Event-related potentials during encoding coincide with subsequent forced-choice mnemonic discrimination.

Area of Science:

• Cognitive Neuroscience
• Psychology
• Neuroscience

Background:

• Computational and eye-tracking models propose encoding variability influences recognition.
• This variability explains poorer target recognition with non-corresponding lures compared to corresponding lures.

Purpose of the Study:

• To investigate if neural activity during learning correlates with subsequent performance on the Mnemonic Similarity Task (MST).
• To examine the neural underpinnings of memory discrimination using event-related potentials (ERPs).

Main Methods:

• Adult participants completed forced-choice Mnemonic Similarity Task (MST) trials (A-B' and A-A').
• Event-related potential (ERP) responses were recorded during the encoding phase.
• Analysis focused on the subsequent memory effect and Accuracy × Stimulus interactions.

Main Results:

• Performance was lower on A-B' trials (non-corresponding lures) than A-A' trials (corresponding lures).
• No significant subsequent memory effect was found for A-A' trials.
• A significant Accuracy × Stimulus interaction occurred in A-B' trials (1000-1200 ms poststimulus) at frontal electrodes, indicating differential neural responses to targets versus lures based on accuracy.

Conclusions:

• Neural activity during encoding differentiates subsequently remembered targets from lures in the A-B' condition.
• Subsequently correct trials showed greater neural response to the target (A) than the lure (B).
• Subsequently incorrect trials showed greater neural response to the lure (B) than the target (A), supporting encoding variability's role in mnemonic discrimination.