Interaction Between Memory Load and Experimental Design on Brain Connectivity and Network Topology.
Heming Zhang1, Xin Di2, Bart Rypma3
1The Clinical Hospital of Chengdu Brain Science Institute, MOE Key Laboratory for Neuroinformation, Center for Information in Medicine, School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu, 611731, China.
Neuroscience Bulletin
|December 24, 2022
Summary
Continuous task design in functional magnetic resonance imaging (fMRI) offers a purer blood oxygen-level-dependent signal for assessing brain connectivity. This design reveals more subtle brain-behavioral relationships than traditional block designs.
Area of Science:
- Neuroscience
- Cognitive Neuroscience
- Neuroimaging
Background:
- Functional connectivity analysis in task-based functional magnetic resonance imaging (fMRI) traditionally uses block designs, which can compromise blood oxygen-level-dependent (BOLD) signal purity.
- Continuous designs, using single long runs of a single task condition, offer a potentially purer signal for assessing task-related functional connectivity.
- The comparative influence of block versus continuous designs on functional connectivity networks remains unclear.
Purpose of the Study:
- To differentiate the effects of block versus continuous designs on task-related functional connectivity networks.
- To investigate the impact of working memory load on these networks.
- To examine the interaction between design type and working memory load on brain activity and connectivity.
Main Methods:
- Utilized a repeated-measures analysis of variance (ANOVA) to analyze data from 50 healthy young adults.
- Compared behavioral data (accuracy, reaction time) and neuroimaging data (functional connectivity, network topology) between block and continuous designs under varying working memory loads.
- Focused on cingulo-opercular, fronto-parietal, and default mode networks.
Main Results:
- Behavioral analysis showed significant main effects of design and load, along with an interaction effect on accuracy and reaction time.
- Neuroimaging revealed significant main effects of design and load, and their interaction, on intra- and inter-network functional connectivity and global network topology within key brain networks.
- A significant association between behavior and brain activity was observed specifically for the continuous design.
Conclusions:
- Continuous task design provides a valuable method for studying task-related functional connectivity with potentially enhanced BOLD signal purity.
- This design is sensitive to variations in working memory load and their effects on brain network organization.
- Continuous designs facilitate the identification of subtle brain-behavioral relationships, advancing our understanding of cognitive neuroscience.
Keywords:
Block designContinuous designFunctional connectivityMemory loadNetwork topologyWorking memory
