Coordinates of Human Visual and Inertial Heading Perception

Area of Science:

• Neuroscience
• Human Perception
• Sensory Integration

Background:

• Heading estimation integrates inertial and visual cues from the labyrinth, body, and retina.
• The reference frames for these sensory inputs are distinct, raising questions about a common perceptual reference frame.
• Previous neurophysiological studies suggested separate reference frames but did not explore the resulting perception.

Purpose of the Study:

• To investigate whether heading perception occurs in a common reference frame.
• To determine the reference frames used for visual and inertial heading estimation.
• To examine the influence of gaze and head position on heading perception.

Main Methods:

• Seven human subjects performed translation and/or visual motion tasks.
• Stimuli involved 360° rotations in 5° increments.
• Perceived heading was reported using a mechanical dial, with variations in gaze and head position examined.
• Data were analyzed using a two degree-of-freedom population vector decoder (PVD) model.

Main Results:

• Visual stimuli-based heading perception was biased towards retinal coordinates, with gaze shifts altering perceived heading.
• Inertial heading perception was not significantly influenced by prior gaze or head direction shifts.
• Combined visual and inertial stimuli resulted in intermediate perceived headings.

Conclusions:

• Visual heading is perceived in retina-centered coordinates.
• Inertial heading is perceived in body-centered coordinates.
• Sensory information for heading is processed in distinct reference frames, influencing overall perception.