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Carrarini C, Pappalettera C, Le Pera D, Rossini PM. Non-invasive brain stimulation in cognitive sciences and Alzheimer's disease. Front Hum Neurosci 2025; 18:1500502. [PMID: 39877800 PMCID: PMC11772349 DOI: 10.3389/fnhum.2024.1500502] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2024] [Accepted: 12/17/2024] [Indexed: 01/31/2025] Open
Abstract
Over the last four decades, non-invasive brain stimulation techniques (NIBS) have significantly gained interest in the fields of cognitive sciences and dementia care, including neurorehabilitation, for its emerging potential in increasing the insights over brain functions and in boosting residual cognitive functions. In the present paper, basic physiological and technical mechanisms and different applications of NIBS were reviewed and discussed to highlight the importance of NIBS in multidisciplinary and translational approaches in clinical and research settings of cognitive sciences and neurodegenerative diseases, especially in Alzheimer's disease. Indeed, NIBS strategies may represent a promising opportunity to increase the potential of neuromodulation as efficacious interventions for individualized patients care.
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Affiliation(s)
- Claudia Carrarini
- Department of Neuroscience and Neurorehabilitation, IRCCS San Raffaele Roma, Rome, Italy
| | - Chiara Pappalettera
- Department of Neuroscience and Neurorehabilitation, IRCCS San Raffaele Roma, Rome, Italy
- Department of Theoretical and Applied Sciences, eCampus University, Como, Italy
| | - Domenica Le Pera
- Department of Neuroscience and Neurorehabilitation, IRCCS San Raffaele Roma, Rome, Italy
| | - Paolo Maria Rossini
- Department of Neuroscience and Neurorehabilitation, IRCCS San Raffaele Roma, Rome, Italy
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2
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Arar T, Hirsch GV, Chamberlain TA, Malone M, Wakeland-Hart CD, Snarskis M, Lauderdale DS, Schumm LP, Gallo DA. Prefrontal tDCS fails to modulate memory retrieval in younger and older adults. Curr Biol 2025; 35:50-58.e4. [PMID: 39644890 PMCID: PMC11759060 DOI: 10.1016/j.cub.2024.10.080] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2024] [Revised: 09/24/2024] [Accepted: 10/31/2024] [Indexed: 12/09/2024]
Abstract
Previous research shows that a single session of anodal transcranial direct current stimulation (tDCS) to the left dorsolateral prefrontal cortex (dlPFC) can improve the accuracy of episodic memory retrieval, but stimulation effects are not always found and may be moderated by time of day. Here, we report the results from a rigorous clinical trial (NCT03723850) designed to replicate these tDCS findings in younger adults and extend them to cognitively normal older adults. We conducted the largest double-blind, between-subjects tDCS study on memory retrieval in younger and older adults to date. 150 younger adults and 91 older adults received anodal tDCS or sham stimulation to the left dlPFC prior to episodic memory retrieval and working memory tasks. We also manipulated when tDCS was administered (time of day: morning vs. afternoon), task difficulty (easy vs. hard), and stimulus format (verbal vs. visual/pictorial) to test the extent that these variables are important for identifying tDCS effects. Contrary to our preregistered predictions, we did not find any effect of tDCS or time of day on younger or older adults' episodic or working memory performance. This outcome was not due to insensitivity of our cognitive tasks, given that we found expected effects of task difficulty and age-related effects on our memory measures. Based on these and prior tDCS results, we conclude that a single dose of tDCS using the typical and often recommended parameters does not reliably improve episodic memory retrieval in either age group.
