scholarly journals Ocellar spatial vision in Myrmecia ants

2021 ◽  
Author(s):  
Bhavana Penmetcha ◽  
Yuri Ogawa ◽  
Laura A. Ryan ◽  
Nathan S. Hart ◽  
Ajay Narendra
Keyword(s):  
Apis Mellifera ◽  
Contrast Sensitivity ◽  
Spatial Vision ◽  
Flight Time ◽  
Resolving Power ◽  
Compound Eyes ◽  
Pattern Electroretinography ◽  
Visual Systems ◽  
Visual Properties ◽  
European Honeybee

In addition to the compound eyes, insects possess simple eyes known as ocelli. Input from the ocelli modulates optomotor responses, flight-time initiation, and phototactic responses—behaviours that are mediated predominantly by the compound eyes. In this study, using pattern electroretinography (pERG), we investigated the contribution of the compound eyes to ocellar spatial vision in the diurnal Australian bull ant Myrmecia tarsata by measuring the contrast sensitivity and spatial resolving power of the ocellar second-order neurons under various occlusion conditions. Furthermore, in four species of Myrmecia ants active at different times of the day, and in European honeybee Apis mellifera, we characterized the ocellar visual properties when both visual systems were available. Among the ants, we found that the time of activity had no significant effect on ocellar spatial vision. Comparing day-active ants and the honeybee we did not find any significant effect of locomotion on ocellar spatial vision. In M. tarsata, when the compound eyes were occluded, the amplitude of the pERG signal from the ocelli reduced by three times compared to conditions when the compound eyes were available. The signals from the compound eyes maintained the maximum contrast sensitivity of the ocelli as 13 (7.7%), and the spatial resolving power as 0.29 cpd. We conclude that ocellar spatial vison improves significantly with input from the compound eyes, with a noticeably larger improvement in contrast sensitivity than in spatial resolving power.

scholarly journals Ocellar spatial vision in Myrmecia ants

2021 ◽  
Author(s):  
Bhavana Penmetcha ◽  
Yuri Ogawa ◽  
Laura A Ryan ◽  
Nathan S Hart ◽  
Ajay Narendra
Keyword(s):  
Apis Mellifera ◽  
Contrast Sensitivity ◽  
Spatial Vision ◽  
Flight Time ◽  
Resolving Power ◽  
Compound Eyes ◽  
Pattern Electroretinography ◽  
Visual Systems ◽  
Visual Properties ◽  
European Honeybee

In addition to the compound eyes insects possess simple eyes known as ocelli. Input from the ocelli modulates optomotor responses, flight-time initiation and phototactic responses, behaviours that are predominantly mediated by the compound eyes. In this study, using pattern electroretinography (pERG), we investigated the contribution of the compound eyes to ocellar spatial vision in the diurnal Australian bull ant, Myrmecia tarsata by measuring the contrast sensitivity and spatial resolving power of the ocellar second-order neurons under various occlusion conditions. Furthermore, in four species of Myrmecia ants active at different times of the day and in European honeybee, Apis mellifera, we characterized the ocellar visual properties when both visual systems were available. Among the ants, we found that the time of activity had no significant effect on ocellar spatial vision. Comparing day-active ants and the honeybee we did not find any significant effect of locomotion on ocellar spatial vision. In M. tarsata, when the compound eyes were occluded, the amplitude of the pERG signal from the ocelli reduced by three times compared to conditions when the compound eyes were available. The signals from the compound eyes maintained the maximum contrast sensitivity of the ocelli as 13 (7.7%), and the spatial resolving power as 0.29 cpd. We conclude that ocellar spatial vison improves significantly with input from the compound eyes, with a noticeably larger improvement in contrast sensitivity than in spatial resolving power.

scholarly journals The buzz around spatial resolving power and contrast sensitivity in the honeybee, Apis mellifera

