scholarly journals Local expectation violations result in global activity gain in primary visual cortex

2016 ◽  
Author(s):  
Peter Kok ◽  
Lieke L.F. van Lieshout ◽  
Floris P. de Lange
Keyword(s):  
Visual Field ◽  
Spatial Location ◽  
Sensory Response ◽  
Specific Stimulus ◽  
Specific Location ◽  
Feature Based ◽  
Stimulus Features ◽  
Open Question ◽  
Violation Of Expectation ◽  
Global Activity

AbstractDuring natural perception, we often form expectations about upcoming input. These expectations are usually multifaceted – we expect a particular object at a particular location. However, expectations about spatial location and stimulus features have mostly been studied in isolation, and it is unclear whether feature-based expectation can be spatially specific. Interestingly, feature-based attention automatically spreads to unattended locations. It is still an open question whether the neural mechanisms underlying feature-based expectation differ from those underlying feature-based attention. Therefore, establishing whether the effects of feature-based expectation are spatially specific may inform this debate. Here, we investigated this by inducing expectations of a specific stimulus feature at a specific location, and probing the effects on sensory processing across the visual field using fMRI. We found an enhanced sensory response for unexpected stimuli, which was elicited only when there was a violation of expectation at the specific location where participants formed a stimulus expectation. The neural consequences of this expectation violation, however, spread to cortical locations processing the stimulus in the opposite hemifield. This suggests that an expectation violation at one location in the visual world can lead to a spatially non-specific gain increase across the visual field.

scholarly journals Feature-based and location-based volitional covert attention affect memory at different timescales

2019 ◽  
Author(s):  
Kirsten Ziman ◽  
Madeline R. Lee ◽  
Alejandro R. Martinez ◽  
Ethan D. Adner ◽  
Jeremy R. Manning
Keyword(s):  
Memory Task ◽  
Spatial Location ◽  
Attentional Focus ◽  
Covert Attention ◽  
Subjective Experiences ◽  
Attentional Resources ◽  
Attentional Shifts ◽  
Feature Based ◽  
Stimulus Features ◽  
Prior Experiences

Our ongoing subjective experiences, and our memories of those experiences, are shaped by our prior experiences, goals, and situational understanding. These factors shape how we allocate our attentional resources over different aspects of our ongoing experiences. These attentional shifts may happen overtly (e.g., when we change where we are looking) or covertly (e.g., without any explicit physical manifestation). Additionally, we may attend to what is happening at a specific spatial location (e.g., because we think something important is happening there) or we may attend to particular features irrespective of their locations (e.g., when we search for a friend's face in a crowd). We ran two covert attention experiments that differed in how long they asked participants to maintain the focus of the features or locations they were attending. Later, the participants performed a recognition memory task for attended, unattended, and novel stimuli. Participants were able to shift the location of their covert attentional focus more rapidly than they were able to shift their focus of covert attention to stimulus features, and the effects of location-based attention on memory were longer-lasting than the effects of feature-based attention.

scholarly journals Feature-based attention: it is all bottom-up priming

2013 ◽  
Vol 368 (1628) ◽  
pp. 20130055 ◽  
Author(s):  
Jan Theeuwes
Keyword(s):  
Visual Field ◽  
Imaging Studies ◽  
Top Down ◽  
Bottom Up ◽  
Specific Stimulus ◽  
Image Characteristics ◽  
Feature Based ◽  
Neuro Imaging ◽  
Rule Out

Feature-based attention (FBA) enhances the representation of image characteristics throughout the visual field, a mechanism that is particularly useful when searching for a specific stimulus feature. Even though most theories of visual search implicitly or explicitly assume that FBA is under top-down control, we argue that the role of top-down processing in FBA may be limited. Our review of the literature indicates that all behavioural and neuro-imaging studies investigating FBA suffer from the shortcoming that they cannot rule out an effect of priming. The mere attending to a feature enhances the mandatory processing of that feature across the visual field, an effect that is likely to occur in an automatic, bottom-up way. Studies that have investigated the feasibility of FBA by means of cueing paradigms suggest that the role of top-down processing in FBA is limited (e.g. prepare for red). Instead, the actual processing of the stimulus is needed to cause the mandatory tuning of responses throughout the visual field. We conclude that it is likely that all FBA effects reported previously are the result of bottom-up priming.

