Non-Invasive Brain Stimulation for Working Memory Improvement

Overseen By Ivan Alekseichuk, PhD

Age: 18+

Sex: Any

Trial Phase: Academic

Sponsor: University of Minnesota

Disqualifiers: Diminished capacity to consent

No Placebo Group All trial participants will receive the active study treatment (no placebo)

Compensation: Varies

Number of Visits: Unknown

Duration: Immediate effect during stimulation

16 Participants Needed

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial explores a new method to improve working memory using a non-invasive technique called transcranial alternating current stimulation (tACS). Gentle electrical currents target specific brain areas in people with epilepsy undergoing surgical evaluation. The trial divides participants into two groups: one receiving stimulation at a lower frequency and the other at a higher frequency. Eligible participants must be able to consent and have, or be scheduled for, surgically implanted electrodes as part of their epilepsy treatment. As an unphased trial, this study offers a unique opportunity to contribute to groundbreaking research that could enhance epilepsy treatment options.

Do I need to stop taking my current medications for this trial?

The trial information does not specify whether you need to stop taking your current medications.

What prior data suggests that this method is safe for improving working memory?

Research has shown that transcranial alternating current stimulation (tACS) is generally safe and easy to tolerate. In one study, young people with a specific genetic condition managed tACS well and experienced no major side effects. Other research indicates that tACS is safe and painless when used to alter brain activity patterns. It is considered safer than other brain stimulation methods. Overall, these findings suggest that tACS is a safe option for those considering participation in related studies. ^{1 2 3 4 5}

Why are researchers excited about this trial?

Researchers are excited about the use of transcranial alternating current stimulation (tACS) for improving working memory because it offers a non-invasive approach that distinguishes itself from traditional treatments like medication or cognitive therapy. Unlike most treatments that rely on chemical interactions within the brain, tACS directly influences brain activity by applying electrical currents to specific regions. This method is unique as it targets neural oscillations, with the Theta Group using 4 Hz and the Beta Group using 23 Hz stimulation, potentially enhancing memory function more precisely and rapidly. The hope is that this innovative technique could lead to more effective and faster improvements in memory without the side effects commonly associated with medications.

What evidence suggests that this trial's treatments could be effective for improving working memory?

Research has shown mixed results for a technique called transcranial alternating current stimulation (tACS) in improving working memory. In this trial, participants will divide into two groups to receive different types of tACS. The Stimulation Theta Group will receive theta tACS, using low frequencies like 4 Hz, which has shown inconsistent effects in previous studies. Some studies found no improvement in memory, while others observed moderate benefits. Meanwhile, the Stimulation Beta Group will receive beta tACS, using higher frequencies like 23 Hz, which seems more promising. Several studies report that beta tACS improved working memory compared to no treatment. Overall, while tACS might help with memory, more research is needed to confirm its effectiveness. ^{1 6 7 8 9}

Who Is on the Research Team?

Alexander Opitz, PhD

Principal Investigator

University of Minnesota

Are You a Good Fit for This Trial?

This trial is for adults over 18 who can give their own consent and are undergoing phase II epilepsy surgical evaluation with implanted electrodes. It's not suitable for those unable to consent.

Inclusion Criteria

The patient can consent for themselves

I have or will have electrodes implanted for epilepsy surgery evaluation.

Exclusion Criteria

I have difficulty understanding and making health decisions.

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Treatment

Participants receive traveling wave transcranial alternating current stimulation to modify working memory performance and brain connectivity

Immediate effect during stimulation

Follow-up

Participants are monitored for safety and effectiveness after treatment

4 weeks

What Are the Treatments Tested in This Trial?

Interventions

• Transcranial Alternating Current Stimulation

Trial Overview The study tests if a non-invasive brain stimulation technique, called traveling wave transcranial alternating current stimulation (tACS), can improve working memory and alter brain connectivity in epilepsy patients.

How Is the Trial Designed?

Group I: Stimulation Theta Group Experimental Treatment 1 Intervention

Participants will experience traveling wave transcranial alternating current stimulation over the fronto-parietal regions at 4 Hz (theta condition).

Group II: Stimulation Beta Group Experimental Treatment 1 Intervention

Participants will experience traveling wave transcranial alternating current stimulation over the fronto-parietal regions at 23 Hz (beta condition).

