scholarly journals Visual motion speed determines a behavioral switch from forward flight to expansion avoidance in Drosophila

2012 ◽  
Vol 216 (4) ◽  
pp. 719-732 ◽  
Author(s):  
M. B. Reiser ◽  
M. H. Dickinson
Keyword(s):  
Visual Motion ◽  
Forward Flight ◽  
Motion Speed

scholarly journals Development of motion speed perception from infancy to early adulthood: a high-density EEG study of simulated forward motion through optic flow

2021 ◽  
Author(s):  
Stefania Rasulo ◽  
Kenneth Vilhelmsen ◽  
F. R. van der Weel ◽  
Audrey L. H. van der Meer
Keyword(s):  
Optic Flow ◽  
Visual Motion ◽  
Road Traffic ◽  
Brain Activity ◽  
Primary School Children ◽  
Time Frequency ◽  
Road Traffic Safety ◽  
Motion Speed ◽  
Speed Perception ◽  
Oscillatory Brain Activity

AbstractThis study investigated evoked and oscillatory brain activity in response to forward visual motion at three different ecologically valid speeds, simulated through an optic flow pattern consisting of a virtual road with moving poles at either side of it. Participants were prelocomotor infants at 4–5 months, crawling infants at 9–11 months, primary school children at 6 years, adolescents at 12 years, and young adults. N2 latencies for motion decreased significantly with age from around 400 ms in prelocomotor infants to 325 ms in crawling infants, and from 300 and 275 ms in 6- and 12-year-olds, respectively, to 250 ms in adults. Infants at 4–5 months displayed the longest latencies and appeared unable to differentiate between motion speeds. In contrast, crawling infants at 9–11 months and 6-year-old children differentiated between low, medium and high speeds, with shortest latency for low speed. Adolescents and adults displayed similar short latencies for the three motion speeds, indicating that they perceived them as equally easy to detect. Time–frequency analyses indicated that with increasing age, participants showed a progression from low- to high-frequency desynchronized oscillatory brain activity in response to visual motion. The developmental differences in motion speed perception are interpreted in terms of a combination of neurobiological development and increased experience with self-produced locomotion. Our findings suggest that motion speed perception is not fully developed until adolescence, which has implications for children’s road traffic safety.

Perception of Self-Motion and Regulation of Walking Speed in Young-Old Adults

Motor Control ◽  
2015 ◽  
Vol 19 (3) ◽  
pp. 191-206 ◽  
Author(s):  
Marie-Jasmine Lalonde-Parsi ◽  
Anouk Lamontagne
Keyword(s):  
Visual Motion ◽  
Walking Speed ◽  
Perceptual Task ◽  
Old Adults ◽  
Motion Speed ◽  
Perception Of Self ◽  
Speed Discrimination ◽  
Self Motion ◽  
The Relationship ◽  
Young Old

Whether a reduced perception of self-motion contributes to poor walking speed adaptations in older adults is unknown. In this study, speed discrimination thresholds (perceptual task) and walking speed adaptations (walking task) were compared between young (19–27 years) and young-old individuals (63–74 years), and the relationship between the performance on the two tasks was examined. Participants were evaluated while viewing a virtual corridor in a helmet-mounted display. Speed discrimination thresholds were determined using a staircase procedure. Walking speed modulation was assessed on a self-paced treadmill while exposed to different self-motion speeds ranging from 0.25 to 2 times the participants’ comfortable speed. For each speed, participants were instructed to match the self-motion speed described by the moving corridor. On the walking task, participants displayed smaller walking speed errors at comfortable walking speeds compared with slower of faster speeds. The young-old adults presented larger speed discrimination thresholds (perceptual experiment) and larger walking speed errors (walking experiment) compared with young adults. Larger walking speed errors were associated with higher discrimination thresholds. The enhanced performance on the walking task at comfortable speed suggests that intersensory calibration processes are influenced by experience, hence optimized for frequently encountered conditions. The altered performance of the young-old adults on the perceptual and walking tasks, as well as the relationship observed between the two tasks, suggest that a poor perception of visual motion information may contribute to the poor walking speed adaptations that arise with aging.

scholarly journals Contribution of Individual Retinal Ganglion Cell Responses to Velocity and Acceleration Encoding

2007 ◽  
Vol 98 (4) ◽  
pp. 2285-2296 ◽  
Author(s):  
Andreas Thiel ◽  
Martin Greschner ◽  
Christian W. Eurich ◽  
Josef Ammermüller ◽  
Jutta Kretzberg
Keyword(s):  
Ganglion Cell ◽  
Retinal Ganglion Cell ◽  
Visual Motion ◽  
Retinal Ganglion ◽  
Motion Direction ◽  
Velocity Signal ◽  
Stimulus Velocity ◽  
Firing Rates ◽  
Motion Speed ◽  
Velocity Changes

We investigate the capability of turtle retinal ganglion cell (RGC) ensembles to simultaneously encode multiple aspects of visual motion: speed, direction, and acceleration of moving patterns. Bayesian stimulus reconstruction reveals that the instantaneous firing rates of RGCs contain information about all of these stimulus properties. Stimulus velocity is mainly encoded by steady-state firing rates, whereas acceleration can be reconstructed from transient components in RGC activity induced by abrupt velocity changes. Therefore neurons in higher brain areas may in principle extract information about changing velocity from the instantaneous firing activity of RGCs, without the need to compare responses to present velocities to previous ones. However, reconstruction requires the estimation of a combined acceleration and velocity signal, indicating that RGC ensembles signal both properties simultaneously. In accordance with this conclusion, combined velocity/acceleration sensitivity enhances the similarity of artificial spike trains to experimental data by 50% compared with the case of pure velocity tuning. Decoding of motion direction in addition to speed and acceleration requires direction-sensitive cells, which generate higher firing rates for one of the motion directions and therefore show asymmetric velocity tuning. By dividing the entire ensemble of simultaneously recorded cells into one group of direction-sensitive cells and one group with symmetric tuning, we demonstrate that the population of direction-sensitive cells encodes a combination of motion speed, acceleration, and direction. However, estimation of velocity and acceleration is improved by including the larger group of RGC responses that are sensitive to speed but not to motion direction.

Misdirected visual motion: Mae and phi

1991 ◽  
Author(s):  
Eric J. Hiris ◽  
Robert H. Cormack ◽  
Randolph Blake
Keyword(s):  
Visual Motion

Effects of forward flight on jet mixing noise from fine-scale turbulence

AIAA Journal ◽  
2001 ◽  
Vol 39 ◽  
pp. 1261-1269 ◽  
Author(s):  
Christopher K. W. Tam ◽  
Nikolai Pastouchenko ◽  
Laurent Auriault
Keyword(s):  
Fine Scale ◽  
Forward Flight ◽  
Jet Mixing ◽  
Mixing Noise ◽  
Scale Turbulence
Sign in / Sign up

Export Citation Format

Share Document