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Meléndez JC, Satorres E, Pitarque A, Escudero J, Delhom I, Navarro-Prados AB. Transcranial Direct Current Stimulation Intervention in Alzheimer's Disease and Its Follow-Up. J Alzheimers Dis 2023; 96:1685-1693. [PMID: 38007663 DOI: 10.3233/jad-230826] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2023]
Abstract
BACKGROUND Alzheimer's disease (AD) stands as the prevailing type of dementia, marked by gradual memory loss and cognitive decline. Transcranial direct current stimulation (tDCS) is a non-invasive method used to regulate cortical brain function and has been explored as a potential treatment for cognitive impairment. OBJECTIVE This study aimed to compare the effects of daily home-based active or sham tDCS on cognitive function in patients with early-stage AD and its follow-up after one month. METHODS The study involved a randomized, blinded, and controlled-placebo design, with 18 participants enrolled. The primary outcome measures were general cognitive function, immediate, and delayed recall, and executive function. Participants included in the study were randomly assigned to the anodal and sham tDCS groups. Participants were assessed before and after the intervention and one month after the end of treatment. The home-based intervention was applied for 5 consecutive days, daily. RESULTS The results showed a significant interaction between the active and sham groups; in particular, improvements in MMSE scores, immediate memory and delayed recall were observed at one-month follow-up in the active group. CONCLUSIONS The positive effects of tDCS on cognitive function in AD patients observed suggest that tDCS may induce long-term neuroplastic changes, leading to sustained improvements in cognitive abilities.
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Affiliation(s)
- Juan C Meléndez
- Department of Developmental Psychology, Faculty of Psychology, University of Valencia, Valencia, Spain
| | - Encarnación Satorres
- Department of Developmental Psychology, Faculty of Psychology, University of Valencia, Valencia, Spain
| | - Alfonso Pitarque
- Department of Methodology, Faculty of Psychology, University of Valencia, Valencia, Spain
| | | | | | - Ana-Belén Navarro-Prados
- Department of Developmental Psychology, Faculty of Psychology, University of Salamanca, Salamanca, Spain
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Parkin A, Parker A, Dagnall N. Effects of saccadic eye movements on episodic & semantic memory fluency in older and younger participants. Memory 2023; 31:34-46. [PMID: 36131611 DOI: 10.1080/09658211.2022.2122997] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
Abstract
Research has demonstrated that performing a sequence of saccadic horizontal eye movements prior to retrieval facilitates performance on tests of episodic memory. This has been observed in both laboratory tasks of retention and autobiographical memory. To date, the work has centred on performance in younger individuals. This paper extends previous investigations by examining the effects of saccadic eye movements in older persons. Autobiographical episodic and semantic memory fluency was assessed in younger (age range 18-35, mean = 22.50), and older (age range 55-87, mean = 70.35) participants following saccadic (vs. fixation control) manipulations. The main effects of eye movements and age were found for episodic autobiographical memory (greater fluency after eye movements and in younger participants). Semantic autobiographical memory showed a main effect of age (greater fluency in younger participants), whereas general semantic memory showed no effect of age or eye movement. These findings indicate that saccadic horizontal eye movements can enhance episodic personal memory in older individuals. This has implications as a technique to improve autobiographical recollection in the elderly and as an adjunct in reminiscence therapy.
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Affiliation(s)
- Adam Parkin
- Department of Psychology, Manchester Metropolitan University, Manchester, United Kingdom
| | - Andrew Parker
- Department of Psychology, Manchester Metropolitan University, Manchester, United Kingdom
| | - Neil Dagnall
- Department of Psychology, Manchester Metropolitan University, Manchester, United Kingdom
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3
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BDNF Val66Met gene polymorphism modulates brain activity following rTMS-induced memory impairment. Sci Rep 2022; 12:176. [PMID: 34997117 PMCID: PMC8741781 DOI: 10.1038/s41598-021-04175-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2021] [Accepted: 12/16/2021] [Indexed: 01/19/2023] Open
Abstract
The BDNF Val66Met gene polymorphism is a relevant factor explaining inter-individual differences to TMS responses in studies of the motor system. However, whether this variant also contributes to TMS-induced memory effects, as well as their underlying brain mechanisms, remains unexplored. In this investigation, we applied rTMS during encoding of a visual memory task either over the left frontal cortex (LFC; experimental condition) or the cranial vertex (control condition). Subsequently, individuals underwent a recognition memory phase during a functional MRI acquisition. We included 43 young volunteers and classified them as 19 Met allele carriers and 24 as Val/Val individuals. The results revealed that rTMS delivered over LFC compared to vertex stimulation resulted in reduced memory performance only amongst Val/Val allele carriers. This genetic group also exhibited greater fMRI brain activity during memory recognition, mainly over frontal regions, which was positively associated with cognitive performance. We concluded that BDNF Val66Met gene polymorphism, known to exert a significant effect on neuroplasticity, modulates the impact of rTMS both at the cognitive as well as at the associated brain networks expression levels. This data provides new insights on the brain mechanisms explaining cognitive inter-individual differences to TMS, and may inform future, more individually-tailored rTMS interventions.
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Neri F, Cappa SF, Mencarelli L, Momi D, Santarnecchi E, Rossi S. Brain Functional Correlates of Episodic Memory Using an Ecological Free Recall Task. Brain Sci 2021; 11:brainsci11070911. [PMID: 34356144 PMCID: PMC8303916 DOI: 10.3390/brainsci11070911] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Revised: 06/28/2021] [Accepted: 07/05/2021] [Indexed: 11/16/2022] Open
Abstract
Episodic Memory (EM) allows us to revive a past event through mental time-travel. The neural correlates of memories recollection have been identified in hippocampal regions and multiple neocortical areas, but few neuroimaging studies have used an ecological task such as a free recall of a structured story. Using an ecological fMRI-free recall (FR) task, we aimed to investigate the relevant recruitment of the brain networks associated with the story recollection process and its performance. Fourteen healthy participants listened to a brief story and were tested for Immediate-Recall (IR), a task that is widely used in a neuropsychological evaluation. Then, the subjects underwent an fMRI session, where they had to perform a free recall (FR) of the story subvocally. Finally, the participants were tested for Delayed-Recall (DR). IR and DR scores were significantly (r = 0.942; p < 0.001) correlated. FR enhanced the activity of the Language, the Left Executive Control, the Default Mode and the Precuneus brain networks, with the strongest BOLD signal localized in the left Angular Gyrus (AG) (p < 0.05; FWE-corrected). Furthermore, the story recall performance covaried with specific network activation patterns and the recruitment of the left anterior/posterior AG correlated, respectively, with higher/lower performance scores (p > 0.05). FR seems to be a promising task to investigate ecologically the neural correlates of EM. Moreover, the recruitment of the anterior AG might be a marker for an optimal functioning of the recall process. Preliminary outcomes lay the foundation for the investigation of the brain networks in the healthy and pathological elderly population during FR.
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Affiliation(s)
- Francesco Neri
- Siena Brain Investigation and Neuromodulation Lab (Si-BIN Lab), Unit of Neurology and Clinical Neurophysiology, Department of Medicine, Surgery and Neuroscience, University of Siena, 53100 Siena, SI, Italy; (L.M.); (D.M.); (S.R.)
- Correspondence: ; Tel.: +39-339-341-257
| | - Stefano F. Cappa
- Institute for Advanced Study, IUSS, 27100 Pavia, PV, Italy;
- IRCCS Mondino Foundation, 27100 Pavia, PV, Italy
| | - Lucia Mencarelli
- Siena Brain Investigation and Neuromodulation Lab (Si-BIN Lab), Unit of Neurology and Clinical Neurophysiology, Department of Medicine, Surgery and Neuroscience, University of Siena, 53100 Siena, SI, Italy; (L.M.); (D.M.); (S.R.)
| | - Davide Momi
- Siena Brain Investigation and Neuromodulation Lab (Si-BIN Lab), Unit of Neurology and Clinical Neurophysiology, Department of Medicine, Surgery and Neuroscience, University of Siena, 53100 Siena, SI, Italy; (L.M.); (D.M.); (S.R.)
| | - Emiliano Santarnecchi
- Berenson-Allen Center for Noninvasive Brain Stimulation, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02115, USA;
- Department of Cognitive Neurology, Harvard Medical School, Boston, MA 02115, USA
| | - Simone Rossi
- Siena Brain Investigation and Neuromodulation Lab (Si-BIN Lab), Unit of Neurology and Clinical Neurophysiology, Department of Medicine, Surgery and Neuroscience, University of Siena, 53100 Siena, SI, Italy; (L.M.); (D.M.); (S.R.)
