Increased functional connectivity between dorsal posterior parietal and ventral occipitotemporal cortex during...

Area of Science:

• Cognitive Neuroscience
• Neuroimaging
• Memory Research

Background:

• Episodic memory retrieval involves complex cognitive operations.
• The posterior parietal cortex (PPC) is increasingly implicated in these retrieval computations.
• Dorsal PPC subregions may differentially contribute to distinct aspects of retrieval decisions.

Purpose of the Study:

• To investigate the role of dorsal PPC subregions in episodic memory retrieval.
• To examine how activation and connectivity within dorsal PPC and with visual cue-processing regions vary with retrieval decision uncertainty.
• To elucidate the basic operations performed by the dorsal PPC during memory retrieval.

Main Methods:

• Functional magnetic resonance imaging (fMRI) was employed to measure brain activity.
• Functional connectivity analyses assessed relationships between brain regions.
• Participants performed a recognition memory task with confidence judgments for visual words.

Main Results:

• Activity in left dorsal PPC subregions dissociated: lateral IPS activity correlated with perceived oldness, while SPL activity increased with decision uncertainty.
• Whole-brain functional connectivity revealed stronger correlations between SPL and the visual word-form area during uncertain decisions.
• These findings link SPL function to the processing of retrieval cues.

Conclusions:

• The superior parietal lobule (SPL) appears to play a role in processing retrieval cues during episodic memory retrieval.
• SPL's involvement may support efforts to enhance mnemonic evidence, particularly under conditions of uncertainty.
• Understanding dorsal PPC subregion contributions advances theories of memory retrieval components.