scholarly journals Visual navigation in insects: coupling of egocentric and geocentric information

1996 ◽  
Vol 199 (1) ◽  
pp. 129-140 ◽  
Author(s):  
R Wehner ◽  
B Michel ◽  
P Antonsen
Keyword(s):  
Path Integration ◽  
Dead Reckoning ◽  
Positional Information ◽  
Central Place ◽  
Visual Navigation ◽  
Topographic Map ◽  
Integration System ◽  
First Case ◽  
Starting Point ◽  
Vector Information

Social hymenopterans such as bees and ants are central-place foragers; they regularly depart from and return to fixed positions in their environment. In returning to the starting point of their foraging excursion or to any other point, they could resort to two fundamentally different ways of navigation by using either egocentric or geocentric systems of reference. In the first case, they would rely on information continuously collected en route (path integration, dead reckoning), i.e. integrate all angles steered and all distances covered into a mean home vector. In the second case, they are expected, at least by some authors, to use a map-based system of navigation, i.e. to obtain positional information by virtue of the spatial position they occupy within a larger environmental framework. In bees and ants, path integration employing a skylight compass is the predominant mechanism of navigation, but geocentred landmark-based information is used as well. This information is obtained while the animal is dead-reckoning and, hence, added to the vector course. For example, the image of the horizon skyline surrounding the nest entrance is retinotopically stored while the animal approaches the goal along its vector course. As shown in desert ants (genus Cataglyphis), there is neither interocular nor intraocular transfer of landmark information. Furthermore, this retinotopically fixed, and hence egocentred, neural snapshot is linked to an external (geocentred) system of reference. In this way, geocentred information might more and more complement and potentially even supersede the egocentred information provided by the path-integration system. In competition experiments, however, Cataglyphis never frees itself of its homeward-bound vector - its safety-line, so to speak - by which it is always linked to home. Vector information can also be transferred to a longer-lasting (higher-order) memory. There is no need to invoke the concept of the mental analogue of a topographic map - a metric map - assembled by the insect navigator. The flexible use of vectors, snapshots and landmark-based routes suffices to interpret the insect's behaviour. The cognitive-map approach in particular, and the representational paradigm in general, are discussed.

scholarly journals Path integration in mammals and its interaction with visual landmarks.

1996 ◽  
Vol 199 (1) ◽  
pp. 201-209 ◽  
Author(s):  
A S Etienne ◽  
R Maurer ◽  
V Séguinot
Keyword(s):  
Path Integration ◽  
Visual Cues ◽  
Dead Reckoning ◽  
Visual Landmarks ◽  
Integration System ◽  
External Cues ◽  
Rapid Accumulation ◽  
Types Of Information ◽  
Point Of Departure ◽  
Inertial Cues

During locomotion, mammals update their position with respect to a fixed point of reference, such as their point of departure, by processing inertial cues, proprioceptive feedback and stored motor commands generated during locomotion. This so-called path integration system (dead reckoning) allows the animal to return to its home, or to a familiar feeding place, even when external cues are absent or novel. However, without the use of external cues, the path integration process leads to rapid accumulation of errors involving both the direction and distance of the goal. Therefore, even nocturnal species such as hamsters and mice rely more on previously learned visual references than on the path integration system when the two types of information are in conflict. Recent studies investigate the extent to which path integration and familiar visual cues cooperate to optimize the navigational performance.

scholarly journals Visual navigation in desert ants Cataglyphis fortis: are snapshots coupled to a celestial system of reference?

2002 ◽  
Vol 205 (14) ◽  
pp. 1971-1978 ◽  
Author(s):  
Susanne Åkesson ◽  
Rüdiger Wehner
Keyword(s):  
Path Integration ◽  
Central Place ◽  
Visual Navigation ◽  
Central Place Foraging ◽  
Nest Location ◽  
Compass Direction ◽  
Desert Ants ◽  
Reference Information ◽  
Cataglyphis Fortis

SUMMARY Central-place foraging insects such as desert ants of the genus Cataglyphis use both path integration and landmarks to navigate during foraging excursions. The use of landmark information and a celestial system of reference for nest location was investigated by training desert ants returning from an artificial feeder to find the nest at one of four alternative positions located asymmetrically inside a four-cylinder landmark array. The cylindrical landmarks were all of the same size and arranged in a square, with the nest located in the southeast corner. When released from the compass direction experienced during training (southeast), the ants searched most intensely at the fictive nest position. When instead released from any of the three alternative directions of approach (southwest, northwest or northeast), the same individuals instead searched at two of the four alternative positions by initiating their search at the position closest to the direction of approach when entering the landmark square and then returning to the position at which snapshot, current landmark image and celestial reference information were in register. The results show that, in the ants'visual snapshot memory, a memorized landmark scene can temporarily be decoupled from a memorized celestial system of reference.

