Can ongoing movements be guided by allocentric visual information when the target is visible?

Area of Science:

• Cognitive Psychology
• Neuroscience
• Human Motor Control

Background:

• Humans utilize both egocentric (self-to-object) and allocentric (object-to-object) spatial information for navigation and interaction.
• Previous research suggested allocentric information guides actions when target locations change relative to other objects.
• The role of allocentric information when the target remains visible during movement is less understood.

Purpose of the Study:

• To investigate whether people utilize allocentric spatial information to guide ongoing visually guided actions when the target remains visible.
• To determine the extent to which egocentric versus allocentric spatial representations are prioritized in a dynamic interception task.

Main Methods:

• Participants performed a visually guided target interception task using a cursor representing finger movement.
• Simultaneous perturbations of target, cursor, and background were introduced, maintaining relative positions.
• Isolated perturbations were compared with simultaneous perturbations to assess reliance on egocentric versus allocentric information.

Main Results:

• Hand movements reflected the sum of responses to isolated perturbations, indicating egocentric control.
• This egocentric reliance persisted even when perturbations were repeated, suggesting adaptation was minimal.
• Participants showed little evidence of utilizing allocentric spatial information to adjust ongoing movements.

Conclusions:

• Visually guided actions, like target interception, predominantly rely on egocentric spatial information.
• Allocentric spatial information appears to play a limited role in online motor control when targets remain visible.
• The findings challenge the notion that allocentric representations are readily employed for real-time motor adjustments in this context.