2020 ◽  
Vol 169 ◽  
pp. 25-32
Author(s):  
Laura A. Ryan ◽  
Rhianon Cunningham ◽  
Nathan S. Hart ◽  
Yuri Ogawa
Keyword(s):  
Apis Mellifera ◽  
Contrast Sensitivity ◽  
Resolving Power

scholarly journals Spectral tuning and the visual ecology of mantis shrimps

2000 ◽  
Vol 355 (1401) ◽  
pp. 1263-1267 ◽  
Author(s):  
Thomas W. Cronin ◽  
N. Justin Marshall ◽  
Roy L. Caldwell
Keyword(s):  
Motion Detection ◽  
Visual Pigment ◽  
Spatial Vision ◽  
Compound Eyes ◽  
Polarization Vision ◽  
Spectral Tuning ◽  
Maximum Coverage ◽  
Visual Systems ◽  
Visual Tasks

The compound eyes of mantis shrimps (stomatopod crustaceans) include an unparalleled diversity of visual pigments and spectral receptor classes in retinas of each species. We compared the visual pigment and spectral receptor classes of 12 species of gonodactyloid stomatopods from a variety of photic environments, from intertidal to deep water (> 50 m), to learn how spectral tuning in the different photoreceptor types is modified within different photic environments. Results show that receptors of the peripheral photoreceptors, those outside the midband which are responsible for standard visual tasks such as spatial vision and motion detection, reveal the well–known pattern of decreasing λ max with increasing depth. Receptors of midband rows 5 and 6, which are specialized for polarization vision, are similar in all species, having visual λ max –values near 500 nm, independent of depth. Finally, the spectral receptors of midband rows 1 to 4 are tuned for maximum coverage of the spectrum of irradiance available in the habitat of each species. The quality of the visual worlds experienced by each species we studied must vary considerably, but all appear to exploit the full capabilities offered by their complex visual systems.

Behavioral determination of the spatial selectivity of contrast adaptation in cats: Some evidence for a common plan in the mammmlian visual system

1990 ◽  
Vol 4 (05) ◽  
pp. 413-426 ◽  
Author(s):  
M.A. Berkley
Keyword(s):  
Spatial Frequency ◽  
Contrast Sensitivity ◽  
Striate Cortex ◽  
Frequency Tuning ◽  
Spatial Vision ◽  
Adaptation Effect ◽  
Test Grating ◽  
Contrast Adaptation ◽  
Visual Systems ◽  
Spatial Frequencies

AbstractAn aftereffects paradigm was used to behaviorally measure contrast sensitivity of cats to gratings of three different test spatial frequencies after adaptation to gratings of various spatial frequencies, contrasts, and durations. Post-adaptation reductions in sensitivity occurred even after short periods of adaptation (<7 s) and could be as large as 1.0 log unit under some conditions. The magnitude of the adaptation effect varied monotonically with (1) adaptation grating contrast, (2) duration, and (3) the contrast sensitivity for the test grating. Average half-width (at half-height) of the spatial-frequency tuning curves constructed from the data was 1.4 octaves, and was not dependent upon the level of adaptation or the spatial frequency of the test grating. Post-adaptation psychometric functions of the cats showed reduced slopes and maxima suggesting that, unlike humans, in cats apparent contrast grows more slowly with increases in physical contrast after contrast adaptation. All of the characteristics observed are in excellent agreement with electrophysiologically measured properties of neurons in striate cortex of cats. In addition, there was a remarkable similarity of the cat tuning functions, both in shape and bandpass, to those measured in man with a similar paradigm suggesting that (1) the two visual systems are sufficiently similar to make the cat a useful spatial vision model and (2) there is a common functional plan to all mammalian visual systems despite significant anatomical differences between species.

Differentiation Processes of the Ocellar Retina of the Honeybee (Apis Mellifera L.)

