Brain Fog and the Rhythm of Attention
What Emerging Research May Mean for Women With Primary Ovarian Insufficiency — and What It Does Not Yet Prove
An In the News Reflection
Brain fog — difficulty concentrating, remembering, finding words, or thinking clearly — can be a frustrating cognitive complaint for women with Primary Ovarian Insufficiency (POI). New research into the brain’s natural rhythms may offer clues about how attention works and, eventually, how some cognitive difficulties might be treated.
A recent report from Georgia Tech and Emory University describes an emerging approach to improving attention: carefully timed pulses of light and sound designed to influence the brain’s natural rhythms. Researchers found that healthy adults exposed to stimulation at 40 hertz performed better on a sustained-attention task and showed corresponding changes in brain activity.
The findings raise an intriguing but still preliminary question: Could patterned sensory stimulation eventually help people experiencing cognitive difficulties commonly described as brain fog?
Why 40 Hertz?
Brain cells do not work alone. Networks of neurons communicate through patterns of electrical activity known as brain oscillations. Gamma oscillations, generally described as rhythms between approximately 30 and 100 hertz, are associated with attention, sensory processing, memory, and communication across brain networks.
Forty hertz means 40 cycles per second. Researchers can attempt to influence brain activity at this frequency using carefully timed pulses of light, sound, vibration, or electrical stimulation. This is not the same as simply listening to ordinary music. The stimulation is deliberately delivered at a precise rhythm with the aim of producing, or “entraining,” a corresponding neural response.
Much of the foundational research on 40-Hz sensory stimulation has been conducted in animal models. In mice, including mouse models of Alzheimer’s disease, researchers have reported effects on disease pathology, memory-related activity, and coordination between regions of the hippocampus.
These findings help explain why researchers are interested in 40-Hz stimulation. But results in mice cannot be assumed to occur in people.
A Human Study of Attention
In a study published in Imaging Neuroscience in May 2026, researchers studied 62 healthy adults during a one-hour sustained-attention task. Participants received either 40-Hz audiovisual stimulation, constant light, or randomly timed flicker.
Those exposed to 40-Hz stimulation responded more accurately and more quickly than participants in the comparison groups. Electroencephalography (EEG) also showed changes in brain activity associated with attention, including increased activity at 40 Hz and altered connectivity in lower-frequency networks.
This finding is noteworthy because it moves beyond asking whether sensory stimulation changes an electrical signal in the brain. It asks whether that change is accompanied by a measurable difference in human performance.
However, the participants were healthy adults. They were not selected because they had brain fog, Primary Ovarian Insufficiency, or another cognitive disorder. The study measured performance during a single laboratory session and did not establish whether the effect continued after stimulation ended.
It therefore cannot tell us whether 40-Hz stimulation produces lasting improvement in everyday cognitive symptoms.
A Small Study in People With Brain Fog
A separate 2025 pilot study published in Frontiers in Cognition examined 40-Hz auditory and vibrotactile stimulation in people with long COVID who reported cognitive difficulty and fatigue.
Their symptoms included trouble concentrating, slowed thinking, word-finding difficulty, memory problems, and mental fatigue — the cluster of cognitive symptoms commonly called brain fog.
Twenty participants completed the study. They were assigned either to four weeks of 40-Hz stimulation or to a control group that did not receive a device during the comparison period. Following treatment, the stimulation group showed improvement in selective attention and response inhibition, as well as an increase in circulating brain-derived neurotrophic factor, or BDNF.
BDNF is a protein involved in the growth, maintenance, and adaptability of neurons. Its increase is scientifically interesting, but it does not by itself establish that the treatment produced lasting cognitive improvement.
The results of the study are encouraging but preliminary. The study was small and open-label, and the control group did not receive sham stimulation. It also studied brain fog associated with long COVID, not Primary Ovarian Insufficiency.
These results should generate further research rather than establish a treatment recommendation.
What This Means for Women With Primary Ovarian Insufficiency
These studies do not demonstrate that 40-Hz stimulation treats brain fog in women with Primary Ovarian Insufficiency.
They do, however, offer a useful scientific insight: attention and cognitive clarity depend in part on coordination across brain networks, and patterned sensory input may influence that coordination.
For women with Primary Ovarian Insufficiency, the priority remains identifying and addressing contributors to cognitive symptoms that are already clinically actionable. These may include the effects of ovarian hormone deficiency and whether hormone replacement is physiologically appropriate and adequate, as well as poor sleep, depression or anxiety, medication effects, nutritional deficiencies, thyroid disease, anemia, and the cognitive burden of navigating fragmented care.
Brain fog should not be dismissed. But neither should an emerging technology distract from careful evaluation of its underlying causes.
Follow the Evidence
Forty-Hz sensory stimulation is an investigational approach, not an established treatment for brain fog associated with Primary Ovarian Insufficiency.
Larger, blinded, sham-controlled trials are needed to determine who may benefit, how long any effects last, what form and dose of stimulation are appropriate, and what risks may accompany repeated use.
The hopeful message is not that researchers have found a cure for brain fog. It is that cognitive difficulty is increasingly being studied as a measurable problem involving brain networks — and researchers are testing noninvasive ways to help those networks work together more effectively.
Women deserve both hope and scientific honesty. At My28Days®, we follow the evidence closely enough to hold onto both.
Read the news reports and source studies:
My28Days.org is an educational and advocacy platform supported by the Mary Elizabeth Conover Foundation. For more information or to lend support, contact Office@ConoverFoundation.org