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Medvedeva A, Saw R, Silvestri C, Sirota M, Fuggetta G, Galli G. Offset-related brain activity in the left ventrolateral prefrontal cortex promotes long-term memory formation of verbal events. Brain Stimul 2021; 14:564-570. [PMID: 33722660 DOI: 10.1016/j.brs.2021.03.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Revised: 02/18/2021] [Accepted: 03/03/2021] [Indexed: 10/21/2022] Open
Abstract
BACKGROUND Recent evidence suggests that brain activity following the offset of a stimulus during encoding contributes to long-term memory formation, however the exact mechanisms underlying offset-related encoding are still unclear. OBJECTIVES Here, in three repetitive transcranial magnetic stimulation studies (rTMS) we investigated offset-related activity in the left ventrolateral prefrontal cortex (VLPFC). rTMS was administered at different points in time around stimulus offset while participants encoded visually-presented words or pairs of words. The analyses focused on the effects of the stimulation on subsequent memory performance. RESULTS rTMS administered at the offset of the stimuli, but not during online encoding, disrupted subsequent memory performance. In Experiment 1 we found that rTMS specifically disrupted encoding mechanisms initiated by the offset of the stimuli rather than general, post-stimulus processes. Experiment 2 showed that this effect was not dependent upon rTMS-induced somatosensory effects. In a third rTMS experiment we further demonstrated a robust decline in associative memory performance when the stimulation was delivered at the offset of the word pairs, suggesting that offset-related encoding may contribute to the binding of information into an episodic memory trace. CONCLUSIONS The offset of the stimulus may represent an event boundary that promotes the reinstatement of the previously experienced event and episodic binding.
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Affiliation(s)
- Angela Medvedeva
- Department of Psychology, Kingston University, Penrhyn Road, Kingston Upon Thames KT1 2EE, United Kingdom; Vivian L. Smith Department of Neurosurgery, University of Texas Medical School at Houston, Houston, TX, 77030, United States
| | - Rebecca Saw
- Department of Psychology, University of Roehampton, Holybourne Avenue, London, SW15 4JD, United Kingdom
| | - Carla Silvestri
- Department of Psychology, University of Roehampton, Holybourne Avenue, London, SW15 4JD, United Kingdom
| | - Miroslav Sirota
- Department of Psychology, University of Essex, Wivenhoe Park, Colchester, CO4 3SQ, United Kingdom
| | - Giorgio Fuggetta
- Department of Psychology, University of Roehampton, Holybourne Avenue, London, SW15 4JD, United Kingdom
| | - Giulia Galli
- Department of Psychology, Kingston University, Penrhyn Road, Kingston Upon Thames KT1 2EE, United Kingdom.
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Hobot J, Klincewicz M, Sandberg K, Wierzchoń M. Causal Inferences in Repetitive Transcranial Magnetic Stimulation Research: Challenges and Perspectives. Front Hum Neurosci 2021; 14:586448. [PMID: 33584220 PMCID: PMC7873895 DOI: 10.3389/fnhum.2020.586448] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Accepted: 11/30/2020] [Indexed: 11/29/2022] Open
Abstract
Transcranial magnetic stimulation (TMS) is used to make inferences about relationships between brain areas and their functions because, in contrast to neuroimaging tools, it modulates neuronal activity. The central aim of this article is to critically evaluate to what extent it is possible to draw causal inferences from repetitive TMS (rTMS) data. To that end, we describe the logical limitations of inferences based on rTMS experiments. The presented analysis suggests that rTMS alone does not provide the sort of premises that are sufficient to warrant strong inferences about the direct causal properties of targeted brain structures. Overcoming these limitations demands a close look at the designs of rTMS studies, especially the methodological and theoretical conditions which are necessary for the functional decomposition of the relations between brain areas and cognitive functions. The main points of this article are that TMS-based inferences are limited in that stimulation-related causal effects are not equivalent to structure-related causal effects due to TMS side effects, the electric field distribution, and the sensitivity of neuroimaging and behavioral methods in detecting structure-related effects and disentangling them from confounds. Moreover, the postulated causal effects can be based on indirect (network) effects. A few suggestions on how to manage some of these limitations are presented. We discuss the benefits of combining rTMS with neuroimaging in experimental reasoning and we address the restrictions and requirements of rTMS control conditions. The use of neuroimaging and control conditions allows stronger inferences to be gained, but the strength of the inferences that can be drawn depends on the individual experiment's designs. Moreover, in some cases, TMS might not be an appropriate method of answering causality-related questions or the hypotheses have to account for the limitations of this technique. We hope this summary and formalization of the reasoning behind rTMS research can be of use not only for scientists and clinicians who intend to interpret rTMS results causally but also for philosophers interested in causal inferences based on brain stimulation research.
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Affiliation(s)
- Justyna Hobot
- Consciousness Lab, Psychology Institute, Jagiellonian University, Krakow, Poland
- Center of Functionally Integrative Neuroscience, Aarhus University, Aarhus, Denmark
| | - Michał Klincewicz
- Cognitive Science, Institute of Philosophy, Jagiellonian University, Krakow, Poland
- Department of Cognitive Science and Artificial Intelligence, Tilburg University, Tilburg, Netherlands
| | - Kristian Sandberg
- Center of Functionally Integrative Neuroscience, Aarhus University, Aarhus, Denmark
- Center of Functionally Integrative Neuroscience, Aarhus University Hospital, Aarhus, Denmark
| | - Michał Wierzchoń
- Consciousness Lab, Psychology Institute, Jagiellonian University, Krakow, Poland
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7
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Cross-modal involvement of the primary somatosensory cortex in visual working memory: A repetitive TMS study. Neurobiol Learn Mem 2020; 175:107325. [PMID: 33059033 DOI: 10.1016/j.nlm.2020.107325] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Revised: 09/01/2020] [Accepted: 10/08/2020] [Indexed: 12/23/2022]
Abstract
Recent literature suggests that the primary somatosensory cortex (S1), once thought to be a low-level area only modality-specific, is also involved in higher-level, cross-modal, cognitive functions. In particular, electrophysiological studies have highlighted that the cross-modal activation of this area may also extend to visual Working Memory (WM), being part of a mnemonic network specific for the temporary storage and manipulation of visual information concerning bodies and body-related actions. However, the causal recruitment of S1 in the WM network remains speculation. In the present study, by taking advantage of repetitive Transcranial Magnetic Stimulation (rTMS), we look for causal evidence that S1 is implicated in the retention of visual stimuli that are salient for this cortical area. To this purpose, in a first experiment, high-frequency (10 Hz) rTMS was delivered over S1 of the right hemisphere, and over two control sites, the right lateral occipital cortex (LOC) and the right dorsolateral prefrontal cortex (dlPFC), during the maintenance phase of a high-load delayed match-to-sample task in which body-related visual stimuli (non-symbolic hand gestures) have to be retained. In a second experiment, the specificity of S1 recruitment was deepened by using a version of the delayed match-to-sample task in which visual stimuli depict geometrical shapes (non-body related stimuli). Results show that rTMS perturbation of S1 activity leads to an enhancement of participants' performance that is selective for body-related visual stimuli; instead, the stimulation of the right LOC and dlPFC does not affect the temporary storage of body-related visual stimuli. These findings suggest that S1 may be recruited in visual WM when information to store (and recall) is salient for this area, corroborating models which suggest the existence of a dedicated mnemonic system for body-related information in which also somatosensory cortices play a key role, likely thanks to their cross-modal (visuo-tactile) properties.
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Sander MC, Fandakova Y, Grandy TH, Shing YL, Werkle-Bergner M. Oscillatory Mechanisms of Successful Memory Formation in Younger and Older Adults Are Related to Structural Integrity. Cereb Cortex 2020; 30:3744-3758. [PMID: 31989153 PMCID: PMC7232990 DOI: 10.1093/cercor/bhz339] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Revised: 11/01/2019] [Indexed: 01/21/2023] Open
Abstract
We studied oscillatory mechanisms of memory formation in 48 younger and 51 older adults in an intentional associative memory task with cued recall. While older adults showed lower memory performance than young adults, we found subsequent memory effects (SME) in alpha/beta and theta frequency bands in both age groups. Using logistic mixed effects models, we investigated whether interindividual differences in structural integrity of key memory regions could account for interindividual differences in the strength of the SME. Structural integrity of inferior frontal gyrus (IFG) and hippocampus was reduced in older adults. SME in the alpha/beta band were modulated by the cortical thickness of IFG, in line with its hypothesized role for deep semantic elaboration. Importantly, this structure–function relationship did not differ by age group. However, older adults were more frequently represented among the participants with low cortical thickness and consequently weaker SME in the alpha band. Thus, our results suggest that differences in the structural integrity of the IFG contribute not only to interindividual, but also to age differences in memory formation.