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Affiliation(s)
- Tesnim Arar
- Department of Psychology, University of Chicago, Chicago, IL 60637, USA.
| | | | | | - Miranda Malone
- Department of Psychology, University of Chicago, Chicago, IL 60637, USA
| | | | - Martynas Snarskis
- School of Psychology, University of Auckland, Auckland 1010, New Zealand
| | - Diane S Lauderdale
- Department of Public Health Sciences, University of Chicago, Chicago, IL 60637, USA
| | - L Philip Schumm
- Department of Public Health Sciences, University of Chicago, Chicago, IL 60637, USA
| | - David A Gallo
- Department of Psychology, University of Chicago, Chicago, IL 60637, USA
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3
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Perret M, Neige C, Brunelin J, Mondino M. Unraveling the brain mechanisms of source monitoring with non-invasive brain stimulation: A systematic review. Int J Clin Health Psychol 2024; 24:100449. [PMID: 38406179 PMCID: PMC10884508 DOI: 10.1016/j.ijchp.2024.100449] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2023] [Accepted: 02/14/2024] [Indexed: 02/27/2024] Open
Abstract
Background/Objective Source monitoring refers to the ability to determine the source of memories and encompasses three subprocesses: internal source monitoring, reality monitoring, and external source monitoring. Neuroimaging studies provide valuable insights about neural correlates of source monitoring, but the causal relationship between brain and behavior is lacking. This study aimed to identify brain circuits involved in source monitoring by synthesizing the effects of brain stimulation on source monitoring as a function of the targeted brain regions or circuits. Method We conducted a systematic review of interventional studies that have examined the effects of brain stimulation on source monitoring across six databases. The principal outcome was the difference of source monitoring performance between active and control stimulation conditions. Results 23 studies (920 healthy participants and 54 patients with schizophrenia) were included. Our findings revealed the involvement of i) the lateral prefrontal and temporoparietal cortices in internal source monitoring, ii) the medial prefrontal and temporoparietal cortices in reality monitoring, and iii) the precuneus and the left angular gyrus in external source monitoring. Conclusions These findings deepen our understanding of the brain mechanisms of source monitoring and highlight specific stimulation targets to alleviate source monitoring deficits.
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Affiliation(s)
- Mélanie Perret
- Université Claude Bernard Lyon 1, CNRS, INSERM, Centre de Recherche en Neurosciences de Lyon CRNL U1028 UMR5292, PSYR2, F-69500 Bron, France
- Centre Hospitalier Le Vinatier, 95 Boulevard Pinel, F-69500 Bron, France
| | - Cécilia Neige
- Université Claude Bernard Lyon 1, CNRS, INSERM, Centre de Recherche en Neurosciences de Lyon CRNL U1028 UMR5292, PSYR2, F-69500 Bron, France
- Centre Hospitalier Le Vinatier, 95 Boulevard Pinel, F-69500 Bron, France
| | - Jerome Brunelin
- Université Claude Bernard Lyon 1, CNRS, INSERM, Centre de Recherche en Neurosciences de Lyon CRNL U1028 UMR5292, PSYR2, F-69500 Bron, France
- Centre Hospitalier Le Vinatier, 95 Boulevard Pinel, F-69500 Bron, France
| | - Marine Mondino
- Université Claude Bernard Lyon 1, CNRS, INSERM, Centre de Recherche en Neurosciences de Lyon CRNL U1028 UMR5292, PSYR2, F-69500 Bron, France
- Centre Hospitalier Le Vinatier, 95 Boulevard Pinel, F-69500 Bron, France
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4
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Bjekić J, Manojlović M, Filipović SR. Transcranial Electrical Stimulation for Associative Memory Enhancement: State-of-the-Art from Basic to Clinical Research. Life (Basel) 2023; 13:life13051125. [PMID: 37240770 DOI: 10.3390/life13051125] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Revised: 04/29/2023] [Accepted: 05/01/2023] [Indexed: 05/28/2023] Open
Abstract
Associative memory (AM) is the ability to bind new information into complex memory representations. Noninvasive brain stimulation (NIBS), especially transcranial electric stimulation (tES), has gained increased interest in research of associative memory (AM) and its impairments. To provide an overview of the current state of knowledge, we conducted a systematic review following PRISMA guidelines covering basic and clinical research. Out of 374 identified records, 41 studies were analyzed-twenty-nine in healthy young adults, six in the aging population, three comparing older and younger adults, as well as two studies on people with MCI, and one in people with Alzheimer's dementia. Studies using transcranial direct current stimulation (tDCS), transcranial alternating current stimulation (tACS) as well as oscillatory (otDCS) and high-definition protocols (HD-tDCS, HD-tACS) have been included. The results showed methodological heterogeneity in terms of study design, stimulation type, and parameters, as well as outcome measures. Overall, the results show that tES is a promising method for AM enhancement, especially if the stimulation is applied over the parietal cortex and the effects are assessed in cued recall paradigms.
