# The Guidance of Attentional Selectivity in Visual Search Is Always Feature‐Based: Behavioral and Electrophysiological Evidence From Feature and Conjunction Search Tasks

## TL;DR

This study shows that visual attention is always guided by individual features, even when searching for complex combinations of features.

## Contribution

The study provides behavioral and electrophysiological evidence that attentional templates are always feature-based, even in conjunction search tasks.

## Key findings

- Load effects on search performance were more pronounced during conjunction search tasks.
- Electrophysiological markers showed stronger effects in conjunction search tasks.
- Attentional templates are fundamentally feature-based, not object-based.

## Abstract

It is generally assumed that the guidance of attention in visual search operates in a feature‐based fashion, but this conclusion is mainly based on the results of search tasks with feature‐defined targets. Here, we investigated whether attentional templates may contain integrated object‐based representations in tasks where targets are defined by feature conjunctions. Attentional load was manipulated by instructing participants to search for a single or one of two different possible targets. Search targets were either defined by a particular color or shape (feature search tasks) or by a color/shape combination (conjunction search task), and load effects were compared between these two types of tasks. Load effects on search performance as well as on electrophysiological markers of attentional guidance (N2pc components) and the number of attentional templates activated in working memory (CDA components) were much more pronounced during conjunction search. This suggests that attentional templates are always feature‐based, even when object‐based templates are in principle available to reduce memory load.

This study provides decisive evidence that attentional templates guiding visual search are fundamentally feature‐based, even in conjunction search tasks in which object‐based representations might be beneficial. By combining behavioral and electrophysiological measures of search efficiency and memory load, the study challenges the assumption that working memory capacity for integrated objects extends to attentional guidance. These findings refine existing models of visual search and advance understanding of the interactions between visual attention and working memory.