TY  - CONF
AU  - Paunović, Dunja
AU  - Bjekić, Jovana
AU  - Filipović, Saša
PY  - 2023
UR  - http://rimi.imi.bg.ac.rs/handle/123456789/1443
AB  - Associative memory (AM) represents an ability to bind unrelated information into meaningful units and encode them as distinct memories. AM has been the function of interest in many non-invasive transcranial electrical stimulation (tES) studies aiming to maximize the potential for memory modulation by varying stimulation loci, frequency, and amplitude.
In the current study, we aimed to capture modulation potential of AM performance when tailoring the stimulation protocols to the individual brain rhythms. By matching the stimulation frequency to the frequency of each subject’s AM task-induced electrophysiological (EEG) activity in theta spectrum (4-8 Hz), we developed two types of personalized oscillatory protocols: theta-modulated transcranial direct current stimulation (otDCS) and transcranial alternating current stimulation (tACS), which we administered alongside the constant tDCS and a sham condition in the single-blind cross-over experiment. To comparatively assess the effects of different tES protocols delivered over the posterior parietal cortex, we tested the recognition and recall ability of the 42 healthy young adults on paired-associate paradigms after each of four conditions. During AM assessment participant’s EEG activity was recorded.
Group-level comparisons of each active tES condition against sham did not show differences in AM task performance either on recognition or cued-recall. However, data showed variability in performance depending on the task and the outcome measures precluding straightforward comparison between the conditions. To explore the potential sources of variability in effect expression, we propose a methodology for isolating different aspects of the function-relevant neurophysiological markers that could depict the modulatory tES effect, setting the groundwork for further analysis.
Apart from introducing a novel approach to probing AM with personalized tES, this well-powered, multi-protocol, multi-task, and multi-measure study produced a comprehensive dataset for the exploration of factors that could uncover patterns in responsiveness to tES, as well as the insight into the relationship between neurophysiological and behavioral indicators.
C3  - BrainBox Initiative Conference 2023, 21-23 September 2023, London, UK
T1  - Theta-modulated transcranial electrical stimulation for targeting Associative memory: A cross-modal integration of EEG and behavioral indicators
UR  - https://hdl.handle.net/21.15107/rcub_rimi_1443
ER  - 

@conference{
author = "Paunović, Dunja and Bjekić, Jovana and Filipović, Saša",
year = "2023",
abstract = "Associative memory (AM) represents an ability to bind unrelated information into meaningful units and encode them as distinct memories. AM has been the function of interest in many non-invasive transcranial electrical stimulation (tES) studies aiming to maximize the potential for memory modulation by varying stimulation loci, frequency, and amplitude.
In the current study, we aimed to capture modulation potential of AM performance when tailoring the stimulation protocols to the individual brain rhythms. By matching the stimulation frequency to the frequency of each subject’s AM task-induced electrophysiological (EEG) activity in theta spectrum (4-8 Hz), we developed two types of personalized oscillatory protocols: theta-modulated transcranial direct current stimulation (otDCS) and transcranial alternating current stimulation (tACS), which we administered alongside the constant tDCS and a sham condition in the single-blind cross-over experiment. To comparatively assess the effects of different tES protocols delivered over the posterior parietal cortex, we tested the recognition and recall ability of the 42 healthy young adults on paired-associate paradigms after each of four conditions. During AM assessment participant’s EEG activity was recorded.
Group-level comparisons of each active tES condition against sham did not show differences in AM task performance either on recognition or cued-recall. However, data showed variability in performance depending on the task and the outcome measures precluding straightforward comparison between the conditions. To explore the potential sources of variability in effect expression, we propose a methodology for isolating different aspects of the function-relevant neurophysiological markers that could depict the modulatory tES effect, setting the groundwork for further analysis.
Apart from introducing a novel approach to probing AM with personalized tES, this well-powered, multi-protocol, multi-task, and multi-measure study produced a comprehensive dataset for the exploration of factors that could uncover patterns in responsiveness to tES, as well as the insight into the relationship between neurophysiological and behavioral indicators.",
journal = "BrainBox Initiative Conference 2023, 21-23 September 2023, London, UK",
title = "Theta-modulated transcranial electrical stimulation for targeting Associative memory: A cross-modal integration of EEG and behavioral indicators",
url = "https://hdl.handle.net/21.15107/rcub_rimi_1443"
}

Paunović, D., Bjekić, J.,& Filipović, S.. (2023). Theta-modulated transcranial electrical stimulation for targeting Associative memory: A cross-modal integration of EEG and behavioral indicators. in BrainBox Initiative Conference 2023, 21-23 September 2023, London, UK.
https://hdl.handle.net/21.15107/rcub_rimi_1443

Paunović D, Bjekić J, Filipović S. Theta-modulated transcranial electrical stimulation for targeting Associative memory: A cross-modal integration of EEG and behavioral indicators. in BrainBox Initiative Conference 2023, 21-23 September 2023, London, UK. 2023;.
https://hdl.handle.net/21.15107/rcub_rimi_1443 .

