AN ANALOG VLSI INPLEMENTATION OF A VISUAL INTERNEURON: ENHANCED SENSORY PROCESSING THROUGH BIOPHYSICAL MODELING

1999 ◽  
Vol 09 (05) ◽  
pp. 391-395 ◽  
Author(s):  
REID R. HARRISON ◽  
CHRISTOF KOCH
Keyword(s):  
Sensory Processing ◽  
Visual Processing ◽  
Visual Motion ◽  
Gain Control ◽  
Analog Vlsi ◽  
Neuronal Model ◽  
Wide Field ◽  
Motion Information ◽  
Biophysical Modeling ◽  
Pattern Size

Flies are capable of rapid, coordinated flight through unstructured environments. This flight is guided by visual motion information that is extracted from photoreceptors in a robust manner. One feature of the fly's visual processing that adds to this robustness is the saturation of wide-field motion-sensitive neuron responses with increasing pattern size. This makes the cell's responses less dependent on the sparseness of the optical flow field while retaining motion information. By implementing a compartmental neuronal model in silicon, we add this "gain control" to an existing analog VLSI model of fly vision. This results in enhanced performance in a compact, low-power CMOS motion sensor. Our silicon system also demonstrates that modern, biophysically-detailed models of neural sensory processing systems can be instantiated in VLSI hardware.

Linking Neuronal Direction Selectivity to Perceptual Decisions About Visual Motion

2020 ◽  
Vol 6 (1) ◽  
pp. 335-362
Author(s):  
Tatiana Pasternak ◽  
Duje Tadin
Keyword(s):  
Prefrontal Cortex ◽  
Visual Processing ◽  
Visual Motion ◽  
Neuronal Response ◽  
Physiological Responses ◽  
Direction Selectivity ◽  
Motion Information ◽  
Motion Direction ◽  
Neurophysiological Studies ◽  
Selective Activity

Psychophysical and neurophysiological studies of responses to visual motion have converged on a consistent set of general principles that characterize visual processing of motion information. Both types of approaches have shown that the direction and speed of target motion are among the most important encoded stimulus properties, revealing many parallels between psychophysical and physiological responses to motion. Motivated by these parallels, this review focuses largely on more direct links between the key feature of the neuronal response to motion, direction selectivity, and its utilization in memory-guided perceptual decisions. These links were established during neuronal recordings in monkeys performing direction discriminations, but also by examining perceptual effects of widespread elimination of cortical direction selectivity produced by motion deprivation during development. Other approaches, such as microstimulation and lesions, have documented the importance of direction-selective activity in the areas that are active during memory-guided direction comparisons, area MT and the prefrontal cortex, revealing their likely interactions during behavioral tasks.

scholarly journals Acute Application of Imidacloprid Alters the Sensitivity of Direction Selective Motion Detecting Neurons in an Insect Pollinator

2021 ◽  
Vol 12 ◽  
Author(s):  
Elisa Rigosi ◽  
David C. O’Carroll
Keyword(s):  
Flight Control ◽  
Visual Processing ◽  
Visual Cues ◽  
Visual Motion ◽  
Plant Protection ◽  
Control Treatment ◽  
Wide Field ◽  
General Effect ◽  
The Brain

Cholinergic pesticides, such as the neonicotinoid imidacloprid, are the most important insecticides used for plant protection worldwide. In recent decades, concerns have been raised about side effects on non-target insect species, including altered foraging behavior and navigation. Although pollinators rely on visual cues to forage and navigate their environment, the effects of neonicotinoids on visual processing have been largely overlooked. To test the effect of acute treatment with imidacloprid at known concentrations in the brain, we developed a modified electrophysiological setup that allows recordings of visually evoked responses while perfusing the brain in vivo. We obtained long-lasting recordings from direction selective wide-field, motion sensitive neurons of the hoverfly pollinator, Eristalis tenax. Neurons were treated with imidacloprid (3.9 μM, 0.39 μM or a sham control treatment using the solvent (dimethylsulfoxide) only. Exposure to a high, yet sub-lethal concentration of imidacloprid significantly alters their physiological response to motion stimuli. We observed a general effect of imidacloprid (3.9 μM) increasing spontaneous activity, reducing contrast sensitivity and giving weaker directional tuning to wide-field moving stimuli, with likely implications for errors in flight control, hovering and routing. Our electrophysiological approach reveals the robustness of the fly visual pathway against cholinergic perturbance (i.e., at 0.39 μM) but also potential threatening effects of cholinergic pesticides (i.e., evident at 3.9 μM) for the visual motion detecting system of an important pollinator.