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Affiliation(s)
- Jovana Bjekić
- Institute for Medical Research, University of Belgrade, 11000 Belgrade, Serbia
| | - Milica Manojlović
- Institute for Medical Research, University of Belgrade, 11000 Belgrade, Serbia
| | - Saša R Filipović
- Institute for Medical Research, University of Belgrade, 11000 Belgrade, Serbia
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Alonso MA, Díez-Álamo AM, Gómez-Ariza CJ, Díez E, Fernandez A. Transcranial Direct Current Stimulation Over the Right Anterior Temporal Lobe Does Not Modulate False Recognition. Front Psychol 2021; 12:718118. [PMID: 34603142 PMCID: PMC8484642 DOI: 10.3389/fpsyg.2021.718118] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Accepted: 08/20/2021] [Indexed: 11/13/2022] Open
Abstract
Non-invasive transcranial direct current stimulation (tDCS) over the left anterior temporal lobe (ATL) has been shown to cause a reduction in the rate of false memories with semantically related words. Such a reduction seems to be specific to false memories induced by the study of associative lists, but is not observed when the studied lists are categorical in nature. These findings are interpreted as evidence that the left ATL functions as an integration hub that is crucial for the binding of semantic information into coherent representations of concepts. In order to investigate whether the right ATL might also contribute to semantic integration in the processing of verbal associative material, a follow-up tDCS study was conducted with the stimulation at study lateralized on the right ATL. A sample of 75 undergraduate students participated in an experiment in which they studied 8 associative lists and 8 categorical lists. One third of the participants studied all their word lists under anodal stimulation, another third studied under cathodal stimulation and the other third under sham stimulation. Results showed that stimulation of the right ATL by tDCS does not modulate false recognition for either association-related critical words or category-related critical words. These results provide preliminary support to views positing asymmetric connectivity between the anterior temporal lobes and the semantic representational network, and provide evidence for understanding bilateral brain dynamics and the nature of semantically induced memory distortions.
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Affiliation(s)
- María Angeles Alonso
- Instituto Universitario de Neurociencia (IUNE), University of La Laguna, San Cristóbal de La Laguna, Spain.,Institute on Community Integration (INICO), University of Salamanca, Salamanca, Spain
| | - Antonio M Díez-Álamo
- Institute on Community Integration (INICO), University of Salamanca, Salamanca, Spain
| | | | - Emiliano Díez
- Instituto Universitario de Neurociencia (IUNE), University of La Laguna, San Cristóbal de La Laguna, Spain.,Institute on Community Integration (INICO), University of Salamanca, Salamanca, Spain
| | - Angel Fernandez
- Instituto Universitario de Neurociencia (IUNE), University of La Laguna, San Cristóbal de La Laguna, Spain.,Institute on Community Integration (INICO), University of Salamanca, Salamanca, Spain
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6
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Guo J, Shubeck K, Hu X. Relationship Between Item and Source Memory: Explanation of Connection-Strength Model. Front Psychol 2021; 12:691577. [PMID: 34659007 PMCID: PMC8511408 DOI: 10.3389/fpsyg.2021.691577] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Accepted: 08/11/2021] [Indexed: 11/24/2022] Open
Abstract
The controversy in the relationship between item memory and source memory is a focus of episodic memory. Some studies show the trade-off between item memory and source memory, some show the consistency between them, and others show the independence between them. This review attempts to point out the connection-strength model, implying the different types and strengths of the important role of the item-source connections in the relationship between item memory and source memory, which is based on the same essence in the unified framework. The logic of the model is that when item memory and source memory share the same or relevant connection between item and source, they positively connect, or they are independently or negatively connected. This review integrates empirical evidence from the domains of cognition, cognitive neuroscience, and mathematical modeling to validate our hypothesis.
