scholarly journals Spatial specificity and inheritance of adaptation in human visual cortex

2015 ◽  
Vol 114 (2) ◽  
pp. 1211-1226 ◽  
Author(s):  
Jonas Larsson ◽  
Sarah J. Harrison
Keyword(s):  
Visual Cortex ◽  
Visual Processing ◽  
Visual Motion ◽  
Downstream Processing ◽  
Selective Adaptation ◽  
Motion Direction ◽  
Visual Areas ◽  
Spatial Specificity ◽  
Fmri Adaptation ◽  
The Impact

Adaptation at early stages of sensory processing can be propagated to downstream areas. Such inherited adaptation is a potential confound for functional magnetic resonance imaging (fMRI) techniques that use selectivity of adaptation to infer neuronal selectivity. However, the relative contributions of inherited and intrinsic adaptation at higher cortical stages, and the impact of inherited adaptation on downstream processing, remain unclear. Using fMRI, we investigated how adaptation to visual motion direction and orientation influences visually evoked responses in human V1 and extrastriate visual areas. To dissociate inherited from intrinsic adaptation, we quantified the spatial specificity of adaptation for each visual area as a measure of the receptive field sizes of the area where adaptation originated, predicting that adaptation originating in V1 should be more spatially specific than adaptation intrinsic to extrastriate visual cortex. In most extrastriate visual areas, the spatial specificity of adaptation did not differ from that in V1, suggesting that adaptation originated in V1. Only in one extrastriate area—MT—was the spatial specificity of direction-selective adaptation significantly broader than in V1, consistent with a combination of inherited V1 adaptation and intrinsic MT adaptation. Moreover, inherited adaptation effects could be both facilitatory and suppressive. These results suggest that adaptation at early visual processing stages can have widespread and profound effects on responses in extrastriate visual areas, placing important constraints on the use of fMRI adaptation techniques, while also demonstrating a general experimental strategy for systematically dissociating inherited from intrinsic adaptation by fMRI.

scholarly journals Orientation Selectivity of Motion-Boundary Responses in Human Visual Cortex

2010 ◽  
Vol 104 (6) ◽  
pp. 2940-2950 ◽  
Author(s):  
Jonas Larsson ◽  
David J. Heeger ◽  
Michael S. Landy
Keyword(s):  
Visual Cortex ◽  
Visual Motion ◽  
Selective Adaptation ◽  
Probe Stimulus ◽  
Human Visual Cortex ◽  
Boundary Orientation ◽  
Transparent Motion ◽  
Visual Areas ◽  
Motion Boundaries ◽  
Motion Boundary

Motion boundaries (local changes in visual motion direction) arise naturally when objects move relative to an observer. In human visual cortex, neuroimaging studies have identified a region (the kinetic occipital area [KO]) that responds more strongly to motion-boundary stimuli than to transparent-motion stimuli. However, some functional magnetic resonance imaging (fMRI) studies suggest that KO may encompass multiple visual areas and single-unit studies in macaque visual cortex have identified neurons selective for motion-boundary orientation in areas V2, V3, and V4, implying that motion-boundary selectivity may not be restricted to a single area. It is not known whether fMRI responses to motion boundaries are selective for motion-boundary orientation, as would be expected if these responses reflected the population activity of motion-boundary–selective neurons. We used an event-related fMRI adaptation protocol to measure orientation-selective responses to motion boundaries in human visual cortex. On each trial, we measured the response to a probe stimulus presented after an adapter stimulus (a vertical or horizontal motion-boundary grating). The probe stimulus was either a motion-boundary grating oriented parallel or orthogonal to the adapter stimulus or a transparent-motion stimulus. Orientation-selective adaptation for motion boundaries—smaller responses for trials in which test and adapter stimuli were parallel to each other—was observed in multiple extrastriate visual areas. The strongest adaptation, relative to the unadapted responses, was found in V3A, V3B, LO1, LO2, and V7. Most of the visual areas that exhibited orientation-selective adaptation in our data also showed response preference for motion boundaries over transparent motion, indicating that most of the human visual areas previously shown to respond to motion boundaries are also selective for motion-boundary orientation. These results suggest that neurons selective for motion-boundary orientation are distributed across multiple human visual cortical areas and argue against the existence of a single region or area specialized for motion-boundary processing.

