scholarly journals Impact of visual motion adaptation on neural responses to objects and its dependence on the temporal characteristics of optic flow

2011 ◽  
Vol 105 (4) ◽  
pp. 1825-1834 ◽  
Author(s):  
Pei Liang ◽  
Roland Kern ◽  
Rafael Kurtz ◽  
Martin Egelhaaf
Keyword(s):  
Optic Flow ◽  
Visual Motion ◽  
Induced Response ◽  
Neural Responses ◽  
Neuronal Responses ◽  
Motion Adaptation ◽  
Preferred Direction ◽  
Pure Rotation ◽  
Normal Behavior ◽  
Natural Dynamics

It is still unclear how sensory systems efficiently encode signals with statistics as experienced by animals in the real world and what role adaptation plays during normal behavior. Therefore, we studied the performance of visual motion-sensitive neurons of blowflies, the horizontal system neurons, with optic flow that was reconstructed from the head trajectories of semi-free-flying flies. To test how motion adaptation is affected by optic flow dynamics, we manipulated the seminatural optic flow by targeted modifications of the flight trajectories and assessed to what extent neuronal responses to an object located close to the flight trajectory depend on adaptation dynamics. For all types of adapting optic flow object-induced response increments were stronger in the adapted compared with the nonadapted state. Adaptation with optic flow characterized by the typical alternation between translational and rotational segments produced this effect but also adaptation with optic flow that lacked these distinguishing features and even pure rotation at a constant angular velocity. The enhancement of object-induced response increments had a direction-selective component because preferred-direction rotation and natural optic flow were more efficient adaptors than null-direction rotation. These results indicate that natural dynamics of optic flow is not a basic requirement to adapt neurons in a specific, presumably functionally beneficial way. Our findings are discussed in the light of adaptation mechanisms proposed on the basis of experiments previously done with conventional experimenter-defined stimuli.

Motion Adaptation in Area MT

2002 ◽  
Vol 88 (6) ◽  
pp. 3469-3476 ◽  
Author(s):  
Richard J. A. Van Wezel ◽  
Kenneth H. Britten
Keyword(s):  
Opposite Direction ◽  
Human Motion ◽  
Neural Responses ◽  
Motion Adaptation ◽  
Area Mt ◽  
Temporal Area ◽  
Subsequent Test ◽  
Preferred Direction ◽  
Perceptual Shift ◽  
Static Pattern

In many sensory systems, exposure to a prolonged stimulus causes adaptation, which tends to reduce neural responses to subsequent stimuli. Such effects are usually stimulus-specific, making adaptation a powerful probe into information processing. We used dynamic random dot kinematograms to test the magnitude and selectivity of adaptation effects in the middle temporal area (MT) and to compare them to effects on human motion discrimination. After 3 s of adaptation to a random dot pattern moving in the preferred direction, MT neuronal responses to subsequent test patterns were reduced by 26% on average compared with adaptation to a static pattern. This reduction in response magnitude was largely independent of what test stimulus was presented. However, adaptation in the opposite direction changed responses less often and very inconsistently. Therefore motion adaptation systematically and profoundly affects the neurons in MT representing the adapted direction, but much less those representing the opposite direction. In human psychophysical experiments, such adapting stimuli affected direction discrimination, biasing choices away from the adaptation direction. The magnitude of this perceptual shift was consistent with the magnitude of the changes seen in area MT, if one assumes that a motion comparison step occurs after MT.

scholarly journals Dendritic Calcium Accumulation Associated With Direction-Selective Adaptation in Visual Motion-Sensitive Neurons In Vivo

2000 ◽  
Vol 84 (4) ◽  
pp. 1914-1923 ◽  
Author(s):  
Rafael Kurtz ◽  
Volker Dürr ◽  
Martin Egelhaaf
Keyword(s):  
Visual Motion ◽  
Selective Adaptation ◽  
Direction Selectivity ◽  
Motion Adaptation ◽  
Stimulus Velocity ◽  
Calcium Accumulation ◽  
Calcium Dependent ◽  
Preferred Direction ◽  
Cell Class

