Browse
Submit Data
Databases
API
Help

Dataset Information

27 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Feature integration across space, time, and orientation.

ABSTRACT: The perception of a visual target can be strongly influenced by flanking stimuli. In static displays, performance on the target improves when the distance to the flanking elements increases-presumably because feature pooling and integration vanishes with distance. Here, we studied feature integration with dynamic stimuli. We show that features of single elements presented within a continuous motion stream are integrated largely independent of spatial distance (and orientation). Hence, space-based models of feature integration cannot be extended to dynamic stimuli. We suggest that feature integration is guided by perceptual grouping operations that maintain the identity of perceptual objects over space and time.

SUBMITTER: Otto TU

PROVIDER: S-EPMC3277857 | biostudies-literature | 2009 Dec

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Feature integration across space, time, and orientation.

Otto Thomas U TU Ogmen Haluk H Herzog Michael H MH

Journal of experimental psychology. Human perception and performance 20091201 6

The perception of a visual target can be strongly influenced by flanking stimuli. In static displays, performance on the target improves when the distance to the flanking elements increases-presumably because feature pooling and integration vanishes with distance. Here, we studied feature integration with dynamic stimuli. We show that features of single elements presented within a continuous motion stream are integrated largely independent of spatial distance (and orientation). Hence, space-base ...[more]

PMID: 19968428

Similar Datasets

Feature integration within discrete time windows.

Project description:Sensory information must be integrated over time to perceive, for example, motion and melodies. Here, to study temporal integration, we used the sequential metacontrast paradigm in which two expanding streams of lines are presented. When a line in one stream is offset observers perceive all other lines to be offset too, even though they are straight. When more lines are offset the offsets integrate mandatorily, i.e., observers cannot report the individual offsets. We show that mandatory integration lasts for up to 450?ms, depending on the observer. Importantly, integration occurs only when offsets are presented within a discrete window of time. Even stimuli that are in close spatio-temporal proximity do not integrate if they are in different windows. A window of integration starts with stimulus onset and integration in the next window has similar characteristics. We present a two-stage computational model based on discrete time windows that captures these effects.

| S-EPMC6814726 | biostudies-literature

Sex-specific ornament evolution is a consistent feature of climatic adaptation across space and time in dragonflies.

Project description:Adaptation to different climates fuels the origins and maintenance of biodiversity. Detailing how organisms optimize fitness for their local climates is therefore an essential goal in biology. Although we increasingly understand how survival-related traits evolve as organisms adapt to climatic conditions, it is unclear whether organisms also optimize traits that coordinate mating between the sexes. Here, we show that dragonflies consistently adapt to warmer climates across space and time by evolving less male melanin ornamentation-a mating-related trait that also absorbs solar radiation and heats individuals above ambient temperatures. Continent-wide macroevolutionary analyses reveal that species inhabiting warmer climates evolve less male ornamentation. Community-science observations across 10 species indicate that populations adapt to warmer parts of species' ranges through microevolution of smaller male ornaments. Observations from 2005 to 2019 detail that contemporary selective pressures oppose male ornaments in warmer years; and our climate-warming projections predict further decreases by 2070. Conversely, our analyses show that female ornamentation responds idiosyncratically to temperature across space and time, indicating the sexes evolve in different ways to meet the demands of the local climate. Overall, these macro- and microevolutionary findings demonstrate that organisms predictably optimize their mating-related traits for the climate just as they do their survival-related traits.

| S-EPMC8285952 | biostudies-literature

Feature space resampling for protein conformational search.

