Persistent states in vision break universality and time invariance

Area of Science:

• Cognitive Neuroscience
• Visual Perception
• Psychophysics

Background:

• Traditional perception studies assume universal and stationary processes.
• Ambiguous visual stimuli challenge these assumptions by allowing multiple interpretations.

Purpose of the Study:

• To investigate the universality and stationarity of perceptual biases using ambiguous visual stimuli.
• To characterize the dynamics of these biases over various timescales.

Main Methods:

• A large-sample study using two families of ambiguous visual stimuli.
• Parameterization of perception by a continuous circular variable representing two opposite directions.
• Analysis of observer biases, their population distributions, and temporal dynamics.

Main Results:

• Almost all observers exhibit significant perceptual biases, with preferred directions.
• Biases vary greatly between individuals and show non-uniform population distributions.
• Biases exhibit complex dynamics, including decay, persistence, drifts, jumps, and oscillations over time.

Conclusions:

• The assumptions of universality and stationarity in perception are challenged by individual and time-varying biases.
• Perceptual models should incorporate covert, persistent states alongside directly observable variables.
• These findings reveal previously unknown degrees of freedom influencing visual perception.