External Source Monitoring and Reality Monitoring: Meta-Analysis of fMRI Studies

Area of Science:

• Cognitive Neuroscience
• Neuroimaging
• Memory Research

Background:

• Memory for information is intrinsically linked to memory for its origin (source monitoring).
• The precise neural mechanisms underlying source memory monitoring remain incompletely understood.
• Distinguishing between external sources (Source Monitoring, SM) and internal/external origins (Reality Monitoring, RM) are key cognitive processes.

Purpose of the Study:

• To clarify the specific brain structures essential for source memory monitoring using fMRI data.
• To investigate the neural underpinnings of both external source monitoring and reality monitoring.
• To identify overlapping and distinct brain regions involved in SM and RM.

Main Methods:

• An fMRI meta-analysis was conducted on 51 eligible articles selected using PRISMA guidelines.
• Ginger ALE software was employed for data analysis.
• Separate analyses were performed for SM (34 articles) and RM (17 articles) paradigms.

Main Results:

• Concordance between SM and RM was found in 10 clusters, with the largest in the left claustrum and middle frontal gyrus (BA 46, 9, 10).
• SM contrasts revealed seven clusters, notably in the left middle frontal (BA 9) and inferior frontal gyrus (BA 45).
• RM contrasts identified five clusters, with the largest in the left inferior parietal lobule (BA 40) and angular gyrus (BA 39).

Conclusions:

• The findings support neural differentiation between source monitoring and reality monitoring, alongside partial overlap.
• The results contribute to understanding divergent findings in fMRI studies, potentially due to stimulus characteristics.
• This meta-analysis provides a clearer map of the brain regions involved in monitoring the origin of memories.