Neuromodulation of Cognition in Older Adults

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.

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