An interventional study of Tailored Rhythmic Lighting Intervention and Placebo Rhythmic Lighting Intervention in Mild Cognitive Impairment, sponsored by Icahn School of Medicine at Mount Sinai. Completed at 2 sites in United States. Open to participants aged 55 Years and older, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-06-23.
Sponsored by Icahn School of Medicine at Mount Sinai · Not applicable, Interventional, and Treatment
The investigator will investigate how light delivering 40 hertz (Hz) affects subjective sleep and cognition in a controlled laboratory study. A lab study will allow the collection of electroencephalogram (EEG) data, perform cognitive tests, and observe the response in those with mild cognitive impairment (MCI) compared to a healthy control group (HC).
Participants will attend two study sessions over the course of two weeks. During both sessions, all participants will experience 10 minutes of a low-level light, followed by a data collection period which involves a sleepiness rating, an electroencephalogram (EEG) recording, and a computerized memory test. Participants will then experience either a RL or a placebo RL condition for one hour, after which there will be a second data collection.
The investigator will demonstrate the effect of 40 hertz (Hz) rhythmic light (RL) to promote gamma wave entrainment (rhythmic light [RL]) on: brain response (electroencephalography [EEG]); cognitive performance (working memory task); and subjective sleepiness (questionnaires). The study will recruit 20 adult mild cognitive impairment (MCI) patients and 20 healthy, age-matched controls (HC) to participate in this study.
Sessions will initiate with a 10-minute adaptation period to a low-level ambient light providing illuminance of 15 lux at participants' eye level on a vertical plane, followed by a pre-exposure data collection period, including Karolinska Sleepiness Scale (KSS), EEG, and a working memory task. Participants will experience either 40 Hz RL or placebo RL conditions for a duration of 1 hour, followed by the second data collection period. On the second data collection day, participants will experience the other condition, so that all participants experience both lighting conditions. The experimental sessions will start at 14:00 on each experimental day which will be separated by 1 week.
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Exclusion Criteria:
1. hour intervention period where active lighting is experienced by participants. then 1 hour intervention period where an inactive, placebo lighting condition is experienced by participants. 2. sessions, 1 week apart
Device: Tailored Rhythmic Lighting Intervention
1. hour intervention period where an inactive, placebo lighting condition is experienced by participants. then 1 hour intervention period where active lighting is experienced by participants. 2. sessions, 1 week apart
Device: Placebo Rhythmic Lighting Intervention
40 hertz (Hz) rhythmic lighting (RL) for a duration of 1 hour. The flicker frequency of the 40 Hz RL will be 40 Hz and the stimulation will be a square wave with a 50 % duty cycle (i.e., 12.5 milliseconds light- on and 12.5 milliseconds light-off). The RL will provide a 30 lux of red light on a vertical plane at the eye level.
Placebo rhythmic light (RL) for a duration of 1 hour. In the placebo RL condition, the duty cycle will be delivered at randomly varying frequencies of 20 Hz and 50 Hz, specifically avoiding the frequency of 40 Hz. The placebo RL conditions will provide a 30 lux of red light on a vertical plane at the eye level.
Change in Electroencephalography (EEG) Power at 40 Hertz (Hz)
Electroencephalography (EEG) recordings - the change in 40 Hz gamma power, computed by calculating the difference between the average gamma power at baseline (T1) and during the light intervention (T2). This difference was obtained by subtracting baseline 40 Hz power from the intervention 40 Hz power to assess acute neural effects
Time frame: baseline and during the light intervention
Mean Change in Subjective Sleepiness Using the Karolinska Sleepiness Scale (KSS)
The Karolinska Sleepiness Scale (KSS) outcome prompts participants to rate how sleepy or alert they are feeling on a scale ranging from 1 to 9, where 1 = "very alert," 3 = "rather alert," 5 = "neither alert nor sleepy," 7 = "sleepy, but no difficulty remaining awake," and 9 = "very sleepy, fighting sleep, an effort to remain awake."