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Affiliation(s)
- Junjun Guo
- School of Psychology, Central China Normal University, Wuhan, China
| | - Keith Shubeck
- Department of Psychology, The University of Memphis, Memphis, TN, United States
- Institute for Intelligent Systems, The University of Memphis, Memphis, TN, United States
| | - Xiangen Hu
- School of Psychology, Central China Normal University, Wuhan, China
- Department of Psychology, The University of Memphis, Memphis, TN, United States
- Institute for Intelligent Systems, The University of Memphis, Memphis, TN, United States
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7
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Petrovskaya A, Kirillov B, Asmolova A, Galli G, Feurra M, Medvedeva A. Examining the effects of transcranial direct current stimulation on human episodic memory with machine learning. PLoS One 2020; 15:e0235179. [PMID: 33296363 PMCID: PMC7725363 DOI: 10.1371/journal.pone.0235179] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Accepted: 11/21/2020] [Indexed: 11/29/2022] Open
Abstract
We aimed to replicate a published effect of transcranial direct-current stimulation (tDCS)-induced recognition enhancement over the human ventrolateral prefrontal cortex (VLPFC) and analyse the data with machine learning. We investigated effects over an adjacent region, the dorsolateral prefrontal cortex (DLPFC). In total, we analyzed data from 97 participants after exclusions. We found weak or absent effects over the VLPFC and DLPFC. We conducted machine learning studies to examine the effects of semantic and phonetic features on memorization, which revealed no effect of VLPFC tDCS on the original dataset or the current data. The highest contributing factor to memory performance was individual differences in memory not explained by word features, tDCS group, or sample size, while semantic, phonetic, and orthographic word characteristics did not contribute significantly. To our knowledge, this is the first tDCS study to investigate cognitive effects with machine learning, and future studies may benefit from studying physiological as well as cognitive effects with data-driven approaches and computational models.
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Affiliation(s)
- Aleksandra Petrovskaya
- Psychology Department, National Research University Higher School of Economics, Moscow, Russian Federation
- Institute of Cognitive Neuroscience, National Research University Higher School of Economics, Moscow, Russian Federation
| | - Bogdan Kirillov
- Center of Life Sciences, Skolkovo Institute of Science and Technology, Skolkovo, Russia
- * E-mail:
| | - Anastasiya Asmolova
- Psychology Department, National Research University Higher School of Economics, Moscow, Russian Federation
- Institute of Cognitive Neuroscience, National Research University Higher School of Economics, Moscow, Russian Federation
| | - Giulia Galli
- Department of Psychology, Kingston University, Kingston Upon Thames, United Kingdom
| | - Matteo Feurra
- Psychology Department, National Research University Higher School of Economics, Moscow, Russian Federation
- Institute of Cognitive Neuroscience, National Research University Higher School of Economics, Moscow, Russian Federation
| | - Angela Medvedeva
- Vivian L. Smith Department of Neurosurgery, University of Texas Medical School at Houston, Houston, Texas, United States of America
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Transcranial Direct Current Stimulation Enhances Episodic Memory in Healthy Older Adults by Modulating Retrieval-Specific Activation. Neural Plast 2020; 2020:8883046. [PMID: 33354206 PMCID: PMC7735856 DOI: 10.1155/2020/8883046] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Revised: 10/28/2020] [Accepted: 11/20/2020] [Indexed: 11/18/2022] Open
Abstract
Memory decline has become an issue of major importance in the aging society. Anodal transcranial direct current stimulation (atDCS) is a viable tool to counteract age-associated episodic memory deterioration. However, the underlying neural mechanisms are unclear. In this single-blind, sham-controlled study, we combined atDCS and functional magnetic resonance imaging to assess the behavioral and neural consequences of multiple-session atDCS in older adults. Forty-nine healthy older adults received either 10 sessions of anodal or sham stimulation over the left dorsolateral prefrontal cortex. Before and after stimulation, participants performed a source memory task in the MRI scanner. Compared to sham stimulation, atDCS significantly improved item memory performance. Additionally, atDCS significantly increased regional brain activity around the stimulation area in the prefrontal cortex and extended to the bilateral anterior cingulate cortex. Neural changes in the prefrontal cortex correlated with memory gains. Our findings therefore indicate that multiple-session offline atDCS may improve memory in older adults by inducing neural alterations.
