scholarly journals The limits of apparent motion perception in the praying mantis

2018 ◽  
Vol 18 (10) ◽  
pp. 349
Author(s):  
Jenny Read ◽  
Lisa Jones ◽  
Candy Rowe ◽  
Claire Rind ◽  
Vivek Nityananda ◽  
...  
Vision ◽  
2018 ◽  
Vol 2 (3) ◽  
pp. 32
Author(s):  
Ghaith Tarawneh ◽  
Lisa Jones ◽  
Vivek Nityananda ◽  
Ronny Rosner ◽  
Claire Rind ◽  
...  

Apparent motion is the perception of motion created by rapidly presenting still frames in which objects are displaced in space. Observers can reliably discriminate the direction of apparent motion when inter-frame object displacement is below a certain limit, Dmax . Earlier studies of motion perception in humans found that Dmax is lower-bounded at around 15 arcmin, and thereafter scales with the size of the spatial elements in the images. Here, we run corresponding experiments in the praying mantis Sphodromantis lineola to investigate how Dmax scales with the element size. We use random moving chequerboard patterns of varying element and displacement step sizes to elicit the optomotor response, a postural stabilization mechanism that causes mantids to lean in the direction of large-field motion. Subsequently, we calculate Dmax as the displacement step size corresponding to a 50% probability of detecting an optomotor response in the same direction as the stimulus. Our main findings are that the mantis Dmax scales roughly as a square-root of element size and that, in contrast to humans, it is not lower-bounded. We present two models to explain these observations: a simple high-level model based on motion energy in the Fourier domain and a more-detailed one based on the Reichardt Detector. The models present complementary intuitive and physiologically-realistic accounts of how Dmax scales with the element size in insects. We conclude that insect motion perception is limited by only a single stage of spatial filtering, reflecting the optics of the compound eye. In contrast, human motion perception reflects a second stage of spatial filtering, at coarser scales than imposed by human optics, likely corresponding to the magnocellular pathway. After this spatial filtering, mantis and human motion perception and Dmax are qualitatively very similar.


2018 ◽  
Author(s):  
Ghaith Tarawneh ◽  
Lisa Jones ◽  
Vivek Nityananda ◽  
Ronny Rosner ◽  
Claire Rind ◽  
...  

AbstractApparent motion is the perception of a motion created by rapidly presenting still frames in which objects are displaced in space. Observers can reliably discriminate the direction of apparent motion when inter-frame object displacement is below a certain limit, Dmax. Earlier studies of motion perception in humans found that Dmax scales with spatial element size, interpreting the relationship between the two as linear, and that Dmax appears to be lower-bounded at around 15 arcmin. Here, we run corresponding experiments in the praying mantisSphodromantis lineolato investigate how Dmax scales with element size. We used moving random chequerboard patterns of varying element and displacement step sizes to elicit the optomotor response, a postural stabilization mechanism that causes mantids to lean in the direction of large-field motion. Subsequently, we calculated Dmax as the displacement step size corresponding to a 50% probability of detecting an optomotor response in the same direction as the stimulus. Our main findings are that mantis Dmax appears to scale as a power-law of element size and that, in contrast to humans, it does not appear to be lower-bounded. We present two models to explain these observations: a simple high-level model based on motion energy in the Fourier domain and a more detailed one based on the Reichardt Detector. The models present complementary intuitive and physiologically-realistic accounts of how Dmax scales with element size in insects.Author SummaryComputer monitors, smart phone screens and other forms of digital displays present a series of still images (frames) in which objects are displaced in small steps, tricking us into perceiving smooth motion. This illusion is referred to as “apparent motion”, and for it to work effectively the magnitude of each displacement step must be smaller than a certain limit, referred to as Dmax. Previous studies have investigated the relationship between this limit and object size in humans and found that larger objects can be displaced in larger steps without affecting motion perception. In this work, we investigated the same relationship in the praying mantisSphodromantis lineolaby presenting them with moving chequerboard patterns on a computer monitor. Even though motion perception in humans and insects are believed to be explained equally well by the same underlying model, we found that Dmax scales with object size differently in mantids. These results suggest that there may be qualitative differences in how mantids perceive apparent motion compared to humans.


NeuroImage ◽  
2001 ◽  
Vol 13 (6) ◽  
pp. 893
Author(s):  
C.I. Horenstein ◽  
R.R. Ramirez ◽  
E. Kronberg ◽  
U. Ribary ◽  
R.R. Llinas

Author(s):  
Brian Rogers

The ability to detect motion is one of the most important properties of our visual system and the visual systems of nearly every other species. Motion perception is not just important for detecting the movement of objects—both for catching prey and for avoiding predators—but it is also important for providing information about the 3-D structure of the world, for maintaining balance, determining our direction of heading, segregating the scene and breaking camouflage, and judging time-to-contact with other objects in the world. ‘Motion perception’ describes the spatio-temporal process of motion perception and the perceptual effects that tell us something about the characteristics of the motion system: apparent motion, the motion after-effect, and induced motion.


Perception ◽  
1985 ◽  
Vol 14 (2) ◽  
pp. 135-143 ◽  
Author(s):  
Vilayanur S Ramachandran ◽  
Stuart M Anstis

Is motion perception based on a local piecemeal analysis of the image or do ‘global’ effects also play an important role? Use was made of bistable apparent-motion displays in trying to answer this question. Two spots were flashed simultaneously on diagonally opposite corners of a 1 deg wide square and then switched off and replaced by two spots appearing on the other two corners. One can either see vertical or horizontal oscillation and the display is bistable just as a Necker cube is. If several such bistable figures are randomly scattered on the screen and presented simultaneously, then one usually sees the same motion axis in all of them, suggesting the presence of field-like effects for resolving ambiguity in apparent motion. While viewing a single figure observers experience hysteresis: they tend to adhere to one motion axis or the other and can switch the axis only by looking away and looking back after 10–30 s have elapsed. The figure can be switched off and made to reappear at some other random location on the screen and it is then always found to retain its motion axis. Several such demonstrations are presented to show that spatial induction effects in metastable motion displays may provide a particularly valuable probe for studying ‘laws’ of perceptual organization.


Perception ◽  
1983 ◽  
Vol 12 (3) ◽  
pp. 305-312 ◽  
Author(s):  
Kathleen Mutch ◽  
Isabel M Smith ◽  
Albert Yonas

The problem of how the visual system matches corresponding inputs from one instant to the next to produce the perception of motion has been experimentally examined. The specific concern was whether this correspondence problem is solved prior to the interpretation of three-dimensional distance. Observers judged the degree of apparent motion between pairs of lights in a conflicting motion display. Spatial separation of the lights was varied in two and three dimensions in order to assess whether retinal distance, actual depth, or some combination of these provided critical information for correspondence. The results support Ullman's contention that only two-dimensional (retinal) distances are used in establishing correspondence in motion perception.


Perception ◽  
1973 ◽  
Vol 2 (2) ◽  
pp. 167-180 ◽  
Author(s):  
C Lamontagne

An experimental paradigm is derived from a computational model of visual motion perception. The new family of phenomena that support this paradigm is presented in the context of the model. The basic phenomenon can be considered as being the apparent motion and the sustained eyetracking of a physically still object (relative to the subject) in the absence of any other object moving relative to the subject.


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