Project description:De novo protein structure prediction requires location of the lowest energy state of the polypeptide chain among a vast set of possible conformations. Powerful approaches include conformational space annealing, in which search progressively focuses on the most promising regions of conformational space, and genetic algorithms, in which features of the best conformations thus far identified are recombined. We describe a new approach that combines the strengths of these two approaches. Protein conformations are projected onto a discrete feature space which includes backbone torsion angles, secondary structure, and beta pairings. For each of these there is one "native" value: the one found in the native structure. We begin with a large number of conformations generated in independent Monte Carlo structure prediction trajectories from Rosetta. Native values for each feature are predicted from the frequencies of feature value occurrences and the energy distribution in conformations containing them. A second round of structure prediction trajectories are then guided by the predicted native feature distributions. We show that native features can be predicted at much higher than background rates, and that using the predicted feature distributions improves structure prediction in a benchmark of 28 proteins. The advantages of our approach are that features from many different input structures can be combined simultaneously without producing atomic clashes or otherwise physically inviable models, and that the features being recombined have a relatively high chance of being correct.

| S-EPMC2854516 | biostudies-literature

Feature expectation heightens visual sensitivity during fine orientation discrimination.

Project description:Attending to a stimulus enhances the sensitivity of perceptual decisions. However, it remains unclear how perceptual sensitivity varies according to whether a feature is expected or unexpected. Here, observers made fine discrimination judgments about the orientation of visual gratings embedded in low spatial-frequency noise, and psychophysical reverse correlation was used to estimate decision 'kernels' that revealed how visual features influenced choices. Orthogonal cues alerted subjects to which of two spatial locations was likely to be probed (spatial attention cue) and which of two oriented gratings was likely to occur (feature expectation cue). When an expected (relative to unexpected) feature occurred, decision kernels shifted away from the category boundary, allowing observers to capitalize on more informative, "off-channel" stimulus features. By contrast, the spatial attention cue had a multiplicative influence on decision kernels, consistent with an increase in response gain. Feature expectation thus heightens sensitivity to the most informative visual features, independent of selective attention.

| S-EPMC4633117 | biostudies-literature

Feature space optical coherence tomography based micro-angiography.

Project description:Current optical coherence tomography (OCT) based micro-angiography is prone to noise that arises from static background. This work presents a novel feature space based optical micro-angiography (OMAG) method (fsOMAG) that can effectively differentiate flow signal from static background in the feature space. fsOMAG consists of two steps. In the first step a classification map is generated that provides criterion for classification in the second step to extract functional blood flow from experimental data set. The performance of fsOMAG is examined through phantom experiments and in-vivo human retinal imaging, and compared with the existing OMAG. The results indicate its potential for clinical applications.

| S-EPMC4467717 | biostudies-other

Sensory integration across space and in time for decision making in the somatosensory system of rodents.

Project description:Environment is represented in the brain by a neural code that is a result of the spatiotemporal pattern of incoming sensory information. Sensory neurons encode inputs across space and in time such that activity of a given cell inhibits the ability of near-simultaneously arriving sensory stimuli to excite the cell. At the behavioral level, consequences of such suppression are unknown. We investigated the contribution of spatially distributed, near-simultaneous sensory inputs to decision making in a whisker-dependent learning task. Mice learned the task with a single whisker or multiple whiskers alike. Both groups of mice had similar learning curves and final success rates. However, multiple-whisker animals had faster response times than single-whisker mice, requiring only about half the time to perform the task successfully. The results show that spatially distributed sensory inputs in a highly redundant sensory environment improve speed but not accuracy of the decisions made during simple sensory detection. Suppression of the near-simultaneous sensory inputs could, therefore, act to reduce the sensory redundancy.

| S-EPMC1783091 | biostudies-literature

Feature detection and orientation tuning in the Drosophila central complex.