scholarly journals The cholinergic pesticide imidacloprid impairs contrast and direction sensitivity in motion detecting neurons of an insect pollinator

2018 ◽  
Author(s):  
Elisa Rigosi ◽  
David C. O’Carroll
Keyword(s):  
Flight Control ◽  
Visual Processing ◽  
Visual Cues ◽  
Visual Motion ◽  
Plant Protection ◽  
Wide Field ◽  
Insect Pollinator ◽  
Direction Sensitivity ◽  
Spontaneous Firing Rate

AbstractCholinergic pesticides such as the neonicotinoid imidacloprid are the most important insecticides used for plant protection worldwide. In recent decades concerns have been raised about side effects on non-target insect species, including altered foraging behaviour and navigation. Although pollinators rely on visual cues to forage and navigate their environment, the effect of neonicotinoids on visual processing have been largely overlooked. Here we describe a modified electrophysiological setup that allowed recordings of visually evoked responses while perfusing the brain in vivo. Long-lasting recordings from wide-field motion sensitive neurons of the hoverfly pollinator, Eristalis tenax, revealed that sub-lethal exposure to imidacloprid alters their physiological response to motion stimuli. We observed substantially increased spontaneous firing rate, reduced contrast sensitivity and weaker directional tuning to wide-field moving stimuli. This approach reveals sub-lethal effects of imidacloprid in the visual motion detecting system of an important pollinator with likely implications for flight control, hovering and routing.

scholarly journals Disentangling of Local and Wide-Field Motion Adaptation

2021 ◽  
Vol 15 ◽  
Author(s):  
Jinglin Li ◽  
Miriam Niemeier ◽  
Roland Kern ◽  
Martin Egelhaaf
Keyword(s):  
Optic Flow ◽  
Visual Processing ◽  
Visual Motion ◽  
Spatial Scales ◽  
Stimulus Level ◽  
The Other ◽  
Wide Field ◽  
Local Motion ◽  
Motion Direction ◽  
Motion Adaptation

Motion adaptation has been attributed in flying insects a pivotal functional role in spatial vision based on optic flow. Ongoing motion enhances in the visual pathway the representation of spatial discontinuities, which manifest themselves as velocity discontinuities in the retinal optic flow pattern during translational locomotion. There is evidence for different spatial scales of motion adaptation at the different visual processing stages. Motion adaptation is supposed to take place, on the one hand, on a retinotopic basis at the level of local motion detecting neurons and, on the other hand, at the level of wide-field neurons pooling the output of many of these local motion detectors. So far, local and wide-field adaptation could not be analyzed separately, since conventional motion stimuli jointly affect both adaptive processes. Therefore, we designed a novel stimulus paradigm based on two types of motion stimuli that had the same overall strength but differed in that one led to local motion adaptation while the other did not. We recorded intracellularly the activity of a particular wide-field motion-sensitive neuron, the horizontal system equatorial cell (HSE) in blowflies. The experimental data were interpreted based on a computational model of the visual motion pathway, which included the spatially pooling HSE-cell. By comparing the difference between the recorded and modeled HSE-cell responses induced by the two types of motion adaptation, the major characteristics of local and wide-field adaptation could be pinpointed. Wide-field adaptation could be shown to strongly depend on the activation level of the cell and, thus, on the direction of motion. In contrast, the response gain is reduced by local motion adaptation to a similar extent independent of the direction of motion. This direction-independent adaptation differs fundamentally from the well-known adaptive adjustment of response gain according to the prevailing overall stimulus level that is considered essential for an efficient signal representation by neurons with a limited operating range. Direction-independent adaptation is discussed to result from the joint activity of local motion-sensitive neurons of different preferred directions and to lead to a representation of the local motion direction that is independent of the overall direction of global motion.

