Task-based functional connectivity during mnemonic discrimination and cognitive training effects
Poster No:
1074
Submission Type:
Abstract Submission
Authors:
Panagiotis Iliopoulos1, Jeremie Güsten1, Eoin Molloy2,3, Anne Maass2, Emrah Düzel1,2
Institutions:
1Institute of Cognitive Neurology and Dementia Research, Otto-von-Guericke University, Magdeburg, Germany, 2German Center of Neurodegenerative Diseases (DZNE), Magdeburg, Germany, 3Division of Nuclear Medicine, Department of Radiology & Nuclear Medicine, Faculty of Medicine, Otto von Guericke University, Magdeburg, Germany
First Author:
Panagiotis Iliopoulos
Institute of Cognitive Neurology and Dementia Research, Otto-von-Guericke University
Magdeburg, Germany
Institute of Cognitive Neurology and Dementia Research, Otto-von-Guericke University
Magdeburg, Germany
Co-Author(s):
Jeremie Güsten
Institute of Cognitive Neurology and Dementia Research, Otto-von-Guericke University
Magdeburg, Germany
Institute of Cognitive Neurology and Dementia Research, Otto-von-Guericke University
Magdeburg, Germany
Eoin Molloy, PhD
German Center of Neurodegenerative Diseases (DZNE)|Division of Nuclear Medicine, Department of Radiology & Nuclear Medicine, Faculty of Medicine, Otto von Guericke University
Magdeburg, Germany|Magdeburg, Germany
German Center of Neurodegenerative Diseases (DZNE)|Division of Nuclear Medicine, Department of Radiology & Nuclear Medicine, Faculty of Medicine, Otto von Guericke University
Magdeburg, Germany|Magdeburg, Germany
Emrah Düzel
Institute of Cognitive Neurology and Dementia Research, Otto-von-Guericke University|German Center of Neurodegenerative Diseases (DZNE)
Magdeburg, Germany|Magdeburg, Germany
Institute of Cognitive Neurology and Dementia Research, Otto-von-Guericke University|German Center of Neurodegenerative Diseases (DZNE)
Magdeburg, Germany|Magdeburg, Germany
Introduction:
Successful memory relies on the process of mnemonic discrimination (MD) to establish distinct representations1,4,5,9. Despite extensive research on the role of medial temporal lobe (MTL) areas in MD2,4,9, little is known about MTL interactions with prefrontal (PFC) and visual (VIS) areas and the impact of cognitive training on functional communication and MD performance. Here, we investigated the task-based functional connectivity underlying MD, focusing on major MTL-PFC-VIS areas, in addition to the effects of a 2-week cognitive training intervention on connectivity and behavior.
Methods:
In a longitudinal study, 54 young adults (M = 23.76 years, SD = 3.35, 61.11% female) underwent a cognitive task differentiating similar objects and scenes ('lures'; correct response: 'new') from repeated items ('repeats', correct response: 'old'). Stimuli were presented in 12-item sequences with the first six being new images, while each of the subsequent six could be either a lure or a repeat trial (Fig.1). Data were acquired on a 3T-MRI Siemens scanner, using a BOLD-EPI (2 runs x 12 min; resolution 2 mm isotropic, TR= 2.2 secs) and MPRAGE sequence (1 mm isotropic), pre- and post- a 2-week web-based cognitive training intervention (three 45-minute sessions per week). Participants were divided into an experimental group (n=26) that underwent training using a web-based version of the task, and an active control group (n=27) that was presented with the same set of stimuli but performed a psychomotor task clicking on moving icons on top of the images. Data were preprocessed using the fMRIPrep pipeline3, denoised and modeled with generalized psychophysiological interaction (gPPI) analysis6,8.All fMRI analyses focused on the MD contrast (correct lures versus repeats). First, we performed a hypothesis-driven region of interest (ROI)-to-ROI analysis on the whole-sample pre-training data. Major MTL, PFC, VIS regions were used as ROIs. Time x Group interaction analyses (ANOVA) assessed cognitive training effects on memory performance and the task-based functional connections identified in the previous step. Gender and age were used as covariates.
·Figure 1. Experimental Design
Results:
In the whole-sample pre-training analysis, we identified three significant connectivity clusters during successful MD (cluster-based inference p < .05 p-FDR): 1) reduced VIS-to-VIS and VIS-MTL connectivity, and increased 2) VIS-PFC and 3) hippocampal-PFC connectivity (Fig.2A). Focusing on the individual connections within these three clusters, we found a significant training effect (MD contrast, Time x Group interaction: F(1,49)=10.00, η2p = .170, p-FDR=.016) observing post-training increase in task connectivity specifically from the lateral occipital cortex (LOC) to the occipital pole (OP) (Fig.2B, 2C). Notably, Time x Group interaction analyses indicated that the training group exhibited improved memory performance after training, reflected in higher discriminability (A') (F(1,49) = 9.34, η2p = .160, p=.004) and improved correct lure performance (F(1,49) = 15.73, η2p = .243, p<.001) compared to the control group (Fig.2D).
·Figure 2. Results
Conclusions:
Our results highlight the role of VIS-to-VIS, VIS-MTL, VIS-PFC, and PFC-hippocampal connectivity during successful MD. They extend previous findings that involve wider networks in MD1,7, suggesting a role of MTL-PFC-VIS connectivity. A brief 2-week cognitive training not only enhanced MD performance but also increased LOC-OP task-based functional connectivity. This suggests improved functional communication from higher to lower-order visual areas, indicating a potential enhancement in neural visual processing. Our findings demonstrate that even a short-duration intervention can induce neural changes, boosting memory performance. Future investigations may test whether more prolonged training yields broader functional alterations in MD.
Learning and Memory:
Long-Term Memory (Episodic and Semantic) 1
Neural Plasticity and Recovery of Function 2
Modeling and Analysis Methods:
Connectivity (eg. functional, effective, structural)
fMRI Connectivity and Network Modeling
Keywords:
FUNCTIONAL MRI
Learning
Memory
Plasticity
Other - cognitive training
1|2Indicates the priority used for review
Provide references using author date format
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