1990 ◽  
Vol 48 (3) ◽  
pp. 430-431
Author(s):  
Maria Anna Pabst
Keyword(s):  
Apis Mellifera ◽  
Distal Part ◽  
Cell Layer ◽  
Single Layer ◽  
Photoreceptor Cells ◽  
Distal Segment ◽  
Compound Eyes ◽  
Thin Sections ◽  
Ultrastructural Studies ◽  
Adult Worker

In addition to the compound eyes, honeybees have three dorsal ocelli on the vertex of the head. Each ocellus has about 800 elongated photoreceptor cells. They are paired and the distal segment of each pair bears densely packed microvilli forming together a platelike fused rhabdom. Beneath a common cuticular lens a single layer of corneagenous cells is present.Ultrastructural studies were made of the retina of praepupae, different pupal stages and adult worker bees by thin sections and freeze-etch preparations. In praepupae the ocellar anlage consists of a conical group of epidermal cells that differentiate to photoreceptor cells, glial cells and corneagenous cells. Some photoreceptor cells are already paired and show disarrayed microvilli with circularly ordered filaments inside. In ocelli of 2-day-old pupae, when a retinogenous and a lentinogenous cell layer can be clearly distinguished, cell membranes of the distal part of two photoreceptor cells begin to interdigitate with each other and so start to form the definitive microvilli. At the beginning the microvilli often occupy the whole width of the developing rhabdom (Fig. 1).

The variation of resolution and of ommatidial dimensions in the compound eyes of the fiddler crab Uca lactea annulipes (Ocypodidae, Brachyura, Decapoda)

1996 ◽  
Vol 199 (7) ◽  
pp. 1569-1577 ◽  
Author(s):  
J Zeil ◽  
M Al-Mutairi
Keyword(s):  
Visual Field ◽  
Fiddler Crab ◽  
Visual Fields ◽  
Horizontal Resolution ◽  
Resolving Power ◽  
Compound Eyes ◽  
Vertical Resolution ◽  
Histological Techniques ◽  
Uca Lactea

We studied variations in the optical properties of the compound eyes of Uca lactea annulipes using in vivo optical and histological techniques. The distribution of resolving power in the eyes of this fiddler crab species is typical for arthropods that inhabit flat environments: the eyes possess a panoramic equatorial acute zone for vertical resolution and a steep decrease of resolution away from the eye equator in the dorsal and ventral visual fields. The dimensions of the cellular components of the ommatidia vary accordingly: in the equatorial part of the eyes, facets are larger, and crystalline cones and rhabdoms are longer than in the dorsal and ventral parts of the eyes. Along the eye equator, horizontal resolution is low compared with vertical resolution and varies little throughout the visual field. The eyes of Uca lactea annulipes are unusual in that the gradient of vertical anatomical and optical resolution is steeper in the dorsal than in the ventral visual field. We interpret this difference as indicating that the information content of the world as seen by the crabs differs above and below the horizon line in specific and predictable ways.

Spatial vision in strabismic cats

1983 ◽  
Vol 50 (1) ◽  
pp. 287-296 ◽  
Author(s):  
K. Holopigian ◽  
R. Blake
Keyword(s):  
Contrast Sensitivity ◽  
Preceding Paper ◽  
Spatial Vision ◽  
Performance Difference ◽  
Single Class ◽  
Convergent Strabismus ◽  
Contrast Thresholds

Contrast thresholds for detection of stationary and flickering gratings were measured behaviorally for each eye of cats raised with induced convergent strabismus. The performance of the deviating eye was inferior to that of the nondeviating eye when test patterns were stationary. Flicker served to reduce the performance difference between the eyes in two cats but not in a third. These results suggest that strabismus amblyopia may not result from deficits within a single class of neurons. In all strabismic cats the contrast sensitivity of the nondeviating eye was significantly reduced relative to normal cats. These behavioral findings, including the deficits found bilaterally, correspond very well with results from cortical recordings from these and other strabismic cats presented in the preceding paper (7).

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