Researchers explore the intelligence of octopuses because these creatures stand among the planet’s sharpest minds. They learn quickly, store information, and apply it when needed. Scientists are asking how the octopus brain works, given its one central brain plus eight peripheral brains in each tentacle. A collaborative team has achieved a landmark: they recorded brainwaves from octopuses moving freely. The takeaway is striking—octopuses are extraordinary animals.
Octopuses lack a skeleton and possess eight highly flexible arms whose sensing and movement operate with a degree of autonomy and coordination. Their nervous system is sprawling, with a central brain and many neurons arranged in multiple lobes. In many animals, linking brain activity to behavior is done by placing electrodes on the skull and correlating electrical signals with what is observed. In octopuses, the flexible body and missing rigid frame made such recording especially challenging.
Forty years of work faced a barrier: attaching recording equipment without restricting movement or causing harm was nearly impossible. The ability of octopuses to maneuver their eight arms and remove foreign objects complicates any attempt to measure brain activity while moving untethered.
That hurdle persisted until now. Recording electrical signals in a freely moving octopus required a creative approach and careful engineering to keep the animal safe and comfortable while data was collected.
An octopus resting on the seabed offers a vivid image of its natural habitat. The study relied on such scenes, with photographs from underwater regions illustrating the animal in its element.
Lead author and former researcher Tamar Gutnick, from the Okinawa Institute of Science and Technology, explains that wires would easily be ripped off. The team devised a method to tuck the recording equipment under the skin so the octopus could move without interference, enabling long-term observation without anesthesia.
Twelve hours of continuous recording
The recent work, featured in Current Biology, introduced a portable data logger mounted in the octopus and electrodes positioned in the vertical lobe system of the brain. The device choices were lightweight and compact, originally designed to monitor avian brain activity during flight, but adapted for aquatic life. Waterproofing and size adjustments allowed a snug fit inside the octopus, with battery performance sustaining twelve hours of data collection in a low-oxygen environment.
Researchers selected the larger great blue octopus for this study, anesthetizing three individuals to insert recording devices into a mantle-wall cavity. Electrodes were placed in the vertical lobe and upper frontal regions, areas thought to be important for visual learning and memory.
As data were collected, simultaneous video captured the animals’ behavior as they slept, fed, and moved at will. The team could then correlate brain activity with observed actions across a long recording period without restraining the animals.
Patterns emerged in the brain activity that appeared consistently across all subjects. Some signals resembled activity seen in mammalian nervous tissue, while other slower oscillations were previously undocumented in octopuses.
Enhanced cognitive abilities
Although the team could not directly tie specific brain patterns to particular behaviors in the video, the study marks a first step in understanding how octopus brains govern behavior. It also offers clues about universal principles underlying the development of intelligence and cognition. The region studied is linked to learning and memory, and future work will pursue repetitive memory tasks to further map this circuit. The researchers anticipate testing with octopuses soon to uncover how these animals learn, socialize, and coordinate the movements of their tentacles.
Researchers emphasize that studying the octopus brain provides a compelling comparison with mammals. The octopus has a large brain and a unique body form, shaped through a distinct evolutionary path. Its cognitive abilities are high, yet many questions about brain operation remain. The new recording technique makes it possible to look inside the brains as octopuses perform tasks, which is both exciting and powerful, according to the project leader from the Physics and Biology Unit at OIST.
Science teams from Japan, Italy, Germany, Ukraine and Switzerland contributed to the work. The study is documented in Current Biology and builds on prior investigations into neural activity in cephalopods.
Notes: this rewrite maintains the original study’s intent and findings while presenting them in accessible terms. The approach highlights how freely moving octopuses can now be observed in ways that reveal their remarkable neural dynamics and cognitive potential.