Paunović, Dunja, Bjekić, Jovana, Filipović, Saša, "Theta-modulated transcranial electrical stimulation for targeting Associative memory: A cross-modal integration of EEG and behavioral indicators" in BrainBox Initiative Conference 2023, 21-23 September 2023, London, UK (2023),
https://hdl.handle.net/21.15107/rcub_rimi_1443 .

TY  - CONF
AU  - Stanković, Marija
AU  - Bjekić, Jovana
AU  - Teovanović, P.
AU  - Konstantinović, Uroš
AU  - Paunović, Dunja
AU  - Đukić, Bojana
AU  - Filipović, Saša
PY  - 2023
UR  - http://rimi.imi.bg.ac.rs/handle/123456789/1445
AB  - Gambling represents a reward-based activity that many people engage in for fun and leisure. However, excessive gambling may lead to Gambling Disorder (GD), the most prevalent behavioural addiction. There is evidence that neural circuits behind some of the cognitive processes that drive GD can be modulated by Transcranial Electrical Stimulation (tES). To comprehensively understand the potential of tES in targeting cognitive mechanisms implicated in GD, we conducted a PRISMA-guided systematic review of studies that applied tES to modulate gambling-related cognitive processes in a diverse range of population samples, including healthy participants, participants with GD, as well as other addictions. Most of the studies used transcranial direct current stimulation (tDCS) to target dorsolateral prefrontal cortex (DLPFC). While 70% of studies showed neuromodulatory effects, the results varied considerably depending on the stimulation parameters, sample characteristics, as well as outcome measures used. We noticed that studies predominantly focused on the DLPFC without providing a clear rationale, even though other brain regions have shown greater relevance to the cognitive functions affected in GD. Furthermore, we have identified a gap in the existing literature regarding the use of tES among participants with gambling-related issues. Based on these findings, we propose a study protocol for investigating the effects of tES on cognitive functions affected in GD, in a sample of at-risk gamblers. In a sham-controlled, parallel-group study we will use multichannel tDCS to modulate the activity of anterior cingulate cortex, due to its key role in gambling-related cognitive processes. The electrode montage will be optimized based on current flow modeling. We will test the effects on cognitive tasks measuring risk-taking, impulsivity, inhibition, and decision-making. In addition to at risk-gamblers, we will sample control participants with no gambling-related issues. This approach will enable us to examine whether and how this factor may determine the responsiveness to tES.
C3  - BrainBox Initiative Conference 2023, 21-23 September 2023, London, UK, 2023
T1  - Using Transcranial Electrical Stimulation to modulate gambling-related cognitive functions: A systematic review and study protocol
UR  - https://hdl.handle.net/21.15107/rcub_rimi_1445
ER  - 

@conference{
author = "Stanković, Marija and Bjekić, Jovana and Teovanović, P. and Konstantinović, Uroš and Paunović, Dunja and Đukić, Bojana and Filipović, Saša",
year = "2023",
abstract = "Gambling represents a reward-based activity that many people engage in for fun and leisure. However, excessive gambling may lead to Gambling Disorder (GD), the most prevalent behavioural addiction. There is evidence that neural circuits behind some of the cognitive processes that drive GD can be modulated by Transcranial Electrical Stimulation (tES). To comprehensively understand the potential of tES in targeting cognitive mechanisms implicated in GD, we conducted a PRISMA-guided systematic review of studies that applied tES to modulate gambling-related cognitive processes in a diverse range of population samples, including healthy participants, participants with GD, as well as other addictions. Most of the studies used transcranial direct current stimulation (tDCS) to target dorsolateral prefrontal cortex (DLPFC). While 70% of studies showed neuromodulatory effects, the results varied considerably depending on the stimulation parameters, sample characteristics, as well as outcome measures used. We noticed that studies predominantly focused on the DLPFC without providing a clear rationale, even though other brain regions have shown greater relevance to the cognitive functions affected in GD. Furthermore, we have identified a gap in the existing literature regarding the use of tES among participants with gambling-related issues. Based on these findings, we propose a study protocol for investigating the effects of tES on cognitive functions affected in GD, in a sample of at-risk gamblers. In a sham-controlled, parallel-group study we will use multichannel tDCS to modulate the activity of anterior cingulate cortex, due to its key role in gambling-related cognitive processes. The electrode montage will be optimized based on current flow modeling. We will test the effects on cognitive tasks measuring risk-taking, impulsivity, inhibition, and decision-making. In addition to at risk-gamblers, we will sample control participants with no gambling-related issues. This approach will enable us to examine whether and how this factor may determine the responsiveness to tES.",
journal = "BrainBox Initiative Conference 2023, 21-23 September 2023, London, UK, 2023",
title = "Using Transcranial Electrical Stimulation to modulate gambling-related cognitive functions: A systematic review and study protocol",
url = "https://hdl.handle.net/21.15107/rcub_rimi_1445"
}

