Patient Centered-Rehabilitation ver111090.1 (PCN1)

Effects of 3mA HD-tDCS on Associative and Working Memory in Cognitively Intact Older Adults

As we age, a number of factors can reduce our cognitive (or thinking) abilities. This study will evaluate whether transcranial electrical stimulation (TES), which uses small amounts of electricity to modulate brain functioning, can improve cognitive abilities. Here, the effects of TES on working memory, learning, and memory, will be evaluated in a group of healthy older adults.

Study Overview

• Status: Completed
• Conditions: Cognitive Change
• Intervention / Treatment: Device: Active HD-tDCS; Device: Sham HD-tDCS

Detailed Description

The primary objective is to investigate the cognitive effects of high definition anodal tDCS (HD-tDCS; anode at center electrode) at 3 mA (for 20 minutes) on learning, memory, and working memory. Participants will be randomized to active or sham stimulation and will complete a series of cognitive tests both during and after stimulation.

Tolerability and blinding will also be evaluated using standard side effect questionnaires.

• Study Type: Interventional
• Enrollment (Actual): 42
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • Michigan
    • Ann Arbor, Michigan, United States, 48109
      • University of Michigan - Department of Psychiatry

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 50 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: All

Description

Inclusion Criteria:

1. Individuals with intact cognitive functioning.
2. Participants will be age 50 or older.

Exclusion Criteria:

1. Individuals with a documented history of cognitive impairment.
2. A history of serious mental illness (e.g., bipolar disorder, schizophrenia, axis 2 disorders)
3. Sensory or motor impairments that limit the ability to take part in the study
4. A significant history or current use of alcohol or drug abuse/dependence
5. Those who are currently pregnant (if there is a question of pregnancy, pregnancy tests will be available for participants at no charge)
6. Participants with an Mini Mental State Examination score <24 at screening.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Active HD-tDCS; Participants will receive "real" HD-tDCS (3 milliamps for 20 minutes) for a single session.	Device: Active HD-tDCS; Participants will receive active HD-tDCS at 3mA for 20 minutes; Other Names: HD-tDCS
Sham Comparator: Sham HD-tDCS; Participants will undergo the exact same procedures as the active group but will receive sham stimulation for a single session.	Device: Sham HD-tDCS; Participants will receive sham HD-tDCS