scholarly journals Dissociating Reward- and Attention-driven Biasing of Global Feature-based Selection in Human Visual Cortex

2019 ◽  
Vol 31 (4) ◽  
pp. 469-481 ◽  
Author(s):  
Haydee G. Garcia-Lazaro ◽  
Mandy V. Bartsch ◽  
Carsten N. Boehler ◽  
Ruth M. Krebs ◽  
Sarah E. Donohue ◽  
...  
Keyword(s):  
Visual Cortex ◽  
Target Selection ◽  
Target Color ◽  
Selective Area ◽  
Early Visual Cortex ◽  
Feature Based ◽  
Irrelevant Color ◽  
Task Irrelevant ◽  
Open Question ◽  
Attention Demands

Objects that promise rewards are prioritized for visual selection. The way this prioritization shapes sensory processing in visual cortex, however, is debated. It has been suggested that rewards motivate stronger attentional focusing, resulting in a modulation of sensory selection in early visual cortex. An open question is whether those reward-driven modulations would be independent of similar modulations indexing the selection of attended features that are not associated with reward. Here, we use magnetoencephalography in human observers to investigate whether the modulations indexing global color-based selection in visual cortex are separable for target- and (monetary) reward-defining colors. To assess the underlying global color-based activity modulation, we compare the event-related magnetic field response elicited by a color probe in the unattended hemifield drawn either in the target color, the reward color, both colors, or a neutral task-irrelevant color. To test whether target and reward relevance trigger separable modulations, we manipulate attention demands on target selection while keeping reward-defining experimental parameters constant. Replicating previous observations, we find that reward and target relevance produce almost indistinguishable gain modulations in ventral extratriate cortex contralateral to the unattended color probe. Importantly, increasing attention demands on target discrimination increases the response to the target-defining color, whereas the response to the rewarded color remains largely unchanged. These observations indicate that, although task relevance and reward influence the very same feature-selective area in extrastriate visual cortex, the associated modulations are largely independent.

scholarly journals Constant spread of feature-based attention across the visual field

2011 ◽  
Vol 51 (1) ◽  
pp. 26-33 ◽  
Author(s):  
Taosheng Liu ◽  
Irida Mance
Keyword(s):  
Visual Field ◽  
Feature Based

scholarly journals Predictive remapping of visual features beyond saccadic targets

2018 ◽  
Author(s):  
Tao He ◽  
Matthias Fritsche ◽  
Floris P. de Lange
Keyword(s):  
Visual Field ◽  
Strong Evidence ◽  
Visual Features ◽  
Visual Stability ◽  
Relevant Object ◽  
Saccade Onset ◽  
Predictive Remapping ◽  
Feature Information ◽  
Stimulus Features ◽  
Predictive Feature

AbstractVisual stability is thought to be mediated by predictive remapping of the relevant object information from its current, pre-saccadic locations to its future, post-saccadic location on the retina. However, it is heavily debated whether and what feature information is predictively remapped during the pre-saccadic interval. Using an orientation adaptation paradigm, we investigated whether predictive remapping occurs for stimulus features and whether adaptation itself is remapped. We found strong evidence for predictive remapping of a stimulus presented shortly before saccade onset, but no remapping of adaptation. Furthermore, we establish that predictive remapping also occurs for stimuli that are not saccade targets, pointing toward a ‘forward remapping’ process operating across the whole visual field. Together, our findings suggest that predictive feature remapping of object information plays an important role in mediating visual stability.

scholarly journals Visual numerosity estimation is based on anisotropic representations of visual space

2021 ◽  
Author(s):  
Miao Li ◽  
Bert Reynvoet ◽  
Bilge Sayim
Keyword(s):  
Visual Field ◽  
Convex Hull ◽  
Visual Fields ◽  
Spatial Vision ◽  
Visual Space ◽  
Stimulus Features ◽  
Numerosity Estimation ◽  
Numerosity Perception ◽  
Average Eccentricity ◽  
Shed Light