Stanković, M., Bjekić, J., Teovanović, P., Konstantinović, U., Paunović, D., Đukić, B.,& Filipović, S.. (2023). Using Transcranial Electrical Stimulation to modulate gambling-related cognitive functions: A systematic review and study protocol. in BrainBox Initiative Conference 2023, 21-23 September 2023, London, UK, 2023.
https://hdl.handle.net/21.15107/rcub_rimi_1445

Stanković M, Bjekić J, Teovanović P, Konstantinović U, Paunović D, Đukić B, Filipović S. Using Transcranial Electrical Stimulation to modulate gambling-related cognitive functions: A systematic review and study protocol. in BrainBox Initiative Conference 2023, 21-23 September 2023, London, UK, 2023. 2023;.
https://hdl.handle.net/21.15107/rcub_rimi_1445 .

Stanković, Marija, Bjekić, Jovana, Teovanović, P., Konstantinović, Uroš, Paunović, Dunja, Đukić, Bojana, Filipović, Saša, "Using Transcranial Electrical Stimulation to modulate gambling-related cognitive functions: A systematic review and study protocol" in BrainBox Initiative Conference 2023, 21-23 September 2023, London, UK, 2023 (2023),
https://hdl.handle.net/21.15107/rcub_rimi_1445 .

TY  - JOUR
AU  - Bjekić, Jovana
AU  - Živanović, Marko
AU  - Paunović, Dunja
AU  - Vulić, Katarina
AU  - Konstantinović, Uroš
AU  - Filipović, Saša
PY  - 2022
UR  - http://rimi.imi.bg.ac.rs/handle/123456789/1230
AB  - Associative memory (AM) is the ability to remember the relationship between previously unrelated items. AM is significantly affected by normal aging and neurodegenerative conditions, thus there is a growing interest in applying non-invasive brain stimulation (NIBS) techniques for AM enhancement. A growing body of studies identifies posterior parietal cortex (PPC) as the most promising cortical target for both transcranial magnetic stimulation (TMS) and transcranial electrical stimulation (tES) to modulate a cortico-hippocampal network that underlines AM. In that sense, theta frequency oscillatory tES protocols, targeted towards the hallmark oscillatory activity within the cortico-hippocampal network, are increasingly coming to prominence. To increase precision and effectiveness, the need for EEG guided individualization of the tES protocols is proposed. Here, we present the study protocol in which two types of personalized oscillatory tES–transcranial alternating current stimulation (tACS) and oscillatory transcranial direct current stimulation (otDCS), both frequency-modulated to the individual theta-band frequency (ITF), are compared to the non-oscillatory transcranial direct current stimulation (tDCS) and to the sham stimulation. The study has cross-over design with four tES conditions (tACS, otDCS, tDCS, sham), and the comprehensive set of neurophysiological (resting state EEG and AM-evoked EEG) and behavioral outcomes, including AM tasks (short-term associative memory, face–word, face–object, object-location), as well as measures of other cognitive functions (cognitive control, verbal fluency, and working memory).
T2  - Brain Sciences
T1  - Personalized Frequency Modulated Transcranial Electrical Stimulation for Associative Memory Enhancement
IS  - 4
SP  - 472
VL  - 12
DO  - 10.3390/brainsci12040472
ER  - 

@article{
author = "Bjekić, Jovana and Živanović, Marko and Paunović, Dunja and Vulić, Katarina and Konstantinović, Uroš and Filipović, Saša",
year = "2022",
abstract = "Associative memory (AM) is the ability to remember the relationship between previously unrelated items. AM is significantly affected by normal aging and neurodegenerative conditions, thus there is a growing interest in applying non-invasive brain stimulation (NIBS) techniques for AM enhancement. A growing body of studies identifies posterior parietal cortex (PPC) as the most promising cortical target for both transcranial magnetic stimulation (TMS) and transcranial electrical stimulation (tES) to modulate a cortico-hippocampal network that underlines AM. In that sense, theta frequency oscillatory tES protocols, targeted towards the hallmark oscillatory activity within the cortico-hippocampal network, are increasingly coming to prominence. To increase precision and effectiveness, the need for EEG guided individualization of the tES protocols is proposed. Here, we present the study protocol in which two types of personalized oscillatory tES–transcranial alternating current stimulation (tACS) and oscillatory transcranial direct current stimulation (otDCS), both frequency-modulated to the individual theta-band frequency (ITF), are compared to the non-oscillatory transcranial direct current stimulation (tDCS) and to the sham stimulation. The study has cross-over design with four tES conditions (tACS, otDCS, tDCS, sham), and the comprehensive set of neurophysiological (resting state EEG and AM-evoked EEG) and behavioral outcomes, including AM tasks (short-term associative memory, face–word, face–object, object-location), as well as measures of other cognitive functions (cognitive control, verbal fluency, and working memory).",
journal = "Brain Sciences",
title = "Personalized Frequency Modulated Transcranial Electrical Stimulation for Associative Memory Enhancement",
number = "4",
pages = "472",
volume = "12",
doi = "10.3390/brainsci12040472"
}