Computations on metric maps in mammals: getting oriented and choosing a multi-destination route.

1996 ◽  
Vol 199 (1) ◽  
pp. 211-217 ◽  
Author(s):  
C R Gallistel ◽  
A E Cramer
Keyword(s):  
Path Integration ◽  
Dead Reckoning ◽  
Positional Information ◽  
Cognitive Map ◽  
Geometric Features ◽  
Vervet Monkeys ◽  
Perceived Environment ◽  
The Relationship ◽  
Terrain Features

The capacity to construct a cognitive map is hypothesized to rest on two foundations: (1) dead reckoning (path integration); (2) the perception of the direction and distance of terrain features relative to the animal. A map may be constructed by combining these two sources of positional information, with the result that the positions of all terrain features are represented in the coordinate framework used for dead reckoning. When animals need to become reoriented in a mapped space, results from rats and human toddlers indicate that they focus exclusively on the shape of the perceived environment, ignoring non-geometric features such as surface colors. As a result, in a rectangular space, they are misoriented half the time even when the two ends of the space differ strikingly in their appearance. In searching for a hidden object after becoming reoriented, both kinds of subjects search on the basis of the object's mapped position in the space rather than on the basis of its relationship to a goal sign (e.g. a distinctive container or nearby marker), even though they have demonstrably noted the relationship between the goal and the goal sign. When choosing a multidestination foraging route, vervet monkeys look at least three destinations ahead, even though they are only capable of keeping a maximum of six destinations in mind at once.

scholarly journals Penerapan metode k-means clustering data COVID-19 di Provinsi Jakarta

Teknologi ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 59-68
Author(s):  
Meida Cahyo Untoro ◽  
◽  
Leslie Anggraini ◽  
Maria Andini ◽  
Hesti Retnosari ◽  
...  
Keyword(s):  
Data Distribution ◽  
Urban Village ◽  
Corona Virus ◽  
First Case ◽  
Starting Point ◽  
Clustering Data ◽  
Cure Rates ◽  
Cluster 2 ◽  
Respiratory Area

The disease epidemic that attacked the respiratory area and was detected in Indonesia starting in early 2020 is the Corona Virus (COVID-19). This virus's spread is relatively easy, namely through droplets from infected patients, so that the spread is very rapid. This research was conducted to cluster the data on Covid-19 cases in Jakarta Province considering that Jakarta is the starting point for the first case of Corona in Indonesia and until now has become one of the most significant contributors to COVID-19 issues in Indonesia, namely as of December 2020 positive cases of Covid-19 reached 154,000. Souls with the healing of 139.0000 souls. The grouping was carried out based on positive and dead patients from each urban village in Jakarta Province. This study uses the k-means Method to cluster in the handling of COVID-19 cases with 2 clusters. Data distribution in cluster 1 consists of 173 data and 18 data in cluster 2. The use of k-means in this study provides information on areas with the highest and lowest number of positive cases and the highest and lowest cure rates that can be used as an evaluation in handling the Covid-virus 19.

Extending Metadata Standards for Historical GIS Research

2016 ◽  
pp. 1243-1265
Author(s):  
Shelley Burleson ◽  
Alberto Giordano
Keyword(s):  
Geographical Information Systems ◽  
Historical Data ◽  
Geographical Information ◽  
Historical Sources ◽  
Historical Gis ◽  
First Case ◽  
Metadata Standards ◽  
Starting Point ◽  
The Holocaust ◽  
Definitive Solution

This chapter proposes a structure for handling commonly observed uncertainties in geo-historical data, using as case studies two historical geographical information systems (HGIS) projects that interweave historical research with the geography of genocide. The first case involves the ghettoization of Budapest's Jews during the Holocaust in the second half of 1944. The more recent work, and the second case, covers the Armenian genocide spanning most of WWI and several years afterwards. The authors suggest using existing metadata standards as one way of handling the inherent uncertainties of geo-historical sources. While not a definitive solution, they argue that such an approach provides a starting point and a platform to conceptually frame the use of geo-historical data in HGIS.