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Affiliation(s)
- Myriam C Sander
- Center for Lifespan Psychology, Max Planck Institute for Human Development, Berlin 14195, Germany
| | - Yana Fandakova
- Center for Lifespan Psychology, Max Planck Institute for Human Development, Berlin 14195, Germany
| | - Thomas H Grandy
- Center for Lifespan Psychology, Max Planck Institute for Human Development, Berlin 14195, Germany
| | - Yee Lee Shing
- Center for Lifespan Psychology, Max Planck Institute for Human Development, Berlin 14195, Germany.,Department of Developmental Psychology, Goethe University Frankfurt, Frankfurt am Main 60323, Germany
| | - Markus Werkle-Bergner
- Center for Lifespan Psychology, Max Planck Institute for Human Development, Berlin 14195, Germany
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Yeh N, Rose NS. How Can Transcranial Magnetic Stimulation Be Used to Modulate Episodic Memory?: A Systematic Review and Meta-Analysis. Front Psychol 2019; 10:993. [PMID: 31263433 PMCID: PMC6584914 DOI: 10.3389/fpsyg.2019.00993] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Accepted: 04/15/2019] [Indexed: 12/19/2022] Open
Abstract
A systematic review and meta-analysis were conducted to synthesize the existing literature on how transcranial magnetic stimulation (TMS) has been used to modulate episodic memory. Given the numerous parameters of TMS protocols and experimental design characteristics that can be manipulated, a mechanistic understanding of how changes in the combination of parameters (e.g., frequency, timing, intensity, targeted brain region, memory task) modulate episodic memory is needed. To address this, we reviewed 59 studies and conducted a meta-analysis on 245 effect sizes from 37 articles on healthy younger adults (N = 1,061). Analyses revealed generally more beneficial effects of 1-Hz rTMS vs. other frequencies on episodic memory. Moderation analyses revealed complex interactions as online 20-Hz rTMS protocols led to negative effects, while offline 20-Hz rTMS led to enhancing effects. There was also an interaction between stimulation intensity and frequency as 20-Hz rTMS had more negative effects when applied below- vs. at-motor threshold. Conversely, 1-Hz rTMS had more beneficial effects than other frequencies when applied below- vs. at- or above-motor threshold. No reliable aggregate or hypothesized interactions were found when assessing stimulation site (frontal vs. parietal cortex, left vs. right hemisphere), stimulated memory process (during encoding vs. retrieval), the type of retrieval (associative/recollection vs. item/familiarity), or the type of control comparison (active vs. sham or no TMS) on episodic memory. However, there is insufficient data to make strong inference based on the lack of aggregate or two-way interactions between these factors, or to assess more complex (e.g., 3-way) interactions. We reviewed the effects on other populations (healthy older adults and clinical populations), but systematic comparison of parameters was also prevented due to insufficient data. A database of parameters and effects sizes is available as an open source repository so that data from studies can be continuously accumulated in order to facilitate future meta-analysis. In conclusion, modulating episodic memory relies on complex interactions among the numerous moderator variables that can be manipulated. Therefore, rigorous, systematic comparisons need to be further investigated as the body of literature grows in order to fully understand the combination of parameters that lead to enhancing, detrimental or null effects on episodic memory.
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Affiliation(s)
- Nicholas Yeh
- Department of Psychology, University of Notre Dame, Notre Dame, IN, United States
| | - Nathan S Rose
- Department of Psychology, University of Notre Dame, Notre Dame, IN, United States
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Im JJ, Jeong H, Bikson M, Woods AJ, Unal G, Oh JK, Na S, Park JS, Knotkova H, Song IU, Chung YA. Effects of 6-month at-home transcranial direct current stimulation on cognition and cerebral glucose metabolism in Alzheimer's disease. Brain Stimul 2019; 12:1222-1228. [PMID: 31196835 DOI: 10.1016/j.brs.2019.06.003] [Citation(s) in RCA: 88] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Revised: 05/09/2019] [Accepted: 06/01/2019] [Indexed: 01/21/2023] Open
Abstract
BACKGROUND Although single or multiple sessions of transcranial direct current stimulation (tDCS) on the prefrontal cortex over a few weeks improved cognition in patients with Alzheimer's disease (AD), effects of repeated tDCS over longer period and underlying neural correlates remain to be elucidated. OBJECTIVE This study investigated changes in cognitive performances and regional cerebral metabolic rate for glucose (rCMRglc) after administration of prefrontal tDCS over 6 months in early AD patients. METHODS Patients with early AD were randomized to receive either active (n = 11) or sham tDCS (n = 7) over the dorsolateral prefrontal cortex (DLPFC) at home every day for 6 months (anode F3/cathode F4, 2 mA for 30 min). All patients underwent neuropsychological tests and brain 18F-fluoro-2-deoxyglucose positron emission tomography (FDG-PET) scans at baseline and 6-month follow-up. Changes in cognitive performances and rCMRglc were compared between the two groups. RESULTS Compared to sham tDCS, active tDCS improved global cognition measured with Mini-Mental State Examination (p for interaction = 0.02) and language function assessed by Boston Naming Test (p for interaction = 0.04), but not delayed recall performance. In addition, active tDCS prevented decreases in executive function at a marginal level (p for interaction < 0.10). rCMRglc in the left middle/inferior temporal gyrus was preserved in the active group, but decreased in the sham group (p for interaction < 0.001). CONCLUSIONS Daily tDCS over the DLPFC for 6 months may improve or stabilize cognition and rCMRglc in AD patients, suggesting the therapeutic potential of repeated at-home tDCS.
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Affiliation(s)
- Jooyeon Jamie Im
- Department of Radiology, Incheon St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, South Korea
| | - Hyeonseok Jeong
- Department of Radiology, Incheon St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, South Korea
| | - Marom Bikson
- Department of Biomedical Engineering, The City College of New York, New York, NY, USA
| | - Adam J Woods
- Center for Cognitive Aging and Memory, McKnight Brain Institute, Department of Clinical and Health Psychology, University of Florida, FL, USA
| | - Gozde Unal
- Department of Biomedical Engineering, The City College of New York, New York, NY, USA
| | - Jin Kyoung Oh
- Department of Radiology, Incheon St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, South Korea
| | - Seunghee Na
- Department of Neurology, Incheon St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, South Korea
| | - Jong-Sik Park
- Department of Neurology, Incheon St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, South Korea
| | - Helena Knotkova
- MJHS Institute for Innovation in Palliative Care, New York, NY, USA; Department of Family and Social Medicine, Albert Einstein College of Medicine, The Bronx, NY, USA
| | - In-Uk Song
- Department of Neurology, Incheon St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, South Korea.
| | - Yong-An Chung
- Department of Radiology, Incheon St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, South Korea.
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Martin-Trias P, Lanteaume L, Solana E, Cassé-Perrot C, Fernández-Cabello S, Babiloni C, Marzano N, Junqué C, Rossini PM, Micallef J, Truillet R, Charles E, Jouve E, Bordet R, Santamaria J, Jovicich J, Rossi S, Pascual-Leone A, Blin O, Richardson J, Bartrés-Faz D. Adaptability and reproducibility of a memory disruption rTMS protocol in the PharmaCog IMI European project. Sci Rep 2018; 8:9371. [PMID: 29921865 PMCID: PMC6008461 DOI: 10.1038/s41598-018-27502-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2017] [Accepted: 06/03/2018] [Indexed: 11/29/2022] Open
Abstract
Transcranial magnetic stimulation (TMS) can interfere with cognitive processes, such as transiently impairing memory. As part of a multi-center European project, we investigated the adaptability and reproducibility of a previously published TMS memory interfering protocol in two centers using EEG or fMRI scenarios. Participants were invited to attend three experimental sessions on different days, with sham repetitive TMS (rTMS) applied on day 1 and real rTMS on days 2 and 3. Sixty-eight healthy young men were included. On each experimental day, volunteers were instructed to remember visual pictures while receiving neuronavigated rTMS trains (20 Hz, 900 ms) during picture encoding at the left dorsolateral prefrontal cortex (L-DLPFC) and the vertex. Mixed ANOVA model analyses were performed. rTMS to the L-DLPFC significantly disrupted recognition memory on experimental day 2. No differences were found between centers or between fMRI and EEG recordings. Subjects with lower baseline memory performances were more susceptible to TMS disruption. No stability of TMS-induced memory interference could be demonstrated on day 3. Our data suggests that adapted cognitive rTMS protocols can be implemented in multi-center studies incorporating standardized experimental procedures. However, our center and modality effects analyses lacked sufficient statistical power, hence highlighting the need to conduct further studies with larger samples. In addition, inter and intra-subject variability in response to TMS might limit its application in crossover or longitudinal studies.