Motion adaptation in directionally selective tangential cells (TC) of the fly visual system has previously been explained as a presynaptic mechanism. Based on the observation that adaptation is in part direction selective, which is not accounted for by the former models of motion adaptation, we investigated whether physiological changes located in the TC dendrite can contribute to motion adaptation. Visual motion in the neuron's preferred direction (PD) induced stronger adaptation than motion in the opposite direction and was followed by an afterhyperpolarization (AHP). The AHP subsides in the same time as adaptation recovers. By combining in vivo calcium fluorescence imaging with intracellular recording, we show that dendritic calcium accumulation following motion in the PD is correlated with the AHP. These results are consistent with a calcium-dependent physiological change in TCs underlying adaptation during continuous stimulation with PD motion, expressing itself as an AHP after the stimulus stops. However, direction selectivity of adaptation is probably not solely related to a calcium-dependent mechanism because direction-selective effects can also be observed for fast moving stimuli, which do not induce sizeable calcium accumulation. In addition, a comparison of two classes of TCs revealed differences in the relationship of calcium accumulation and AHP when the stimulus velocity was varied. Thus the potential role of calcium in motion adaptation depends on stimulation parameters and cell class.

scholarly journals Motion Adaptation Leads to Parsimonious Encoding of Natural Optic Flow by Blowfly Motion Vision System

2005 ◽  
Vol 94 (3) ◽  
pp. 1761-1769 ◽  
Author(s):  
J. Heitwerth ◽  
R. Kern ◽  
J. H. van Hateren ◽  
M. Egelhaaf
Keyword(s):  
Optic Flow ◽  
Visual Motion ◽  
Vision System ◽  
Relevant Information ◽  
Spike Timing ◽  
Motion Vision ◽  
Motion Adaptation ◽  
Time Motion ◽  
Count Response ◽  
Latency Jitter

Neurons sensitive to visual motion change their response properties during prolonged motion stimulation. These changes have been interpreted as adaptive and were concluded, for instance, to adjust the sensitivity of the visual motion pathway to velocity changes or to increase the reliability of encoding of motion information. These conclusions are based on experiments with experimenter-designed motion stimuli that differ substantially with respect to their dynamical properties from the optic flow an animal experiences during normal behavior. We analyze for the first time motion adaptation under natural stimulus conditions. The experiments are done on the H1-cell, an identified neuron in the blowfly visual motion pathway that has served in many previous studies as a model system for visual motion computation. We reconstructed optic flow perceived by a blowfly in free flight and used this behaviorally generated optic flow to study motion adaptation. A variety of measures (variability in spike count, response latency, jitter of spike timing) suggests that the coding quality does not improve with prolonged stimulation. However, although the number of spikes decreases considerably during stimulation with natural optic flow, the amount of information that is conveyed stays nearly constant. Thus the information per spike increases, and motion adaptation leads to parsimonious coding without sacrificing the reliability with which behaviorally relevant information is encoded.

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 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 Evidence accumulation relates to perceptual consciousness and monitoring

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Michael Pereira ◽  
Pierre Megevand ◽  
Mi Xue Tan ◽  
Wenwen Chang ◽  
Shuo Wang ◽  
...  
Keyword(s):  
Posterior Parietal Cortex ◽  
Detection Threshold ◽  
Task Demands ◽  
Neuron Activity ◽  
Neural Responses ◽  
Neuronal Responses ◽  
Neural Basis ◽  
Perceptual Consciousness ◽  
Evidence Accumulation ◽  
Posterior Parietal

AbstractA fundamental scientific question concerns the neural basis of perceptual consciousness and perceptual monitoring resulting from the processing of sensory events. Although recent studies identified neurons reflecting stimulus visibility, their functional role remains unknown. Here, we show that perceptual consciousness and monitoring involve evidence accumulation. We recorded single-neuron activity in a participant with a microelectrode in the posterior parietal cortex, while they detected vibrotactile stimuli around detection threshold and provided confidence estimates. We find that detected stimuli elicited neuronal responses resembling evidence accumulation during decision-making, irrespective of motor confounds or task demands. We generalize these findings in healthy volunteers using electroencephalography. Behavioral and neural responses are reproduced with a computational model considering a stimulus as detected if accumulated evidence reaches a bound, and confidence as the distance between maximal evidence and that bound. We conclude that gradual changes in neuronal dynamics during evidence accumulation relates to perceptual consciousness and perceptual monitoring in humans.

Children’s perceptual sensitivity to optic flow-like visual motion differs from adults.

