TDCS to Improve Motivation and Memory in Elderly (TIME)

Summary

Fundamental advancements in understanding successful aging are limited by the lack of causal, rather than just correlational methods to connect age-related changes in memory ability to changes in brain structure and function. In this study, non-invasive electric brain stimulation will be used as a tool to create causal links between successful memory function in aging and brain structures associated with motivation. Recently, it was shown that a group of elderly, dubbed "superagers", are indistinguishable from young adults in memory performance and the structure of cortical limbic regions. A key superaging region is mid-cingulate cortex (MCC), a brain structure associated with motivation and tenacity. The MCC is a hub region that synchronizes information flow between three core brain networks. The goal of the research is to explore the contribution of motivation to memory performance by modulating MCC connectivity with transcranial direct current stimulation (tDCS) to provide the first causal evidence that experimentally induced motivation can improve memory performance. Since MCC has not been stimulated with tDCS before, we will test three different stimulation protocols and compare against a placebo. The stimulation protocols were computationally optimized for this project. The primary aim is to find the stimulation protocol most successful at improving memory performance. In order to elucidate the mechanisms behind these changes, effects of stimulation on motivation and network connectivity will be investigated. If indeed memory can be improved by increasing motivation and effort via stimulating MCC, this study will generate new insights into the motivational mechanisms of successful aging.

Conditions

• Motivation

Interventions

DEVICE

Direct tDCS

Transcranial direct current stimulation (tDCS) will be applied. Stimulation amplitude is 2 mA. Stimulation duration is 20 minutes. The configuration used is two electrodes at AFz and CPz of the 10-10 electrode system.

DEVICE

Indirect tDCS

Transcranial direct current stimulation (tDCS) will be applied. Stimulation amplitude is 2 mA. Stimulation duration is 20 minutes. The configuration used is two electrodes at AF3 and AF4 of the 10-10 electrode system.

DEVICE

Personalized tDCS

Transcranial direct current stimulation (tDCS) will be applied. Stimulation amplitude is 2 mA. Stimulation duration is 20 minutes. The configuration used will be optimized to stimulate key nodes connected to MCC, including anterior insula, MFG and supramarginal gyrus, and designed using an individual head model that will be combined with each subject's measured connectivity map. The number of electrodes will be minimally 2 and maximally 32.

DEVICE

Sham tDCS

Transcranial direct current stimulation (tDCS) will be applied. Stimulation amplitude is 2 mA. Stimulation duration is 20 minutes. Placebo stimulation will be applied by ramping the current up and immediately down over 30 seconds. The configuration used is two electrodes at AF3 and AF4 of the 10-10 electrode system.

Sponsors & Collaborators

• Massachusetts General Hospital

  collaborator OTHER

• National Institute on Aging (NIA)

  collaborator NIH

• Northeastern University

  lead OTHER

Principal Investigators

• Sumientra M Rampersad, PhD · Northeastern University

Study Design

Allocation

RANDOMIZED

Purpose

BASIC_SCIENCE

Masking

TRIPLE

Model

PARALLEL

Eligibility

Min Age

65 Years

Max Age

80 Years

Sex

ALL

Healthy Volunteers

Yes

Timeline & Regulatory

Start

2020-01-22

Primary Completion

2020-09-30

Completion

2020-09-30

Countries

• United States

Study Locations