Improvement of Absolute Distance Estimation Under Water: Use of Monocular Motion Parallax

1973 ◽  
Author(s):  
Steven H. Ferris
Keyword(s):  
Water Use ◽  
Motion Parallax ◽  
Distance Estimation ◽  
Absolute Distance

Motion Parallax and Distance Estimation Underwater

1974 ◽  
Vol 38 (3) ◽  
pp. 747-750
Author(s):  
Steven H. Ferris
Keyword(s):  
Head Movement ◽  
Distance Perception ◽  
Motion Parallax ◽  
Distance Estimation ◽  
Vertical Axis ◽  
Improve Performance ◽  
Water Turbidity ◽  
Position Constancy ◽  
Before And After ◽  
Positive Results

The possible value of monocular motion parallax for improving distance perception underwater was investigated. Submerged Ss either kept their heads stationary or rotated their heads about a vertical axis while judging the distance of objects placed 4 to 15 ft. away. Both before and after training with feedback to increase accuracy of judgment, head movement did not significantly improve performance. Water turbidity and loss of position constancy are two probable reasons for the failure to replicate the positive results previously obtained in air.

Magnitude Estimation of Absolute Distance Underwater

1972 ◽  
Vol 35 (3) ◽  
pp. 963-971 ◽  
Author(s):  
Steven H. Ferris
Keyword(s):  
Power Function ◽  
Magnitude Estimation ◽  
Distance Estimation ◽  
Optical Distortion ◽  
General Tendency ◽  
Absolute Distance ◽  
Water Turbidity ◽  
Power Function Exponent

Direct estimates of absolute distance were obtained in air and in water of varying turbidity. Distance in water was under- or overestimated, depending on the interaction of 3 factors: (1) a general tendency to underestimate; (2) optical distortion, which causes underestimation; and (3) water turbidity, which increases the magnitude of judgments, and whose effect increases with distance. Also, whereas the power-function exponent for distance estimation in air was slightly less than 1.0, exponents in water were greater than 1.0 and increased with increased turbidity.

scholarly journals Does Vision Extract Absolute Distance from Vergence?

2019 ◽  
Author(s):  
Paul Linton
Keyword(s):  
Binocular Disparity ◽  
Motion Parallax ◽  
Absolute Distance ◽  
Angular Rotation ◽  
Visual Scale ◽  
First Time ◽  
Real Challenge

AbstractSince Kepler (1604) and Descartes (1638), ‘vergence’ (the angular rotation of the eyes) has been thought of as one of our most important absolute distance cues. But vergence has never been tested as an absolute distance cue divorced from obvious confounding cues such as binocular disparity. In this article we control for these confounding cues for the first time by gradually manipulating vergence, and find that observers fail to accurately judge distance from vergence. We consider a number of different interpretations of these results, and argue that the most principled response to these results is to question the general effectiveness of vergence as an absolute distance cue. Given other absolute distance cues (such as motion parallax and vertical disparities) are limited in application, this poses a real challenge to our contemporary understanding of visual scale.

scholarly journals Distance estimation from monocular cues in an ethological visuomotor task

2021 ◽  
Author(s):  
Philip R L Parker ◽  
Eliott T T Abe ◽  
Natalie T Beatie ◽  
Emmalyn S P Leonard ◽  
Dylan M Martins ◽  
...  
Keyword(s):  
Visual Cortex ◽  
Stereo Vision ◽  
Visual Processing ◽  
Motion Parallax ◽  
Sensory Information ◽  
Distance Estimation ◽  
Motor Output ◽  
Head Movements ◽  
Visuomotor Task ◽  
Head Fixation

In natural contexts, sensory processing and motor output are closely coupled, which is reflected in the fact that many brain areas contain both sensory and movement signals. However, standard reductionist paradigms decouple sensory decisions from their natural motor consequences, and head-fixation prevents the natural sensory consequences of self-motion. In particular, movement through the environment provides a number of depth cues beyond stereo vision that are poorly understood. To study the integration of visual processing and motor output in a naturalistic task, we investigated distance estimation in freely moving mice. We found that mice use vision to accurately jump across a variable gap, thus directly coupling a visual computation to its corresponding ethological motor output. Monocular eyelid suture did not affect performance, thus mice can use cues that do not depend on binocular disparity and stereo vision. Under monocular conditions, mice performed more vertical head movements, consistent with the use of motion parallax cues, and optogenetic suppression of primary visual cortex impaired task performance. Together, these results show that mice can use monocular cues, relying on visual cortex, to accurately judge distance. Furthermore, this behavioral paradigm provides a foundation for studying how neural circuits convert sensory information into ethological motor output.