Bjekić, J., Živanović, M., Paunović, D., Vulić, K., Konstantinović, U.,& Filipović, S.. (2022). Personalized Frequency Modulated Transcranial Electrical Stimulation for Associative Memory Enhancement. in Brain Sciences, 12(4), 472.
https://doi.org/10.3390/brainsci12040472

Bjekić J, Živanović M, Paunović D, Vulić K, Konstantinović U, Filipović S. Personalized Frequency Modulated Transcranial Electrical Stimulation for Associative Memory Enhancement. in Brain Sciences. 2022;12(4):472.
doi:10.3390/brainsci12040472 .

Bjekić, Jovana, Živanović, Marko, Paunović, Dunja, Vulić, Katarina, Konstantinović, Uroš, Filipović, Saša, "Personalized Frequency Modulated Transcranial Electrical Stimulation for Associative Memory Enhancement" in Brain Sciences, 12, no. 4 (2022):472,
https://doi.org/10.3390/brainsci12040472 . .

TY  - JOUR
AU  - Bjekić, Jovana
AU  - Paunović, Dunja
AU  - Živanović, Marko
AU  - Stanković, Marija
AU  - Griskova-Bulanova, Inga
AU  - Filipović, Saša
PY  - 2022
UR  - http://rimi.imi.bg.ac.rs/handle/123456789/1259
AB  - Non-invasive brain stimulation (NIBS) methods have gained increased interest in research and therapy of associative memory (AM) and its impairments. However, the one-size-fits-all approach yields inconsistent findings, thus putting forward the need for electroencephalography (EEG)-guided personalized frequency-modulated NIBS protocols to increase the focality and the effectiveness of the interventions. Still, extraction of individual frequency, especially in the theta band, turned out to be a challenging task. Here we present an approach to extracting the individual theta-band frequency (ITF) from EEG signals recorded during the AM task. The method showed a 93% success rate, good reliability, and the full range of variability of the extracted ITFs. This paper provides a rationale behind the adopted approach and critically evaluates it in comparison to the alternative methods that have been reported in the literature. Finally, we discuss how it could be used as an input parameter for personalized frequency-modulated NIBS approaches—transcranial alternating current stimulation (tACS) and transcranial oscillatory current stimulation (otDCS) directed at AM neuromodulation.
PB  - Frontiers Media S.A.
T2  - Journal of Personalized Medicine
T1  - Determining the Individual Theta Frequency for Associative Memory Targeted Personalized Transcranial Brain Stimulation
IS  - 9
SP  - 1367
VL  - 12
DO  - 10.3390/jpm12091367
ER  - 

@article{
author = "Bjekić, Jovana and Paunović, Dunja and Živanović, Marko and Stanković, Marija and Griskova-Bulanova, Inga and Filipović, Saša",
year = "2022",
abstract = "Non-invasive brain stimulation (NIBS) methods have gained increased interest in research and therapy of associative memory (AM) and its impairments. However, the one-size-fits-all approach yields inconsistent findings, thus putting forward the need for electroencephalography (EEG)-guided personalized frequency-modulated NIBS protocols to increase the focality and the effectiveness of the interventions. Still, extraction of individual frequency, especially in the theta band, turned out to be a challenging task. Here we present an approach to extracting the individual theta-band frequency (ITF) from EEG signals recorded during the AM task. The method showed a 93% success rate, good reliability, and the full range of variability of the extracted ITFs. This paper provides a rationale behind the adopted approach and critically evaluates it in comparison to the alternative methods that have been reported in the literature. Finally, we discuss how it could be used as an input parameter for personalized frequency-modulated NIBS approaches—transcranial alternating current stimulation (tACS) and transcranial oscillatory current stimulation (otDCS) directed at AM neuromodulation.",
publisher = "Frontiers Media S.A.",
journal = "Journal of Personalized Medicine",
title = "Determining the Individual Theta Frequency for Associative Memory Targeted Personalized Transcranial Brain Stimulation",
number = "9",
pages = "1367",
volume = "12",
doi = "10.3390/jpm12091367"
}

Bjekić, J., Paunović, D., Živanović, M., Stanković, M., Griskova-Bulanova, I.,& Filipović, S.. (2022). Determining the Individual Theta Frequency for Associative Memory Targeted Personalized Transcranial Brain Stimulation. in Journal of Personalized Medicine
Frontiers Media S.A.., 12(9), 1367.
https://doi.org/10.3390/jpm12091367

Bjekić J, Paunović D, Živanović M, Stanković M, Griskova-Bulanova I, Filipović S. Determining the Individual Theta Frequency for Associative Memory Targeted Personalized Transcranial Brain Stimulation. in Journal of Personalized Medicine. 2022;12(9):1367.
doi:10.3390/jpm12091367 .