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Affiliation(s)
- Pablo Martin-Trias
- Medical Psychology Unit, Department of Medicine, Faculty of Medicine and Health Sciences, University of Barcelona, Barcelona, Spain
| | - Laura Lanteaume
- Department of Clinical Pharmacology CIC-CPCET, AP-HM and Institut de Neurosciences des Systèmes (INS) UMR1106, Aix-Marseille University, Marseille, France
| | - Elisabeth Solana
- Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
| | - Catherine Cassé-Perrot
- Department of Clinical Pharmacology CIC-CPCET, AP-HM and Institut de Neurosciences des Systèmes (INS) UMR1106, Aix-Marseille University, Marseille, France
| | - Sara Fernández-Cabello
- Medical Psychology Unit, Department of Medicine, Faculty of Medicine and Health Sciences, University of Barcelona, Barcelona, Spain
| | - Claudio Babiloni
- Department of Physiology and Pharmacology, University of Rome "La Sapienza", Rome, Italy
- Department of Neuroscience, IRCCS San Raffaele Pisana, Rome, Italy
| | | | - Carme Junqué
- Medical Psychology Unit, Department of Medicine, Faculty of Medicine and Health Sciences, University of Barcelona, Barcelona, Spain
| | - Paolo Maria Rossini
- Department of Neuroscience, IRCCS San Raffaele Pisana, Rome, Italy
- Department of Geriatrics, Neuroscience & Orthopedics, Catholic University, Policlinic Gemelli, Rome, Italy
| | - Joëlle Micallef
- Department of Clinical Pharmacology CIC-CPCET, AP-HM and Institut de Neurosciences des Systèmes (INS) UMR1106, Aix-Marseille University, Marseille, France
| | - Romain Truillet
- Department of Clinical Pharmacology CIC-CPCET, AP-HM and Institut de Neurosciences des Systèmes (INS) UMR1106, Aix-Marseille University, Marseille, France
| | - Estelle Charles
- Department of Clinical Pharmacology CIC-CPCET, AP-HM and Institut de Neurosciences des Systèmes (INS) UMR1106, Aix-Marseille University, Marseille, France
| | - Elisabeth Jouve
- Department of Clinical Pharmacology CIC-CPCET, AP-HM and Institut de Neurosciences des Systèmes (INS) UMR1106, Aix-Marseille University, Marseille, France
| | - Régis Bordet
- University of Lille, Inserm, CHU Lille, U1171, Degenerative and Vascular Cognitive Disorders, Lille, France
| | - Joan Santamaria
- Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
- Sleep Unit, Neurology Department, Hospital Clinic, Barcelona, Spain
| | - Jorge Jovicich
- Center for Mind/Brain Sciences (CIMEC), University of Trento, Trento, Italy
| | - Simone Rossi
- Dipartimento di Scienze Mediche, Chirurgiche e Neuroscienze, Brain Investigation & Neuromodulation Laboratory (Si-BIN Lab), University of Siena, Siena, Italy
| | - Alvaro Pascual-Leone
- Berenson-Allen Center for Noninvasive Brain Stimulation and Division of Cognitive Neurology, Department of Neurology, Beth Israel Deaconess Medical Center, Harvard Medical School, MA, 02215, USA
- Institut Guttmann de Neurorehabilitacio, Universitat Autonoma de Barcelona, Barcelona, Spain
| | - Olivier Blin
- Department of Clinical Pharmacology CIC-CPCET, AP-HM and Institut de Neurosciences des Systèmes (INS) UMR1106, Aix-Marseille University, Marseille, France
| | - Jill Richardson
- Neurosciences Therapeutic Area, GlaxoSmithKline R&D, Stevenage, UK
| | - David Bartrés-Faz
- Medical Psychology Unit, Department of Medicine, Faculty of Medicine and Health Sciences, University of Barcelona, Barcelona, Spain.
- Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain.
- Institut Guttmann de Neurorehabilitacio, Universitat Autonoma de Barcelona, Barcelona, Spain.
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12
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Parker A, Powell D, Dagnall N. Effects of Saccade Induced Retrieval Enhancement on conceptual and perceptual tests of explicit & implicit memory. Brain Cogn 2017; 121:1-10. [PMID: 29275124 DOI: 10.1016/j.bandc.2017.12.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2017] [Revised: 10/21/2017] [Accepted: 12/13/2017] [Indexed: 11/28/2022]
Abstract
The effects of saccadic horizontal (bilateral) eye movements upon tests of both conceptual and perceptual forms of explicit and implicit memory were investigated. Participants studied a list of words and were then assigned to one of four test conditions: conceptual explicit, conceptual implicit, perceptual explicit, or perceptual implicit. Conceptual tests comprised category labels with either explicit instructions to recall corresponding examples from the study phase (category-cued recall), or implicit instructions to generate any corresponding examples that spontaneously came to mind (category-exemplar generation). Perceptual tests comprised of word-fragments with either explicit instructions to complete these with study items (word-fragment-cued recall), or implicit instructions to complete each fragment with the first word that simply 'popped to mind' (word-fragment completion). Just prior to retrieval, participants were required to engage in 30 s of bilateral vs. no eye movements. Results revealed that saccadic horizontal eye movements enhanced performance in only the conceptual explicit condition, indicating that Saccade-Induced Retrieval Enhancement is a joint function of conceptual and explicit retrieval mechanisms. Findings are discussed from both a cognitive and neuropsychological perspective, in terms of their potential functional and neural underpinnings.
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Affiliation(s)
- Andrew Parker
- Manchester Metropolitan University, Department of Psychology, 53 Bonsall Street, Manchester M15 6GX, United Kingdom.
| | - Daniel Powell
- Manchester Metropolitan University, Department of Psychology, 53 Bonsall Street, Manchester M15 6GX, United Kingdom
| | - Neil Dagnall
- Manchester Metropolitan University, Department of Psychology, 53 Bonsall Street, Manchester M15 6GX, United Kingdom
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13
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Manenti R, Sandrini M, Gobbi E, Cobelli C, Brambilla M, Binetti G, Cotelli M. Strengthening of Existing Episodic Memories Through Non-invasive Stimulation of Prefrontal Cortex in Older Adults with Subjective Memory Complaints. Front Aging Neurosci 2017; 9:401. [PMID: 29259554 PMCID: PMC5723311 DOI: 10.3389/fnagi.2017.00401] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Accepted: 11/20/2017] [Indexed: 11/21/2022] Open
Abstract
Episodic memory is critical to daily life functioning. This type of declarative memory declines with age and is the earliest cognitive function to be compromised in Alzheimer’s disease (AD). Subjective memory complaints are commonly reported by older adults and have been considered a risk factor for developing AD. The possibilities for prevention of memory disorders in older adults have increased substantially in recent years. Previous studies have shown that anodal transcranial Direct Current Stimulation (tDCS) applied over the left lateral prefrontal cortex (PFC) after a contextual reminder strengthened existing verbal episodic memories, conceivably through reconsolidation, in elderly people. In this study, we hypothesized that anodal tDCS applied over the left lateral PFC after a contextual reminder would improve delayed memory retrieval relative to placebo (sham) stimulation in elderly individuals with SMC. Twenty-two subjects learned a list of words. Twenty-four hour later, tDCS (anodal or placebo) was applied over the left lateral PFC after a contextual reminder. Memory retrieval was tested 48h and 30 days later. These findings showed that anodal tDCS over the left lateral PFC strengthened existing episodic memories, a behavioral effect documented by improved recognition up to 30 days, relative to placebo stimulation. This study suggests that tDCS after a contextual reminder can induce long-lasting beneficial effects by facilitating the consolidation processes and opens up the possibility to design specific non-invasive interventions aimed at preventing memory decline in this at-risk population.
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Affiliation(s)
- Rosa Manenti
- Neuropsychology Unit, IRCCS Istituto Centro San Giovanni di Dio Fatebenefratelli, Brescia, Italy
| | - Marco Sandrini
- Department of Neurorehabilitation Sciences, Casa di Cura Privata del Policlinico, Milan, Italy
| | - Elena Gobbi
- Neuropsychology Unit, IRCCS Istituto Centro San Giovanni di Dio Fatebenefratelli, Brescia, Italy
| | - Chiara Cobelli
- Neuropsychology Unit, IRCCS Istituto Centro San Giovanni di Dio Fatebenefratelli, Brescia, Italy
| | - Michela Brambilla
- Neuropsychology Unit, IRCCS Istituto Centro San Giovanni di Dio Fatebenefratelli, Brescia, Italy
| | - Giuliano Binetti
- Molecular Markers Laboratory, IRCCS Istituto Centro San Giovanni di Dio Fatebenefratelli, Brescia, Italy.,MAC Memory Center, IRCCS Istituto Centro San Giovanni di Dio Fatebenefratelli, Brescia, Italy
| | - Maria Cotelli
- Neuropsychology Unit, IRCCS Istituto Centro San Giovanni di Dio Fatebenefratelli, Brescia, Italy
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14
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Moran JK, Crombach A, Elbert T, Nandi C, Bambonyé M, Wienbruch C, Lommen U, Weierstall R. The individual contribution of DSM 5 symptom clusters of PTSD, life events, and childhood adversity to frontal oscillatory brain asymmetry in a large sample of active combatants. Biol Psychol 2017; 129:305-313. [PMID: 28958482 PMCID: PMC5678498 DOI: 10.1016/j.biopsycho.2017.09.014] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2017] [Revised: 08/14/2017] [Accepted: 09/23/2017] [Indexed: 12/11/2022]
Abstract
Post-Traumatic Stress Disorder (PTSD) has been linked to deviations in lateralized frontal functional oscillatory activity. This is possibly because left and right DLPFC have differential roles in regulating both memory and stress response, which are both dysfunctional in PTSD. However, previous results are heterogeneous, and could be attributable to individual symptom clusters, traumatic or aggressive life events, early life stress, or the interaction of these factors. In a large sample of active combatants (N=401), we regressed these factors on frontal electroencephalography (EEG) asymmetry across 5 frequency bands (delta: 2-4Hz; theta: 4-8Hz; alpha: 8-12Hz; beta: 12-24Hz; gamma: 24-48Hz). Negative cognition and mood was associated with stronger relative left delta and theta band power. Traumatic life events showed stronger right alpha and beta band power. Traumatic life events in interaction with hyperarousal predicted stronger relative right left-right imbalance (theta, alpha, and beta bands), whereas childhood adversity, in interaction with negative cognition and mood, predicted stronger relative left left-right imbalance (delta, theta, alpha and beta bands). The contribution of lateralized DLPFC dysfunction to PTSD is thus dependent on the individual complexities of subsymptom clusters and life history, and future studies need to take these factors into account.