scholarly journals Neural selectivity for visual motion in macaque area V3A

2020 ◽  
Author(s):  
Nardin Nakhla ◽  
Yavar Korkian ◽  
Matthew R. Krause ◽  
Christopher C. Pack
Keyword(s):  
Visual Cortex ◽  
Optic Flow ◽  
Functional Role ◽  
Visual Motion ◽  
Flow Patterns ◽  
Brain Regions ◽  
Direction Selectivity ◽  
Motion Processing ◽  
Imaging Studies ◽  
Motion Direction

AbstractThe processing of visual motion is carried out by dedicated pathways in the primate brain. These pathways originate with populations of direction-selective neurons in the primary visual cortex, which project to dorsal structures like the middle temporal (MT) and medial superior temporal (MST) areas. Anatomical and imaging studies have suggested that area V3A might also be specialized for motion processing, but there have been very few studies of single-neuron direction selectivity in this area. We have therefore performed electrophysiological recordings from V3A neurons in two macaque monkeys (one male and one female) and measured responses to a large battery of motion stimuli that includes translation motion, as well as more complex optic flow patterns. For comparison, we simultaneously recorded the responses of MT neurons to the same stimuli. Surprisingly, we find that overall levels of direction selectivity are similar in V3A and MT and moreover that the population of V3A neurons exhibits somewhat greater selectivity for optic flow patterns. These results suggest that V3A should be considered as part of the motion processing machinery of the visual cortex, in both human and non-human primates.Significance statementAlthough area V3A is frequently the target of anatomy and imaging studies, little is known about its functional role in processing visual stimuli. Its contribution to motion processing has been particularly unclear, with different studies yielding different conclusions. We report a detailed study of direction selectivity in V3A. Our results show that single V3A neurons are, on average, as capable of representing motion direction as are neurons in well-known structures like MT. Moreover, we identify a possible specialization for V3A neurons in representing complex optic flow, which has previously been thought to emerge in higher-order brain regions. Thus it appears that V3A is well-suited to a functional role in motion processing.

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 Behavioral response to visual motion impacts population coding in the mouse visual thalamus

2018 ◽  
Author(s):  
Karolina Socha ◽  
Matt Whiteway ◽  
Daniel A. Butts ◽  
Vincent Bonin
Keyword(s):  
Visual Processing ◽  
Behavioral Response ◽  
Neural Coding ◽  
Visual Motion ◽  
Population Coding ◽  
Behavioral State ◽  
Visual Thalamus ◽  
Thalamocortical Axons ◽  
And Function ◽  
The Impact

SummaryVisual motion is a ubiquitous component of animals’ sensory experience and its encoding is critical for navigation and movement. Yet its impact on behavior and neural coding is not well understood. Combining pupillometry with cellular calcium imaging measurements of thalamocortical axons in awake behaving mice, we examined the impact of arousal and behavioral state on encoding of visual motion in the visual thalamus. We discovered that back-to-front visual motions elicits a robust behavioral response that shapes tunings of visual thalamic responses. Consistent with an arousal mechanism, the effects were pronounced during stillness and weak or absent during locomotor activity and under anesthesia. The impact on neuronal tuning was specific, biasing population response patterns in favor of back-to-front motion. The potent influence of visual motion on behavioral state dynamically affect sensory coding at early visual processing stages. Further research is required to reveal the circuitry and function of this novel mechanism.

scholarly journals Characterizing the effects of feature salience and top-down attention in the early visual system

2017 ◽  
Vol 118 (1) ◽  
pp. 564-573 ◽  
Author(s):  
Sonia Poltoratski ◽  
Sam Ling ◽  
Devin McCormack ◽  
Frank Tong
Keyword(s):  
Visual System ◽  
Spatial Attention ◽  
Visual Processing ◽  
Visual Pathway ◽  
Additive Effects ◽  
Voluntary Attention ◽  
Top Down ◽  
Motion Direction ◽  
Bottom Up ◽  
Visual Areas