Bjekić, Jovana, Paunović, Dunja, Živanović, Marko, Stanković, Marija, Griskova-Bulanova, Inga, Filipović, Saša, "Determining the Individual Theta Frequency for Associative Memory Targeted Personalized Transcranial Brain Stimulation" in Journal of Personalized Medicine, 12, no. 9 (2022):1367,
https://doi.org/10.3390/jpm12091367 . .

TY  - GEN
AU  - Bjekić, Jovana
AU  - Paunović, Dunja
AU  - Živanović, Marko
AU  - Stanković, Marija
AU  - Griškova-Bulanova, Inga
AU  - Filipović, Saša
PY  - 2022
UR  - http://rimi.imi.bg.ac.rs/handle/123456789/1356
AB  - Non-invasive brain stimulation (NIBS) has gained increased interest in research and therapy of associative memory (AM) and its impairments. However, the one-size-fits-all approach yields inconsistent findings, thus putting forward the need for the development of personalized frequency-modulated NIBS protocols to increase the focality and the effectiveness of the interventions. There have been only a few attempts to deliver theta frequency-personalized tES. The current study explores the feasibility of determining dominant individual theta-band frequency (ITF) based on AM task evoked EEG activity. In a sample of 42 healthy young adults, we extracted the frequencies (2-15 Hz, in 0.5 Hz steps) with the highest event-related spectral perturbation from the EEG recorded during successful encoding in the AM task. The developed method for extraction of the dominant theta-band frequency based on the AM-evoked EEG changes is able to reliably determine the AM-related ITF and can be used for personalization of the oscillatory NIBS techniques.
PB  - Cold Spring Harbor Laboratory
T2  - bioRxiv
T1  - Extraction of individual associative memory related dominant theta frequency for personalized transcranial brain stimulation
DO  - 10.1101/2022.03.07.483124
ER  - 

@misc{
author = "Bjekić, Jovana and Paunović, Dunja and Živanović, Marko and Stanković, Marija and Griškova-Bulanova, Inga and Filipović, Saša",
year = "2022",
abstract = "Non-invasive brain stimulation (NIBS) has gained increased interest in research and therapy of associative memory (AM) and its impairments. However, the one-size-fits-all approach yields inconsistent findings, thus putting forward the need for the development of personalized frequency-modulated NIBS protocols to increase the focality and the effectiveness of the interventions. There have been only a few attempts to deliver theta frequency-personalized tES. The current study explores the feasibility of determining dominant individual theta-band frequency (ITF) based on AM task evoked EEG activity. In a sample of 42 healthy young adults, we extracted the frequencies (2-15 Hz, in 0.5 Hz steps) with the highest event-related spectral perturbation from the EEG recorded during successful encoding in the AM task. The developed method for extraction of the dominant theta-band frequency based on the AM-evoked EEG changes is able to reliably determine the AM-related ITF and can be used for personalization of the oscillatory NIBS techniques.",
publisher = "Cold Spring Harbor Laboratory",
journal = "bioRxiv",
title = "Extraction of individual associative memory related dominant theta frequency for personalized transcranial brain stimulation",
doi = "10.1101/2022.03.07.483124"
}

Bjekić, J., Paunović, D., Živanović, M., Stanković, M., Griškova-Bulanova, I.,& Filipović, S.. (2022). Extraction of individual associative memory related dominant theta frequency for personalized transcranial brain stimulation. in bioRxiv
Cold Spring Harbor Laboratory..
https://doi.org/10.1101/2022.03.07.483124

Bjekić J, Paunović D, Živanović M, Stanković M, Griškova-Bulanova I, Filipović S. Extraction of individual associative memory related dominant theta frequency for personalized transcranial brain stimulation. in bioRxiv. 2022;.
doi:10.1101/2022.03.07.483124 .

Bjekić, Jovana, Paunović, Dunja, Živanović, Marko, Stanković, Marija, Griškova-Bulanova, Inga, Filipović, Saša, "Extraction of individual associative memory related dominant theta frequency for personalized transcranial brain stimulation" in bioRxiv (2022),
https://doi.org/10.1101/2022.03.07.483124 . .

