries, reshape rehabilitation approaches, and feed ongoing debates about animal rights and the moral status of non-human minds. The work also invites a careful reconsideration of what we mean by conscious experience and how we measure it in both humans and animals.

Experts outside Coppola’s field acknowledge that the conclusions are provocative and call for further rigorous study. While the cortex undoubtedly plays a critical role in the elaborate features of human consciousness—language, planning, abstract thought—the proposed emphasis on deep-brain structures as a foundational source adds an important dimension to the ongoing scientific conversation about one of neuroscience’s most enduring puzzles.

As researchers continue to map the brain’s complex networks, Coppola’s synthesis serves as a reminder that the quest to understand consciousness remains unsettled, and that even well-established ideas can be revised in light of new evidence.