Decisions in motion: vestibular contributions to saccadic target selection

Area of Science:

• Neuroscience
• Human Motor Control
• Sensory Integration

Background:

• Understanding target selection is crucial for action execution.
• Previous research focused on stationary environments, leaving a gap in knowledge regarding target selection during self-motion.

Purpose of the Study:

• To investigate how self-motion signals affect saccadic target selection in a dynamic environment.
• To differentiate the impact of body acceleration versus velocity on eye movement choices.

Main Methods:

• Human subjects were sinusoidally translated on a vestibular sled.
• Two visual targets were presented, and their timing was adaptively adjusted to find a balance point for selection.
• The balanced time delay was measured across different phases of motion to isolate acceleration and velocity effects.

Main Results:

• Body acceleration, not velocity, significantly affected saccadic target selection.
• Subjects showed a bias to look towards the direction of acceleration.
• Saccadic reaction times were shorter for targets presented in the direction of acceleration.

Conclusions:

• Saccade target selection mechanisms are modulated by self-motion cues.
• These modulations may be directly influenced by signals from the otolith system.