Reference induces biases in late visual processing

Area of Science:

• Cognitive Neuroscience
• Visual Perception
• Human Information Processing

Background:

• Context significantly influences visual stimulus perception.
• Reference repulsion, where a reference skews perception, is a known phenomenon.
• The precise stage of visual processing where reference repulsion occurs remains unclear.

Purpose of the Study:

• To investigate the influence of a reference on late-stage visual processing.
• To determine if reference repulsion occurs during later stages of visual information processing.

Main Methods:

• Measured the orientation repulsion effect using a post-stimulus orientation reference.
• Presented an orientation ensemble stimulus followed by a reference.
• Analyzed how explicit discrimination choices affected repulsion magnitude.

Main Results:

• Participants' reported orientations were significantly biased away from the post-stimulus reference.
• Repulsion effect magnitude varied with explicit discrimination between stimulus and reference.
• Results align with an encoding-decoding model involving re-weighted sensory representations.

Conclusions:

• Reference repulsion likely arises at a late, decision-related stage of visual processing.
• Task-specific sensory decoding strategies influence the magnitude of reference repulsion.
• This suggests late-stage processing and decision-making are critical for contextual effects in perception.