TY  - CONF
AU  - Vulić, Katarina
AU  - Bajada, Claude
AU  - Paunović, Dunja
AU  - Bjekić, Jovana
AU  - Filipović, Saša
AU  - Sandberg, Kristian
PY  - 2022
UR  - http://rimi.imi.bg.ac.rs/handle/123456789/1358
AB  - The hippocampus (HC) is traditionally considered the key neuroanatomical hub responsible for memory. However, previous MRI studies that aimed to relate volumetric hippocampal measures to associative memory (AM) performance have yielded mixed results. In the current study, we aimed to reevaluate these findings in a large sample of young healthy participants (N = 246; age M = 24.95, SD = 4.58; 56% female). Participants were scanned with 3T MAGNETOM Prisma using a 64-channel head coil, followed by the AM assessment in the lab setting. To maximize the scope of AM assessment, we employed four paired-associate tasks of various stimuli modalities (faces, words, scenes) and outcome measure types (recognition, recall). Synthetic T1-weighted images were produced out of relaxometry parameter maps, after which volumetric measures were 
calculated using FreeSurfer. The whole HC volume showed no correlation with any of the memory measures. However, further segmentation of HC into its functional and anatomical subfields (Parasubiculum, Presubiculum, Subiculum, CA1, CA2/3, CA4, GC-DG, HATA, Fimbria, Molecular layer, Hippocampal fissure, Hippocampal tail) showed scattered yet consistent patterns of significant correlations between different subfield volumes and memory outcomes. The results suggest that distinctive contributions of HC subfields may lead to a null effect when the whole HC volume is considered, thus demonstrating that drawing conclusions based on the volumetric measures of neural macrostructures can be misleading. The results highlight the importance of in-depth segmentation for neural mapping.
C3  - FENS Forum 2022, E-Book of Abstracts, 09-13th July, Paris, France
T1  - On the importance of hippocampal segmentation for the neural mapping of memory: Evidence from a large-scale study of neural architecture in healthy adults
UR  - https://hdl.handle.net/21.15107/rcub_rimi_1358
ER  - 

@conference{
author = "Vulić, Katarina and Bajada, Claude and Paunović, Dunja and Bjekić, Jovana and Filipović, Saša and Sandberg, Kristian",
year = "2022",
abstract = "The hippocampus (HC) is traditionally considered the key neuroanatomical hub responsible for memory. However, previous MRI studies that aimed to relate volumetric hippocampal measures to associative memory (AM) performance have yielded mixed results. In the current study, we aimed to reevaluate these findings in a large sample of young healthy participants (N = 246; age M = 24.95, SD = 4.58; 56% female). Participants were scanned with 3T MAGNETOM Prisma using a 64-channel head coil, followed by the AM assessment in the lab setting. To maximize the scope of AM assessment, we employed four paired-associate tasks of various stimuli modalities (faces, words, scenes) and outcome measure types (recognition, recall). Synthetic T1-weighted images were produced out of relaxometry parameter maps, after which volumetric measures were 
calculated using FreeSurfer. The whole HC volume showed no correlation with any of the memory measures. However, further segmentation of HC into its functional and anatomical subfields (Parasubiculum, Presubiculum, Subiculum, CA1, CA2/3, CA4, GC-DG, HATA, Fimbria, Molecular layer, Hippocampal fissure, Hippocampal tail) showed scattered yet consistent patterns of significant correlations between different subfield volumes and memory outcomes. The results suggest that distinctive contributions of HC subfields may lead to a null effect when the whole HC volume is considered, thus demonstrating that drawing conclusions based on the volumetric measures of neural macrostructures can be misleading. The results highlight the importance of in-depth segmentation for neural mapping.",
journal = "FENS Forum 2022, E-Book of Abstracts, 09-13th July, Paris, France",
title = "On the importance of hippocampal segmentation for the neural mapping of memory: Evidence from a large-scale study of neural architecture in healthy adults",
url = "https://hdl.handle.net/21.15107/rcub_rimi_1358"
}

Vulić, K., Bajada, C., Paunović, D., Bjekić, J., Filipović, S.,& Sandberg, K.. (2022). On the importance of hippocampal segmentation for the neural mapping of memory: Evidence from a large-scale study of neural architecture in healthy adults. in FENS Forum 2022, E-Book of Abstracts, 09-13th July, Paris, France.
https://hdl.handle.net/21.15107/rcub_rimi_1358

Vulić K, Bajada C, Paunović D, Bjekić J, Filipović S, Sandberg K. On the importance of hippocampal segmentation for the neural mapping of memory: Evidence from a large-scale study of neural architecture in healthy adults. in FENS Forum 2022, E-Book of Abstracts, 09-13th July, Paris, France. 2022;.
https://hdl.handle.net/21.15107/rcub_rimi_1358 .

Vulić, Katarina, Bajada, Claude, Paunović, Dunja, Bjekić, Jovana, Filipović, Saša, Sandberg, Kristian, "On the importance of hippocampal segmentation for the neural mapping of memory: Evidence from a large-scale study of neural architecture in healthy adults" in FENS Forum 2022, E-Book of Abstracts, 09-13th July, Paris, France (2022),
https://hdl.handle.net/21.15107/rcub_rimi_1358 .

