These cute hats are helping scientists unlock the mysteries of pain with the help of advanced brain-monitoring technology — without the need for sedation or discomfort. In fact, the hats are playing an important role for feline research.

As you may imagine, assessing chronic pain conditions in cats is not the easiest thing in the world. Awake cats tend to shake off and chew the wired electrodes placed on their heads and rarely stand still long enough for testing.

Now, in a groundbreaking study published in the Journal of Neuroscience Methods, researchers have developed a non-invasive method to monitor brain activity in awake cats using electroencephalography (EEG) using knitted hats fitted with electrodes.

The study offers promising insights into how cats experience chronic pain, particularly those suffering from osteoarthritis, a condition that affects over 25% of adult cats. This is the first study to use surface electrodes to record EEG from conscious, awake cats.

Why it’s so important to study pain in cats

Cats are remarkably tough. They hide their pain and even when they’re going through major hardship. So, it can be hard for their owners to realize and recognize their discomfort. That’s why it’s so important to study pain in a clinical setting.

Previous EEG studies in felines required sedation or anesthesia, but those approaches can distort brain activity, especially when studying pain perception. They’re also disruptive and unpleasant for the cats. That’s why, in the new study, researchers led by Éric Troncy and Aude Castel of Montreal University developed a new technique to keep the electrodes in place: by placing them in knitted beanies.

They tested the method on 11 cats with osteoarthritis.

The research team placed ten gold-plated electrodes on the cats’ heads and measured their brain responses to a variety of stimuli, including mechanical touch, grapefruit scent, and different wavelengths of light (blue, green, and red). The EEG readings revealed distinct brain activity patterns, known as event-related potentials (ERPs), which signal how the brain processes sensory information. Importantly, this technique was well-tolerated by the cats, and none of the animals required sedation.

Better treatment

Researchers first assessed stress and pain in cats by using stimuli passed through the electrodes. Afterwards, they tested out how some stimuli could reduce pain.

Interestingly, exposure to different types of light — especially blue light — resulted in significant changes in brainwave patterns. These findings echo previous studies in humans and rodents, where exposure to specific wavelengths of light has been shown to alter pain perception.

One particularly novel aspect of the study was the examination of olfactory responses. Cats were exposed to grapefruit scent, which is known to elicit an aversive reaction in felines. The EEG captured how the cats’ brains reacted to the smell, providing a unique window into how unpleasant odors might influence their experience of pain.

The goal is to create better treatment options and improve quality of life. Currently, treatment options for feline osteoarthritis are limited, with most relying on non-steroidal anti-inflammatory drugs, which can have significant side effects.

The study’s lead author, Dr. Aude Castel, explained that this research opens the door to new ways of managing feline pain, potentially using sensory modulation — such as light therapy or odor interventions — to alleviate discomfort.

“We now plan to obtain funding, in partnership with private companies, to enable us to establish a genuine EEG signature for chronic pain, and many other applications that will enable us to automate chronic pain detection in the future,” said Troncy.

Journal Reference: Aliénor Delsart et al, Non-invasive electroencephalography in awake cats: Feasibility and application to sensory processing in chronic pain, Journal of Neuroscience Methods (2024). DOI: 10.1016/j.jneumeth.2024.110254