Who Is Running the Clinical Trial?

University of Minnesota

Lead Sponsor

Trials

1,459

Recruited

1,623,000+

National Institute of Mental Health (NIMH)

Collaborator

Trials

3,007

Recruited

2,852,000+

Published Research Related to This Trial

The study found that online repetitive transcranial magnetic stimulation (rTMS) applied to the left dorsolateral prefrontal cortex significantly improved memory recall accuracy in both young and older adults, particularly during the most challenging cognitive tasks.

This suggests that rTMS could be a promising method for enhancing working memory manipulation, especially in high-demand situations, warranting further research into its potential benefits.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Online repetitive transcranial magnetic stimulation during working memory in younger and older adults: A randomized within-subject comparison. Beynel, L., Davis, SW., Crowell, CA., et al.[2022]

Transcranial Alternating Current Stimulation (tACS) has shown a small-to-medium effect on improving both working memory (WM) and long-term memory (LTM) in healthy adults, based on a systematic review of 104 studies.

Specific tACS parameters, such as posterior theta-tACS for WM and anterior gamma-tACS for LTM, were found to effectively modulate memory performance, with results correlating with brain oscillatory activity measured by EEG and MEG.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

The effects of transcranial alternating current stimulation on memory performance in healthy adults: A systematic review. Booth, SJ., Taylor, JR., Brown, LJE., et al.[2022]

Transcranial alternating current stimulation (tACS) at a frequency tailored to individual brain activity (Tuned condition) significantly improved visuospatial working memory (vsWM) and mental rotation tasks in 20 adults, compared to a sham stimulation.

The improvement in performance was linked to increased synchrony in the fronto-parietal brain network, suggesting that targeted stimulation can enhance specific cognitive functions related to spatial abilities.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Individually tuned theta HD-tACS improves spatial performance. Zhang, DW., Moraidis, A., Klingberg, T.[2023]

In a randomized crossover study involving 43 participants (22 with major depression and 21 healthy volunteers), gamma transcranial alternating current stimulation (tACS) did not improve working memory performance during a computerized task, regardless of whether the stimulation was active or sham.

The study highlights the need for standardized methodologies in gamma tACS research, as the lack of cognitive improvement aligns with previous inconsistent findings in the field.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Single session gamma transcranial alternating stimulation does not modulate working memory in depressed patients and healthy controls. Palm, U., Baumgartner, C., Hoffmann, L., et al.[2022]

Transcranial alternating-current stimulation (tACS) is a promising non-invasive brain stimulation technique that may enhance working memory (WM) performance, particularly in older adults and individuals with cognitive deficits, due to its superior safety and tolerability compared to repetitive transcranial magnetic stimulation (rTMS).

Research indicates that tACS can effectively manipulate brain oscillations associated with WM, suggesting its potential as a non-pharmacological tool for cognitive rehabilitation in aging populations and those with conditions like dementia and depression.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Working Memory and Transcranial-Alternating Current Stimulation-State of the Art: Findings, Missing, and Challenges. Al Qasem, W., Abubaker, M., Kvašňák, E.[2023]

Frequency-tuned noninvasive brain stimulation can effectively modulate brain oscillations, which are linked to working memory, leading to changes in behavior and cognitive functions.

This technique has advanced our understanding of how brain oscillations influence memory and has potential therapeutic applications for enhancing cognitive abilities.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Driving working memory with frequency-tuned noninvasive brain stimulation. Albouy, P., Baillet, S., Zatorre, RJ.[2019]

In a study involving 38 healthy adults, temporal interference transcranial alternating current stimulation (TI-tACS) was found to be safe, with no significant adverse effects reported after active stimulation at 2 mA for 30 minutes.

The study showed no significant differences in neurological and neuropsychological measurements between the active TI-tACS group and the sham group, indicating that TI-tACS does not negatively impact brain function under the tested conditions.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Safety Evaluation of Employing Temporal Interference Transcranial Alternating Current Stimulation in Human Studies. Piao, Y., Ma, R., Weng, Y., et al.[2022]

Transcranial alternating current stimulation (tACS) is a promising non-invasive technique that may help improve cognitive deficits by targeting and enhancing cortical network synchronization.

