# Practice makes imperfect: stronger implicit interference with practice in individuals at high risk of developing Alzheimer’s disease

## TL;DR

High-risk individuals for Alzheimer’s show stronger implicit interference with practice, suggesting early attention differences.

## Contribution

New evidence that attention modulates implicit interference differently in Alzheimer’s high-risk individuals.

## Key findings

- High-risk individuals showed stronger implicit interference with practice.
- Low-risk individuals exhibited less interference and a correlation with EEG alpha desynchronization.
- Results highlight early perceptual differences in Alzheimer’s risk groups.

## Abstract

Early screening to determine patient risk of developing Alzheimer’s will allow better interventions and planning but necessitates accessible methods such as behavioral biomarkers. Previously, we showed that cognitively healthy older individuals whose cerebrospinal fluid amyloid/tau ratio indicates high risk of cognitive decline experienced implicit interference during a high-effort task, signaling early changes in attention. To further investigate attention’s effect on implicit interference, we analyzed two experiments completed sequentially by the same high- and low-risk individuals. We hypothesized that if attention modulates interference, practice would affect the influence of implicit distractors. Indeed, while both groups experienced a strong practice effect, the association between practice and interference effects diverged between groups: stronger practice effects correlated with more implicit interference in high-risk participants, but less interference in low-risk individuals. Furthermore, low-risk individuals showed a positive correlation between implicit interference and EEG low-range alpha event-related desynchronization when switching from high- to low-load tasks. This suggests that lower attention on the task was correlated with stronger interference, a typical phenomenon in the younger population. These results demonstrate how attention impacts implicit interference and highlight early differences in perception between high- and low-risk individuals.

The online version contains supplementary material available at 10.1007/s11357-023-00953-9.