High Frequency Stimulation to Improve Cognition, Mobility, and Affect in Individuals With and Without Subjective Cognitive Decline

The goal is to determine whether three months of at least three times / week of sensory flicker stimulation improves cognition, mobility, and affect in healthy older adults and older adults with and without Subjective Cognitive Decline (SCD). Investigators will also determine whether the intervention slows cortical thinning and declines in brain functional network segregation and changes in blood biomarkers of Alzheimer's Disease (AD).

Study Overview

• Status: Recruiting
• Conditions: Healthy Subjects; Subjective Cognitive Decline (SCD)
• Intervention / Treatment: Behavioral: Control - 1Hz Visual Occlusion; Behavioral: Experimental -- 16.67 Hz Visual Occlusion

• Study Type: Interventional
• Enrollment (Estimated): 60
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Alyssa Hayes; Phone Number: (352) 273-2134; Email: alyssa.hayes@ufl.edu
• Study Contact Backup: Name: Sarah Verdecia-Zabala; Phone Number: (352) 273-2141; Email: sverdeciazabala@ufl.edu

Study Locations

• United States
  • Florida
    • Gainesville, Florida, United States, 32611
      • Recruiting
      • University of Florida
      • Contact: Rachael Seidler, PhD; Phone Number: 734-834-0385; Email: rachaelseidler@ufl.edu
      • Contact: Email: natalie.ebner@ufl.edu
      • Sub-Investigator: Natalie C. Ebner, PhD
      • Principal Investigator: Rachael Seidler, PhD

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Older Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria

• Community dwelling men and women 65-89 years old
• Ability to walk unassisted for 10 min
• English speaking Additional Inclusion Criteria for SCD
• No evidence of dementia or MCI based on cognitive screening (i.e., Montreal Cognitive Assessment (MoCA) score within normal limits for age, education, and sex using the NACC Uniform Data Set (UDS) norms
• Global Clinic Dementia Rating (CDR) score must be 0 or 0.531
• Subjective report of cognitive complaints with scores >20 on the Cognitive Change Index (CCI-20), a validated scale of subjective cognitive decline6; this scale consists of 20 items that are rated on a 5-point Likert scale, where 1= "Normal: No change compared to 5 years ago", 3= "Mild Problem: Some change compared to 5 years ago) and 5="Severe Problem: Much worse compared to 5 years ago"
• Family history of dementia/probable AD in first degree relative (parents, children, siblings)
• Normal functional behavior in terms of daily activities, based on the Functional Activities Scale In line with recommendations of the SCD task force an informant must be available for two reasons: a) to provide information about the participant's cognition using the informant version of the CDR and CCI-20, and b) to corroborate normal IADL's on the Functional Activity Questionnaire (informant data will be collected via a phone call and linked by code with the participant data).

Exclusion criteria

• If participants score less than 21 on the Telephone Interview for Cognitive Status (TICS)
• Significant medical event requiring hospitalization in the past 6 months that has the potential to contaminate data being collected (fracture, hospitalization etc.)
• Severe visual impairment or corrected visual acuity less than 20/40 (as per self-report), which would preclude completion of assessments
• Inability to undergo MRI brain imaging due to claustrophobia or implants such as pacemakers, heart valves, brain aneurysm clips, orthodontics, certain non-removable body jewelry, or shrapnel containing ferromagnetic metal
• History of severe stroke
• Epilepsy or family history of epilepsy, past seizure history, as well as history of migraines
• Current use of psychotropic medications
• Any major ADL disability (unable to feed, dress, bath, use the toilet, or transfer)
• Report of lower extremity pain due to osteoarthritis that significantly limits mobility
• Diagnosis or treatment for rheumatoid arthritis
• Known neuromuscular disorder or overt neurological disease (e.g., Multiple Sclerosis, Rhabdomyolysis, Myasthenia Gravis, Ataxia, Apraxia, post-polio syndrome, mitochondrial myopathy, Parkinson's Disease, ALS etc.)
• Unable to communicate because of severe hearing loss or speech disorder
• Planned surgical procedure or hospitalization in the next 4 months (joint replacement, coronary artery bypass graft, etc.)
• Severe pulmonary disease, requiring the use of supplemental oxygen
• Severe cardiac disease, including NYHA Class III or IV congestive heart failure, clinically significant aortic stenosis, recent history of cardiac arrest, use of a cardiac defibrillator, or uncontrolled angina
• Use of walker or wheelchair