TY  - JOUR
AU  - Vulić, Katarina
AU  - Bjekić, Jovana
AU  - Paunović, Dunja
AU  - Jovanović, Miloš
AU  - Milanović, Slađan
AU  - Filipović, Saša
PY  - 2021
UR  - http://rimi.imi.bg.ac.rs/handle/123456789/1087
AB  - Associative memory (AM) reflects the ability to remember and retrieve multiple pieces of information bound together thus enabling complex episodic experiences. Despite growing interest in the use of transcranial direct current stimulation (tDCS) for the modulation of AM, there are inconsistent evidence regarding its benefits. An alternative to standard constant tDCS could be the application of frequency-modulated tDCS protocols, that mimic natural function-relevant brain rhythms. Here, we show the effects of anodal tDCS oscillating in theta rhythm (5 Hz; 1.5 ± 0.1 mA) versus constant anodal tDCS and sham over left posterior parietal cortex on cued recall of face-word associations. In a crossover design, each participant completed AM assessment immediately following 20-min theta-oscillatory, constant, and sham tDCS, as well as 1 and 5 days after. Theta oscillatory tDCS increased initial AM performance in comparison to sham, and so did constant tDCS. On the group level, no differences between oscillatory and constant tDCS were observed, but individual-level analysis revealed that some participants responded to theta-oscillatory but not to constant tDCS, and vice versa, which could be attributed to their different physiological modes of action. This study shows the potential of oscillatory tDCS protocols for memory enhancement to produce strong and reliable memory-modulating effects which deserve to be investigated further.
T2  - Scientific Reports
T1  - Theta-modulated oscillatory transcranial direct current stimulation over posterior parietal cortex improves associative memory
IS  - 1
SP  - 3013
VL  - 11
DO  - 10.1038/s41598-021-82577-7
ER  - 

@article{
author = "Vulić, Katarina and Bjekić, Jovana and Paunović, Dunja and Jovanović, Miloš and Milanović, Slađan and Filipović, Saša",
year = "2021",
abstract = "Associative memory (AM) reflects the ability to remember and retrieve multiple pieces of information bound together thus enabling complex episodic experiences. Despite growing interest in the use of transcranial direct current stimulation (tDCS) for the modulation of AM, there are inconsistent evidence regarding its benefits. An alternative to standard constant tDCS could be the application of frequency-modulated tDCS protocols, that mimic natural function-relevant brain rhythms. Here, we show the effects of anodal tDCS oscillating in theta rhythm (5 Hz; 1.5 ± 0.1 mA) versus constant anodal tDCS and sham over left posterior parietal cortex on cued recall of face-word associations. In a crossover design, each participant completed AM assessment immediately following 20-min theta-oscillatory, constant, and sham tDCS, as well as 1 and 5 days after. Theta oscillatory tDCS increased initial AM performance in comparison to sham, and so did constant tDCS. On the group level, no differences between oscillatory and constant tDCS were observed, but individual-level analysis revealed that some participants responded to theta-oscillatory but not to constant tDCS, and vice versa, which could be attributed to their different physiological modes of action. This study shows the potential of oscillatory tDCS protocols for memory enhancement to produce strong and reliable memory-modulating effects which deserve to be investigated further.",
journal = "Scientific Reports",
title = "Theta-modulated oscillatory transcranial direct current stimulation over posterior parietal cortex improves associative memory",
number = "1",
pages = "3013",
volume = "11",
doi = "10.1038/s41598-021-82577-7"
}

Vulić, K., Bjekić, J., Paunović, D., Jovanović, M., Milanović, S.,& Filipović, S.. (2021). Theta-modulated oscillatory transcranial direct current stimulation over posterior parietal cortex improves associative memory. in Scientific Reports, 11(1), 3013.
https://doi.org/10.1038/s41598-021-82577-7

Vulić K, Bjekić J, Paunović D, Jovanović M, Milanović S, Filipović S. Theta-modulated oscillatory transcranial direct current stimulation over posterior parietal cortex improves associative memory. in Scientific Reports. 2021;11(1):3013.
doi:10.1038/s41598-021-82577-7 .

Vulić, Katarina, Bjekić, Jovana, Paunović, Dunja, Jovanović, Miloš, Milanović, Slađan, Filipović, Saša, "Theta-modulated oscillatory transcranial direct current stimulation over posterior parietal cortex improves associative memory" in Scientific Reports, 11, no. 1 (2021):3013,
https://doi.org/10.1038/s41598-021-82577-7 . .

