Electric images of two low resistance objects in weakly electric fish

Rother, Diego; Migliaro, Adriana; Canetti, Rafael; Gómez, Leonel; Caputi, Ángel A.; Budelli, Rubén

doi:10.1016/s0303-2647(03)00124-2

Cited by 37 publications

(55 citation statements)

References 12 publications

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“…Here, we experimentally confirm predictions made by Rother et al (Rother et al, 2003) that when one object is intercalated between another object and the fish's body, there is mutual polarization and, consequently, the image is modified in a non-additive manner. If the two objects are very close (according to our results, ≤2mm apart) their mutual polarization results in changes of the image of a nearby object even though the farthest object alone is unable to yield a distinguishable image (see Figs1 and 2).…”

Section: Discussionsupporting

confidence: 89%

“…Theoretical predictions (Rother et al, 2003;Migliaro et al, 2005;Caputi and Budelli, 2006;Pereira and Caputi, 2010) indicate that the presence of one object modifies the field in which it is placed. Thus, the field polarizing an object potentially introduced into the scene is dependent on the presence of neighboring objects.…”

Section: Discussionmentioning

confidence: 99%

“…The corollary of the concept of 'stamp' is that the presence of every polarized object may also polarize the rest of the objects in the scene with a ponderance inversely dependent on a power function of the distance between the objects. This concept of electric image formation provides some suggestions about how object images might be modified by the presence of other objects in the scene (Sicardi et al, 2000;Rother et al, 2003;Chen et al, 2005;Caputi and Budelli, 2006;Nelson and MacIver, 2006) and how clues that objects offer to an active electrolocating agent vary with context (Pereira et al, 2007;Pereira and Caputi, 2010;Sanguinetti et al, 2011).…”

Section: Introductionmentioning

confidence: 99%

“…Theoretical predictions and experimental results indicate that the image of that second object is modified by the presence of a third object (besides the object generating the image and the fish's body). Modeling analysis of this type of scene predicted that: (a) the presence of a third object in a scene may cause a change in the clues that another object offers to the agent (Rother et al, 2003;Chen et al, 2005) and (b) contextual objects may contribute with parallax references for object active electrosensing (Babineau et al, 2006;Babineau et al, 2007). However, these studies focused mainly on the side of the fish and not on the foveal region, where the electroreceptor density and central representation are more important (Castelló et al, 2000).…”

Section: Introductionmentioning

confidence: 99%

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Active electrolocation in pulse gymnotids: sensory consequences of objects’ mutual polarization

Aguilera

Pereira

Caputi

2012

Journal of Experimental Biology

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SUMMARYWe examined non-linear effects of the presence of one object on the electric image of another placed at the foveal region in Gymnotus omarorum. The sensory consequences of object mutual polarization on electric images were also depicted using behavioral procedures. Image measurements show that objects whose electric image is not detectable may modify the electric image of another placed closer to the fish and suggest that detection range and discrimination parameters used for one object may be affected when the presence of others enriches the scene. Behavioral experiments confirm that these changes in object images resulting from mutual polarization may be exploited for improving perception. While conductive objects close to the skin allow the fish to detect other objects placed out of the active electrodetection range, non-conductive objects may hide objects that otherwise show clear electric images. This suggests that fish movements may orient the self-generated field to exploit object mutual polarization, increasing or decreasing the active electrolocation range. In addition, images of a nearby object may be modulated by the presence of another object placed outside the detection range and the corresponding behavioral responses suggest that a moving or impedance-changing context may modify a fishʼs discrimination abilities for closer objects.

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Section: Discussionsupporting

confidence: 89%

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Active electrolocation in pulse gymnotids: sensory consequences of objects’ mutual polarization

Aguilera

Pereira

Caputi

2012

Journal of Experimental Biology

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“…[12][13][14][15][16][17][18][19][20][21][22][23] In active electroreception objects are polarized by the self-emitted field and behave as if they were emitting an objectemitted signals (as the moon appears as a light-emitter body during the night). As the self-generated electric field attenuates with a power function of distance, 16,21,24,25 these object-emitted signals also decay with a power function of distance.…”

mentioning

confidence: 99%

Waveform Sensors: The Next Challenge in Biomimetic Electroreception

Pereira¹

2017

IJBSBE

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The interest in developing bioinspired electric sensors increased after the rising use of electric fields as image carriers in underwater robots and medical devices using artificial electroreception (electrotomography and electric catheterism). Electric images of objects have been most often conceived as the amplitude modulation of the local electric field on a sensory mosaic, but recent research in electric fish indicates that the evaluation of time waveform of local stimulus can increase the electrosensory channels capacities and therefore improve discrimination and recognition of target objects. This minireview deals with the present importance of developing electric sensors specifically tuned to the expected carrier waveforms to improve design of artificial bioinspired agents and diagnosis devices.

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Non-visual environmental imaging and object detection through active electrolocation in weakly electric fish

2006

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Weakly electric fish orient at night by employing active electrolocation. South American and African species emit electric signals and perceive the consequences of these emissions with epidermal electroreceptors. Objects are detected by analyzing the electric images which they project onto the animal's electroreceptive skin surface. Electric images depend on size, distance, shape, and material of objects and on the morphology of the electric organ and the fish's body. It is proposed that the mormyrid Gnathonemus petersii possesses two electroreceptive "foveae" at its Schnauzenorgan and its nasal region, both of which resemble the visual fovea in the retina of many animals in design, function, and behavioral use. Behavioral experiments have shown that G. petersii can determine the resistive and capacitive components of an object's complex impedance in order to identify prey items during foraging. In addition, fish can measure the distance and three-dimensional shape of objects. In order to determine object properties during active electrolocation, the fish have to determine at least four parameters of the local signal within an object's electric image: peak amplitude, maximal slope, image width, and waveform distortions. A crucial parameter is the object distance, which is essential for unambiguous evaluation of object properties.

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Electric images of two low resistance objects in weakly electric fish

Cited by 37 publications

References 12 publications

Active electrolocation in pulse gymnotids: sensory consequences of objects’ mutual polarization

Active electrolocation in pulse gymnotids: sensory consequences of objects’ mutual polarization

Waveform Sensors: The Next Challenge in Biomimetic Electroreception

Non-visual environmental imaging and object detection through active electrolocation in weakly electric fish

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