Time frame: Baseline and 1 hour after intervention (intervention is 2 hours)
| Milestone | Health Control Group 1 | Health Control Group 2 | Mild Cognitive Impairment Group 1 | Mild Cognitive Impairment Group 2 |
|---|---|---|---|---|
| Started | 11 | 15 | 12 | 14 |
| Completed | 11 | 15 | 12 | 14 |
| Not completed | 0 | 0 | 0 | 0 |
| Milestone | Health Control Group 1 | Health Control Group 2 | Mild Cognitive Impairment Group 1 | Mild Cognitive Impairment Group 2 |
|---|---|---|---|---|
| Started | 11 | 15 | 12 | 14 |
| Completed | 11 | 15 | 12 | 13 |
| Not completed | 0 | 0 | 0 | 1 |
| Withdrew: Withdrawal by subject | 0 | 0 | 0 | 1 |
Electroencephalography (EEG) recordings - the change in 40 Hz gamma power, computed by calculating the difference between the average gamma power at baseline (T1) and during the light intervention (T2). This difference was obtained by subtracting baseline 40 Hz power from the intervention 40 Hz power to assess acute neural effects
| μV2/Hz | MCI - Inactive Placebo Rhythmic Lighting | MCI - Active Tailored Rhythmic Lighting | HC - Placebo Rhythmic Lighting | HC - Active Tailored Rhythmic Lighting |
|---|---|---|---|---|
| Oz | 3.54 ± 0.43 | 5.28 ± 0.82 | 2.83 ± 0.53 | 4.10 ± 0.66 |
| Pz | 2.69 ± 0.53 | 5.24 ± 0.94 | 3.86 ± 0.51 | 3.56 ± 0.55 |
| POz | 2.87 ± 0.43 | 5.18 ± 0.88 | 3.29 ± 0.51 | 3.57 ± 0.64 |
The Karolinska Sleepiness Scale (KSS) outcome prompts participants to rate how sleepy or alert they are feeling on a scale ranging from 1 to 9, where 1 = "very alert," 3 = "rather alert," 5 = "neither alert nor sleepy," 7 = "sleepy, but no difficulty remaining awake," and 9 = "very sleepy, fighting sleep, an effort to remain awake."
| score on a scale | Active Tailored Rhythmic Lighting | Inactive Placebo Rhythmic Lighting |
|---|---|---|
| Mean Change in Subjective Sleepiness Using the Karolinska Sleepiness Scale (KSS) | 0.44 ± 0 | 0.49 ± 0 |
Collected over 2 hours. Non-serious events are listed at a 0% frequency threshold.
| Group | Deaths | Serious | Other |
|---|---|---|---|
| MCI - Active Tailored Rhythmic Lighting | 0/26 (0%) | 0/26 (0%) | 0/26 (0%) |
| MCI - Inactive Placebo Rhythmic Lighting | 0/26 (0%) | 0/26 (0%) | 0/26 (0%) |
| HC - Active Tailored Rhythmic Lighting | 0/26 (0%) | 0/26 (0%) | 0/26 (0%) |
| MC - Inactive Placebo Rhythmic Lighting | 0/26 (0%) | 0/26 (0%) | 0/26 (0%) |
| Age, Categorical(Participants) | Health Control | Mild Cognitive Impairment | Total |
|---|---|---|---|
| <=18 years | 0 | 0 | 0 |
| Between 18 and 65 years | 10 | 10 | 20 |
| >=65 years | 16 | 16 | 32 |
| Sex: Female, Male(Participants) | Health Control | Mild Cognitive Impairment | Total |
|---|---|---|---|
| Female | 16 | 16 | 32 |
| Male | 10 | 10 | 20 |
| Ethnicity (NIH/OMB)(Participants) | Health Control | Mild Cognitive Impairment | Total |
|---|---|---|---|
| Hispanic or Latino | 1 | 1 | 2 |
| Not Hispanic or Latino | 21 | 21 | 42 |
| Unknown or Not Reported | 4 | 4 | 8 |
| Race (NIH/OMB)(Participants) | Health Control | Mild Cognitive Impairment | Total |
|---|---|---|---|
| American Indian or Alaska Native | 0 | 0 | 0 |
| Asian | 3 | 3 | 6 |
| Native Hawaiian or Other Pacific Islander | 0 | 0 | 0 |
| Black or African American | 3 | 3 | 6 |
| White | 19 | 19 | 38 |
| More than one race | 0 | 0 | 0 |
| Unknown or Not Reported | 1 | 1 | 2 |
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Icahn School of Medicine at Mount Sinai