Everything is subjective under water surface, too: visual illusions in fish

Area of Science:

• Comparative psychology
• Neuroethology
• Visual perception

Background:

• Visual illusions offer insights into complex perceptual mechanisms.
• Research has historically focused on mammals and birds, with recent expansion to fish.
• Fish species like guppies, redtail splitfin, and bamboo sharks are increasingly studied.

Purpose of the Study:

• To review the current understanding of visual illusions in fish.
• To highlight the importance of fish in comparative perceptual studies.
• To explore how fish visual perception informs broader questions in vertebrate perception.

Main Methods:

• Observational studies of animal behavior in response to visual illusions.
• Testing various fish species with illusions affecting size, number, motion, brightness, and contours.
• Review of existing literature on fish and visual illusions.

Main Results:

• Tested fish species exhibit human-like perception of various visual illusions.
• Some studies report no illusory effects or evidence of reverse illusions in fish.
• Findings suggest complex visual processing in fish.

Conclusions:

• Expanding visual illusion research in fish is crucial for understanding vertebrate perceptual systems.
• Fish studies can address ecological influences on perception, interindividual variability, and the role of cortical activity.
• This research broadens the scope of comparative psychology and neuroethology.