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9
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Non-invasive Brain Stimulation Effects on the Perceptual and Cognitive Processes Underlying Decision-making: a Mini Review. JOURNAL OF COGNITIVE ENHANCEMENT 2020. [DOI: 10.1007/s41465-020-00186-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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10
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Effects of transcranial direct current stimulation over the posterior parietal cortex on episodic memory reconsolidation. Cortex 2019; 121:78-88. [PMID: 31550617 DOI: 10.1016/j.cortex.2019.08.009] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2019] [Revised: 08/07/2019] [Accepted: 08/07/2019] [Indexed: 01/13/2023]
Abstract
Consolidated memories may return to labile/unstable states after their reactivation, thus requiring a restabilization process that is known as reconsolidation. During this time-limited reconsolidation window, reactivated existing memories can be strengthened, weakened or updated with new information. Previous studies have shown that non-invasive stimulation of the lateral prefrontal cortex after memory reactivation strengthened existing verbal episodic memories through reconsolidation, an effect documented by enhanced delayed memory recall (24 h post-reactivation). However, it remains unknown whether the left posterior parietal cortex (PPC), a region involved during reactivation of existing episodic memories, contributes to reconsolidation. To address this question, in this double-blind experiment healthy participants (n = 27) received transcranial direct current stimulation (tDCS) with the anode over the left PPC after reactivation of previously learned verbal episodic memories. Memory recall was tested 24 h later. To rule out unspecific effects of memory reactivation or tDCS alone, we included two control groups: one that receives tDCS with the anode over the left PPC without reactivation (n = 27) and another one that receives tDCS with the anode over a control site (primary visual cortex) after reactivation (n = 27). We hypothesized that tDCS with the anode over the left PPC after memory reactivation would enhance delayed recall through reconsolidation relative to the two control groups. No significant between groups differences in the mean number of words recalled on day 3 occurred, suggesting no beneficial effect of tDCS over the left PPC. Alternative explanations were discussed, including efficacy of tDCS, different stimulation parameters, electrode montage, and stimulation site within the PPC.
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11
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Theta band high definition transcranial alternating current stimulation, but not transcranial direct current stimulation, improves associative memory performance. Sci Rep 2019; 9:8562. [PMID: 31189985 PMCID: PMC6561937 DOI: 10.1038/s41598-019-44680-8] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2019] [Accepted: 05/22/2019] [Indexed: 11/08/2022] Open
Abstract
Associative memory (AM) deficits are common in neurodegenerative disease and novel therapies aimed at improving these faculties are needed. Theta band oscillations within AM networks have been shown to be important for successful memory encoding and modulating these rhythms represents a promising strategy for cognitive enhancement. Transcranial alternating current stimulation (TACS) has been hypothesized to entrain and increase power of endogenous brain rhythms. For this reason, we hypothesized that focal delivery of theta band electrical current, using high-definition TACS, would result in improved AM performance compared to sham stimulation or transcranial direct current stimulation (TDCS). In this pilot study, 60 healthy subjects were randomized to receive high definition TACS, high definition TDCS, or sham stimulation delivered to the right fusiform cortex during encoding of visual associations. Consistent with our hypothesis, improved AM performance was observed in the TACS group, while TDCS had no effect. However, TACS also resulted in improved correct rejection of never seen items, reduced false memory, and reduced forgetting, suggesting the effect may not be specific for AM processes. Overall, this work informs strategies for improving associative memory and suggests alternating current is more effective than direct current stimulation in some contexts.