The visual system employs a sophisticated balance of attentional mechanisms: salient stimuli are prioritized for visual processing, yet observers can also ignore such stimuli when their goals require directing attention elsewhere. A powerful determinant of visual salience is local feature contrast: if a local region differs from its immediate surround along one or more feature dimensions, it will appear more salient. We used high-resolution functional MRI (fMRI) at 7T to characterize the modulatory effects of bottom-up salience and top-down voluntary attention within multiple sites along the early visual pathway, including visual areas V1–V4 and the lateral geniculate nucleus (LGN). Observers viewed arrays of spatially distributed gratings, where one of the gratings immediately to the left or right of fixation differed from all other items in orientation or motion direction, making it salient. To investigate the effects of directed attention, observers were cued to attend to the grating to the left or right of fixation, which was either salient or nonsalient. Results revealed reliable additive effects of top-down attention and stimulus-driven salience throughout visual areas V1–hV4. In comparison, the LGN exhibited significant attentional enhancement but was not reliably modulated by orientation- or motion-defined salience. Our findings indicate that top-down effects of spatial attention can influence visual processing at the earliest possible site along the visual pathway, including the LGN, whereas the processing of orientation- and motion-driven salience primarily involves feature-selective interactions that take place in early cortical visual areas. NEW & NOTEWORTHY While spatial attention allows for specific, goal-driven enhancement of stimuli, salient items outside of the current focus of attention must also be prioritized. We used 7T fMRI to compare salience and spatial attentional enhancement along the early visual hierarchy. We report additive effects of attention and bottom-up salience in early visual areas, suggesting that salience enhancement is not contingent on the observer’s attentional state.

scholarly journals A Theory of the Visual Motion Coding in the Primary Visual Cortex

1996 ◽  
Vol 8 (4) ◽  
pp. 705-730 ◽  
Author(s):  
Zhaoping Li
Keyword(s):  
Visual Cortex ◽  
Primary Visual Cortex ◽  
Visual Motion ◽  
Ocular Dominance ◽  
Phase Relationship ◽  
Field Size ◽  
Color Channel ◽  
Cortical Cells ◽  
Motion Direction ◽  
Motion Coding

This paper demonstrates that much of visual motion coding in the primary visual cortex can be understood from a theory of efficient motion coding in a multiscale representation. The theory predicts that cortical cells can have a spectrum of directional indices, be tuned to different directions of motion, and have spatiotemporally separable or inseparable receptive fields (RF). The predictions also include the following correlations between motion coding and spatial, chromatic, and stereo codings: the preferred speed is greater when the cell receptive field size is larger, the color channel prefers lower speed than the luminance channel, and both the optimal speeds and the preferred directions of motion can be different for inputs from different eyes to the same neuron. These predictions agree with experimental observations. In addition, this theory makes predictions that have not been experimentally investigated systematically and provides a testing ground for an efficient multiscale coding framework. These predictions are as follows: (1) if nearby cortical cells of a given preferred orientation and scale prefer opposite directions of motion and have a quadrature RF phase relationship with each other, then they will have the same directional index, (2) a single neuron can have different optimal motion speeds for opposite motion directions of monocular stimuli, and (3) a neuron's ocular dominance may change with motion direction if the neuron prefers opposite directions for inputs from different eyes.

Spatial Coincidence of Intentional Actions Modulates an Implicit Visuomotor Control

2010 ◽  
Vol 103 (5) ◽  
pp. 2717-2727 ◽  
Author(s):  
Naotoshi Abekawa ◽  
Hiroaki Gomi
Keyword(s):  
Visual Processing ◽  
Visual Motion ◽  
Motor Coordination ◽  
Spatial Relationship ◽  
Spatial Separation ◽  
Motor Command ◽  
The Body ◽  
Motion Sensitivity ◽  
Arm Reaching ◽  
The Impact

We investigated a visuomotor mechanism contributing to reach correction: the manual following response (MFR), which is a quick response to background visual motion that frequently occurs as a reafference when the body moves. Although several visual specificities of the MFR have been elucidated, the functional and computational mechanisms of its motor coordination remain unclear mainly because it involves complex relationships among gaze, reaching target, and visual stimuli. To directly explore how these factors interact in the MFR, we assessed the impact of spatial coincidences among gaze, arm reaching, and visual motion on the MFR. When gaze location was displaced from the reaching target with an identical visual motion kept on the retina, the amplitude of the MFR significantly decreased as displacement increased. A factorial manipulation of gaze, reaching-target, and visual motion locations showed that the response decrease is due to the spatial separation between gaze and reaching target but is not due to the spatial separation between visual motion and reaching target. Additionally, elimination of visual motion around the fovea attenuated the MFR. The effects of these spatial coincidences on the MFR are completely different from their effects on the perceptual mislocalization of targets caused by visual motion. Furthermore, we found clear differences between the modulation sensitivities of the MFR and the ocular following response to spatial mismatch between gaze and reaching locations. These results suggest that the MFR modulation observed in our experiment is not due to changes in visual interaction between target and visual motion or to modulation of motion sensitivity in early visual processing. Instead the motor command of the MFR appears to be modulated by the spatial relationship between gaze and reaching.

