Two distinct functional networks for successful resolution of proactive interference.

Area of Science:

• Neuroscience
• Cognitive Neuroscience
• Neuroimaging

Background:

• Proactive interference (PI) impairs new learning due to prior information.
• Cholinergic pathways from the basal forebrain (BF) are crucial for resolving PI in rats.

Purpose of the Study:

• To investigate if humans resolve PI via a functional network involving the medial septum/diagonal band of Broca (MS/DB) nuclei within the BF.
• To identify the neural correlates of PI resolution in humans.

Main Methods:

• Functional magnetic resonance imaging (fMRI) was used to record brain activity in human participants.
• Participants underwent a learning task involving color-paired associates with interfering information.
• Multivariate partial least-squares analysis identified functional networks associated with PI resolution.

Main Results:

• A medial septum/diagonal band of Broca (MS/DB)-dependent network, involving areas for attention and memory (e.g., hippocampus, intraparietal sulcus), correlated with effective PI resolution.
• A second, MS/DB-independent network (including lateral orbitofrontal cortex) also correlated with PI resolution.
• Patients with impaired BF function relied more on the second network for PI resolution.

Conclusions:

• Two distinct functional networks underlie proactive interference resolution in humans.
• The MS/DB-dependent network integrates attention and memory for efficient PI resolution.
• An alternative network compensates for compromised BF function, maintaining cognitive performance.