scholarly journals Correlation versus gradient type motion detectors: the pros and cons

2007 ◽  
Vol 362 (1479) ◽  
pp. 369-374 ◽  
Author(s):  
Alexander Borst
Keyword(s):  
Nervous System ◽  
Visual Motion ◽  
Automatic Gain Control ◽  
Three Dimensional ◽  
Gain Control ◽  
Dimensional Structure ◽  
Motion Information ◽  
Stimulus Velocity ◽  
Functional Aspects ◽  
Gradient Type

Visual motion contains a wealth of information about self-motion as well as the three-dimensional structure of the environment. Therefore, it is of utmost importance for any organism with eyes. However, visual motion information is not explicitly represented at the photoreceptor level, but rather has to be computed by the nervous system from the changing retinal images as one of the first processing steps. Two prominent models have been proposed to account for this neural computation: the Reichardt detector and the gradient detector. While the Reichardt detector correlates the luminance levels derived from two adjacent image points, the gradient detector provides an estimate of the local retinal image velocity by dividing the spatial and the temporal luminance gradient. As a consequence of their different internal processing structure, both the models differ in a number of functional aspects such as their dependence on the spatial-pattern structure as well as their sensitivity to photon noise. These different properties lead to the proposal that an ideal motion detector should be of Reichardt type at low luminance levels, but of gradient type at high luminance levels. However, experiments on the fly visual systems provided unambiguous evidence in favour of the Reichardt detector under all luminance conditions. Does this mean that the fly nervous system uses suboptimal computations, or is there a functional aspect missing in the optimality criterion? In the following, I will argue in favour of the latter, showing that Reichardt detectors have an automatic gain control allowing them to dynamically adjust their input–output relationships to the statistical range of velocities presented, while gradient detectors do not have this property. As a consequence, Reichardt detectors, but not gradient detectors, always provide a maximum amount of information about stimulus velocity over a large range of velocities. This important property might explain why Reichardt type of computations have been demonstrated to underlie the extraction of motion information in the fly visual system under all luminance levels.

Disturbances in sensory processing of visual motion information to association cortex in affective psychosis and schizophrenia

2011 ◽  
Vol 26 ◽  
pp. e154-e155
Author(s):  
Rebekka Lencer ◽  
Sarah K. Keedy ◽  
James L. Reilly ◽  
Bruce E. McDonough ◽  
Margret S.H. Harris ◽  
...  
Keyword(s):  
Sensory Processing ◽  
Visual Motion ◽  
Association Cortex ◽  
Motion Information ◽  
Affective Psychosis

scholarly journals Differential adaptation to visual motion allows robust encoding of optic flow in the dragonfly

2018 ◽  
Author(s):  
Bernard J E Evans ◽  
David C O'Carroll ◽  
Joseph M Fabian ◽  
Steven D Wiederman
Keyword(s):  
Optic Flow ◽  
Visual Processing ◽  
Visual Motion ◽  
Slow Motion ◽  
Wide Field ◽  
Motion Adaptation ◽  
Early Visual Processing ◽  
Differential Adaptation ◽  
Analysis System ◽  
Great Complexity

