# The effect of feedback timing on category learning and feedback processing in younger and older adults

## TL;DR

This study shows that older adults learn better with delayed feedback, possibly due to increased brain activity in the medial temporal lobes.

## Contribution

The study reveals age-related differences in feedback processing and learning, suggesting delayed feedback benefits older adults.

## Key findings

- Younger adults learned better with immediate feedback, linked to typical striatal activity.
- Older adults showed comparable learning with delayed feedback, associated with increased MTL activation.
- Delayed feedback elicited a larger N170 in both age groups, indicating greater MTL involvement.

## Abstract

Corrective feedback can be received immediately after an action or with a temporal delay. Neuroimaging studies suggest that immediate and delayed feedback are processed by the striatum and medial temporal lobes (MTL), respectively. Age-related changes in the striatum and MTL may influence the efficiency of feedback-based learning in older adults. The current study leverages event-related potentials (ERPs) to evaluate age-related differences in immediate and delayed feedback processing and consequences for learning. The feedback-related negativity (FRN) captures activity in the frontostriatal circuit while the N170 is hypothesized to reflect MTL activation.

18 younger (Myears = 24.4) and 20 older (Myears = 65.5) adults completed learning tasks with immediate and delayed feedback. For each group, learning outcomes and ERP magnitudes were evaluated across timing conditions.

Younger adults learned better than older adults in the immediate timing condition. This performance difference was associated with a typical FRN signature in younger but not older adults. For older adults, impaired processing of immediate feedback in the striatum may have negatively impacted learning. Conversely, learning was comparable across groups when feedback was delayed. For both groups, delayed feedback was associated with a larger magnitude N170 relative to immediate feedback, suggesting greater MTL activation.

Delaying feedback may increase MTL involvement and, for older adults, improve category learning. Age-related neural changes may differentially affect MTL- and striatal-dependent learning. Future research can evaluate the locus of age-related learning differences and how feedback can be manipulated to optimize learning across the lifespan.