Optimizing tACS for working memory: differential outcomes in healthy aging and non-amnestic mild cognitive impairment

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216224%3A14740%2F25%3A00143794" target="_blank" >RIV/00216224:14740/25:00143794 - isvavai.cz</a>

Výsledek na webu

<a href="https://link.springer.com/article/10.1186/s13195-025-01922-4" target="_blank" >https://link.springer.com/article/10.1186/s13195-025-01922-4</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1186/s13195-025-01922-4" target="_blank" >10.1186/s13195-025-01922-4</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Optimizing tACS for working memory: differential outcomes in healthy aging and non-amnestic mild cognitive impairment

Popis výsledku v původním jazyce

Transcranial alternating current stimulation (tACS) in the theta frequency range has been shown to enhance working memory (WM) performance. However, no studies have directly compared the effects of theta tACS between cognitively healthy elderly (HE) subjects and subjects with non-amnestic mild cognitive impairment (MCI). Our proof-of-concept study investigated the effects of monofocal (frontal) and bifocal (frontoparietal) theta tACS on WM in two cognitive loads in HE subjects and in subjects with MCI. In this sham-controlled, single-blinded, repeated-measures study with counterbalanced stimulation order across subjects (n = 55), theta tACS (4.51 Hz, 1.5 mA, 20 min) was applied either over the frontal site alone or simultaneously over frontal and parietal sites. WM 2-back and 3-back tasks were performed during and after each stimulation session. In the HE group, both frontal and frontoparietal stimulations improved performance, albeit with load-dependent differences. Frontal stimulation was particularly effective in the higher cognitive load, enhancing accuracy (beta = -3.87; p = .033) and reaction times (beta = - .042; p = .002) in the 3-back task. Frontoparietal stimulation improved accuracy (beta = -3.74; p = .027) but not reaction time (p &gt; .22) in the 2-back task in the HE group. Frontoparietal stimulation enhanced accuracy in the 3-back task across all participants (beta = 1.91; p = .043). In the MCI group, frontal stimulation led to faster reaction times in the 3-back task, although the effects were not robust. Lastly, a marginally significant improvement in reaction times was observed in a letter 2-back transfer task following frontal stimulation (beta = - .034; p &lt; .092) across all participants. Our findings indicate that theta tACS over the frontal and frontoparietal areas elicits benefits in WM performance, driven mainly by enhancements in HE subjects. The effects of stimulation varied with cognitive load and montage, suggesting that optimal stimulation parameters may differ depending on task demands. The non-amnestic MCI group did not exhibit greater improvements despite their lower baseline performance, possibly due to higher variability in pathology and compensation. Multiple sessions or alternative stimulation parameters may be needed to achieve robust effects in subjects with MCI. The study was retrospectively registered on ClinicalTrials.gov (NCT06563453).

Název v anglickém jazyce

Optimizing tACS for working memory: differential outcomes in healthy aging and non-amnestic mild cognitive impairment

Popis výsledku anglicky

Transcranial alternating current stimulation (tACS) in the theta frequency range has been shown to enhance working memory (WM) performance. However, no studies have directly compared the effects of theta tACS between cognitively healthy elderly (HE) subjects and subjects with non-amnestic mild cognitive impairment (MCI). Our proof-of-concept study investigated the effects of monofocal (frontal) and bifocal (frontoparietal) theta tACS on WM in two cognitive loads in HE subjects and in subjects with MCI. In this sham-controlled, single-blinded, repeated-measures study with counterbalanced stimulation order across subjects (n = 55), theta tACS (4.51 Hz, 1.5 mA, 20 min) was applied either over the frontal site alone or simultaneously over frontal and parietal sites. WM 2-back and 3-back tasks were performed during and after each stimulation session. In the HE group, both frontal and frontoparietal stimulations improved performance, albeit with load-dependent differences. Frontal stimulation was particularly effective in the higher cognitive load, enhancing accuracy (beta = -3.87; p = .033) and reaction times (beta = - .042; p = .002) in the 3-back task. Frontoparietal stimulation improved accuracy (beta = -3.74; p = .027) but not reaction time (p &gt; .22) in the 2-back task in the HE group. Frontoparietal stimulation enhanced accuracy in the 3-back task across all participants (beta = 1.91; p = .043). In the MCI group, frontal stimulation led to faster reaction times in the 3-back task, although the effects were not robust. Lastly, a marginally significant improvement in reaction times was observed in a letter 2-back transfer task following frontal stimulation (beta = - .034; p &lt; .092) across all participants. Our findings indicate that theta tACS over the frontal and frontoparietal areas elicits benefits in WM performance, driven mainly by enhancements in HE subjects. The effects of stimulation varied with cognitive load and montage, suggesting that optimal stimulation parameters may differ depending on task demands. The non-amnestic MCI group did not exhibit greater improvements despite their lower baseline performance, possibly due to higher variability in pathology and compensation. Multiple sessions or alternative stimulation parameters may be needed to achieve robust effects in subjects with MCI. The study was retrospectively registered on ClinicalTrials.gov (NCT06563453).

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

30210 - Clinical neurology

Projekt

Výsledek vznikl pri realizaci vícero projektů. Více informací v záložce Projekty.

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2025

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

ALZHEIMERS RESEARCH & THERAPY

ISSN

1758-9193

e-ISSN

1758-9193

Svazek periodika

18

Číslo periodika v rámci svazku

1

Stát vydavatele periodika

GB - Spojené království Velké Británie a Severního Irska

Počet stran výsledku

12

Strana od-do

1-12

Kód UT WoS článku

001655320200001

EID výsledku v databázi Scopus

2-s2.0-105026868679