Hippocampal-striatal functional connectivity supports processing of temporal expectations from associative memory.

Area of Science:

• Neuroscience
• Cognitive Neuroscience
• Neuroimaging

Background:

• The hippocampus and dorsal striatum are involved in temporal processing but with distinct roles.
• Hippocampus: temporal structure of events in memory.
• Striatum: temporal motor preparation and reward anticipation.

Purpose of the Study:

• Investigate striatal cooperation with the hippocampus in processing temporal context of memorized visual associations.
• Examine neural mechanisms underlying implicit temporal expectation formation and violation.

Main Methods:

• Participants implicitly learned temporal expectations for cue-target associations.
• Ultra-high-field 7T functional magnetic resonance imaging (fMRI) was used during testing.
• Temporal expectation violations were introduced during fMRI scanning.

Main Results:

• Reduced activity in hippocampal subfields and putamen when temporal expectations were met versus violated.
• Decreased functional connectivity between hippocampal subfields and the caudate when expectations were violated.
• Psycho-physiological interaction analysis revealed altered network dynamics.

Conclusions:

• The hippocampus and striatum cooperate to process implicit temporal expectations linked to mnemonic associations.
• Findings support a role for the hippocampal-striatal network in temporal associative processing.