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Reliability and reproducibility of individual differences in functional connectivity acquired during task and resting state.

Shah LM, Cramer JA, Ferguson MA, Birn RM, Anderson JS - Brain Behav (2016)

Bottom Line: Randomly removing up to 50% of time points had little effect on reliability, while truncating an acquisition was associated with decreased reliability.This study found systematic differences in group-mean connectivity acquired during task and rest acquitisions and preserved individual differences in connectivity due to intrinsic differences in an individual's brain activity and structural brain architecture.Longer scans may be facilitated by acquisition during task paradigms, which will systematically affect functional connectivity but may preserve individual differences in connectivity on top of task modulations.

View Article: PubMed Central - PubMed

Affiliation: Department of Radiology University of Utah Salt Lake City Utah 84132.

ABSTRACT

Objectives: Application of fMRI connectivity metrics as diagnostic biomarkers at the individual level will require reliability, sensitivity and specificity to longitudinal changes in development, aging, neurocognitive, and behavioral performance and pathologies. Such metrics have not been well characterized for recent advances in BOLD acquisition.

Experimental design: Analysis of multiband BOLD data from the HCP 500 Subjects Release was performed with FIX ICA and with WM, CSF and motion parameter regression. Analysis with ROIs covering the gray matter at 5 mm resolution was performed to assess functional connectivity. ROIs in key areas were used to demonstrate statistical differences between specific connections. Reproducibility of group-mean functional connectivity and for single connections for individuals was evaluated for both resting state and task acquisitions.

Principal observations: Systematic differences in group-mean connectivity were demonstrated during task and rest and during different tasks, although individual differences in connectivity were maintained. Reproducibility of a single connection for a subject and across subjects for resting and task acquisition was demonstrated to be a linear function of the square root of imaging time. Randomly removing up to 50% of time points had little effect on reliability, while truncating an acquisition was associated with decreased reliability. Reliability was highest within the cortex, and lowest for deep gray nuclei, gray-white junction, and near large sulci.

Conclusions: This study found systematic differences in group-mean connectivity acquired during task and rest acquitisions and preserved individual differences in connectivity due to intrinsic differences in an individual's brain activity and structural brain architecture. We also show that longer scan times are needed to acquire data on single subjects for information on connections between specific ROIs. Longer scans may be facilitated by acquisition during task paradigms, which will systematically affect functional connectivity but may preserve individual differences in connectivity on top of task modulations.

No MeSH data available.


Related in: MedlinePlus

Preservation of individual differences in connectivity at task and rest. (A) One representative connection (left ACC to left anterior insula) showing for 476 subjects comparison of functional connectivity acquired during 6 tasks (1 acquisition) versus rest (60 min). (B) For each connection, the correlation across 476 subjects was computed for 264 × 264 ROIs. Error bars show standard deviation across connections. Correlation across subjects improves with the square root of imaging time of the shortest sequence.
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brb3456-fig-0005: Preservation of individual differences in connectivity at task and rest. (A) One representative connection (left ACC to left anterior insula) showing for 476 subjects comparison of functional connectivity acquired during 6 tasks (1 acquisition) versus rest (60 min). (B) For each connection, the correlation across 476 subjects was computed for 264 × 264 ROIs. Error bars show standard deviation across connections. Correlation across subjects improves with the square root of imaging time of the shortest sequence.

Mentions: To address this question, we measured the correlation coefficient across subjects for each individual connection acquired during two different task or resting acquisitions. This probes whether subjects that show particularly strong connectivity in a given connection might also show relatively strong connectivity for the same connection during a different task compared to other subjects. As an example, Figure 5A shows a single connection from the left anterior cingulate cortex to the left anterior insula correlation across all subjects, acquired during each task compared to acquisition during resting state. The significant correlation across subjects for a specific connection between rest and task is evidence that individual differences in connectivity persist during rest and task acquisitions. Regardless of which task was performed, differences in connectivity for that individual compared to other subjects may be expected to be similar regardless of the task condition. In other words, the same connections tend to show higher or lower functional connectivity in the same subjects whether data were acquired during a resting state or task condition.