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Weintraub-Brevda RR, Chua EF. Transcranial direct current stimulation over the right and left VLPFC leads to differential effects on working and episodic memory. Brain Cogn 2019; 132:98-107. [DOI: 10.1016/j.bandc.2019.03.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2018] [Revised: 03/19/2019] [Accepted: 03/24/2019] [Indexed: 11/28/2022]
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Bjekić J, Čolić MV, Živanović M, Milanović SD, Filipović SR. Transcranial direct current stimulation (tDCS) over parietal cortex improves associative memory. Neurobiol Learn Mem 2019; 157:114-120. [DOI: 10.1016/j.nlm.2018.12.007] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2018] [Revised: 10/09/2018] [Accepted: 12/12/2018] [Indexed: 10/27/2022]
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Galli G, Vadillo MA, Sirota M, Feurra M, Medvedeva A. A systematic review and meta-analysis of the effects of transcranial direct current stimulation (tDCS) on episodic memory. Brain Stimul 2018; 12:231-241. [PMID: 30503376 DOI: 10.1016/j.brs.2018.11.008] [Citation(s) in RCA: 63] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2018] [Revised: 10/26/2018] [Accepted: 11/11/2018] [Indexed: 11/25/2022] Open
Abstract
BACKGROUND In the past decade, several studies have examined the effects of transcranial direct current stimulation (tDCS) on long-term episodic memory formation and retrieval. These studies yielded conflicting results, likely due to differences in stimulation parameters, experimental design and outcome measures. OBJECTIVES In this work we aimed to assess the robustness of tDCS effects on long-term episodic memory using a meta-analytical approach. METHODS We conducted four meta-analyses to analyse the effects of anodal and cathodal tDCS on memory accuracy and response times. We also used a moderator analysis to examine whether the size of tDCS effects varied as a function of specific stimulation parameters and experimental conditions. RESULTS Although all selected studies reported a significant effect of tDCS in at least one condition in the published paper, the results of the four meta-analyses showed only statistically non-significant close-to-zero effects. A moderator analysis suggested that for anodal tDCS, the duration of the stimulation and the task used to probe memory moderated the effectiveness of tDCS. For cathodal tDCS, site of stimulation was a significant moderator, although this result was based on only a few observations. CONCLUSIONS To warrant theoretical advancement and practical implications, more rigorous research is needed to fully understand whether tDCS reliably modulates episodic memory, and the specific circumstances under which this modulation does, and does not, occur.
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Affiliation(s)
- Giulia Galli
- Department of Psychology, Kingston University, Penrhyn Road, Kingston Upon Thames, KT1 2EE, United Kingdom.
| | - Miguel A Vadillo
- Departamento de Psicología Básica, Universidad Autónoma de Madrid, 28049 Cantoblanco, Madrid, Spain
| | - Miroslav Sirota
- Department of Psychology, University of Essex, Wivenhoe Park, Colchester, CO4 3SQ, United Kingdom
| | - Matteo Feurra
- School of Psychology, Centre for Cognition and Decision Making, National Research University Higher School of Economics, 101000, Moscow, Armyanskiy per. 4, c2, Russian Federation
| | - Angela Medvedeva
- Department of Psychology, Kingston University, Penrhyn Road, Kingston Upon Thames, KT1 2EE, United Kingdom
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15
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Wong LYX, Gray SJ, Gallo DA. Does tDCS over prefrontal cortex improve episodic memory retrieval? Potential importance of time of day. Cogn Neurosci 2018; 9:167-180. [DOI: 10.1080/17588928.2018.1504014] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Affiliation(s)
- Lidia Y. X. Wong
- Department of Psychology, University of Chicago, Chicago, IL, United States of America
| | - Stephen J. Gray
- Department of Psychology, University of Chicago, Chicago, IL, United States of America
| | - David A. Gallo
- Department of Psychology, University of Chicago, Chicago, IL, United States of America
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Westwood SJ, Romani C. Null Effects on Working Memory and Verbal Fluency Tasks When Applying Anodal tDCS to the Inferior Frontal Gyrus of Healthy Participants. Front Neurosci 2018; 12:166. [PMID: 29615855 PMCID: PMC5867342 DOI: 10.3389/fnins.2018.00166] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2017] [Accepted: 03/01/2018] [Indexed: 01/22/2023] Open
