scholarly journals Vision, touch and object manipulation in Senegal parrots Poicephalus senegalus

2011 ◽  
Vol 278 (1725) ◽  
pp. 3687-3693 ◽  
Author(s):  
Zoe P. Demery ◽  
Jackie Chappell ◽  
Graham R. Martin
Keyword(s):  
Visual Fields ◽  
Bird Species ◽  
Object Manipulation ◽  
Field Configuration ◽  
Tactile Information ◽  
Binocular Field ◽  
Prime Determinant ◽  
Tactile Cues ◽  
Foraging Method ◽  
Visual Coverage

Parrots are exceptional among birds for their high levels of exploratory behaviour and manipulatory abilities. It has been argued that foraging method is the prime determinant of a bird's visual field configuration. However, here we argue that the topography of visual fields in parrots is related to their playful dexterity, unique anatomy and particularly the tactile information that is gained through their bill tip organ during object manipulation. We measured the visual fields of Senegal parrots Poicephalus senegalus using the ophthalmoscopic reflex technique and also report some preliminary observations on the bill tip organ in this species. We found that the visual fields of Senegal parrots are unlike those described hitherto in any other bird species, with both a relatively broad frontal binocular field and a near comprehensive field of view around the head. The behavioural implications are discussed and we consider how extractive foraging and object exploration, mediated in part by tactile cues from the bill, has led to the absence of visual coverage of the region below the bill in favour of more comprehensive visual coverage above the head.

scholarly journals Hi-Speed Tactile Sensing for Array-type Tactile Sensor and Object Manipulation based on Tactile Information

2012 ◽  
Vol 25 (5) ◽  
pp. 117-125
Author(s):  
Wataru Fukui ◽  
Futoshi Kobayashi ◽  
Fumio Kojima ◽  
Hiroyuki Nakamoto ◽  
Tadashi Maeda ◽  
...  
Keyword(s):  
Tactile Sensor ◽  
Object Manipulation ◽  
Tactile Sensing ◽  
Tactile Information ◽  
Array Type

External Design and Field of View of the Compound Eyes in a Raptorial Neuropteran Insect, Mantispa Styriaca

1990 ◽  
Vol 148 (1) ◽  
pp. 353-365 ◽  
Author(s):  
U. EGGENREICH ◽  
K. KRAL
Keyword(s):  
Dark Adaptation ◽  
Visual Fields ◽  
Field Of View ◽  
Compound Eyes ◽  
Praying Mantis ◽  
Binocular Field ◽  
Frontal Part

Visual fields and ommatidial angles of the compound eyes of Mantispa styriaca were determined using luminous pseudopupil and histological-anatomical techniques. The maximal horizontal overlap averaged 42.7° in femalesand 52.4° in males; females had only one overlap maximum, whereas males had two. In the dorsoventral direction, the binocular field had an overlap of 135.2° in the female and 142° in the male. In light-adapted eyes, optical acceptance angles reached values of 2.0°, and they reached 3.6° with dark adaptation; interommatidial angles were between 1.8° and 2.3°. The angles were very similar over the entire eye; no acute zone was found in the frontal part of the eye, as the large binocular overlap would suggest. The results are compared with those for the praying mantis: this animal is in no way related to Mantispa but resembles it in appearance and capture behaviour.

scholarly journals Vision and touch in relation to foraging and predator detection: insightful contrasts between a plover and a sandpiper

2008 ◽  
Vol 276 (1656) ◽  
pp. 437-445 ◽  
Author(s):  
Graham R Martin ◽  
Theunis Piersma
Keyword(s):  
Visual Fields ◽  
Skeletal Structure ◽  
Visually Guided ◽  
Sources Of Information ◽  
Predator Detection ◽  
Food Items ◽  
Binocular Field ◽  
Blind Area ◽  
Wide Range ◽  
Breeding Grounds

