Poster No:
844
Submission Type:
Abstract Submission
Authors:
Bi Zhu1, Jiahui Zhang1, Xuhao Shao1
Institutions:
1Beijing Normal University, Beijing, Beijing
First Author:
Bi Zhu
Beijing Normal University
Beijing, Beijing
Co-Author(s):
Xuhao Shao
Beijing Normal University
Beijing, Beijing
Introduction:
As image-based misinformation, fake photos can create false memories (Schacter, 2022). For example, a witness saw a thief put money in the shirt pocket, later saw the thief put money in the pants pocket in a fake image, and then falsely remembered seeing the thief put money in the pants pocket in the original event. A study using fMRI showed that the left hippocampal tail had higher neural activity for true memories than false memories when photos of events were first seen, but lower activity when fake photos of these events were later seen (Okado & Stark, 2005). However, it has been unclear whether witnesses are able to reactivate their representations of original event details when seeing fake photos. This study used fMRI and cross-stage inter-subject neural pattern similarity analyses to investigate which brain regions reactivate neural signals of original event details when witnesses see a fake photo.
Methods:
A total of 33 healthy university students completed the experiment. Functional magnetic resonance imaging (fMRI) data were obtained from all subjects at two stages (i.e., the original-event stage and the misinformation stage, separated by 3 hours). The experimental materials were taken from our previous study (Shao et al., 2023). Of the 400 photos of the 8 events seen by each subject at each stage, there were two versions of 96 critical photos. These two versions differ only in details. Half of the subjects saw version A of the photos at the original-event stage and version B at the misinformation stage. The other half of the subjects saw version B of the photos at the original-event stage and version A at the misinformation stage. One day later, subjects completed recognition tests based on what they saw for the first time. For example, a subject saw version A of the photo at the original-event stage (e.g., a thief put money in the shirt pocket), and then saw the version B of the photo (e.g., a thief put money in the pants pocket). True memory is when this subject reports seeing a thief put money in the shirt pocket, whereas false memory is when this subject reports seeing a thief put money in the pants pocket at the original-event stage. To examine neural representations of event details shared across subjects at the original-event stage, we computed the neural pattern similarity between subjects who saw the same version and compared it to those who saw different versions. To investigate neural reactivations of event details, we computed the neural pattern similarity between subjects seeing the fake photo at the misinformation stage and other subjects seeing the original photo at the original-event stage. They were computed separately for subjects presented with the same version and for subjects presented with different versions, and the two were compared. For example, if a subject's neural pattern when seeing version B of a photo at the misinformation stage is more similar to the neural pattern of other subjects when seeing version A rather than version B of the photo at the original-event stage, then it represents the neural reactivation of original event details.
Results:
During the original-event stage, neural representations of event details in the visual cortex are shared across subjects, for both true and false memories. During the post-event misinformation stage, neural reactivations of original event details in the parietal cortex are shared across subjects, for true memory but not for false memory.
Conclusions:
When eyewitnesses first see an event, neural representations of the original event details in the visual cortex are shared between eyewitnesses, regardless of whether the later reported memory is true or false. However, when eyewitnesses are subsequently exposed to fake photos, their parietal cortex reactivates neural signals about the original event details, which may help to counteract image-based misinformation and thus report true memory.
Learning and Memory:
Long-Term Memory (Episodic and Semantic) 1
Modeling and Analysis Methods:
Multivariate Approaches
Novel Imaging Acquisition Methods:
BOLD fMRI 2
Keywords:
FUNCTIONAL MRI
Memory
1|2Indicates the priority used for review
By submitting your proposal, you grant permission for the Organization for Human Brain Mapping (OHBM) to distribute your work in any format, including video, audio print and electronic text through OHBM OnDemand, social media channels, the OHBM website, or other electronic publications and media.
I accept
The Open Science Special Interest Group (OSSIG) is introducing a reproducibility challenge for OHBM 2025. This new initiative aims to enhance the reproducibility of scientific results and foster collaborations between labs. Teams will consist of a “source” party and a “reproducing” party, and will be evaluated on the success of their replication, the openness of the source work, and additional deliverables. Click here for more information.
Propose your OHBM abstract(s) as source work for future OHBM meetings by selecting one of the following options:
I do not want to participate in the reproducibility challenge.
Please indicate below if your study was a "resting state" or "task-activation” study.
Task-activation
Healthy subjects only or patients (note that patient studies may also involve healthy subjects):
Healthy subjects
Was this research conducted in the United States?
No
Were any human subjects research approved by the relevant Institutional Review Board or ethics panel?
NOTE: Any human subjects studies without IRB approval will be automatically rejected.
Yes
Were any animal research approved by the relevant IACUC or other animal research panel?
NOTE: Any animal studies without IACUC approval will be automatically rejected.
Not applicable
Please indicate which methods were used in your research:
Functional MRI
Behavior
For human MRI, what field strength scanner do you use?
3.0T
Which processing packages did you use for your study?
FSL
Provide references using APA citation style.
Okado, Y., & Stark, C. E. (2005). Neural activity during encoding predicts false memories created by misinformation. Learning & Memory, 12(1), 3–11.
Schacter, D. L. (2022). Memory sins in applied settings: What kind of progress? Journal of Applied Research in Memory and Cognition, 11(4), 445–460.
Shao, X., Li, A., Chen, C., Loftus, E. F., & Zhu, B. (2023). Cross-stage neural pattern similarity in the hippocampus predicts false memory derived from post-event inaccurate information. Nature Communications, 14(1), 2299.
No