Abstract
Transcranial direct current stimulation (tDCS) is a technique used to modify cognition by modulating underlying cortical excitability via weak electric current applied through the scalp. Although many studies have reported positive effects with tDCS, a number of recent studies highlight that tDCS effects can be small and difficult to reproduce. This is especially the case when attempting to modulate performance using single applications of tDCS in healthy participants. Possible reasons may be that optimal stimulation parameters have yet to be identified, and that individual variation in cortical activity and/or level of ability confound outcomes. To address these points, we carried out a series of experiments in which we attempted to modulate performance in fluency and working memory probe tasks using stimulation parameters which have been associated with positive outcomes: we targeted the left inferior frontal gyrus (LIFG) and compared performance when applying a 1.5 mA anodal current for 25 min and with sham stimulation. There is evidence that LIFG plays a role in these tasks and previous studies have found positive effects of stimulation. We also compared our experimental group (N = 19–20) with a control group receiving no stimulation (n = 24). More importantly, we also considered effects on subgroups subdivided according to memory span as well as to more direct measures of executive function abilities and motivational levels. We found no systematic effect of stimulation. Our findings are in line with a growing body of evidence that tDCS produces unreliable effects. We acknowledge that our findings speak to the conditions we investigated, and that alternative protocols (e.g., multiple sessions, clinical samples, and different stimulation polarities) may be more effective. We encourage further research to explore optimal conditions for tDCS efficacy, given the potential benefits that this technique poses for understanding and enhancing cognition.
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Affiliation(s)
- Samuel J Westwood
- School of Life & Health Sciences, Aston University, Birmingham, United Kingdom
| | - Cristina Romani
- School of Life & Health Sciences, Aston University, Birmingham, United Kingdom
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Leshikar ED, Leach RC, McCurdy MP, Trumbo MC, Sklenar AM, Frankenstein AN, Matzen LE. Transcranial direct current stimulation of dorsolateral prefrontal cortex during encoding improves recall but not recognition memory. Neuropsychologia 2017; 106:390-397. [DOI: 10.1016/j.neuropsychologia.2017.10.022] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2017] [Revised: 09/20/2017] [Accepted: 10/18/2017] [Indexed: 10/18/2022]
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Stephan-Otto C, Siddi S, Senior C, Muñoz-Samons D, Ochoa S, Sánchez-Laforga AM, Brébion G. Visual Imagery and False Memory for Pictures: A Functional Magnetic Resonance Imaging Study in Healthy Participants. PLoS One 2017; 12:e0169551. [PMID: 28046076 PMCID: PMC5207728 DOI: 10.1371/journal.pone.0169551] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2016] [Accepted: 12/19/2016] [Indexed: 11/18/2022] Open
Abstract
Background Visual mental imagery might be critical in the ability to discriminate imagined from perceived pictures. Our aim was to investigate the neural bases of this specific type of reality-monitoring process in individuals with high visual imagery abilities. Methods A reality-monitoring task was administered to twenty-six healthy participants using functional magnetic resonance imaging. During the encoding phase, 45 words designating common items, and 45 pictures of other common items, were presented in random order. During the recall phase, participants were required to remember whether a picture of the item had been presented, or only a word. Two subgroups of participants with a propensity for high vs. low visual imagery were contrasted. Results Activation of the amygdala, left inferior occipital gyrus, insula, and precuneus were observed when high visual imagers encoded words later remembered as pictures. At the recall phase, these same participants activated the middle frontal gyrus and inferior and superior parietal lobes when erroneously remembering pictures. Conclusions The formation of visual mental images might activate visual brain areas as well as structures involved in emotional processing. High visual imagers demonstrate increased activation of a fronto-parietal source-monitoring network that enables distinction between imagined and perceived pictures.