Visual fields were determined in two species of shorebirds (Charadriiformes) whose foraging is guided primarily by different sources of information: red knots ( Calidris canutus , tactile foragers) and European golden plovers ( Pluvialis apricaria , visual foragers). The visual fields of both species showed features that are found in a wide range of birds whose foraging involves precision pecking or lunging at food items. Surprisingly, red knots did not show comprehensive panoramic vision as found in some other tactile feeders; they have a binocular field surrounding the bill and a substantial blind area behind the head. We argue that this is because knots switch to more visually guided foraging on their breeding grounds. However, this visual field topography leaves them vulnerable to predation, especially when using tactile foraging in non-breeding locations where predation by falcons is an important selection factor. Golden plovers use visually guided foraging throughout the year, and so it is not surprising that they have precision-pecking frontal visual fields. However, they often feed at night and this is associated with relatively large eyes. These are anchored in the skull by a wing of bone extending from the dorsal perimeter of each orbit; a skeletal structure previously unreported in birds and which we have named ‘supraorbital aliform bone’, Os supraorbitale aliforme . The larger eyes and their associated supraorbital wings result in a wide blind area above the head, which may leave these plovers particularly vulnerable to predation. Thus, in these two shorebirds, we see clear examples of the trade-off between the two key functions of visual fields: (i) the detection of predators remote from the animal and (ii) the control of accurate behaviours, such as the procurement of food items, at close quarters.

The ipsilateral retinal projection in the fat-tailed dunnart, Sminthopsis crassicaudata

1998 ◽  
Vol 15 (4) ◽  
pp. 677-684 ◽  
Author(s):  
J. RODGER ◽  
S.A. DUNLOP ◽  
L.D. BEAZLEY
Keyword(s):  
Ganglion Cells ◽  
Visual Fields ◽  
Optic Tract ◽  
Retinal Ganglion ◽  
Retinal Projection ◽  
Binocular Field ◽  
Sminthopsis Crassicaudata ◽  
Area Centralis ◽  
Ipsilateral Projection ◽  
The Brain

The population of retinal ganglion cells which project ipsilaterally in the brain was examined in the fat-tailed dunnart, Sminthopsis crassicaudata, following injection of horseradish peroxidase into one optic tract. Retinae were examined as wholemounts and optic nerves as serial sections. In addition, visual fields were measured ophthalmoscopically. Ipsilaterally projecting ganglion cells were located temporal to a line which ran vertically through the middle of the area centralis and extended medially to define a ventrolateral crescent. Temporal to the naso-temporal division, a mean of 77% of ganglion cells projected ipsilaterally; these cells represented 20% of the total ganglion cell population. The magnitude and retinal location of the ipsilateral projection correlated with the extensive binocular field which measured 180 deg in the vertical (from 20 deg below the horizontal axis to 70 deg beyond the zenith) and 140 deg in horizontal meridian. Ipsilaterally projecting axons were restricted to the lateral third of the optic nerve along its length, sharing territory with contralaterally projecting axons.

scholarly journals Fast and accurate edge orientation processing during object manipulation

2017 ◽  
Author(s):  
J. Andrew Pruszynski ◽  
J. Randall Flanagan ◽  
Roland S. Johansson
Keyword(s):  
Object Manipulation ◽  
Spatial Processing ◽  
Processing Capacity ◽  
Critical Aspect ◽  
Dexterous Manipulation ◽  
Tactile Information ◽  
Edge Orientation ◽  
Manipulation Task ◽  
Tactile System ◽  
Better Than

AbstractQuickly and accurately extracting information about a touched object’s orientation is a critical aspect of dexterous object manipulation. However, the speed and acuity of tactile edge orientation processing with respect to the fingertips as reported in previous perceptual studies appear inadequate in these respects. Here we directly establish the tactile system’s capacity to process edge-orientation information during dexterous manipulation. Participants extracted tactile information about edge orientation very quickly, using it within 200 ms of first touching the object. Participants were also strikingly accurate. With edges spanning the entire fingertip, edge-orientation resolution was better than 3° in our object manipulation task, which is several times better than reported in previous perceptual studies. Performance remained impressive even with edges as short as 2 mm, consistent with our ability to precisely manipulate very small objects. Taken together, our results radically redefine the spatial processing capacity of the tactile system.

