INDUCING REPRESENTATIONAL CHANGE IN THE HIPPOCAMPUS THROUGH REAL-TIME NEUROFEEDBACK

Area of Science:

• Cognitive Neuroscience
• Neuroimaging

Background:

• Neural representations of perceived or remembered items can interact, influencing subsequent perception, attention, and memory.
• These interactions are thought to arise from changes in the overlap of neural representations, particularly in the hippocampus.
• Previous research hypothesized that the degree of coactivation between competing representations dictates whether neural representations integrate or differentiate, but this was indirectly tested.

Approach:

• Used closed-loop neurofeedback with real-time functional magnetic resonance imaging (fMRI) to directly induce coactivation of competing memories in the visual cortex.
• Participants were trained to maximize the neural activation of one object's representation while viewing another object.

Key Points:

• Directly induced coactivation of competing visual memories using real-time fMRI neurofeedback.
• Trained objects showed behavioral and neural integration compared to untrained objects.
• Coactivation led to reduced discriminability in a categorical perception task and decreased neural decodability from hippocampal fMRI patterns.

Conclusions:

• Directly manipulating neural coactivation provides a powerful tool for investigating memory interactions.
• The findings support the hypothesis that coactivation is a critical mechanism driving memory integration.
• This research offers new insights into how the brain manages competing representations and integrates related memories.