Target motion misjudgments reflect a misperception of the background; revealed using continuous psychophysics

Area of Science:

• Visual perception
• Neuroscience
• Computational vision

Background:

• Determining object velocities during self-motion is challenging due to added motion signals.
• The flow-parsing hypothesis suggests background motion subtraction helps perceive relative target motion.
• Previous studies have not fully explored background perception's role in incomplete subtraction.

Purpose of the Study:

• Investigate why background motion is only partially subtracted in laboratory settings.
• Examine the perception of background itself within flow-parsing paradigms.
• Develop a model to explain incomplete background subtraction during self-motion perception.

Main Methods:

• Conducted three continuous psychophysical experiments with four participants (three experienced, one inexperienced).
• Manipulated background optic flow patterns, varying local element motion congruence with global flow.
• Collected data on perceived target and background motion to analyze subtraction completeness.

Main Results:

• Incomplete background subtraction was fully explained by misperception when local background motions were congruent with global optic flow.
• An additional factor beyond misperception was required to explain incomplete subtraction when local background velocities were randomly dispersed.
• A computational model inferring scene motion from self-motion successfully accounted for the observed results.

Conclusions:

• Background perception significantly influences the accuracy of target motion estimation during self-motion.
• The brain's inference of self-motion plays a critical role in how visual scene motion is processed.
• Future research should consider both background perception and self-motion inference in visual navigation models.