Dementia patients commonly struggle with surprises and changes to routine. Damage to the brain’s “intelligence network” may explain the problem, researchers say.

Investigators analyzed data from a study involving 75 patients. Each participant had one of four dementia types, affecting different areas of the brain.

While watching a movie without the sound on, these participants heard regular “beep” sounds while their brain activity was recorded by a machine that precisely measures tiny magnetic fields produced by electrical currents in the brain. 

Generally the sounds were steady. But occasionally a different-sounding beep (such as higher-pitched sound) was introduced. The unusual beeps triggered two responses. The first was from the basic auditory system, showing that the brain recognized the beep. All participants had the same first response. A second response quickly followed, signaling that the brain was recognizing that the sound was different or new, the researchers said. Patients with dementia had a much smaller second response than peers without dementia. 

This finding indicates that the participants with dementia were having a harder time recognizing that something had changed, according to Thomas Cope, Ph.D., of the University of Cambridge in the United Kingdom. And the use of magnetic resonance imaging (MRI) scans showed potential damage to areas of the brain known as multiple demand networks, he and his colleagues reported. These are likely the brain areas that would normally would have helped the patients clearly recognize the change in sound, they explained.

Helping patients prepare for change

The results highlight the need to anticipate change in order to help dementia patients better handle new situations, Cope said.

“The advice I give in my clinics is that you can help people who are affected by dementia by taking a lot more time to signpost changes, flagging to them that you’re going to start talking about something different or you’re going to do something different,” he said.

It’s also important to repeat yourself more often when there’s a change, he added, and to understand “why it’s important to be patient as the brain recognizes the new situation.”

Full findings were published in the Journal of Neuroscience.