Humans can estimate the number of visually displayed items without counting. This capacity of numerosity perception has often been attributed to a dedicated system to estimate numerosity, or alternatively to the exploitation of various stimulus features, such as density, convex hull, the size of items and occupancy area. The distribution of the presented items is usually not varied with eccentricity in the visual field. However, our visual fields are highly asymmetric, and to date, it is unclear how inhomogeneities of the visual field impact numerosity perception. Besides eccentricity, a pronounced asymmetry is the radial-tangential anisotropy. For example, in crowding, radially placed flankers interfere more strongly with target perception than tangentially placed flankers. Similarly, in redundancy masking, the number of perceived items in repeating patterns is reduced when the items are arranged radially but not when they are arranged tangentially. Here, we investigated whether numerosity perception is subject to the radial-tangential anisotropy of spatial vision to shed light on the underlying topology of numerosity perception. Observers were presented with varying numbers of discs and asked to report the perceived number. There were two conditions. Discs were predominantly arranged radially in the “radial” condition and tangentially in the “tangential” condition. Additionally, the spacing between discs was scaled with eccentricity. Physical properties, such as average eccentricity, average spacing, convex hull, and density were kept as similar as possible in the two conditions. Radial arrangements were expected to yield underestimation compared to tangential arrangements. Consistent with the hypothesis, numerosity estimates in the radial condition were lower compared to the tangential condition. Magnitudes of radial alignment (as well as predicted crowding strength) correlated with the observed numerosity estimates. Our results demonstrate a robust radial-tangential anisotropy, suggesting that the topology of spatial vision determines numerosity estimation. We suggest that asymmetries of spatial vision should be taken into account when investigating numerosity estimation.

scholarly journals Multivariate EEG analyses support high-resolution tracking of feature-based attentional selection

2016 ◽  
Author(s):  
Johannes Jacobus Fahrenfort ◽  
Anna Grubert ◽  
Christian N. L. Olivers ◽  
Martin Eimer
Keyword(s):  
Visual Field ◽  
Multivariate Analyses ◽  
Target Selection ◽  
Target Position ◽  
Attentional Selection ◽  
Forward Model ◽  
Hemispheric Differences ◽  
Neural Basis ◽  
Eeg Data ◽  
Feature Based

AbstractThe primary electrophysiological marker of feature-based selection is the N2pc, a lateralized posterior negativity emerging around 180-200 ms. As it relies on hemispheric differences, its ability to discriminate the locus of focal attention is severely limited. Here we demonstrate that multivariate analyses of raw EEG data provide a much more fine-grained spatial profile of feature-based target selection. When training a pattern classifier to determine target position from EEG, we were able to decode target positions on the vertical midline, which cannot be achieved using standard N2pc methodology. Next, we used a forward encoding model to construct a channel tuning function that describes the continuous relationship between target position and multivariate EEG in an eight-position display. This model can spatially discriminate individual target positions in these displays and is fully invertible, enabling us to construct hypothetical topographic activation maps for target positions that were never used. When tested against the real pattern of neural activity obtained from a different group of subjects, the constructed maps from the forward model turned out statistically indistinguishable, thus providing independent validation of our model. Our findings demonstrate the power of multivariate EEG analysis to track feature-based target selection with high spatial and temporal precision.Significance StatementFeature-based attentional selection enables observers to find objects in their visual field. The spatiotemporal profile of this process is difficult to assess with standard electrophysiological methods, which rely on activity differences between cerebral hemispheres. We demonstrate that multivariate analyses of EEG data can track target selection across the visual field with high temporal and spatial resolution. Using a forward model, we were able to capture the continuous relationship between target position and EEG measurements, allowing us to reconstruct the distribution of cortical activity for target locations that were never shown during the experiment. Our findings demonstrate the existence of a temporally and spatially precise EEG signal that can be used to study the neural basis of feature-based attentional selection.

scholarly journals Neural evidence supports a dual sensory-motor role for insect wings

2017 ◽  
Vol 284 (1862) ◽  
pp. 20170969 ◽  
Author(s):  
Brandon Pratt ◽  
Tanvi Deora ◽  
Thomas Mohren ◽  
Thomas Daniel
Keyword(s):  
Flight Control ◽  
Information Acquisition ◽  
Receptive Fields ◽  
Mechanical Stimulus ◽  
Sensory Function ◽  
Computational Techniques ◽  
Campaniform Sensilla ◽  
Specific Stimulus ◽  
Processing Times ◽  
Stimulus Features