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Affiliation(s)
- James K Moran
- Department of Psychology, University of Konstanz, Konstanz, Baden-Württemberg, Germany; Charité - Universitätsmedizin Berlin, Department of Psychiatry and Psychotherapy, Berlin, Germany.
| | - Anselm Crombach
- Department of Psychology, University of Konstanz, Konstanz, Baden-Württemberg, Germany; Department of Psychology, University Lumière of Bujumbura, Burundi
| | - Thomas Elbert
- Department of Psychology, University of Konstanz, Konstanz, Baden-Württemberg, Germany; Department of Psychology, University Lumière of Bujumbura, Burundi
| | - Corina Nandi
- Department of Psychology, University of Konstanz, Konstanz, Baden-Württemberg, Germany
| | - Manassé Bambonyé
- Department of Psychology, University Lumière of Bujumbura, Burundi
| | - Christian Wienbruch
- Department of Psychology, University of Konstanz, Konstanz, Baden-Württemberg, Germany
| | - Ursula Lommen
- Department of Psychology, University of Konstanz, Konstanz, Baden-Württemberg, Germany
| | - Roland Weierstall
- Department of Psychology, University of Konstanz, Konstanz, Baden-Württemberg, Germany; MSH Medical School Hamburg, University of Applied Sciences and Medical University, Germany
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15
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Galli G, Feurra M, Pavone EF, Sirota M, Rossi S. Dynamic changes in prefrontal cortex involvement during verbal episodic memory formation. Biol Psychol 2017; 125:36-44. [PMID: 28238886 DOI: 10.1016/j.biopsycho.2017.02.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2016] [Revised: 11/30/2016] [Accepted: 02/22/2017] [Indexed: 10/20/2022]
Abstract
During encoding, the neural activity immediately before or during an event can predict whether that event will be later remembered. The contribution of brain activity immediately after an event to memory formation is however less known. Here, we used repetitive Transcranial Magnetic Stimulation (rTMS) to investigate the temporal dynamics of episodic memory encoding with a focus on post-stimulus time intervals. At encoding, rTMS was applied during the online processing of the word, at its offset, or 100, 200, 300 or 400ms thereafter. rTMS was delivered to the left ventrolateral (VLPFC) or dorsolateral prefrontal cortex (DLPFC). VLPFC rTMS during the first few hundreds of milliseconds after word offset disrupted subsequent recognition accuracy. We did not observe effects of DLPFC rTMS at any time point. These results suggest that encoding-related VLPFC engagement starts at a relatively late processing stage, and may reflect brain processes related to the offset of the stimulus.
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Affiliation(s)
- Giulia Galli
- Department of Medicine, Surgery and Neuroscience, Unit of Neurology and Clinical Neurophysiology, Brain Investigation & Neuromodulation Lab (Si-Bin), University of Siena, Siena, Italy; Department of Psychology, Kingston University, London, United Kingdom.
| | - Matteo Feurra
- Department of Medicine, Surgery and Neuroscience, Unit of Neurology and Clinical Neurophysiology, Brain Investigation & Neuromodulation Lab (Si-Bin), University of Siena, Siena, Italy; School of Psychology, Centre for Cognition and Decision Making, National Research University Higher School of Economics, Russian Federation
| | | | - Miroslav Sirota
- Department of Psychology, University of Essex, Colchester, United Kingdom
| | - Simone Rossi
- Department of Medicine, Surgery and Neuroscience, Unit of Neurology and Clinical Neurophysiology, Brain Investigation & Neuromodulation Lab (Si-Bin), University of Siena, Siena, Italy; Department of Medicine, Surgery and Neuroscience, Human Physiology Section, University of Siena, Italy
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16
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Vukovic N, Feurra M, Shpektor A, Myachykov A, Shtyrov Y. Primary motor cortex functionally contributes to language comprehension: An online rTMS study. Neuropsychologia 2017; 96:222-229. [PMID: 28122198 DOI: 10.1016/j.neuropsychologia.2017.01.025] [Citation(s) in RCA: 85] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2016] [Revised: 11/23/2016] [Accepted: 01/21/2017] [Indexed: 11/19/2022]
Abstract
Among various questions pertinent to grounding human cognitive functions in a neurobiological substrate, the association between language and motor brain structures is a particularly debated one in neuroscience and psychology. While many studies support a broadly distributed model of language and semantics grounded, among other things, in the general modality-specific systems, theories disagree as to whether motor and sensory cortex activity observed during language processing is functional or epiphenomenal. Here, we assessed the role of motor areas in linguistic processing by investigating the responses of 28 healthy volunteers to different word types in semantic and lexical decision tasks, following repetitive transcranial magnetic stimulation (rTMS) of primary motor cortex. We found that early rTMS (delivered within 200ms of word onset) produces a left-lateralised and meaning-specific change in reaction speed, slowing down behavioural responses to action-related words, and facilitating abstract words - an effect present only during semantic, but not lexical, decision. We interpret these data in light of action-perception theory of language, bolstering the claim that motor cortical areas play a functional role in language comprehension.
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Affiliation(s)
- Nikola Vukovic
- Center of Functionally Integrative Neuroscience, Institute for Clinical Medicine, Aarhus University, Denmark; Center for Cognition and Decision Making, Higher School of Economics, Moscow, Russian Federation.
| | - Matteo Feurra
- Center for Cognition and Decision Making, Higher School of Economics, Moscow, Russian Federation
| | - Anna Shpektor
- Center for Cognition and Decision Making, Higher School of Economics, Moscow, Russian Federation
| | - Andriy Myachykov
- Center for Cognition and Decision Making, Higher School of Economics, Moscow, Russian Federation; Department of Psychology, Northumbria University, Newcastle upon Tyne, United Kingdom
| | - Yury Shtyrov
- Center of Functionally Integrative Neuroscience, Institute for Clinical Medicine, Aarhus University, Denmark; Center for Cognition and Decision Making, Higher School of Economics, Moscow, Russian Federation; Medical Research Council Cognition and Brain Sciences Unit, Cambridge, United Kingdom
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17
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Abstract
Previous evidence indicates that the brain stores memory in two complementary systems, allowing both rapid plasticity and stable representations at different sites. For memory to be established in a long-lasting neocortical store, many learning repetitions are considered necessary after initial encoding into hippocampal circuits. To elucidate the dynamics of hippocampal and neocortical contributions to the early phases of memory formation, we closely followed changes in human functional brain activity while volunteers navigated through two different, initially unknown virtual environments. In one condition, they were able to encode new information continuously about the spatial layout of the maze. In the control condition, no information could be learned because the layout changed constantly. Our results show that the posterior parietal cortex (PPC) encodes memories for spatial locations rapidly, beginning already with the first visit to a location and steadily increasing activity with each additional encounter. Hippocampal activity and connectivity between the PPC and hippocampus, on the other hand, are strongest during initial encoding, and both decline with additional encounters. Importantly, stronger PPC activity related to higher memory-based performance. Compared with the nonlearnable control condition, PPC activity in the learned environment remained elevated after a 24-h interval, indicating a stable change. Our findings reflect the rapid creation of a memory representation in the PPC, which belongs to a recently proposed parietal memory network. The emerging parietal representation is specific for individual episodes of experience, predicts behavior, and remains stable over offline periods, and must therefore hold a mnemonic function.
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18
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Steinemann NA, Moisello C, Ghilardi MF, Kelly SP. Tracking neural correlates of successful learning over repeated sequence observations. Neuroimage 2016; 137:152-164. [PMID: 27155129 PMCID: PMC4921688 DOI: 10.1016/j.neuroimage.2016.05.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2016] [Revised: 04/20/2016] [Accepted: 05/02/2016] [Indexed: 10/21/2022] Open
Abstract
The neural correlates of memory formation in humans have long been investigated by exposing subjects to diverse material and comparing responses to items later remembered to those forgotten. Tasks requiring memorization of sensory sequences afford unique possibilities for linking neural memorization processes to behavior, because, rather than comparing across different items of varying content, each individual item can be examined across the successive learning states of being initially unknown, newly learned, and eventually, fully known. Sequence learning paradigms have not yet been exploited in this way, however. Here, we analyze the event-related potentials of subjects attempting to memorize sequences of visual locations over several blocks of repeated observation, with respect to pre- and post-block recall tests. Over centro-parietal regions, we observed a rapid P300 component superimposed on a broader positivity, which exhibited distinct modulations across learning states that were replicated in two separate experiments. Consistent with its well-known encoding of surprise, the P300 deflection monotonically decreased over blocks as locations became better learned and hence more expected. In contrast, the broader positivity was especially elevated at the point when a given item was newly learned, i.e., started being successfully recalled. These results implicate the Broad Positivity in endogenously-driven, intentional memory formation, whereas the P300, in processing the current stimulus to the degree that it was previously uncertain, indexes the cumulative knowledge thereby gained. The decreasing surprise/P300 effect significantly predicted learning success both across blocks and across subjects. This presents a new, neural-based means to evaluate learning capabilities independent of verbal reports, which could have considerable value in distinguishing genuine learning disabilities from difficulties to communicate the outcomes of learning, or perceptual impairments, in a range of clinical brain disorders.