Leaky integration during blindfolded walking along veering paths

2012 ◽  
Vol 25 (0) ◽  
pp. 139
Author(s):  
Markus Lappe ◽  
Claudia Fontaine ◽  
Harald Frenz
Keyword(s):  
Path Integration ◽  
Path Length ◽  
Distance Estimation ◽  
Forward Direction ◽  
Travel Distance ◽  
Integration Model ◽  
Starting Point ◽  
End Distance ◽  
Leaky Integration ◽  
The Right

We compare travel distance estimation from path integration during walking with path integration from visual flow. For visually simulated self-movement humans typically underestimate travel distance, which can be explained by leaky path integration. The amount of leak, i.e., the underestimation, is determined by the length of the path. For visually simulated movements along curved paths that veer left and right around a central forward direction estimates of the start-to-end distance decrease as the veering, i.e., the path length increases. Leaky path integration for visual travel distance estimation thus takes place along the actually traversed path even when a straight beeline distance is calculated. We studied whether the same leaky path integration occurs during real self-motion when vestibular and proprioceptive cues are available instead of vision. Sixteen subjects walked blindfolded from a starting point to targets 20, 30 or 40 m away, guided by an experimenter. They walked either along a straight line, or along paths that deviated first to the right and then to the left (or vice versa) before they reached the end point. This increased the path length by 5, 10, 20 or 30%. Subjects then gave a verbal estimate of their beeline distance from the starting point. Like in the visually simulated case, distance estimates for the same start-to-end distance of 40 m dropped as the path length increased, consistent with the prediction of the leaky integration model. We conclude that travel distance estimation is similar for visual and for vestibular/proprioceptive cues.

The ant?s path integration system: a neural architecture

1995 ◽  
Vol 73 (6) ◽  
pp. 483-497 ◽  
Author(s):  
Georg Hartmann ◽  
R�diger Wehner
Keyword(s):  
Path Integration ◽  
Integration System ◽  
Neural Architecture ◽  
System A

scholarly journals The Body as Interstitial Space between Media in Leçons de Ténèbres by Vincent Dieutre and Histoire d’un Secret by Mariana Otero

2013 ◽  
Vol 7 (1) ◽  
pp. 111-126
Author(s):  
Marlène Monteiro
Keyword(s):  
Drug Addict ◽  
Interstitial Space ◽  
The Body ◽  
Mise En Abyme ◽  
Illegal Abortion ◽  
First Case ◽  
Starting Point ◽  
Looking Back ◽  
The Way

Abstract This essay examines the ways in which the representation of the body in painting is the starting point of a broader reflection on the plasticity of the medium in two French autobiographical films. In Histoire d’un secret (Story of a Secret, 2003) by Mariana Otero and Leçons de ténèbres (Tenebrae Lessons, 2000) by Vincent Dieutre, the body is indeed at the centre, albeit in very different ways. The first is a documentary about the director’s mother who died of the consequences of an illegal abortion in the late sixties. She was an artist and her paintings, many of which depict lascivious female nudes, pervade the film. The second is a self-fictional essay that weaves together narrated episodes of the film-maker’s story as a homosexual and drug addict with close-ups of Caravaggist paintings which tend to focus on bodies in pain. Whether prefiguring death and embodying the absent body through the latent evocation of maternity in the first case, or looking back into figural art in the second, both films point to the plasticity of the medium through the representation of matter, that is, paint and, ultimately, the body. The way in which both film-makers resort to light, the close-up, and, as far as Dieutre is concerned, the diversity of film formats, embodies what Deleuze defines as the haptic gaze to explore cinema’s own materiality. In addition, the presence of the paintings introduces the issue of intermediality which modestly points to a mise en abyme of the broader question of cinema’s shifting ontology.

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