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.

Vestibular and visual responses in human posterior insular cortex

2014 ◽  
Vol 112 (10) ◽  
pp. 2481-2491 ◽  
Author(s):  
Sebastian M. Frank ◽  
Oliver Baumann ◽  
Jason B. Mattingley ◽  
Mark W. Greenlee
Keyword(s):  
Visual Motion ◽  
Insular Cortex ◽  
Vestibular Stimulation ◽  
Visual Responses ◽  
Functional Magnetic Resonance ◽  
Vestibular Information ◽  
Perception Of Self ◽  
Self Motion ◽  
Similar Location ◽  
Trial Participants

The central hub of the cortical vestibular network in humans is likely localized in the region of posterior lateral sulcus. An area characterized by responsiveness to visual motion has previously been described at a similar location and named posterior insular cortex (PIC). Currently it is not known whether PIC processes vestibular information as well. We localized PIC using visual motion stimulation in functional magnetic resonance imaging (fMRI) and investigated whether PIC also responds to vestibular stimuli. To this end, we designed an MRI-compatible caloric stimulation device that allowed us to stimulate bithermally with hot temperature in one ear and simultaneously cold temperature in the other or with warm temperatures in both ears for baseline. During each trial, participants indicated the presence or absence of self-motion sensations. We found activation in PIC during periods of self motion when vestibular stimulation was carried out with minimal visual input. In combined visual-vestibular stimulation area PIC was activated in a similar fashion during congruent and incongruent stimulation conditions. Our results show that PIC not only responds to visual motion but also to vestibular stimuli related to the sensation of self motion. We suggest that PIC is part of the cortical vestibular network and plays a role in the integration of visual and vestibular stimuli for the perception of self motion.

Separate Presentation of Additional Accelerating Motion Does not Enhance Visually Induced Self-Motion Perception

2013 ◽  
Vol 26 (3) ◽  
pp. 277-285 ◽  
Author(s):  
Shinji Nakamura
Keyword(s):  
Motion Perception ◽  
Visual Motion ◽  
Main Axis ◽  
Psychophysical Experiment ◽  
Simple Hypothesis ◽  
Expansion Pattern ◽  
Perception Of Self ◽  
Oscillating Motion ◽  
Self Motion ◽  
Perceptual Mechanism

It has been repeatedly reported that visual stimuli containing a jittering/oscillating motion component can induce self-motion perception more strongly than a pure radial expansion pattern. A psychophysical experiment with 11 observers revealed that the additional accelerating components of the visual motion have to be convoluted with the motion of the main-axis to facilitate self-motion perception; additional motion presented in an isolated fashion impairs the perception of self-motion. These results are inconsistent with a simple hypothesis about the perceptual mechanism underlying the advantage of jitter/oscillation, which assumes that the accelerating component induces an additional self-motion independently of the main motion at the first stage, and then the two self-motions induced by the main motion and the additional component become integrated.

Perceptual Awareness of Optic Flows Paced Optimally and Non-optimally to Walking Speed

Perception ◽  
2021 ◽  
Vol 50 (9) ◽  
pp. 797-818
Author(s):  
Paweł Motyka ◽  
Zuzanna Kozłowska ◽  
Piotr Litwin
Keyword(s):  
Visual Processing ◽  
Walking Speed ◽  
Visual Awareness ◽  
Threshold Level ◽  
Perceptual Awareness ◽  
Flow Speeds ◽  
Motion Speed ◽  
Optic Flows ◽  
Walking Speeds ◽  
Self Motion

Previous research suggests that visual processing depends strongly on locomotor activity and is tuned to optic flows consistent with self-motion speed. Here, we used a binocular rivalry paradigm to investigate whether perceptual access to optic flows depends on their optimality in relation to walking velocity. Participants walked at two different speeds on a treadmill while viewing discrepant visualizations of a virtual tunnel in each eye. We hypothesized that visualizations paced appropriately to the walking speeds will be perceived longer than non optimal (too fast/slow) ones. The presented optic flow speeds were predetermined individually in a task based on matching visual speed to both walking velocities. In addition, perceptual preference for optimal optic flows was expected to increase with proprioceptive ability to detect threshold-level changes in walking speed. Whereas faster (more familiar) optic flows showed enhanced access to awareness during faster compared with slower walking conditions, for slower visual flows, only a nonsignificant tendency for the analogous effect was observed. These effects were not dependent on individual proprioceptive sensitivity. Our findings concur with the emerging view that the velocity of one’s locomotion is used to calibrate visual perception of self-motion and extend the scope of reported action effects on visual awareness.

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