Reliability and reproducibility of individual differences in functional connectivity acquired during task and resting state.

Shah LM, Cramer JA, Ferguson MA, Birn RM, Anderson JS - Brain Behav (2016)

Preservation of individual differences in connectivity at task and rest. (A) One representative connection (left ACC to left anterior insula) showing for 476 subjects comparison of functional connectivity acquired during 6 tasks (1 acquisition) versus rest (60 min). (B) For each connection, the correlation across 476 subjects was computed for 264 × 264 ROIs. Error bars show standard deviation across connections. Correlation across subjects improves with the square root of imaging time of the shortest sequence.
© Copyright Policy - creativeCommonsBy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4814225&req=5

brb3456-fig-0005: Preservation of individual differences in connectivity at task and rest. (A) One representative connection (left ACC to left anterior insula) showing for 476 subjects comparison of functional connectivity acquired during 6 tasks (1 acquisition) versus rest (60 min). (B) For each connection, the correlation across 476 subjects was computed for 264 × 264 ROIs. Error bars show standard deviation across connections. Correlation across subjects improves with the square root of imaging time of the shortest sequence.
Mentions: To address this question, we measured the correlation coefficient across subjects for each individual connection acquired during two different task or resting acquisitions. This probes whether subjects that show particularly strong connectivity in a given connection might also show relatively strong connectivity for the same connection during a different task compared to other subjects. As an example, Figure 5A shows a single connection from the left anterior cingulate cortex to the left anterior insula correlation across all subjects, acquired during each task compared to acquisition during resting state. The significant correlation across subjects for a specific connection between rest and task is evidence that individual differences in connectivity persist during rest and task acquisitions. Regardless of which task was performed, differences in connectivity for that individual compared to other subjects may be expected to be similar regardless of the task condition. In other words, the same connections tend to show higher or lower functional connectivity in the same subjects whether data were acquired during a resting state or task condition.

Bottom Line: Randomly removing up to 50% of time points had little effect on reliability, while truncating an acquisition was associated with decreased reliability.This study found systematic differences in group-mean connectivity acquired during task and rest acquitisions and preserved individual differences in connectivity due to intrinsic differences in an individual's brain activity and structural brain architecture.Longer scans may be facilitated by acquisition during task paradigms, which will systematically affect functional connectivity but may preserve individual differences in connectivity on top of task modulations.

View Article: PubMed Central - PubMed

Affiliation: Department of Radiology University of Utah Salt Lake City Utah 84132.

ABSTRACT

Objectives: Application of fMRI connectivity metrics as diagnostic biomarkers at the individual level will require reliability, sensitivity and specificity to longitudinal changes in development, aging, neurocognitive, and behavioral performance and pathologies. Such metrics have not been well characterized for recent advances in BOLD acquisition.

Experimental design: Analysis of multiband BOLD data from the HCP 500 Subjects Release was performed with FIX ICA and with WM, CSF and motion parameter regression. Analysis with ROIs covering the gray matter at 5 mm resolution was performed to assess functional connectivity. ROIs in key areas were used to demonstrate statistical differences between specific connections. Reproducibility of group-mean functional connectivity and for single connections for individuals was evaluated for both resting state and task acquisitions.

Principal observations: Systematic differences in group-mean connectivity were demonstrated during task and rest and during different tasks, although individual differences in connectivity were maintained. Reproducibility of a single connection for a subject and across subjects for resting and task acquisition was demonstrated to be a linear function of the square root of imaging time. Randomly removing up to 50% of time points had little effect on reliability, while truncating an acquisition was associated with decreased reliability. Reliability was highest within the cortex, and lowest for deep gray nuclei, gray-white junction, and near large sulci.

Conclusions: This study found systematic differences in group-mean connectivity acquired during task and rest acquitisions and preserved individual differences in connectivity due to intrinsic differences in an individual's brain activity and structural brain architecture. We also show that longer scan times are needed to acquire data on single subjects for information on connections between specific ROIs. Longer scans may be facilitated by acquisition during task paradigms, which will systematically affect functional connectivity but may preserve individual differences in connectivity on top of task modulations.

No MeSH data available.


Related in: MedlinePlus