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Affiliation(s)
- Natalie A Steinemann
- Biomedical Engineering Department, The City College of The City University of New York, 160 Convent Ave, New York, NY 10031, USA.
| | - Clara Moisello
- Sophie Davis School of Biomedical Education, The City College of The City University of New York, 160 Convent Ave, New York, NY 10031, USA.
| | - M Felice Ghilardi
- Sophie Davis School of Biomedical Education, The City College of The City University of New York, 160 Convent Ave, New York, NY 10031, USA.
| | - Simon P Kelly
- Biomedical Engineering Department, The City College of The City University of New York, 160 Convent Ave, New York, NY 10031, USA; School of Electrical and Electronic Engineering, University College Dublin, Belfield, Dublin 4, Ireland.
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19
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Manuel AL, Schnider A. Effect of prefrontal and parietal tDCS on learning and recognition of verbal and non-verbal material. Clin Neurophysiol 2016; 127:2592-8. [DOI: 10.1016/j.clinph.2016.04.015] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2016] [Revised: 04/12/2016] [Accepted: 04/15/2016] [Indexed: 11/29/2022]
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20
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Sandrini M, Manenti R, Brambilla M, Cobelli C, Cohen LG, Cotelli M. Older adults get episodic memory boosting from noninvasive stimulation of prefrontal cortex during learning. Neurobiol Aging 2015; 39:210-216. [PMID: 26923418 DOI: 10.1016/j.neurobiolaging.2015.12.010] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2015] [Revised: 12/18/2015] [Accepted: 12/20/2015] [Indexed: 11/17/2022]
Abstract
Episodic memory displays the largest degree of age-related decline, a process that is accelerated in pathological conditions such as amnestic mild cognitive impairment and Alzheimer's disease. Previous studies have shown that the left lateral prefrontal cortex (PFC) contributes to the encoding of episodic memories along the life span. The aim of this randomized, double-blind, placebo-controlled study was to test the hypothesis that anodal trascranial direct current stimulation (tDCS) over the left lateral PFC during the learning phase would enhance delayed recall of verbal episodic memories in elderly individuals. Older adults learned a list of words while receiving anodal or placebo (sham) tDCS. Memory recall was tested 48 hours and 1 month later. The results showed that anodal tDCS strengthened episodic memories, an effect indicated by enhanced delayed recall (48 hours) compared to placebo stimulation (Cohen's d effect size = 1.01). The observation that PFC-tDCS during learning can boost verbal episodic memory in the elderly opens up the possibility to design-specific neurorehabilitation protocols targeted to conditions that affect episodic memory such as mild cognitive impairment.
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Affiliation(s)
- Marco Sandrini
- Department of Psychology, University of Roehampton, London, UK
| | - Rosa Manenti
- Neuropsychology Unit, IRCCS Istituto Centro San Giovanni di Dio Fatebenefratelli, Brescia, Italy
| | - Michela Brambilla
- Neuropsychology Unit, IRCCS Istituto Centro San Giovanni di Dio Fatebenefratelli, Brescia, Italy
| | - Chiara Cobelli
- Neuropsychology Unit, IRCCS Istituto Centro San Giovanni di Dio Fatebenefratelli, Brescia, Italy
| | - Leonardo G Cohen
- Human Cortical Physiology and Neurorehabilitation Section, National Institute of Neurological Disorders and Stroke (NINDS), National Institutes of Health (NIH), Bethesda, USA
| | - Maria Cotelli
- Neuropsychology Unit, IRCCS Istituto Centro San Giovanni di Dio Fatebenefratelli, Brescia, Italy
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21
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Meyer T, Smeets T, Giesbrecht T, Quaedflieg CWEM, Smulders FTY, Meijer EH, Merckelbach HLGJ. The role of frontal EEG asymmetry in post-traumatic stress disorder. Biol Psychol 2015; 108:62-77. [PMID: 25843917 DOI: 10.1016/j.biopsycho.2015.03.018] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2014] [Revised: 02/16/2015] [Accepted: 03/26/2015] [Indexed: 12/15/2022]
Abstract
Frontal alpha asymmetry, a biomarker derived from electroencephalography (EEG) recordings, has often been associated with psychological adjustment, with more left-sided frontal activity predicting approach motivation and lower levels of depression and anxiety. This suggests high relevance to post-traumatic stress disorder (PTSD), a disorder comprising anxiety and dysphoria symptoms. We review this relationship and show that frontal asymmetry can be plausibly linked to neuropsychological abnormalities seen in PTSD. However, surprisingly few studies (k = 8) have directly addressed frontal asymmetry in PTSD, mostly reporting that trait frontal asymmetry has little (if any) predictive value. Meanwhile, preliminary evidence suggest that state-dependent asymmetry during trauma-relevant stimulation distinguishes PTSD patients from resilient individuals. Thus, exploring links between provocation-induced EEG asymmetry and PTSD appears particularly promising. Additionally, we recommend more fine-grained analyses into PTSD symptom clusters in relation to frontal asymmetry. Finally, we highlight hypotheses that may guide future research and help to fully apprehend the practical and theoretical relevance of this biological marker.
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Affiliation(s)
- Thomas Meyer
- Faculty of Psychology and Neuroscience, Maastricht University, PO Box 616, 6200 MD Maastricht, The Netherlands.
| | - Tom Smeets
- Faculty of Psychology and Neuroscience, Maastricht University, PO Box 616, 6200 MD Maastricht, The Netherlands
| | - Timo Giesbrecht
- Faculty of Psychology and Neuroscience, Maastricht University, PO Box 616, 6200 MD Maastricht, The Netherlands
| | - Conny W E M Quaedflieg
- Faculty of Psychology and Neuroscience, Maastricht University, PO Box 616, 6200 MD Maastricht, The Netherlands
| | - Fren T Y Smulders
- Faculty of Psychology and Neuroscience, Maastricht University, PO Box 616, 6200 MD Maastricht, The Netherlands
| | - Ewout H Meijer
- Faculty of Psychology and Neuroscience, Maastricht University, PO Box 616, 6200 MD Maastricht, The Netherlands
| | - Harald L G J Merckelbach
- Faculty of Psychology and Neuroscience, Maastricht University, PO Box 616, 6200 MD Maastricht, The Netherlands
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22
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Galli G. What makes deeply encoded items memorable? Insights into the levels of processing framework from neuroimaging and neuromodulation. Front Psychiatry 2014; 5:61. [PMID: 24904444 PMCID: PMC4035598 DOI: 10.3389/fpsyt.2014.00061] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/01/2014] [Accepted: 05/15/2014] [Indexed: 01/17/2023] Open
Abstract
When we form new memories, their mnestic fate largely depends upon the cognitive operations set in train during encoding. A typical observation in experimental as well as everyday life settings is that if we learn an item using semantic or "deep" operations, such as attending to its meaning, memory will be better than if we learn the same item using more "shallow" operations, such as attending to its structural features. In the psychological literature, this phenomenon has been conceptualized within the "levels of processing" framework and has been consistently replicated since its original proposal by Craik and Lockhart in 1972. However, the exact mechanisms underlying the memory advantage for deeply encoded items are not yet entirely understood. A cognitive neuroscience perspective can add to this field by clarifying the nature of the processes involved in effective deep and shallow encoding and how they are instantiated in the brain, but so far there has been little work to systematically integrate findings from the literature. This work aims to fill this gap by reviewing, first, some of the key neuroimaging findings on the neural correlates of deep and shallow episodic encoding and second, emerging evidence from studies using neuromodulatory approaches such as psychopharmacology and non-invasive brain stimulation. Taken together, these studies help further our understanding of levels of processing. In addition, by showing that deep encoding can be modulated by acting upon specific brain regions or systems, the reviewed studies pave the way for selective enhancements of episodic encoding processes.
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Affiliation(s)
- Giulia Galli
- Brain Investigation and Neuromodulation (BIN) Laboratory, Azienda Ospedaliera Universitaria Senese, Siena, Italy
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23
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Abstract
Human memory is dynamic and flexible but is also susceptible to distortions arising from adaptive as well as pathological processes. Both accurate and false memory formation require executive control that is critically mediated by the left prefrontal cortex (PFC). Transcranial direct current stimulation (tDCS) enables noninvasive modulation of cortical activity and associated behavior. The present study reports that tDCS applied to the left dorsolateral PFC (dlPFC) shaped accuracy of episodic memory via polaritiy-specific modulation of false recognition. When applied during encoding of pictures, anodal tDCS increased whereas cathodal stimulation reduced the number of false alarms to lure pictures in subsequent recognition memory testing. These data suggest that the enhancement of excitability in the dlPFC by anodal tDCS can be associated with blurred detail memory. In contrast, activity-reducing cathodal tDCS apparently acted as a noise filter inhibiting the development of imprecise memory traces and reducing the false memory rate. Consistently, the largest effect was found in the most active condition (i.e., for stimuli cued to be remembered). This first evidence for a polarity-specific, activity-dependent effect of tDCS on false memory opens new vistas for the understanding and potential treatment of disturbed memory control.
