Three-minute EEG 'Fastball' test detects early Alzheimer’s-linked memory decline, study finds

A three-minute brainwave test known as Fastball detected signs of memory impairment linked to Alzheimer’s disease years before patients typically receive a diagnosis, researchers reported. The inexpensive, portable tool produced weaker brain responses in people with amnestic mild cognitive impairment (MCI) than in healthy older adults and those with non-amnestic MCI, suggesting it could identify the form of MCI most likely to lead to Alzheimer’s.

In a clinical trial published in the journal Brain Communications, researchers at the University of Bath tested 53 patients recruited from memory clinics who had been diagnosed with MCI and 54 healthy older adults. The MCI group was divided into amnestic and non-amnestic subgroups based on a standard memory test score. Participants completed the three-minute Fastball task while wearing an electroencephalogram cap that recorded automatic brain responses as images flashed on a screen.

Fastball is passive and requires no active recall: sensors embedded in a knitted cap capture electrical activity from the scalp while the participant watches a rapid sequence of pictures. Researchers said the test provided an objective, rapid measure of memory-related brain activity that could be performed outside specialist clinics, including at home.

The study found that people with amnestic MCI had markedly reduced brain responses to the familiar images compared with healthy controls and those with non-amnestic MCI. All participants were retested after one year to assess consistency and to monitor cognitive change. Among the MCI group, a small number of patients who later developed dementia had slightly lower Fastball scores at baseline, a finding the authors said warrants further investigation as a potential early predictor of worsening memory.

"We're missing the first 10 to 20 years of Alzheimer's with current diagnostic tools," said Dr. George Stothart, a cognitive neuroscientist at the University of Bath and an author on the paper. He and colleagues described Fastball as cheap, portable and suitable for real-world settings.

Current clinical diagnosis of Alzheimer’s disease typically relies on a combination of blood tests, brain imaging, clinician-administered cognitive tests and assessments of language and problem-solving skills. Researchers have long sought more objective, scalable measures because conventional testing can be influenced by education, language, anxiety and other factors.

Early detection has taken on new urgency with the availability of disease-modifying therapies. The study’s authors noted that identifying people with early brain changes could allow treatments to be started before cognitive symptoms become severe. An estimated 7.2 million people in the United States aged 65 and older are living with Alzheimer's disease, the researchers wrote, underscoring the potential public-health implications of earlier diagnosis.

Experts not involved with the study cautioned that larger and longer-term trials are needed to confirm whether Fastball can reliably predict which individuals will progress from MCI to Alzheimer’s dementia. Dr. Julia Dudley, head of research at Alzheimer’s Research UK, said too many families face dementia without answers and welcomed further work to validate the method, noting that a bigger sample and extended follow-up would be required to determine how memory problems unfold over a lifetime.

The University of Bath team previously reported that the Fastball approach could reduce the average age at diagnosis by several years. In the current trial, the device’s simplicity—an EEG cap that fits like a hat and does not require bulky equipment—was highlighted as an advantage for wider deployment. The authors emphasized that while initial results are promising, replication in larger cohorts and evaluation against established biomarkers and clinical outcomes will be necessary before Fastball can be adopted in routine care.