scholarly journals Assessing functional reorganization in visual cortex with simulated retinal lesions

2021 ◽  
Author(s):  
Holly D. H. Brown ◽  
André D. Gouws ◽  
Richard J. W. Vernon ◽  
Samuel J. D. Lawrence ◽  
Gemma Donnelly ◽  
...  
Keyword(s):  
Visual Cortex ◽  
Visual Processing ◽  
Vision Loss ◽  
Visual Stimulation ◽  
Retinal Lesions ◽  
Central Vision Loss ◽  
Central Disk ◽  
Mean Luminance ◽  
Cortical Regions ◽  
The Impact

AbstractMacular degeneration (MD) causes central vision loss, removing input to corresponding representations in the primary visual cortex. There is disagreement concerning whether the cortical regions deprived of input can remain responsive, and the source of reported cortical responses is still debated. To simulate MD in controls, normally sighted participants viewed a bright central disk to adapt the retina, creating a transient ‘retinal lesion’ during a functional MRI experiment. Participants viewed blocks of faces, scrambled faces and uniform grey stimuli, either passively or whilst performing a one-back task. To assess the impact of the simulated lesion, participants repeated the paradigm using a more conventional mean luminance simulated scotoma without adaptation. Our results suggest our attempt to create a more realistic simulation of a lesion did not impact on responses in the representation of the simulated lesion. While most participants showed no evidence of stimulus-driven activation within the lesion representation, a few individuals (22%) exhibited responses similar to a participant with juvenile MD who completed the same paradigm (without adaptation). Reliability analysis showed that responses in the representation of the lesion were generally consistent irrespective of whether positive or negative. We provide some evidence that peripheral visual stimulation can also produce responses in central representations in controls while performing a task. This suggests that the ‘signature of reorganization of visual processing’, is not found solely in patients with retinal lesions, consistent with the idea that activity may be driven by unmasked top–down feedback.

scholarly journals Distributed and Retinotopically Asymmetric Processing of Coherent Motion in Mouse Visual Cortex

2019 ◽  
Author(s):  
Kevin K. Sit ◽  
Michael J. Goard
Keyword(s):  
Visual Cortex ◽  
Visual Motion ◽  
Dorsal Stream ◽  
Coherent Motion ◽  
Motion Processing ◽  
Calcium Indicator ◽  
Mouse Cortex ◽  
Visual Areas ◽  
Cortical Regions ◽  
Visual Cortical

ABSTRACTPerception of visual motion is important for a range of ethological behaviors in mammals. In primates, specific higher visual cortical regions are specialized for processing of coherent visual motion. However, the distribution of motion processing among visual cortical areas in mice is unclear, despite the powerful genetic tools available for measuring population neural activity. Here, we used widefield and 2-photon calcium imaging of transgenic mice expressing a calcium indicator in excitatory neurons to measure mesoscale and cellular responses to coherent motion across the visual cortex. Imaging of primary visual cortex (V1) and several higher visual areas (HVAs) during presentation of natural movies and random dot kinematograms (RDKs) revealed heterogeneous responses to coherent motion. Although coherent motion responses were observed throughout visual cortex, particular HVAs in the putative dorsal stream (PM, AL, AM) exhibited stronger responses than ventral stream areas (LM and LI). Moreover, beyond the differences between visual areas, there was considerable heterogeneity within each visual area. Individual visual areas exhibited an asymmetry across the vertical retinotopic axis (visual elevation), such that neurons representing the inferior visual field exhibited greater responses to coherent motion. These results indicate that processing of visual motion in mouse cortex is distributed unevenly across visual areas and exhibits a spatial bias within areas, potentially to support processing of optic flow during spatial navigation.

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.

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