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Sham Comparator: Control; Participants in this group will receive the control stimulation at the slower rate.	Behavioral: Control - 1Hz Visual Occlusion; This group will wear visual occlusion glasses with visible stimulation at 1 Hz
Experimental: Experimental; Participants in this group will receive the experimental stimulation at the faster rate.	Behavioral: Experimental -- 16.67 Hz Visual Occlusion; This group will wear visual occlusion glasses with visible stimulation at 16.67 Hz (corresponding to flicker of 32-36 Hz)

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Cognition - The Tablet-based Cognitive Assessment Tool (TabCAT)	This test battery assesses performance in various cognitive components. A composite score across subtasks will be computed. Higher scores in the composite indicates better cognition.	Baseline, halfway through (1.5 months), and post-intervention (3 months)
Mobility - Grip Strength	This test assesses grip strength in kg. A composite score across trials will be computed. Higher scores indicate more strength.	Baseline, halfway through (1.5 months), and post-intervention (3 months)
Mobility - 10 Meter Gait Speed	This test assesses speed in seconds during unassisted walking for 10 meters. A composite score across trials will be computed. Higher scores indicate lower walking speed.	Baseline, halfway through (1.5 months), and post-intervention (3 months)
Mobility - Clinical Test of Sensory Interaction on Balance (CTSIB)	This test assesses sway area (measured in m^2/s^4) with eyes open and closed while standing on a hard and a foam surface. A larger sway area indicates greater postural instability and poorer balance control during specific sensory conditions	Baseline, halfway through (1.5 months), and post-intervention (3 months)
Affect - Profile of Mood States Second Edition (POMS-2)	This questionnaire assesses transient feelings and mood on a scale from 0 = not at all to 4 = extremely). A composite score across items will be computed as primary outcome. Higher scores indicate greater intensity of the mood state.	Baseline, halfway through (1.5 months), and post-intervention (3 months)
Affect - Ryff Scales of Psychological Wellbeing	This questionnaire assesses psychological well-being via 42 statements using a 6-point scale (1 = strongly agree; 6 = strongly disagree). A composite score across items will be computed as primary outcome. Higher scores indicate greater psychological wellbeing.	Baseline, halfway through (1.5 months), and post-intervention (3 months)
Affect - Satisfaction with Life Scale	This questionnaire assesses satisfaction with life. A composite score across items will be computed as primary outcome. The possible range of scores is 5-35. Scores between 5-9 indicate the respondent is extremely dissatisfied with life, whereas scores between 31-35 indicate the respondent is extremely satisfied. A composite score across items will be computed as primary outcome. Higher scores indicate greater life satisfaction.	Baseline, halfway through (1.5 months), and post-intervention (3 months)
Brain Markers - Structure	Cortical thickness (in mm) will be determined via a T1 MRI scan in dorsolateral prefrontal, sensorimotor, and insular cortices using the CAT computational anatomy toolbox. Greater values indicate greater cortical thickness.	Baseline, halfway through (1.5 months), and post-intervention (3 months)
AD Biomarkers - Amyloid	These assays will determine amyloid (e.g., Aβ17) sensitive to Alzheimer's Disease. Higher values indicate higher amyloid levels.	Baseline, halfway through (1.5 months), and post-intervention (3 months)
Biomarkers - P-Tau	These assays will determine p-tau levels sensitive to Alzheimer's Disease. A composite score across items will be computed as primary outcome. Higher values indicate higher p-tau levels.	Baseline, halfway through (1.5 months), and post-intervention (3 months)
Brain Markers - Network Function	Brain network function will be assessed via resting-state fMRI (in Blood oxygen level dependent response) to capture functional segregation of dorsolateral prefrontal, sensorimotor, and insular networks using the CONN toolbox. Greater values indicate greater functional connectivity.	Baseline, halfway through (1.5 months), and post-intervention (3 months)

Collaborators and Investigators

• Sponsor: University of Florida
• Investigators: Principal Investigator: Rachael C. Seidler, University of Florida; Principal Investigator: Natalie C. Ebner, PhD, University of Florida

Study record dates

Study Major Dates

• Study Start (Actual): August 14, 2026
• Primary Completion (Estimated): October 31, 2028
• Study Completion (Estimated): October 31, 2028

Study Registration Dates

• First Submitted: September 10, 2025
• First Submitted That Met QC Criteria: February 5, 2026
• First Posted (Actual): February 9, 2026

Study Record Updates

• Last Update Posted (Actual): August 27, 2026
• Last Update Submitted That Met QC Criteria: August 26, 2026
• Last Verified: August 1, 2025

More Information

Terms related to this study

• Other Study ID Numbers: IRB202500587

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: Upon study completion, published data will be made available via established repositories (e.g., NIH OpenNeuro, OSF).
• IPD Sharing Time Frame: Upon publication acceptance of data.
• IPD Sharing Access Criteria: Via open source repositories
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL; ANALYTIC_CODE

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No