# Modelling the impact of single vs. dual presentation on visual discrimination across resolutions

## TL;DR

The study found that higher image resolution improves visual categorization, but showing two images instead of one does not help, even though it makes people more careful.

## Contribution

The paper introduces a novel comparison of single and dual stimulus presentation effects on visual discrimination using the diffusion decision model.

## Key findings

- Higher image resolution consistently improved choice performance.
- Dual presentation did not provide a performance benefit over single presentation.
- Dual presentation increased response caution but not decision accuracy.

## Abstract

Visual categorisation relies on our ability to extract useful diagnostic information from complex stimuli. To do this, we can utilise both the “high-level” and “low-level” information in a stimulus; however, the extent to which changes in these properties impact the decision-making process is less clear. We manipulated participants’ access to high-level category features via gradated reductions to image resolution while exploring the impact of access to additional category features through a dual-stimulus presentation when compared with single stimulus presentation. Results showed that while increasing image resolution consistently resulted in better choice performance, no benefit was found for dual presentation over single presentation, despite responses for dual presentation being slower compared with single presentation. Applying the diffusion decision model revealed increases in drift rate as a function of resolution, but no change in drift rate for single versus dual presentation. The increase in response time for dual presentation was instead accounted for by an increase in response caution for dual presentations. These findings suggest that while increasing access to high-level features (via increased resolution) can improve participants’ categorisation performance, increasing access to both high- and low-level features (via an additional stimulus) does not.