Flying insects use feedback from various sensory modalities including vision and mechanosensation to navigate through their environment. The rapid speed of mechanosensory information acquisition and processing compensates for the slower processing times associated with vision, particularly under low light conditions. While halteres in dipteran species are well known to provide such information for flight control, less is understood about the mechanosensory roles of their evolutionary antecedent, wings. The features that wing mechanosensory neurons (campaniform sensilla) encode remains relatively unexplored. We hypothesized that the wing campaniform sensilla of the hawkmoth, Manduca sexta, rapidly and selectively extract mechanical stimulus features in a manner similar to halteres. We used electrophysiological and computational techniques to characterize the encoding properties of wing campaniform sensilla. To accomplish this, we developed a novel technique for localizing receptive fields using a focused IR laser that elicits changes in the neural activity of mechanoreceptors. We found that (i) most wing mechanosensors encoded mechanical stimulus features rapidly and precisely, (ii) they are selective for specific stimulus features, and (iii) there is diversity in the encoding properties of wing campaniform sensilla. We found that the encoding properties of wing campaniform sensilla are similar to those for haltere neurons. Therefore, it appears that the neural architecture that underlies the haltere sensory function is present in wings, which lends credence to the notion that wings themselves may serve a similar sensory function. Thus, wings may not only function as the primary actuator of the organism but also as sensors of the inertial dynamics of the animal.

scholarly journals Left-Hemispheric Asymmetry for Object-Based Attention: an ERP Study

2019 ◽  
Vol 9 (11) ◽  
pp. 315 ◽  
Author(s):  
Andrea Orlandi ◽  
Alice Mado Proverbio
Keyword(s):  
Visual Attention ◽  
Hemispheric Asymmetry ◽  
Time Course ◽  
Electrophysiological Study ◽  
Target Selection ◽  
Neural Correlates ◽  
Specific Stimulus ◽  
Object Categories ◽  
Object Based ◽  
Stimulus Features

It has been shown that selective attention enhances the activity in visual regions associated with stimulus processing. The left hemisphere seems to have a prominent role when non-spatial attention is directed towards specific stimulus features (e.g., color, spatial frequency). The present electrophysiological study investigated the time course and neural correlates of object-based attention, under the assumption of left-hemispheric asymmetry. Twenty-nine right-handed participants were presented with 3D graphic images representing the shapes of different object categories (wooden dummies, chairs, structures of cubes) which lacked detail. They were instructed to press a button in response to a target stimulus indicated at the beginning of each run. The perception of non-target stimuli elicited a larger anterior N2 component, which was likely associated with motor inhibition. Conversely, target selection resulted in an enhanced selection negativity (SN) response lateralized over the left occipito-temporal regions, followed by a larger centro-parietal P300 response. These potentials were interpreted as indexing attentional selection and categorization processes, respectively. The standardized weighted low-resolution electromagnetic tomography (swLORETA) source reconstruction showed the engagement of a fronto-temporo-limbic network underlying object-based visual attention. Overall, the SN scalp distribution and relative neural generators hinted at a left-hemispheric advantage for non-spatial object-based visual attention.

scholarly journals Serotonergic modulation across sensory modalities

2020 ◽  
Vol 123 (6) ◽  
pp. 2406-2425
Author(s):  
Tyler R. Sizemore ◽  
Laura M. Hurley ◽  
Andrew M. Dacks
Keyword(s):  
Serotonin Receptor ◽  
Physiological State ◽  
Sensory Information ◽  
Specific Stimulus ◽  
Sensory Organization ◽  
Sensory Modalities ◽  
Multiple Levels ◽  
Stimulus Features ◽  
Ubiquitous Presence ◽  
Serotonergic Modulation

The serotonergic system has been widely studied across animal taxa and different functional networks. This modulatory system is therefore well positioned to compare the consequences of neuromodulation for sensory processing across species and modalities at multiple levels of sensory organization. Serotonergic neurons that innervate sensory networks often bidirectionally exchange information with these networks but also receive input representative of motor events or motivational state. This convergence of information supports serotonin’s capacity for contextualizing sensory information according to the animal’s physiological state and external events. At the level of sensory circuitry, serotonin can have variable effects due to differential projections across specific sensory subregions, as well as differential serotonin receptor type expression within those subregions. Functionally, this infrastructure may gate or filter sensory inputs to emphasize specific stimulus features or select among different streams of information. The near-ubiquitous presence of serotonin and other neuromodulators within sensory regions, coupled with their strong effects on stimulus representation, suggests that these signaling pathways should be considered integral components of sensory systems.

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