The Task-Dependent use of Binocular Disparity and Motion Parallax under Natural Viewing Conditions

Perception ◽  
1997 ◽  
Vol 26 (1_suppl) ◽  
pp. 99-99 ◽  
Author(s):  
M F Bradshaw ◽  
B De Bruyn ◽  
R A Eagle ◽  
A D Parton
Keyword(s):  
Binocular Disparity ◽  
Motion Parallax ◽  
Static Condition ◽  
Matching Task ◽  
Viewing Distance ◽  
Horizontal Meridian ◽  
Absolute Distance ◽  
Physical Stimuli ◽  
Additional Improvement ◽  
Better Than

The use of binocular disparity and motion parallax information was compared in three different psychophysical tasks for which natural viewing and physical stimuli were used. Natural viewing may be an important factor in interpreting experiments which have addressed the ability to use disparity and parallax both separately and in combination (see Frisby et al, 1996 Perception25 129 – 154). The stimuli consisted of configurations of three bright LEDs carefully aligned in the horizontal meridian and presented in darkness. The distance of the middle LED (flashing at 5 Hz) could be adjusted along the midline in accordance with the tasks which included: (i) a depth nulling task, (ii) a depth matching task, and (iii) a shape task—match base/height of triangle. Each task was performed at two viewing distances (1.5 and 3.0 m) and under four different viewing conditions: (i) monocular-static, (ii) monocular-moving, (iii) binocular-static, and (iv) binocular-moving. Note that the different tasks differ in their dependence on viewing distance, and the available cues for viewing distance differ between viewing conditions. Four observers made ten settings in each condition at each distance. Observers, as expected, performed badly (bias and accuracy) in all tasks in the monocular-static condition. Nulling was accurate in the other viewing conditions (no estimate of viewing distance required). Performance was best in the matching task (ratio of viewing distances) but although binocular-static was significantly better than monocular-moving performance in this and in the shape task (absolute distance required), there was no additional improvement in the binocular-moving condition. Results show that observers can recover structure accurately from parallax or disparity information in real-world stimuli.

Proprioceptive contribution to distance estimation by motion parallax in a praying mantid

1998 ◽  
Vol 201 (9) ◽  
pp. 1483-1491 ◽  
Author(s):  
M Pabst ◽  
K Kral
Keyword(s):  
Motion Parallax ◽  
Distance Estimation ◽  
Image Motion ◽  
Head Motion ◽  
Jump Frequency ◽  
Praying Mantis ◽  
Retinal Image Motion ◽  
Praying Mantid ◽  
Behavioural Experiments ◽  
Measurement Mechanism

The behavioural experiments described here examined, in the praying mantis Tenodera sinensis, the manner in which the proprioceptive cervical hair plate sensilla are involved in the measurement of the distance to a jump target with the aid of motion parallax actively produced by translatory head motion. Various combinations of surgical deafferentation of the cervical hair plate sensilla had no influence on the linearisation of head motion. However, the measurement of relative and absolute distance and the jump frequency were impaired by these interventions. From the results, it is concluded that the cervical hair plate sensilla are involved in the distance measurement mechanism, probably by allowing the nervous system to compare retinal image motion with head motion. <P>

Lateral optic flow does not influence distance estimation in the desert ant Cataglyphis fortis

2000 ◽  
Vol 203 (7) ◽  
pp. 1113-1121 ◽  
Author(s):  
B. Ronacher ◽  
K. Gallizzi ◽  
S. Wohlgemuth ◽  
R. Wehner
Keyword(s):  
Flow Field ◽  
Optic Flow ◽  
Visual Cues ◽  
Food Source ◽  
Motion Parallax ◽  
Distance Estimation ◽  
Desert Ants ◽  
Desert Ant ◽  
Walking Speeds ◽  
Cataglyphis Fortis

The present account answers the question of whether desert ants (Cataglyphis fortis) gauge the distance they have travelled by using self-induced lateral optic-flow parameters, as has been described for bees. The ants were trained to run to a distant food source within a channel whose walls were covered with black-and-white gratings. From the food source, they were transferred to test channels of double or half the training width, and the distance they travelled before searching for home and their walking speeds were recorded. Since the animals experience different motion parallax cues when walking in the broader or narrower channels, the optic-flow hypothesis predicted that the ants would walk faster and further in the broader channels, but more slowly and less far in the narrower channels. In contrast to this expectation, neither the walking speeds nor the searching distances depended on the width or height of the channels or on the pattern wavelengths. Even when ventral-field visual cues were excluded by covering the eyes with light-tight paint, the ants were not influenced by lateral optic flow-field cues. Hence, walking desert ants do not depend on self-induced visual flow-field cues in gauging the distance they have travelled, as do flying honeybees, but can measure locomotor distance exclusively by idiothetic means.

Sign in / Sign up

Export Citation Format

Share Document