TY  - JOUR
AU  - Balint, Bela
AU  - Paunović, Dunja
AU  - Vucetić, D
AU  - Vojvodić, Danilo
AU  - Petakov, Marijana
AU  - Trkuljić, M
AU  - Stojanović, N.
PY  - 2006
UR  - http://rimi.imi.bg.ac.rs/handle/123456789/129
AB  - BACKGROUND: Cryobiologic variables responsible for cell injuries and freezing techniques applicable in medical cryopractice should be revised and/or reengineered for minimizing cryoinjuries and maximizing cell recovery. In this study, the efficacy of different cryopreservation protocols based on platelet (PLT) recovery was evaluated. STUDY DESIGN AND METHODS: PLTs (n = 33) were prepared from whole-blood units. Cell count and viability, PLT morphologic score (PMS), and hypotonic shock response were determined. PLT surface antigens were measured by flow cytometry. Controlled-rate (with compensated fusion heat) and uncontrolled-rate freezing methods combined with 6 percent dimethyl sulfoxide were used. RESULTS: PLT recovery was superior in the controlled-rate setting (91.0 +/- 5.5 vs. 86.0 +/- 6.5; p  lt  0.05). PMS was significantly better in controlled-rate freezing (p  lt  0.01). GPIb/CD42b expression was reduced in both freezing groups versus control. GP140/CD62p expression was significantly (p  lt  0.05) lower in the controlled-rate group and in both frozen groups was significantly higher than in the control groups. CONCLUSION: The use of strictly equalized (1 degrees C/min) controlled-rate freezing, combined with an intensified cooling rate (2 degrees C/min) during the liquid-to-solid-phase transition period, allows advanced quantitative and qualitative PLT recovery, even though the minor intergroup differences for some variables were observed.
PB  - Wiley, Hoboken
T2  - Transfusion
T1  - Controlled-rate versus uncontrolled-rate freezing as predictors for platelet cryopreservation efficacy
EP  - 235
IS  - 2
SP  - 230
VL  - 46
DO  - 10.1111/j.1537-2995.2006.00706.x
ER  - 

@article{
author = "Balint, Bela and Paunović, Dunja and Vucetić, D and Vojvodić, Danilo and Petakov, Marijana and Trkuljić, M and Stojanović, N.",
year = "2006",
abstract = "BACKGROUND: Cryobiologic variables responsible for cell injuries and freezing techniques applicable in medical cryopractice should be revised and/or reengineered for minimizing cryoinjuries and maximizing cell recovery. In this study, the efficacy of different cryopreservation protocols based on platelet (PLT) recovery was evaluated. STUDY DESIGN AND METHODS: PLTs (n = 33) were prepared from whole-blood units. Cell count and viability, PLT morphologic score (PMS), and hypotonic shock response were determined. PLT surface antigens were measured by flow cytometry. Controlled-rate (with compensated fusion heat) and uncontrolled-rate freezing methods combined with 6 percent dimethyl sulfoxide were used. RESULTS: PLT recovery was superior in the controlled-rate setting (91.0 +/- 5.5 vs. 86.0 +/- 6.5; p  lt  0.05). PMS was significantly better in controlled-rate freezing (p  lt  0.01). GPIb/CD42b expression was reduced in both freezing groups versus control. GP140/CD62p expression was significantly (p  lt  0.05) lower in the controlled-rate group and in both frozen groups was significantly higher than in the control groups. CONCLUSION: The use of strictly equalized (1 degrees C/min) controlled-rate freezing, combined with an intensified cooling rate (2 degrees C/min) during the liquid-to-solid-phase transition period, allows advanced quantitative and qualitative PLT recovery, even though the minor intergroup differences for some variables were observed.",
publisher = "Wiley, Hoboken",
journal = "Transfusion",
title = "Controlled-rate versus uncontrolled-rate freezing as predictors for platelet cryopreservation efficacy",
pages = "235-230",
number = "2",
volume = "46",
doi = "10.1111/j.1537-2995.2006.00706.x"
}

Balint, B., Paunović, D., Vucetić, D., Vojvodić, D., Petakov, M., Trkuljić, M.,& Stojanović, N.. (2006). Controlled-rate versus uncontrolled-rate freezing as predictors for platelet cryopreservation efficacy. in Transfusion
Wiley, Hoboken., 46(2), 230-235.
https://doi.org/10.1111/j.1537-2995.2006.00706.x

Balint B, Paunović D, Vucetić D, Vojvodić D, Petakov M, Trkuljić M, Stojanović N. Controlled-rate versus uncontrolled-rate freezing as predictors for platelet cryopreservation efficacy. in Transfusion. 2006;46(2):230-235.
doi:10.1111/j.1537-2995.2006.00706.x .

Balint, Bela, Paunović, Dunja, Vucetić, D, Vojvodić, Danilo, Petakov, Marijana, Trkuljić, M, Stojanović, N., "Controlled-rate versus uncontrolled-rate freezing as predictors for platelet cryopreservation efficacy" in Transfusion, 46, no. 2 (2006):230-235,
https://doi.org/10.1111/j.1537-2995.2006.00706.x . .