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Affiliation(s)
- Christian Stephan-Otto
- Parc Sanitari Sant Joan de Déu, Universitat de Barcelona, Sant Boi de Llobregat, Spain
- Centro de Investigación Biomédica en Red de Salud Mental (CIBERSAM), Madrid, Spain
| | - Sara Siddi
- Parc Sanitari Sant Joan de Déu, Universitat de Barcelona, Sant Boi de Llobregat, Spain
- Centro de Investigación Biomédica en Red de Salud Mental (CIBERSAM), Madrid, Spain
- Section of Clinical Psychology, Department of Education, Psychology, and Philosophy, University of Cagliari, Cagliari, Italy
- Facultat de Medicina, Universitat de Barcelona, Barcelona, Spain
| | - Carl Senior
- School of Life & Health Sciences, Aston University, Birmingham, United Kingdom
| | | | - Susana Ochoa
- Parc Sanitari Sant Joan de Déu, Universitat de Barcelona, Sant Boi de Llobregat, Spain
- Centro de Investigación Biomédica en Red de Salud Mental (CIBERSAM), Madrid, Spain
| | | | - Gildas Brébion
- Parc Sanitari Sant Joan de Déu, Universitat de Barcelona, Sant Boi de Llobregat, Spain
- Centro de Investigación Biomédica en Red de Salud Mental (CIBERSAM), Madrid, Spain
- * E-mail:
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Increased contextual cue utilization with tDCS over the prefrontal cortex during a recognition task. Brain Res 2016; 1655:1-9. [PMID: 27845032 DOI: 10.1016/j.brainres.2016.11.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2016] [Revised: 10/07/2016] [Accepted: 11/08/2016] [Indexed: 11/22/2022]
Abstract
The precise role of the prefrontal and posterior parietal cortices in recognition performance remains controversial, with questions about whether these regions contribute to recognition via the availability of mnemonic evidence or via decision biases and retrieval orientation. Here we used an explicit memory cueing paradigm, whereby external cues probabilistically predict upcoming memoranda as old or new, in our case with 75% validity, and these cues affect recognition decision biases in the direction of the cue. The present study applied bilateral transcranial direct current stimulation (tDCS) over prefrontal or posterior parietal cortex, or sham tDCS, to test the causal role of these regions in recognition accuracy or decision biasing. Participants who received tDCS over prefrontal cortex showed increased cue utilization compared to tDCS over posterior parietal cortex and sham tDCS, suggesting that the prefrontal cortex is involved in processes that contribute to decision biases in memory.
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Effects of HD-tDCS on memory and metamemory for general knowledge questions that vary by difficulty. Brain Stimul 2016; 10:231-241. [PMID: 27876306 DOI: 10.1016/j.brs.2016.10.013] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2016] [Revised: 10/24/2016] [Accepted: 10/28/2016] [Indexed: 01/07/2023] Open
Abstract
BACKGROUND The ability to monitor one's own memory is an important feature of normal memory and is an aspect of 'metamemory'. Lesion studies have shown dissociations between memory and metamemory, but only single dissociations have been shown using transcranial direct current stimulation (tDCS). One potential reason that only single dissociations have been shown is that tDCS effects may be moderated by task difficulty. OBJECTIVE/HYPOTHESIS We used high definition (HD) tDCS to test for dissociable roles of the dorsolateral prefrontal cortex (DLPFC) and anterior temporal lobe (ATL) in semantic long-term memory and metamemory tasks. We also tested whether general knowledge question difficulty moderated the effects of HD-tDCS. METHODS Across 3 sessions, participants received active HD-tDCS over the left DLPFC or left ATL, or sham HD-tDCS during general knowledge recall and recognition tests, and a 'feeling-of-knowing' metamemory task. General knowledge questions were blocked by difficulty. Repeated measures ANOVAs were used to examine the effects of HD-tDCS on memory and metamemory tasks by memory question difficulty. RESULTS HD-tDCS over the ATL led to improved recall compared to DLPFC and sham HD-tDCS, and this occurred only for medium difficulty questions. In contrast, for non-recalled questions, HD-tDCS over the DLPFC led to improved recognition accuracy and improved feeling-of-knowing accuracy compared to ATL and sham HD-tDCS, and this was not moderated by memory question difficulty. CONCLUSION (S) HD-tDCS can be used to dissociate the roles of the ATL and DLPFC in different memory and 'metamemory' tasks. The effects of HD-tDCS on task may be moderated by task difficulty, depending on the nature of the task and site of stimulation.
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