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.
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
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
DOUBLE
Enrollment
42
Participants will receive active HD-tDCS at 3mA for 20 minutes
Participants will receive sham HD-tDCS
University of Michigan - Department of Psychiatry
Ann Arbor, Michigan, United States
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.
Time frame: 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.
Time frame: 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.
Time frame: 15 minutes after encoding
Object Location Touchscreen Task (Version C) Cued Recall Total Error
This platform is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional.
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.
Time frame: 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.
Time frame: 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.
Time frame: 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.
Time frame: 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.
Time frame: 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.
Time frame: 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.
Time frame: 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.
Time frame: 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.
Time frame: 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.
Time frame: 30 minutes post-stimulation
Blinding in Total Sample
Participants were asked to estimate which group they were in (i.e., active or sham).
Time frame: ~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".
Time frame: ~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".
Time frame: ~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".
Time frame: ~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".
Time frame: ~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".
Time frame: ~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".
Time frame: ~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".
Time frame: ~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".
Time frame: ~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".
Time frame: ~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".
Time frame: ~1 minute post stimulation