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24
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Hanslmayr S, Matuschek J, Fellner MC. Entrainment of prefrontal beta oscillations induces an endogenous echo and impairs memory formation. Curr Biol 2014; 24:904-9. [PMID: 24684933 DOI: 10.1016/j.cub.2014.03.007] [Citation(s) in RCA: 147] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2013] [Revised: 02/19/2014] [Accepted: 03/04/2014] [Indexed: 11/17/2022]
Abstract
Brain oscillations across all frequency bands play a key role for memory formation. Specifically, desynchronization of local neuronal assemblies in the left inferior prefrontal cortex (PFC) in the beta frequency (∼18 Hz) has been shown to be central for encoding of verbal memories. However, it remains elusive whether prefrontal beta desynchronization is causally relevant for memory formation and whether these endogenous beta oscillations can be entrained by external stimulation. By using combined EEG-TMS (transcranial magnetic stimulation), we here address these fundamental questions in human participants performing a word-list learning task. Confirming our predictions, memory encoding was selectively impaired when the left inferior frontal gyrus (IFG) was driven at beta (18.7 Hz) compared to stimulation at other frequencies (6.8 Hz and 10.7 Hz) and to ineffective sham stimulation (18.7 Hz). Furthermore, a sustained oscillatory "echo" in the left IFG, which outlasted the stimulation period by approximately 1.5 s, was observed solely after beta stimulation. The strength of this beta echo was related to memory impairment on a between-subjects level. These results show endogenous oscillatory entrainment effects and behavioral impairment selectively in beta frequency for stimulation of the left IFG, demonstrating an intimate causal relationship between prefrontal beta desynchronization and memory formation.
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Affiliation(s)
- Simon Hanslmayr
- Department of Psychology, University of Konstanz, 78457 Konstanz, Germany; Zukunftskolleg, University of Konstanz, 78457 Konstanz, Germany; School of Psychology, University of Birmingham, Birmingham B15 2TT, UK.
| | - Jonas Matuschek
- Department of Psychology, University of Konstanz, 78457 Konstanz, Germany
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Blumenfeld RS, Lee TG, D'Esposito M. The effects of lateral prefrontal transcranial magnetic stimulation on item memory encoding. Neuropsychologia 2013; 53:197-202. [PMID: 24316198 DOI: 10.1016/j.neuropsychologia.2013.11.021] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2013] [Revised: 11/22/2013] [Accepted: 11/25/2013] [Indexed: 11/19/2022]
Abstract
Previous neuroimaging research has established that the left ventrolateral prefrontal cortex (VLPFC) is involved in long-term memory (LTM) encoding for individual items. Dorsolateral prefrontal cortex (DLPFC) is implicated less frequently, and one theory that has gained support to explain this discrepancy is that DLPFC is involved in forming item-item relational but not item LTM. Given that neuroimaging results are correlational, complimentary methods such as repetitive transcranial magnetic stimulation (TMS) have been used to test causal hypotheses generated from imaging data. Most TMS studies of LTM encoding have found that disruption of lateral PFC activity impairs subsequent memory. However these studies have lacked methods to precisely localize and directly compare TMS effects from frontal subregions implicated by the neuroimaging literature. Here, we target specific subregions of lateral PFC with TMS to test the prediction from the item/relational framework that temporary disruption of VLPFC during encoding will impair subsequent memory whereas TMS to DLPFC during item encoding will not. Frontal TMS was administered prior to a LTM encoding task in which participants were presented with a list of individual nouns and asked to judge whether each noun was concrete or abstract. After a 40 min delay period, item recognition memory was tested. Results indicate that VLPFC and DLPFC TMS have differential effects on subsequent item memory. VLPFC TMS reliably disrupted subsequent item memory whereas DLPFC TMS led to numerical enhancement in item memory, relative to TMS to a control region.
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Affiliation(s)
- Robert S Blumenfeld
- Department of Neurology, University of California, Irvine, CA 92697, United States.
| | - Taraz G Lee
- Department of Psychological and Brain Sciences, University of California, Santa Barbara, CA, United States
| | - Mark D'Esposito
- Helen Wills Neuroscience Institute and Department of Psychology, University of California, Berkeley, CA 94720, United States; Department of Psychology, University of California, Berkeley, CA 94720, United States
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26
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Hawco C, Berlim MT, Lepage M. The dorsolateral prefrontal cortex plays a role in self-initiated elaborative cognitive processing during episodic memory encoding: rTMS evidence. PLoS One 2013; 8:e73789. [PMID: 24040072 PMCID: PMC3764025 DOI: 10.1371/journal.pone.0073789] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2013] [Accepted: 07/31/2013] [Indexed: 01/18/2023] Open
Abstract
During episodic memory encoding, elaborative cognitive processing can improve later recall or recognition. While multiple studies examined the neural correlates of encoding strategies, few studies have explicitly focused on the self-initiation of elaborative encoding. Repetitive transcranial magnetic stimulation (rTMS), a method which can transiently disrupt neural activity, was administered during an associative encoding task. rTMS was either applied to the left dorsolateral prefrontal cortex (DLPFC) or to the vertex (a control region not involved in memory encoding) during presentation of pairs of words. Pairs could be semantically related or not related. Two encoding instructions were given, either cueing participants to analyze semantic relationships (cued condition), or to memorize the pair without any specific strategy cues (the self-initiated condition). Participants filled out a questionnaire regarding their use of memory strategies and performed a cued-recall task. We hypothesized that if the DLPFC plays a role in the self-initiation of elaborative encoding we would observe a reduction in memory performance in the self-initiated condition, particularly for related. We found a significant correlation between the effects of rTMS and strategy use, only in the self-initiated condition with related pairs. High strategy users showed reduced performance following DLPFC stimulation, while low strategy users tended to show increased recall following DLPFC stimulation during encoding. These results suggest the left DLPFC may be involved in the self-initiation of memory strategy use, and individuals may utilize different neural networks depending on their use of encoding strategies.
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Affiliation(s)
- Colin Hawco
- Department of Neurology and Neurosurgery, Douglas Mental Health University Institute, McGill University, Montreal, Quebec, Canada
| | - Marcelo T. Berlim
- Department of Psychiatry, Douglas Mental Health University Institute, McGill University, Montreal, Quebec, Canada
| | - Martin Lepage
- Department of Psychiatry, Douglas Mental Health University Institute, McGill University, Montreal, Quebec, Canada
- * E-mail:
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27
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Johnson R, Nessler D, Friedman D. Temporally specific divided attention tasks in young adults reveal the temporal dynamics of episodic encoding failures in elderly adults. Psychol Aging 2013; 28:443-56. [PMID: 23276214 PMCID: PMC3692580 DOI: 10.1037/a0030967] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Nessler, Johnson, Bersick, and Friedman (D. Nessler, R. Johnson, Jr., M. Bersick, & D. Friedman, 2006, On why the elderly have normal semantic retrieval but deficient episodic encoding: A study of left inferior frontal ERP activity, NeuroImage, Vol. 30, pp. 299-312) found that, compared with young adults, older adults show decreased event-related brain potential (ERP) activity over posterior left inferior prefrontal cortex (pLIPFC) in a 400- to 1,400-ms interval during episodic encoding. This altered brain activity was associated with significantly decreased recognition performance and reduced recollection-related brain activity at retrieval (D. Nessler, D. Friedman, R. Johnson, Jr., & M. Bersick, 2007, Does repetition engender the same retrieval processes in young and older adults? NeuroReport, Vol. 18, pp. 1837-1840). To test the hypothesis that older adults' well-documented episodic retrieval deficit is related to reduced pLIPFC activity at encoding, we used a novel divided attention task in healthy young adults that was specifically timed to disrupt encoding in either the 1st or 2nd half of a 300- to 1,400-ms interval. The results showed that diverting resources for 550 ms during either half of this interval reproduced the 4 characteristic aspects of the older participants' retrieval performance: normal semantic retrieval during encoding, reduced subsequent episodic recognition and recall, reduced recollection-related ERP activity, and the presence of "compensatory" brain activity. We conclude that part of older adults' episodic memory deficit is attributable to altered pLIPFC activity during encoding due to reduced levels of available processing resources. Moreover, the findings also provide insights into the nature and timing of the putative "compensatory" processes posited to be used by older adults in an attempt to compensate for age-related decline in cognitive function. These results support the scaffolding account of compensation, in which the recruitment of additional cognitive processes is an adaptive response across the life span.
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Affiliation(s)
- Ray Johnson
- Brain and Cognition Laboratory, Department of Psychology, Queens College of CUNY, NY, USA
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28
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Innocenti I, Cappa SF, Feurra M, Giovannelli F, Santarnecchi E, Bianco G, Cincotta M, Rossi S. TMS interference with primacy and recency mechanisms reveals bimodal episodic encoding in the human brain. J Cogn Neurosci 2013. [PMID: 23198892 DOI: 10.1162/jocn_a_00304] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
A classic finding of the psychology of memory is the "serial position effect." Immediate free recall of a word list is more efficient for items presented early (primacy effect) or late (recency effect), with respect to those in the middle. In an event-related, randomized block design, we interfered with the encoding of unrelated words lists with brief trains of repetitive TMS (rTMS), applied coincidently with the acoustic presentation of each word to the left dorsolateral pFC, the left intraparietal lobe, and a control site (vertex). Interference of rTMS with encoding produced a clear-cut double dissociation on accuracy during immediate free recall. The primacy effect was selectively worsened by rTMS of the dorsolateral pFC, whereas recency was selectively worsened by rTMS of the intraparietal lobe. These results are in agreement with the double dissociation between short-term and long-term memory observed in neuropsychological patients and provide direct evidence of distinct cortical mechanisms of encoding in the human brain.
