Prior knowledge biases the visual memory of body postures

Area of Science:

• Cognitive Neuroscience
• Visual Perception
• Human Motor Control

Background:

• Body postures convey significant social and intentional information.
• The neural representation of body postures in the visual system is not well understood.
• Prior visual and motor experiences may influence how body postures are perceived.

Purpose of the Study:

• To investigate how priors, specifically gravity and biomechanical constraints, bias visual representations of body postures.
• To determine if these biases affect visual memory for body postures.

Main Methods:

• Utilized change discrimination and adjustment tasks to probe visual memory.
• Presented briefly flashed body postures to 246 participants across three experiments.
• Manipulated stimuli by inverting body postures to control for visual confounds.

Main Results:

• Participants systematically misremembered lifted arms as being in a lower position.
• Visual memory favored postures that adhered to biomechanical plausibility.
• Biases were eliminated when inverted body stimuli were used, ruling out low-level visual confounds.

Conclusions:

• Visual memory for body postures is not a veridical representation but is modulated by internal priors.
• Both general priors (gravity) and specific priors (biomechanics) shape how we visually remember body configurations.
• These findings highlight the active, constructive nature of visual memory for complex stimuli like body postures.