2021 ◽  
Vol 57 (11) ◽  
pp. 1810-1821
Author(s):  
Yiming Qian ◽  
Andrea R. Seisler ◽  
Rick O. Gilmore
Keyword(s):  
Optic Flow ◽  
Visual Motion ◽  
Perceptual Sensitivity

Neuronal Responses Related to Smooth Pursuit Eye Movements in the Periarcuate Cortical Area of Monkeys

1998 ◽  
Vol 80 (1) ◽  
pp. 28-47 ◽  
Author(s):  
Masaki Tanaka ◽  
Kikuro Fukushima
Keyword(s):  
Eye Movements ◽  
Smooth Pursuit ◽  
Cortical Area ◽  
Eye Position ◽  
Smooth Pursuit Eye Movements ◽  
Neuronal Responses ◽  
Stationary Target ◽  
Pursuit Eye Movements ◽  
Preferred Direction ◽  
Eye Velocity

Tanaka, Masaki and Kikuro Fukushima. Neuronal responses related to smooth pursuit eye movements in the periarcuate cortical area of monkeys. J. Neurophysiol. 80: 28–47, 1998. To examine how the periarcuate area is involved in the control of smooth pursuit eye movements, we recorded 177 single neurons while monkeys pursued a moving target in the dark. The majority (52%, 92/177) of task-related neurons responded to pursuit but had little or no response to saccades. Histological reconstructions showed that these neurons were located mainly in the posterior bank of the arcuate sulcus near the sulcal spur. Twenty-seven percent (48/177) changed their activity at the onset of saccades. Of these, 36 (75%) showed presaccadic burst activity with strong preference for contraversive saccades. Eighteen (10%, 18/177) were classified as eye-position–related neurons, and 11% (19/177) were related to other aspects of the stimuli or response. Among the 92 neurons that responded to pursuit, 85 (92%) were strongly directional with uniformly distributed preferred directions. Further analyses were performed in these directionally sensitive pursuit-related neurons. For 59 neurons that showed distinct changes in activity around the initiation of pursuit, the median latency from target motion was 96 ms and that preceding pursuit was −12 ms, indicating that these neuron can influence the initiation of pursuit. We tested some neurons by briefly extinguishing the tracking target ( n = 39) or controlling its movement with the eye position signal ( n = 24). The distribution of the change in pursuit-related activity was similar to previous data for the dorsomedial part of the medial superior temporal neurons ( Newsome et al. 1988) , indicating that pursuit-related neurons in the periarcuate area also carry extraretinal signals. For 22 neurons, we examined the responses when the animals reversed pursuit direction to distinguish the effects of eye acceleration in the preferred direction from oppositely directed eye velocity. Almost all neurons discharged before eye velocity reached zero, however, only nine neurons discharged before the eyes were accelerated in the preferred direction. The delay in neuronal responses relative to the onset of eye acceleration in these trials might be caused by suppression from oppositely directed pursuit velocity. The results suggest that the periarcuate neurons do not participate in the earliest stage of eye acceleration during the change in pursuit direction, although most of them may participate in the early stages of pursuit initiation in the ordinary step-ramp pursuit trials. Some neurons changed their activity when the animals fixated a stationary target, and this activity could be distinguished easily from the strong pursuit-related responses. Our results suggest that the periarcuate pursuit area carries extraretinal signals and affects the premotor circuitry for smooth pursuit.

scholarly journals Facilitation of neural responses to targets moving against optic flow

2021 ◽  
Vol 118 (38) ◽  
pp. e2024966118
Author(s):  
Sarah Nicholas ◽  
Karin Nordström
Keyword(s):  
Optic Flow ◽  
Target Motion ◽  
Human Observer ◽  
Neural Responses ◽  
Response Facilitation ◽  
Descending Neurons ◽  
The World ◽  
Background Clutter ◽  
Spatial Window ◽  
Target Pursuit

For the human observer, it can be difficult to follow the motion of small objects, especially when they move against background clutter. In contrast, insects efficiently do this, as evidenced by their ability to capture prey, pursue conspecifics, or defend territories, even in highly textured surrounds. We here recorded from target selective descending neurons (TSDNs), which likely subserve these impressive behaviors. To simulate the type of optic flow that would be generated by the pursuer’s own movements through the world, we used the motion of a perspective corrected sparse dot field. We show that hoverfly TSDN responses to target motion are suppressed when such optic flow moves syn-directional to the target. Indeed, neural responses are strongly suppressed when targets move over either translational sideslip or rotational yaw. More strikingly, we show that TSDNs are facilitated by optic flow moving counterdirectional to the target, if the target moves horizontally. Furthermore, we show that a small, frontal spatial window of optic flow is enough to fully facilitate or suppress TSDN responses to target motion. We argue that such TSDN response facilitation could be beneficial in modulating corrective turns during target pursuit.

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