Visual field of the mud crab, Scylla tranquebarica and the whiteleg shrimp, Litopenaeus vannamei

2019 ◽  
Vol 3 (1) ◽  
pp. 33-36
Author(s):  
Gunzo Kawamura ◽  
Hue-Sin Cheah ◽  
Hiroaki Saito ◽  
Mohd Yazreen Syahmie Bin Yusof ◽  
Annita Seok-Kian Yong ◽  
...  
Keyword(s):  
Visual Field ◽  
Litopenaeus Vannamei ◽  
Visual Fields ◽  
Mud Crab ◽  
Light Refraction ◽  
Binocular Field ◽  
Blind Area ◽  
Visual Behaviour ◽  
Whiteleg Shrimp ◽  
Morphological Blocking

The previous behavioural studies on vision of decapod crustaceans were often based on the assumption that the visual field of the test animals was all around and there was little or no blind area above or to the rear of the animals. In the present study, we determined the visual field of the wild captured purple mud crab (Scylla tranquebarica) and the farmed whiteleg shrimp (Litopenaeus vannamei) by eliminating the directions in which vision is anatomically blocked in all directions around the eyes. The mud crab had the visual field covering the entire visual world except for the ventral-most blind area. The whiteleg shrimp has the visual filed with a 66Ëš binocular field and can see all around but is morphologically blocked by the scaphocerite extended forward between the eyes. While the transparent scaphocerites transmit 80 % of light from 400 to 700 nm wavelengths, an object seen through the scaphocerites is faded due to the light refraction, indicating that the morphological blocking is not always negligible. The trait of these visual fields should be taken into consideration in the design of visual behaviour experiments.

scholarly journals Finger Readjustment Algorithm for Object Manipulation Based on Tactile Information

10.5772/53561 ◽  
2013 ◽  
Vol 10 (1) ◽  
pp. 9 ◽  
Author(s):  
Juan Antonio Corrales Ramón ◽  
Fernando Torres Medina ◽  
Véronique Perdereau
Keyword(s):  
Object Manipulation ◽  
Tactile Information

scholarly journals The subtlety of simple eyes: the tuning of visual fields to perceptual challenges in birds

2014 ◽  
Vol 369 (1636) ◽  
pp. 20130040 ◽  
Author(s):  
Graham R. Martin
Keyword(s):  
Visual Field ◽  
Phylogenetic Signal ◽  
Visual Fields ◽  
Interspecific Variation ◽  
Depth Information ◽  
Field Variation ◽  
Maximum Width ◽  
Binocular Field ◽  
Contralateral Projection ◽  
Per Se

Birds show interspecific variation both in the size of the fields of individual eyes and in the ways that these fields are brought together to produce the total visual field. Variation is found in the dimensions of all main parameters: binocular region, cyclopean field and blind areas. There is a phylogenetic signal with respect to maximum width of the binocular field in that passerine species have significantly broader field widths than non-passerines; broadest fields are found among crows (Corvidae). Among non-passerines, visual fields show considerable variation within families and even within some genera. It is argued that (i) the main drivers of differences in visual fields are associated with perceptual challenges that arise through different modes of foraging, and (ii) the primary function of binocularity in birds lies in the control of bill position rather than in the control of locomotion. The informational function of binocular vision does not lie in binocularity per se (two eyes receiving slightly different information simultaneously about the same objects from which higher-order depth information is extracted), but in the contralateral projection of the visual field of each eye. Contralateral projection ensures that each eye receives information from a symmetrically expanding optic flow-field from which direction of travel and time to contact targets can be extracted, particularly with respect to the control of bill position.

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