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29
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Neural predictors of individual differences in response to math tutoring in primary-grade school children. Proc Natl Acad Sci U S A 2013; 110:8230-5. [PMID: 23630286 DOI: 10.1073/pnas.1222154110] [Citation(s) in RCA: 171] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Now, more than ever, the ability to acquire mathematical skills efficiently is critical for academic and professional success, yet little is known about the behavioral and neural mechanisms that drive some children to acquire these skills faster than others. Here we investigate the behavioral and neural predictors of individual differences in arithmetic skill acquisition in response to 8-wk of one-to-one math tutoring. Twenty-four children in grade 3 (ages 8-9 y), a critical period for acquisition of basic mathematical skills, underwent structural and resting-state functional MRI scans pretutoring. A significant shift in arithmetic problem-solving strategies from counting to fact retrieval was observed with tutoring. Notably, the speed and accuracy of arithmetic problem solving increased with tutoring, with some children improving significantly more than others. Next, we examined whether pretutoring behavioral and brain measures could predict individual differences in arithmetic performance improvements with tutoring. No behavioral measures, including intelligence quotient, working memory, or mathematical abilities, predicted performance improvements. In contrast, pretutoring hippocampal volume predicted performance improvements. Furthermore, pretutoring intrinsic functional connectivity of the hippocampus with dorsolateral and ventrolateral prefrontal cortices and the basal ganglia also predicted performance improvements. Our findings provide evidence that individual differences in morphometry and connectivity of brain regions associated with learning and memory, and not regions typically involved in arithmetic processing, are strong predictors of responsiveness to math tutoring in children. More generally, our study suggests that quantitative measures of brain structure and intrinsic brain organization can provide a more sensitive marker of skill acquisition than behavioral measures.
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30
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Cho S, Metcalfe AWS, Young CB, Ryali S, Geary DC, Menon V. Hippocampal-prefrontal engagement and dynamic causal interactions in the maturation of children's fact retrieval. J Cogn Neurosci 2012; 24:1849-66. [PMID: 22621262 DOI: 10.1162/jocn_a_00246] [Citation(s) in RCA: 89] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Children's gains in problem-solving skills during the elementary school years are characterized by shifts in the mix of problem-solving approaches, with inefficient procedural strategies being gradually replaced with direct retrieval of domain-relevant facts. We used a well-established procedure for strategy assessment during arithmetic problem solving to investigate the neural basis of this critical transition. We indexed behavioral strategy use by focusing on the retrieval frequency and examined changes in brain activity and connectivity associated with retrieval fluency during arithmetic problem solving in second- and third-grade (7- to 9-year-old) children. Children with higher retrieval fluency showed elevated signal in the right hippocampus, parahippocampal gyrus (PHG), lingual gyrus (LG), fusiform gyrus (FG), left ventrolateral PFC (VLPFC), bilateral dorsolateral PFC (DLPFC), and posterior angular gyrus. Critically, these effects were not confounded by individual differences in problem-solving speed or accuracy. Psychophysiological interaction analysis revealed significant effective connectivity of the right hippocampus with bilateral VLPFC and DLPFC during arithmetic problem solving. Dynamic causal modeling analysis revealed strong bidirectional interactions between the hippocampus and the left VLPFC and DLPFC. Furthermore, causal influences from the left VLPFC to the hippocampus served as the main top-down component, whereas causal influences from the hippocampus to the left DLPFC served as the main bottom-up component of this retrieval network. Our study highlights the contribution of hippocampal-prefrontal circuits to the early development of retrieval fluency in arithmetic problem solving and provides a novel framework for studying dynamic developmental processes that accompany children's development of problem-solving skills.
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31
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Hanslmayr S, Staudigl T, Fellner MC. Oscillatory power decreases and long-term memory: the information via desynchronization hypothesis. Front Hum Neurosci 2012; 6:74. [PMID: 22514527 PMCID: PMC3322486 DOI: 10.3389/fnhum.2012.00074] [Citation(s) in RCA: 289] [Impact Index Per Article: 24.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2011] [Accepted: 03/16/2012] [Indexed: 11/13/2022] Open
Abstract
The traditional belief is that brain oscillations are important for human long-term memory, because they induce synchronized firing between cell assemblies which shapes synaptic plasticity. Therefore, most prior studies focused on the role of synchronization for episodic memory, as reflected in theta (∼5 Hz) and gamma (>40 Hz) power increases. These studies, however, neglect the role that is played by neural desynchronization, which is usually reflected in power decreases in the alpha and beta frequency band (8-30 Hz). In this paper we present a first idea, derived from information theory that gives a mechanistic explanation of how neural desynchronization aids human memory encoding and retrieval. Thereby we will review current studies investigating the role of alpha and beta power decreases during long-term memory tasks and show that alpha and beta power decreases play an important and active role for human memory. Applying mathematical models of information theory, we demonstrate that neural desynchronization is positively related to the richness of information represented in the brain, thereby enabling encoding and retrieval of long-term memories. This information via desynchronization hypothesis makes several predictions, which can be tested in future experiments.
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Affiliation(s)
- Simon Hanslmayr
- Department of Psychology, University of Konstanz Konstanz, Germany
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32
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Parker A, Dagnall N. Effects of saccadic bilateral eye movements on memory in children and adults: An exploratory study. Brain Cogn 2012; 78:238-47. [DOI: 10.1016/j.bandc.2012.01.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2010] [Revised: 11/05/2011] [Accepted: 01/06/2012] [Indexed: 10/14/2022]
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33
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Wais PE, Kim OY, Gazzaley A. Distractibility during episodic retrieval is exacerbated by perturbation of left ventrolateral prefrontal cortex. ACTA ACUST UNITED AC 2011; 22:717-24. [PMID: 21680847 DOI: 10.1093/cercor/bhr160] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
The presence of irrelevant external stimuli during the retrieval of long-term memory (LTM) has a negative impact on the fidelity of recollected details. Top-down control processes that both guide the selection of internal information relevant to LTM goals and resolve interference on retrieval from irrelevant external information have been associated with the same region in left ventrolateral prefrontal cortex (VLPFC). The current study examined a causal role of the left VLPFC in memory performance when external distraction (i.e., visual stimuli irrelevant to the current task goals) was presented during retrieval of LTM. Immediately after functional perturbation of the left VLPFC with 1-Hz repetitive transcranial magnetic stimulation, participants' memory was tested when their eyes were closed and when their eyes were open and irrelevant visual stimuli were presented. The results showed that visual distraction diminished LTM performance based on an objective measure of recollection and that perturbation of left VLPFC exacerbated the disruptive effect. This is the first evidence of a direct role of the left VLPFC in diminishing the impact of distraction on recollection, elucidating neural mechanisms that are critically involved in how we reconstruct the past while navigating the external environment.
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Affiliation(s)
- Peter E Wais
- Department of Neurology, W. M. Keck Center for Integrative Neurosciences, University of California, San Francisco, CA 94158, USA.
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34
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Innocenti I, Giovannelli F, Cincotta M, Feurra M, Polizzotto NR, Bianco G, Cappa SF, Rossi S. Event-related rTMS at encoding affects differently deep and shallow memory traces. Neuroimage 2010; 53:325-30. [DOI: 10.1016/j.neuroimage.2010.06.011] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2010] [Revised: 05/25/2010] [Accepted: 06/04/2010] [Indexed: 11/16/2022] Open
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35
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The use of transcranial magnetic stimulation in cognitive neuroscience: a new synthesis of methodological issues. Neurosci Biobehav Rev 2010; 35:516-36. [PMID: 20599555 DOI: 10.1016/j.neubiorev.2010.06.005] [Citation(s) in RCA: 221] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2010] [Revised: 06/15/2010] [Accepted: 06/17/2010] [Indexed: 10/19/2022]
Abstract
Transcranial magnetic stimulation (TMS) has become a mainstay of cognitive neuroscience, thus facing new challenges due to its widespread application on behaviorally silent areas. In this review we will summarize the main technical and methodological considerations that are necessary when using TMS in cognitive neuroscience, based on a corpus of studies and technical improvements that has become available in most recent years. Although TMS has been applied only relatively recently on a large scale to the study of higher functions, a range of protocols that elucidate how this technique can be used to investigate a variety of issues is already available, such as single pulse, paired pulse, dual-site, repetitive and theta burst TMS. Finally, we will touch on recent promising approaches that provide powerful new insights about causal interactions among brain regions (i.e., TMS with other neuroimaging techniques) and will enable researchers to enhance the functional resolution of TMS (i.e., state-dependent TMS). We will end by briefly summarizing and discussing the implications of the newest safety guidelines.
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