An important task for any aerial creature is the ability to ascertain their own movement (ego-motion) through their environment. Neurons thought to underlie this behaviour have been well-characterised in many insect models including flies, moths and bees. However, dragonfly wide-field motion pathways remain undescribed. Some species of Dragonflies, such as Hemicordulia tau, engage in hawking behaviour, hovering in a single area for extended periods of time whilst also engaging in fast-moving patrols and highly dynamic pursuits of prey and conspecifics. These varied flight behaviours place very different constraints on establishing ego-motion from optic flow cues hinting at a sophisticated wide-field motion analysis system capable of detecting both fast and slow motion. We characterised wide-field motion sensitive neurons via intracellular recordings in Hemicordulia dragonflies finding similar properties to those found in other species. We found that the spatial and temporal tuning properties of these neurons were broadly similar but differed significantly in their adaptation to sustained motion. We categorised a total of three different subclasses, finding differences between subclasses in their motion adaptation and response to the broadband statistics of natural images. The differences found correspond well with the dynamics of the varied behavioural tasks hawking dragonflies perform. These findings may underpin the exquisite flight behaviours found in dragonflies. They also hint at the need for the great complexity seen in dragonfly early visual processing.

scholarly journals Directional selectivity and its use in early visual processing

1981 ◽  
Vol 211 (1183) ◽  
pp. 151-180 ◽  
Keyword(s):  
Visual Processing ◽  
Visual Motion ◽  
Time Derivative ◽  
Receptive Fields ◽  
Specific Model ◽  
Zero Crossings ◽  
Second Stage ◽  
Early Visual Processing ◽  
Local Direction ◽  
Zero Values

The construction of directionally selective units, and their use in the processing of visual motion, are considered. The zero crossings of ∇ 2 G(x, y) ∗ I(x, y) are located, as in Marr & Hildreth (1980). That is, the image is filtered through centre-surround receptive fields, and the zero values in the output are found. In addition, the time derivative ∂[∇ 2 G(x, y) ∗ l(x, y) ]/∂ t is measured at the zero crossings, and serves to constrain the local direction of motion to within 180°. The direction of motion can be determined in a second stage, for example by combining the local constraints. The second part of the paper suggests a specific model of the information processing by the X and Y cells of the retina and lateral geniculate nucleus, and certain classes of cortical simple cells. A number of psychophysical and neurophysiological predictions are derived from the theory.

scholarly journals Wide-Field Feedback Neurons Dynamically Tune Early Visual Processing

Neuron ◽  
2014 ◽  
Vol 82 (4) ◽  
pp. 887-895 ◽  
Author(s):  
John C. Tuthill ◽  
Aljoscha Nern ◽  
Gerald M. Rubin ◽  
Michael B. Reiser
Keyword(s):  
Visual Processing ◽  
Wide Field ◽  
Early Visual Processing

scholarly journals Binocular Contributions to Optic Flow Processing in the Fly Visual System

2001 ◽  
Vol 85 (2) ◽  
pp. 724-734 ◽  
Author(s):  
Holger G. Krapp ◽  
Roland Hengstenberg ◽  
Martin Egelhaaf
Keyword(s):  
Optic Flow ◽  
Functional Role ◽  
Optic Lobe ◽  
Receptive Fields ◽  
Flow Fields ◽  
Wide Field ◽  
Motion Information ◽  
Local Motion ◽  
Response Field

Integrating binocular motion information tunes wide-field direction-selective neurons in the fly optic lobe to respond preferentially to specific optic flow fields. This is shown by measuring the local preferred directions (LPDs) and local motion sensitivities (LMSs) at many positions within the receptive fields of three types of anatomically identifiable lobula plate tangential neurons: the three horizontal system (HS) neurons, the two centrifugal horizontal (CH) neurons, and three heterolateral connecting elements. The latter impart to two of the HS and to both CH neurons a sensitivity to motion from the contralateral visual field. Thus in two HS neurons and both CH neurons, the response field comprises part of the ipsi- and contralateral visual hemispheres. The distributions of LPDs within the binocular response fields of each neuron show marked similarities to the optic flow fields created by particular types of self-movements of the fly. Based on the characteristic distributions of local preferred directions and motion sensitivities within the response fields, the functional role of the respective neurons in the context of behaviorally relevant processing of visual wide-field motion is discussed.

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