Neuromodulation of Cognition in Older Adults

Not Applicable

Completed

Interventions: Device: Sham Stimulation
Device: Transcranial Direct Current Stimulation

Brief Summary: This study will investigate whether transcranial direct current stimulation enhances the effects of cognitive training in healthy older adults.

Detailed Description: The current study will investigate methods for enhancing cognitive training effects in healthy older adults by employing a combination of interventions facilitating neural plasticity and optimizing readiness for learning. Adults over the age of 65 represent the fastest growing group in the US population. As such, age-related cognitive decline represents a major concern for public health. Recent research suggests that cognitive training in older adults can improve cognitive performance, with effects lasting up to 10 years. However, these effects are typically limited to the tasks trained, with little transfer to other cognitive abilities or everyday skills. A pilot randomized clinical trial will examine the individual and combined impact of pairing cognitive training with transcranial direct current stimulation (tDCS). tDCS is a method of non-invasive brain stimulation that directly stimulates brain regions involved in active cognitive function and enhances neural plasticity when paired with a training task. We will compare changes in cognitive and brain function resulting from CT and CT combined with tDCS using a comprehensive neurocognitive, clinical, and multimodal neuroimaging assessment of brain structure, function, and metabolic state.

Recruitment & Eligibility

Inclusion Criteria

Men and women
Age: 65 to 90 years
English speaking
Physically mobile
working memory function between 0-75th percentile determined by screening results on the POSIT Baseline Cognitive Training computerized tasks.

Exclusion Criteria

Neurological disorders (e.g., dementia, stroke, seizures, traumatic brain injury).
Evidence of dementia (NACC UDS scores of 1.5 standard deviations below the mean for age, sex and education adjusted norms in a single cognitive domain on the task).
Past opportunistic brain infection.
Major psychiatric illness (schizophrenia, intractable affective disorder, current substance dependence diagnosis or severe major depression and/or suicidality).
Unstable (e.g., cancer other than basal cell skin) and chronic (e.g, severe diabetes) medical conditions.
MRI contraindications (e.g., pregnancy, claustrophobia, metal implants that are contraindicated for MRI).
Physical impairment precluding motor response or lying still for 1 hr and inability to walk two blocks without stopping.
Certain prescription medications may possibly reduce effects otherwise induced by the tDCS stimulation protocol.
Hearing or vision deficits that will not allow for standardized cognitive training.
Left handedness

Arm && Interventions

Group	Intervention	Description
Cognitive Training + Sham tDCS	Sham Stimulation	Participants will undergo up to 10 hours of cognitive training. Cognitive training will involve computerized games that stress elements of cognition. The group will undergo sham transcranial direct current stimulation.
Cognitive Training + Active tDCS	Transcranial Direct Current Stimulation	Participants will undergo up to 10 hours of cognitive training. Cognitive training will involve computerized games that stress elements of cognition. The group will undergo active transcranial direct current stimulation.

Primary Outcome Measures

Name	Time	Method
Change in NIH Toolbox Fluid Cognition Composite Score	baseline up to two week post test	The NIH Toolbox is a battery of neurocognitive tests created by the National Institute on Aging as a comprehensive measure of cognitive function. We used the change from baseline to two week post test in the NIH Toolbox Fluid Cognition Composite Score (FCC) to assess outcome. The uncorrected standard score of the FCC was used. The FCC is derived by averaging the standard scores of the NIH Toolbox Flanker, Dimensional Change Card Sort, Picture Sequence Memory, List Sorting, and Pattern Comparison tests and then deriving standard scores based on this new distribution. The uncorrected standard score is on a scale of mean = 100, standard deviation = 15. Higher positive scores mean a greater improvement at the post test. Difference scores ranged from a minimum of -7 to a maximum of 19. FCC scores ranged from a minimum of 73 to a maximum of 112 in this sample. On a population level percentiles are reported from a minimum score of 59 to a maximum of 140, covering 99.3% of the population.

Secondary Outcome Measures

Name	Time	Method

Locations (2): University of Florida
🇺🇸
Gainesville, Florida, United States
McKnight Brain Institute
🇺🇸
Gainesville, Florida, United States