Influence of the background for discriminating object motion from self-induced motion in toadsBufo bufo (L.)

Burghagen, H.; Ewert, Jörg-Peter

doi:10.1007/bf00611188

Cited by 49 publications

(14 citation statements)

References 17 publications

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“…If the speed of movement ( Fig. 6B) (Burghagen 1979;Burghagen & Ewert 1983;Ewert et al 1983a), the movement pattern , the direction of movement ( Fig. 6A) (Beck & Ewert 1979;, or the contrast between stimulus and background ) are changed equally in both W-and A-configurations, the Dw,A values remain positive, although their magnitudes may vary; that is, the "basic patterns" of the stimulus-response relationships shown in Fig.…”

Section: Configura! Featuresmentioning

confidence: 90%

“…The observation that for a moving toad the self-induced motion of the retinal image of a single stationary stimulus against a contrasting homogeneous white background (Fig. 3C) readily elicits prey-catching (orienting and snapping) favors the inhibitory surround hypothesis (Burghagen & Ewert 1983;cf. also Frost 1982).…”

Section: Prey/background Relationshipsmentioning

confidence: 93%

“…(For details on prey/background relationship see Burghagen & Ewert 1983; see also Manteuffel, this volume). We shall return to the "interaction concept" in Sections 4.3, 5.3.4, and 5.5.3. .…”

Section: Prey/background Relationshipsmentioning

confidence: 98%

“…It is important to note that the toad's discrimination pattern for W-, S-, and Astimuli is independent of whether the respective retinal images are produced by a moving visual stimulus, or if they occur in a situation where the toad is passively moved (continuously, stepwise, or with varying acceleration) in front of a stationary stimulus (for details see Burghagen & Ewert 1983;Ewert et al1983a).…”

Section: Some Remarksmentioning

confidence: 99%

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The Release of Visual Behavior in Toads: Stages of Parallel/Hierarchical Information Processing

Ewert

1989

Visuomotor Coordination

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Abstract. The release of toad's prey-catching behavior (orienting, approaching, fixating and snapping) is mediated by releasing schemas, also called releasing mechanisms. The present neuroethological investigation suggests the neurophysiological equivalent of a schema as a combination of neurons specified to encode significant coincidences of stimulus cues in space and time. A correspondingly coded command releasing system results from parallel/hierarchical processing in a neural macro-network whose interacting components evaluate visual input under various aspects such as features, background, space, motivation, and past experience.Essential components of prey-related sensorimotor codes are T5.2 neurons. These neurons are tuned to the spatiotemporal properties of moving objects, in such a manner that elongated worm-like moving shapes are preferred and shapes elongated perpendicular to the direction of movement are neglected. Unlike cortical "orientation detectors," the function of these tectal "configuration discriminators" does not depend on an anisotropic structure; the anisotropy required for configura! discrimination lies in the time domain of the spatiotemporal properties of the moving object itself. Evidence is provided that the direction-and velocity-invariant discriminatory properties of T5.2 neurons are brought about by discrete, parallel evaluations of the spatial and the spatiotemporal stimulus parameters by two-ffiter operations in pretectal and tectal structures, respectively, and through their subtractive interaction. In amphibians, with motionless eyes, the movement-specific analysis of moving objects seems to take advantage of an economical system that has sidestepped the need for a sophisticated anisotropic cortex-like structure known to involve a huge number of asymmetric processors in order to meet direction-invariant discriminatory operations.

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Section: Configura! Featuresmentioning

confidence: 90%

Section: Prey/background Relationshipsmentioning

confidence: 93%

Section: Prey/background Relationshipsmentioning

confidence: 98%

Section: Some Remarksmentioning

confidence: 99%

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The Release of Visual Behavior in Toads: Stages of Parallel/Hierarchical Information Processing

Ewert

1989

Visuomotor Coordination

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“…Perhaps, the textured background used by this author was too small to cover the whole visual field of the toads. In any case, the perception of induced motion was later demon strated in the prey-catching behavior in toads when a large portion of the visual field was stimulated by a patterned background [Kass and Kass, 1960;Burghagen and Ewert, 1983].…”

Section: Introductionmentioning

confidence: 99%

Neuronal Motion After-Response Induced in the Tectal Neurons of Toads by Moving Textured Background

Hj¹

1991

Brain Behav Evol

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When an object is held stationary in the center of the receptive field of a tectal neuron in a toad and a textured background is moved for a period of time, some neurons produce a burst of discharges immediately after the movement of the background ceases. This effect was first found in a recent study and temporarily called 'neuronal motion after-response'. A total of 66 tectal neurons in toads were examined, and 29 out of them showed the effect. In the different neurons under investigation, the firing rate varied from a few spikes to discharges of very long duration. The appearance of the motion after-response was independent of either the object/background contrast (i.e. black against white vs. white against black) or the direction of the background movement. In order to induce this effect, however, the object must be of sufficient size, and the background must be moved for a sufficient length of time. For most tectal neurons, an 8 x 8° square was large enough to induce the motion after-response, but for several others, the size of the object had to be similar to that of the excitatory receptive field of the neuron. The duration of the background movement was also crucial: at least 20 s of background movement was necessary for the motion after-response to occur.

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Stimulus Perception

Burghagen¹,

Ewert²

2021

The Behavior of Animals, 2nd Edition

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Influence of the background for discriminating object motion from self-induced motion in toadsBufo bufo (L.)

Cited by 49 publications

References 17 publications

The Release of Visual Behavior in Toads: Stages of Parallel/Hierarchical Information Processing

The Release of Visual Behavior in Toads: Stages of Parallel/Hierarchical Information Processing

Neuronal Motion After-Response Induced in the Tectal Neurons of Toads by Moving Textured Background

Stimulus Perception

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