Project description:Many animals, including insects, are known to use visual landmarks to orient in their environment. In Drosophila melanogaster, behavioural genetics studies have identified a higher brain structure called the central complex as being required for the fly's innate responses to vertical visual features and its short- and long-term memory for visual patterns. But whether and how neurons of the fly central complex represent visual features are unknown. Here we use two-photon calcium imaging in head-fixed walking and flying flies to probe visuomotor responses of ring neurons--a class of central complex neurons that have been implicated in landmark-driven spatial memory in walking flies and memory for visual patterns in tethered flying flies. We show that dendrites of ring neurons are visually responsive and arranged retinotopically. Ring neuron receptive fields comprise both excitatory and inhibitory subfields, resembling those of simple cells in the mammalian primary visual cortex. Ring neurons show strong and, in some cases, direction-selective orientation tuning, with a notable preference for vertically oriented features similar to those that evoke innate responses in flies. Visual responses were diminished during flight, but, in contrast with the hypothesized role of the central complex in the control of locomotion, not modulated during walking. Taken together, these results indicate that ring neurons represent behaviourally relevant visual features in the fly's environment, enabling downstream central complex circuits to produce appropriate motor commands. More broadly, this study opens the door to mechanistic investigations of circuit computations underlying visually guided action selection in the Drosophila central complex.

| S-EPMC3830704 | biostudies-literature

Feature selection in the human brain: electrophysiological correlates of sensory enhancement and feature integration.

Project description:This study examined the latency and amplitude of cortical processes associated with feature-based visual selective attention, using frequency-domain and time-domain measures derived from dense-array electroencephalography. Participants were asked to identify targets based on conjunctions of three types of object features (color, size, and completeness). This procedure aimed to examine (1) the modulation of sensory responses to one or more stimulus features characterizing an object and (2) the facilitation and reduction effects associated with competing features, attended and unattended, in the same object. The selection negativity, an event-related potential measure of sensory amplification for attended features, showed a parametric increase of amplitude as a function of the number of attended features. Late oscillations in the gamma band range were also smaller for stimuli with one or more non-attended visual features but were enhanced for stimuli sharing the overall gestalt with the target. The latency of this late gamma modulation was delayed when two target features were combined, compared to one single discriminative feature. Latency analyses also showed that late bursts of induced high-frequency oscillatory activity peaked around 60 ms later than the selection negativity. Oscillatory activity reflected both selective amplification and competition between object features. These results suggest that sensory amplification of selected features is followed by integrative processing in more widespread networks. Oscillatory activity in these networks is reduced by distraction and is enhanced when attended features can be mapped to specific action.

| S-EPMC3664361 | biostudies-other

Near-optimal integration of orientation information across saccades.

Project description:We perceive a stable environment despite the fact that visual information is essentially acquired in a sequence of snapshots separated by saccadic eye movements. The resolution of these snapshots varies-high in the fovea and lower in the periphery-and thus the formation of a stable percept presumably relies on the fusion of information acquired at different resolutions. To test if, and to what extent, foveal and peripheral information are integrated, we examined human orientation-discrimination performance across saccadic eye movements. We found that humans perform best when an oriented target is visible both before (peripherally) and after a saccade (foveally), suggesting that humans integrate the two views. Integration relied on eye movements, as we found no evidence of integration when the target was artificially moved during stationary viewing. Perturbation analysis revealed that humans combine the two views using a weighted sum, with weights assigned based on the relative precision of foveal and peripheral representations, as predicted by ideal observer models. However, our subjects displayed a systematic overweighting of the fovea, relative to the ideal observer, indicating that human integration across saccades is slightly suboptimal.

| S-EPMC5079706 | biostudies-literature

A face feature space in the macaque temporal lobe.

Project description:The ability of primates to effortlessly recognize faces has been attributed to the existence of specialized face areas. One such area, the macaque middle face patch, consists almost entirely of cells that are selective for faces, but the principles by which these cells analyze faces are unknown. We found that middle face patch neurons detect and differentiate faces using a strategy that is both part based and holistic. Cells detected distinct constellations of face parts. Furthermore, cells were tuned to the geometry of facial features. Tuning was most often ramp-shaped, with a one-to-one mapping of feature magnitude to firing rate. Tuning amplitude depended on the presence of a whole, upright face and features were interpreted according to their position in a whole, upright face. Thus, cells in the middle face patch encode axes of a face space specialized for whole, upright faces.

| S-EPMC2819705 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data