Pigeons integrate visual motion signals differently than humans

Yuya Hataji,Kazuo Fujita,Hika Kuroshima

doi:10.1038/s41598-019-49839-x

Abstract

Perceiving motion is a fundamental ability for animals. Primates integrate local 1D motion across orientation and space to compute a rigid 2D motion. It is unknown whether the rule of 2D motion integration is universal within the vertebrate clade; comparative studies of animals with different ecological backgrounds from primates may help answer that question. Here we investigated 2D motion integration in pigeons, using hierarchically structured motion stimuli, namely a barber-pole illusion and plaid motion. The pigeons were trained to report the direction of motion of random dots. When a barber-pole or plaid stimulus was presented, they reported the direction perpendicular to the grating orientation for barber-pole and the vector average of two component gratings for plaid motion. These results demonstrate that pigeons perceive different directions than humans from the same motion stimuli, and suggest that the 2D integrating rules in the primate brain has been elaborated through phylogenetic or ecological factors specific to the clade.

Highlights

Perception of motion is fundamental for animals as it provides information about the presence of prey, predators, mating rivals, and partners
The vector average (VA) solution is dominant for humans in situations such as peripheral viewing or brief presentation of stimuli[3], humans typically perceive plaid motion in the intersection of constraints (IOC) direction[2]
This indicates that humans have multiple solutions to integrate local 1D motion and, when foveally viewing attentively, humans depend on the IOC rule

Summary

Introduction

Perception of motion is fundamental for animals as it provides information about the presence of prey, predators, mating rivals, and partners. Different computational solutions have been proposed to reconstruct the 2D motion from 1D motion components of plaid[2]: intersection of constraints (IOC) or vector average (VA) (Fig. 1D). The VA solution is dominant for humans in situations such as peripheral viewing or brief presentation of stimuli[3], humans typically perceive plaid motion in the IOC direction[2]. This indicates that humans have multiple solutions to integrate local 1D motion and, when foveally viewing attentively, humans depend on the IOC rule. The pigeon’s accessory optic system that processes optic-flow caused by self-motion are selective for integrated 2D motion of plaid[22]

Methods

Results

Discussion

Conclusion