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Object Location Touchscreen Task (Version C) Free Recall Total Error	The Object Location Touchscreen Task (OLTT) is an ecologically relevant measure of object location association memory. The OLTT requires participants to learn and recall the location of 15 object-location associations. Memory is evaluated using a touchscreen monitor, which allows for the continuous measurement of memory accuracy (i.e., distance from targeted location). During the Free Recall, participants are given a black screen and asked to touch the area of the screen an object was located. Total Score is the sum of error for all 15 trials. Lower scores represent better performance.	15 minutes after encoding
Object Location Touchscreen Task (Version C) Free Recall Average Error	The Object Location Touchscreen Task (OLTT) is a measure of object location association memory. The OLTT requires participants to learn and recall the location of 15 object-location associations. Memory is evaluated using a touchscreen monitor, which allows for the continuous measurement of memory accuracy (i.e., distance from targeted location). During the Free Recall, participants are given a blank screen and asked to touch the area of the screen an object was located. Average Score is the average error across all 15 trials. Lower scores represent better performance.	15 minutes after encoding
Object Location Touchscreen Task (Version C) Free Recall Average Time to Respond	The Object Location Touchscreen Task (OLTT) is a measure of object location association memory. The OLTT requires participants to learn and recall the location of 15 object-location associations. Memory is evaluated using a touchscreen monitor, which allows for the continuous measurement of memory accuracy (i.e., distance from targeted location). During the Free Recall, participants are given a blank screen and asked to touch the area of the screen an object was located. Average Time is the average latency to respond across all 15 trials. Lower scores represent faster responses.	15 minutes after encoding
Object Location Touchscreen Task (Version C) Cued Recall Total Error	The Object Location Touchscreen Task (OLTT) requires participants to learn and recall the location of 15 object-location associations. Memory is evaluated using a touchscreen monitor, which allows for the continuous measurement of memory accuracy (i.e., distance from targeted location). During the Cued Recall, participants are shown the "room" or environment on the screen and asked to touch the area of the screen an object was located. Total Score is the sum of error for all 15 trials. Lower scores represent better performance.	15 minutes after encoding
Object Location Touchscreen Task (Version C) Cued Recall Average Error	The Object Location Touchscreen Task (OLTT) requires participants to learn and recall the location of 15 object-location associations. Memory is evaluated using a touchscreen monitor, which allows for the continuous measurement of memory accuracy (i.e., distance from targeted location). During the Cued Recall, participants are shown the "room" or environment on the screen and asked to touch the area of the screen an object was located. Average Score is the average error across all 15 trials. Lower scores represent better performance.	15 minutes after encoding
Object Location Touchscreen Task (Version C) Cued Recall Average Time to Respond	The Object Location Touchscreen Task (OLTT) requires participants to learn and recall the location of 15 object-location associations. Memory is evaluated using a touchscreen monitor, which allows for the continuous measurement of memory accuracy (i.e., distance from targeted location). During the Cued Recall, participants are shown the "room" or environment on the screen and asked to touch the area of the screen an object was located. Average Time is the average latency to respond across all 15 trials. Lower scores represent faster responses.	15 minutes after encoding
Object Location Touchscreen Task (Version C) Recognition Total Correct	The Object Location Touchscreen Task (OLTT) requires participants to learn and recall the location of 15 object-location associations. Memory is evaluated using a touchscreen monitor, which allows for the continuous measurement of memory accuracy (i.e., distance from targeted location). During the Recognition, participants are asked to select the correct location of an object from three options on the screen. Recognition total is the number of correct selections on all 15 trials. Higher scores represent better performance.	15 minutes after encoding
Object Location Touchscreen Task (Version C) Recognition Average Time to Respond	The Object Location Touchscreen Task (OLTT) requires participants to learn and recall the location of 15 object-location associations. Memory is evaluated using a touchscreen monitor, which allows for the continuous measurement of memory accuracy (i.e., distance from targeted location). During the Recognition, participants are asked to select the correct location of an object from three options on the screen. Recognition Average Response Time is the average latency to respond across all 15 trials. Lower scores represent faster responses.	15 minutes after encoding
Performance (d') on a Simple Attention (0-back) Test	The n-back is a well validated measure of working memory. During 0-back, participants are asked to respond by pressing a key when the picture on the screen is the same as the given target (e.g., a cow). Discriminability (d') is a measure of signal detection that accounts for signal to noise ratio. Higher scores represent better discriminability.	30 minutes post-stimulation
Performance (d') on a Working Memory (2-back) Test	The n-back is a well validated measure of working memory. During 2-back, participants are asked to respond when a picture shown is the exact same as two items ago. Discriminability (d') is a measure of signal detection that accounts for signal to noise ratio. Higher scores represent better discriminability.	30 minutes post-stimulation
Performance (d') on a Working Memory (Semantic 2-back) Test	The n-back is a well validated measure of working memory. During Semantic-back, participants are asked to respond when a picture shown is in the same semantic category as the picture two items ago (e.g., both fruits). Discriminability (d') is a measure of signal detection that accounts for signal to noise ratio. Higher scores represent better discriminability.	30 minutes post-stimulation
Calculated Working Memory Performance Accounting for Simple Attention (2-back d' Minus 0-back d')	The n-back is a well validated measure of working memory. During 0-back, participants are asked to respond by pressing a key when the picture on the screen is the same as the given target (e.g., a cow). During 2-back, participants are asked to respond when a picture shown is the exact same as two items ago. Discriminability (d') is a measure of signal detection that accounts for signal to noise ratio. By subtracting the 0-back d', the calculated score represents a more pure working memory measure. Scores closer to zero or positive represent better working memory performance.	30 minutes post-stimulation
Calculated Working Memory Performance Accounting for Simple Attention (Semantic 2-back d' Minus 0-back d')	The n-back is a well validated measure of working memory. During 0-back, participants are asked to respond by pressing a key when the picture on the screen is the same as the given target (e.g., a cow). During Semantic 2-back, participants are asked to respond when a picture shown is in the same semantic category as the picture two items ago (e.g., both fruits). Discriminability (d') is a measure of signal detection that accounts for signal to noise ratio. By subtracting the 0-back d', the calculated score represents a more pure working memory measure. Scores closer to zero or positive represent better working memory performance.	30 minutes post-stimulation