Current research suggests that tACS could clarify the causal relationship between specific brain activity patterns and cognitive abilities, paving the way for new treatment options for cognitive impairments in psychiatric illnesses.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Targeting the neurophysiology of cognitive systems with transcranial alternating current stimulation. Fröhlich, F., Sellers, KK., Cordle, AL.[2018]

Low intensity transcranial electrical stimulation (TES) is considered safe, with no serious adverse events reported in over 18,000 sessions across various populations, including healthy individuals and patients with neurological or psychiatric conditions.

While moderate adverse events like skin burns from tDCS are rare, mild adverse events such as headaches and fatigue are more common, and the safety profile is consistent across different age groups and vulnerable populations.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Low intensity transcranial electric stimulation: Safety, ethical, legal regulatory and application guidelines. Antal, A., Alekseichuk, I., Bikson, M., et al.[2023]

Transcranial Direct Current Stimulation (tDCS) has been shown to be safe, with no reports of Serious Adverse Effects or irreversible injuries across over 33,200 sessions involving more than 1,000 subjects, including vulnerable populations.

Safety assessments indicate that the current densities used in conventional tDCS (≤4 milliamperes) are significantly lower than those that could potentially cause brain injury, suggesting that tDCS protocols are well within safe limits.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Safety of Transcranial Direct Current Stimulation: Evidence Based Update 2016. Bikson, M., Grossman, P., Thomas, C., et al.[2022]

Transcranial alternating current stimulation (tACS) has been shown to lead to modest to moderate improvements in cognitive function across various domains, including working memory and attention, based on a systematic review of 102 studies involving 2893 participants.

The most significant cognitive improvements were observed after tACS treatment (offline effects) rather than during the stimulation (online effects), and studies that optimized stimulation based on current flow models yielded better outcomes.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

A meta-analysis suggests that tACS improves cognition in healthy, aging, and psychiatric populations. Grover, S., Fayzullina, R., Bullard, BM., et al.[2023]

Citations

1. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC10257732/

Efficacy of tACS in the enhancement of working memory ... Active tACS enhances working memory performance in healthy individuals compared to sham, with a moderate effect size.

2. sciencedirect.com sciencedirect.com/science/article/abs/pii/S0006899324002762

Transcranial alternating current stimulation barely ... Our results suggest that current tACS protocols barely enhance WM in healthy adults. More research is needed to develop effective methods for WM stimulation.

3. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC7867505/

Transcranial alternating current stimulation (tACS): from basic ... The same tACS protocol was replicated in the other case report but for five consecutive days, resulting in improved working memory after 6 Hz-tACS, as well as ...

4. biorxiv.org biorxiv.org/content/10.1101/2024.05.31.596854v1.full-text

Working memory enhancement using real-time phase ... Results WM accuracy improved in a phase lag dependent manner (p < 0.05) in the group receiving parietooccipital stimulation, with the strongest ...

5. frontiersin.org frontiersin.org/journals/psychology/articles/10.3389/fpsyg.2024.1405636/full

Research progress on the intervention of cognitive function ... Research has found that: (1) tACS intervention can improve the working memory, learning ability, and exercise decision-making ability of athletes and healthy ...

6. sciencedirect.com sciencedirect.com/science/article/pii/S0165178124001203

A randomized double-blind sham-controlled study Transcranial alternating current stimulation (tACS) was well-tolerated among young individuals with 22q11.2 deletion syndrome (22q11.2DS).

7. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC4889859/

Effects of Transcranial Alternating Current Stimulation on ... Here, we focus on studies that examined tACS-induced modulation of cognitive functions in healthy adults, specifically executive functions and working memory ...

8. frontiersin.org frontiersin.org/journals/psychology/articles/10.3389/fpsyg.2022.822545/full

Working Memory and Transcranial-Alternating Current ... Compared to rTMS, tACS demonstrates superior cost, tolerability, portability, and safety profile, making it an attractive potential tool for ...

9. nature.com nature.com/articles/s41539-022-00152-9

A meta-analysis showing improved cognitive performance ... This systematic review and meta-analysis investigated the effects of tACS protocols on cognitive functions in healthy young adults.