Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Neuronal Modulations in Visual Cortex Are Associated with Only One of Multiple Components of Attention.

ABSTRACT: Neuronal signals related to visual attention are found in widespread brain regions, and these signals are generally assumed to participate in a common mechanism of attention. However, the behavioral effects of attention in detection can be separated into two distinct components: spatially selective shifts in either the criterion or sensitivity of the subject. Here we show that a paradigm used by many single-neuron studies of attention conflates behavioral changes in the subject's criterion and sensitivity. Then, using a task designed to dissociate these two components, we found that multiple aspects of attention-related neuronal modulations in area V4 of monkey visual cortex corresponded to behavioral shifts in sensitivity, but not criterion. This result suggests that separate components of attention are associated with signals in different brain regions and that attention is not a unitary process in the brain, but instead consists of distinct neurobiological mechanisms.

SUBMITTER: Luo TZ

PROVIDER: S-EPMC4458699 | biostudies-literature | 2015 Jun

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Neuronal Modulations in Visual Cortex Are Associated with Only One of Multiple Components of Attention.

Luo Thomas Zhihao TZ Maunsell John H R JH

Neuron 20150601 5

Neuronal signals related to visual attention are found in widespread brain regions, and these signals are generally assumed to participate in a common mechanism of attention. However, the behavioral effects of attention in detection can be separated into two distinct components: spatially selective shifts in either the criterion or sensitivity of the subject. Here we show that a paradigm used by many single-neuron studies of attention conflates behavioral changes in the subject's criterion and s ...[more]

PMID: 26050038

Similar Datasets

Competition in visual cortex impedes attention to multiple items.

Project description:Traditional explanations of our limited attentional capacity focus on our ability to direct attention to multiple items. We ask whether this difficulty in simultaneously attending to multiple items stems from an inability to effectively represent multiple attended items. Although attending to one of a set of neighboring stimuli can isolate it from competitive interactions in visual cortex, no such isolation should occur if multiple competing items are attended. Indeed, we find that attention is ineffective at enhancing blood oxygen level-dependent signal in visual cortical area V4 when it is directed to three stimuli simultaneously, but only when those three stimuli compete in visual cortex. This suggests that competition may prevent attention from acting as effectively on representations of multiple items as it does on representations of a single item. In contrast to traditional explanations that posit limits in the sources of attentional control, we show that mechanisms at the sites of stimulus representation may also impose limits on our ability to attend to multiple items simultaneously.

| S-EPMC3164532 | biostudies-literature

Value-based modulations in human visual cortex.

Project description:Economists and cognitive psychologists have long known that prior rewards bias decision making in favor of options with high expected value. Accordingly, value modulates the activity of sensorimotor neurons involved in initiating movements toward one of two competing decision alternatives. However, little is known about how value influences the acquisition and representation of incoming sensory information or about the neural mechanisms that track the relative value of each available stimulus to guide behavior. Here, fMRI revealed value-related modulations throughout spatially selective areas of the human visual system in the absence of overt saccadic responses (including in V1). These modulations were primarily associated with the reward history of each stimulus and not to self-reported estimates of stimulus value. Finally, subregions of frontal and parietal cortex represent the differential value of competing alternatives and may provide signals to bias spatially selective visual areas in favor of more valuable stimuli.

| S-EPMC3384552 | biostudies-literature

Sustained selective attention to competing amplitude-modulations in human auditory cortex.

Project description:Auditory selective attention plays an essential role for identifying sounds of interest in a scene, but the neural underpinnings are still incompletely understood. Recent findings demonstrate that neural activity that is time-locked to a particular amplitude-modulation (AM) is enhanced in the auditory cortex when the modulated stream of sounds is selectively attended to under sensory competition with other streams. However, the target sounds used in the previous studies differed not only in their AM, but also in other sound features, such as carrier frequency or location. Thus, it remains uncertain whether the observed enhancements reflect AM-selective attention. The present study aims at dissociating the effect of AM frequency on response enhancement in auditory cortex by using an ongoing auditory stimulus that contains two competing targets differing exclusively in their AM frequency. Electroencephalography results showed a sustained response enhancement for auditory attention compared to visual attention, but not for AM-selective attention (attended AM frequency vs. ignored AM frequency). In contrast, the response to the ignored AM frequency was enhanced, although a brief trend toward response enhancement occurred during the initial 15 s. Together with the previous findings, these observations indicate that selective enhancement of attended AMs in auditory cortex is adaptive under sustained AM-selective attention. This finding has implications for our understanding of cortical mechanisms for feature-based attentional gain control.

