Related Experiment Video
Updated: Feb 25, 2026
09:46
MPI CyberMotion Simulator: Implementation of a Novel Motion Simulator to Investigate Multisensory Path Integration in Three Dimensions
Published on: May 10, 2012
13.2K
Intercepting virtual balls approaching under different gravity conditions: evidence for spatial prediction.
Marta Russo1, Benedetta Cesqui2,3, Barbara La Scaleia3
1Centre of Space Bio-medicine, University of Rome Tor Vergata, Rome, Italy; m.russo@hsantalucia.it.
Journal of Neurophysiology
|August 4, 2017
Summary
The brain uses an internal model of gravity to predict where to intercept falling balls. This internal gravity model influences spatial interception predictions, with visual feedback refining movements over longer flight times.
Area of Science:
- Motor control
- Human perception
- Biomechanics
Background:
- Accurate motor timing for intercepting objects relies on an internal model of gravity.
- The role of this internal gravity model in estimating spatial interception locations remains unclear.
Purpose of the Study:
- To investigate whether an internal model of gravity is used to predict the spatial location of interception.
- To examine how gravity affects motor responses and interception point selection.
Main Methods:
- Participants (n=25) intercepted virtual balls under normal (1g) and zero (0g) gravity conditions.
- Trajectories varied in arrival location, flight duration, and gravity.
- Interception points and hand speed profiles were recorded in an immersive virtual reality system.
Main Results:
- Performance was often better under 1g than 0g conditions.
- Interception points aligned with the predicted 1g path, even for 0g balls, suggesting gravity-based spatial prediction.
- The performance difference between 1g and 0g was greater for faster balls (shorter flight durations).
- Increased flight duration led to more adjustments in hand speed, indicating visual feedback use.
Conclusions:
- An internal model of gravity is likely used for predicting interception locations.
- The predictive model is influenced by visual feedback, especially with longer flight durations.
- Humans may assume accelerated motion even when presented with constant velocity, influenced by internal gravity models.
Related Concept Videos
01:23Motion of a Projectile
3.3K
Projectile motion becomes evident when a player kicks the ball into the air. The launch angle, or the angle at which the ball is kicked, plays a crucial role in determining the trajectory of the projectile. As the ball soars through the air, influenced solely by gravity, its motion can be dissected into two independent velocity components: the horizontal and the vertical.
Horizontal motion, governed by the initial kick, maintains a constant velocity throughout the flight of the soccer ball.
Horizontal motion, governed by the initial kick, maintains a constant velocity throughout the flight of the soccer ball.
3.3K
01:27Gravity between Spherical Bodies
9.5K
Newton's law of gravitation describes the gravitational force between any two point masses. However, for extended spherical objects like the Earth, the Moon, and other planets, the law holds with an assumption that masses of spherical objects are concentrated at their respective centers.
This assumption can be proved easily by showing that the expression for gravitational potential energy between a hollow sphere of mass (M) and a point mass (m) is the same as it would be for a pair of extended...
This assumption can be proved easily by showing that the expression for gravitational potential energy between a hollow sphere of mass (M) and a point mass (m) is the same as it would be for a pair of extended...
9.5K
01:23Quadratic Models
273
Quadratic models are mathematical representations used to describe relationships in which the rate of change changes at a constant rate. These models appear in a wide variety of natural and engineered systems, especially those involving motion, forces, and optimization. One common application is analyzing the vertical motion of objects influenced by gravity, such as a ball thrown into the air.In such scenarios, the object's height changes over time in a curved pattern, rising to a maximum point...
273
01:16Circular Orbits and Critical Velocity for Satellites
5.5K
The Moon orbits around the Earth. In turn, the Earth (and other planets) orbit the Sun. The space directly above our atmosphere is filled with artificial satellites in orbit. One can examine the circular orbit, the simplest kind of orbit, to understand the relationship between the speed and the period of planets and satellites with respect to their positions and the bodies that they orbit.
Nicolaus Copernicus (1473-1543) first suggested that the Earth and all other planets orbit the Sun in...
Nicolaus Copernicus (1473-1543) first suggested that the Earth and all other planets orbit the Sun in...
5.5K
01:26Impact: Problem Solving
485
In an experiment conducted during a Mars mission, a rover propels a projectile with an initial velocity, and the projectile rebounds after colliding with the Martian surface. To ascertain the maximum height attained by the projectile after this collision, the known restitution coefficient and acceleration due to gravity are employed.
By designating the launch point as the origin and utilizing kinematic equations, the vertical component of the projectile's velocity at the point of impact is...
By designating the launch point as the origin and utilizing kinematic equations, the vertical component of the projectile's velocity at the point of impact is...
485
04:08The Uncertainty Principle
33.6K
Werner Heisenberg considered the limits of how accurately one can measure properties of an electron or other microscopic particles. He determined that there is a fundamental limit to how accurately one can measure both a particle’s position and its momentum simultaneously. The more accurate the measurement of the momentum of a particle is known, the less accurate the position at that time is known and vice versa. This is what is now called the Heisenberg uncertainty principle. He...
33.6K