# Perceptual grouping and the bounce–stream illusion

## TL;DR

This paper explores how the brain perceives moving spots as either bouncing or streaming, based on Gestalt grouping principles.

## Contribution

The study identifies specific visual conditions that promote either the bounce or stream percept in motion perception.

## Key findings

- Spots that turn back and retrace their path are more likely to be perceived as bouncing.
- Same-size spots moving straight and viewed peripherally are more likely to be perceived as streaming.
- Both percepts are driven by Gestalt grouping principles.

## Abstract

Two spots moving simultaneously along the same path in opposite directions can appear either to bounce or stream. Bouncing is promoted by spots that turn back and retrace their path. Streaming is promoted by same-size spots, moving along a straight path and viewed peripherally. Both percepts are driven by Gestalt grouping.