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Blinding in Total Sample	Participants were asked to estimate which group they were in (i.e., active or sham).	~1 minute post stimulation
Frequency of Endorsement (%) for Headache Item in Active and Sham Participants Undergoing HD-tDCS Session	The side effects were assessed using a modified version of Brunoni et al. (2011) questionnaire. Participants rated common sensory experiences on a scale of "None, Mild, Moderate, or Severe".	~1 minute post stimulation
Frequency of Endorsement (%) for Neck Pain Item in Active and Sham Participants Undergoing HD-tDCS Session	The side effects were assessed using a modified version of Brunoni et al. (2011) questionnaire. Participants rated common sensory experiences on a scale of "None, Mild, Moderate, or Severe".	~1 minute post stimulation
Frequency of Endorsement (%) for Scalp Pain Item in Active and Sham Participants Undergoing HD-tDCS Session	The side effects were assessed using a modified version of Brunoni et al. (2011) questionnaire. Participants rated common sensory experiences on a scale of "None, Mild, Moderate, or Severe".	~1 minute post stimulation
Frequency of Endorsement (%) for Tingling Item in Active and Sham Participants Undergoing HD-tDCS Session	The side effects were assessed using a modified version of Brunoni et al. (2011) questionnaire. Participants rated common sensory experiences on a scale of "None, Mild, Moderate, or Severe".	~1 minute post stimulation
Frequency of Endorsement (%) for Itching Item in Active and Sham Participants Undergoing HD-tDCS Session	The side effects were assessed using a modified version of Brunoni et al. (2011) questionnaire. Participants rated common sensory experiences on a scale of "None, Mild, Moderate, or Severe".	~1 minute post stimulation
Frequency of Endorsement (%) for Burning Item in Active and Sham Participants Undergoing HD-tDCS Session	The side effects were assessed using a modified version of Brunoni et al. (2011) questionnaire. Participants rated common sensory experiences on a scale of "None, Mild, Moderate, or Severe".	~1 minute post stimulation
Frequency of Endorsement (%) for Skin Redness Item in Active and Sham Participants Undergoing HD-tDCS Session	The side effects were assessed using a modified version of Brunoni et al. (2011) questionnaire. Participants rated common sensory experiences on a scale of "None, Mild, Moderate, or Severe".	~1 minute post stimulation
Frequency of Endorsement (%) for Sleepiness Item in Active and Sham Participants Undergoing HD-tDCS Session	The side effects were assessed using a modified version of Brunoni et al. (2011) questionnaire. Participants rated common sensory experiences on a scale of "None, Mild, Moderate, or Severe".	~1 minute post stimulation
Frequency of Endorsement (%) for Concentration Changes Item in Active and Sham Participants Undergoing HD-tDCS Session	The side effects were assessed using a modified version of Brunoni et al. (2011) questionnaire. Participants rated common sensory experiences on a scale of "None, Mild, Moderate, or Severe".	~1 minute post stimulation
Frequency of Endorsement (%) for Mood Changes Item in Active and Sham Participants Undergoing HD-tDCS Session	The side effects were assessed using a modified version of Brunoni et al. (2011) questionnaire. Participants rated common sensory experiences on a scale of "None, Mild, Moderate, or Severe".	~1 minute post stimulation

Collaborators and Investigators

• Sponsor: University of Michigan
• Investigators: Principal Investigator: Benjamin M Hampstead, PhD, University of Michigan

Publications and helpful links

General Publications

• Brunoni AR, Amadera J, Berbel B, Volz MS, Rizzerio BG, Fregni F. A systematic review on reporting and assessment of adverse effects associated with transcranial direct current stimulation. Int J Neuropsychopharmacol. 2011 Sep;14(8):1133-45. doi: 10.1017/S1461145710001690. Epub 2011 Feb 15.

Study record dates

Study Major Dates

• Study Start (Actual): October 1, 2016
• Primary Completion (Actual): June 1, 2017
• Study Completion (Actual): October 1, 2017

Study Registration Dates

• First Submitted: October 24, 2016
• First Submitted That Met QC Criteria: January 26, 2017
• First Posted (Estimate): January 27, 2017

Study Record Updates

• Last Update Posted (Actual): August 16, 2018
• Last Update Submitted That Met QC Criteria: July 17, 2018
• Last Verified: July 1, 2018

More Information

Terms related to this study

• Other Study ID Numbers: HUM00111090.1 PCN

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO