Scientists have now recorded the brain waves of free-moving octopuses

For the first time, scientists have recorded the brain waves of freely moving octopuses. Data reveals unexpected trends, though it’s too early to tell how octopus brains control animal behaviorreport researchers on February 23 to Current biology.

“Historically, it’s been so difficult to make recordings of octopuses, even if they’re sedated,” says neuroscientist Robyn Crook of San Francisco State University, who was not involved in the study. “Even when their arms aren’t moving, their whole body is very flexible,” making it difficult to attach recording equipment.

Octopuses also tend to be feisty and intelligent. This means they generally can’t stand the uncomfortable equipment typically used to record brain waves in animals, says neuroethologist Tamar Gutnick of the University of Naples Federico II in Italy.

To circumvent these obstacles, Gutnick and his colleagues adapted portable data loggers typically used on birds and surgically inserted the devices into three octopuses. The researchers also placed recording electrodes inside areas of the octopus’ brain that deal with learning and memory. The team then recorded the octopuses for 12 hours as the cephalopods went about their daily lives – sleeping, swimming and grooming – in tanks.

Certain brain wave patterns appeared in all three octopuses during the 12-hour period. For example, some waves resembled the activity of the human hippocampus, which plays a crucial role in memory consolidation. Other brain waves were similar to those controlling sleep-wake cycles in other animals.

The researchers also recorded brain waves that they say have never been seen before in any animal. The waves were unusually slow, cycling only two per second, or 2 hertz. They were also exceptionally strong, suggesting a high level of synchronization between neurons. Sometimes a single electrode picked up the strange waves; other times they appeared on electrodes far apart from each other,

Observing these patterns is exciting, but it’s too early to tell whether they’re tied to a specific behavior or type of cognition, Gutnick says. Experiments with repetitive tasks are needed to fully understand how these brain areas are activated in octopuses during learning.

The new research is exciting in that it provides a technique for future researchers to observe brain activity in awake and naturally behaving octopuses, Crook says. It could be used to explore brain activity behind animals color changing capabilitiesspectacular sight, Sleep habits and good arm control (SN: 01/29/16; SN: 03/25/21).

Octopuses are very intelligent, so by studying the creatures “you can get ideas about what’s important for intelligence,” says Gutnick. “The problems animals face are the same problems, but the solutions they find are sometimes similar and sometimes different and all of these comparisons teach us something.”