| S-EPMC4178064 | biostudies-literature

Auditory attention activates peripheral visual cortex.

Project description:BackgroundRecent neuroimaging studies have revealed that putatively unimodal regions of visual cortex can be activated during auditory tasks in sighted as well as in blind subjects. However, the task determinants and functional significance of auditory occipital activations (AOAs) remains unclear.Methodology/principal findingsWe examined AOAs in an intermodal selective attention task to distinguish whether they were stimulus-bound or recruited by higher-level cognitive operations associated with auditory attention. Cortical surface mapping showed that auditory occipital activations were localized to retinotopic visual cortex subserving the far peripheral visual field. AOAs depended strictly on the sustained engagement of auditory attention and were enhanced in more difficult listening conditions. In contrast, unattended sounds produced no AOAs regardless of their intensity, spatial location, or frequency.Conclusions/significanceAuditory attention, but not passive exposure to sounds, routinely activated peripheral regions of visual cortex when subjects attended to sound sources outside the visual field. Functional connections between auditory cortex and visual cortex subserving the peripheral visual field appear to underlie the generation of AOAs, which may reflect the priming of visual regions to process soon-to-appear objects associated with unseen sound sources.

| S-EPMC2644787 | biostudies-literature

Object-based attention to one of two superimposed surfaces alters responses in human early visual cortex.

Project description:Faced with an overwhelming amount of sensory information, we are able to prioritize the processing of select spatial locations and visual features. The neuronal mechanisms underlying such spatial and feature-based selection have been studied in considerable detail. More recent work shows that attention can also be allocated to objects, even spatially superimposed objects composed of dynamically changing features that must be integrated to create a coherent object representation. Much less is known about the mechanisms underlying such object-based selection. Our goal was to investigate behavioral and neuronal responses when attention was directed to one of two objects, specifically one of two superimposed transparent surfaces, in a task designed to preclude space-based and feature-based selection. We used functional magnetic resonance imaging (fMRI) to measure changes in blood oxygen level-dependent (BOLD) signals when attention was deployed to one or the other surface. We found that visual areas V1, V2, V3, V3A, and MT+ showed enhanced BOLD responses to translations of an attended relative to an unattended surface. These results reveal that visual areas as early as V1 can be modulated by attending to objects, even objects defined by dynamically changing elements. This provides definitive evidence in humans that early visual areas are involved in a seemingly high-order process. Furthermore, our results suggest that these early visual areas may participate in object-specific feature "binding," a process that seemingly must occur for an object or a surface to be the unit of attentional selection.

| S-EPMC3074415 | biostudies-literature

The role of early visual cortex in visual short-term memory and visual attention.

Project description:We measured cortical activity with functional magnetic resonance imaging to probe the involvement of early visual cortex in visual short-term memory and visual attention. In four experimental tasks, human subjects viewed two visual stimuli separated by a variable delay period. The tasks placed differential demands on short-term memory and attention, but the stimuli were visually identical until after the delay period. Early visual cortex exhibited sustained responses throughout the delay when subjects performed attention-demanding tasks, but delay-period activity was not distinguishable from zero when subjects performed a task that required short-term memory. This dissociation reveals different computational mechanisms underlying the two processes.

| S-EPMC2696572 | biostudies-literature

Computational Model of Primary Visual Cortex Combining Visual Attention for Action Recognition.

Project description:Humans can easily understand other people's actions through visual systems, while computers cannot. Therefore, a new bio-inspired computational model is proposed in this paper aiming for automatic action recognition. The model focuses on dynamic properties of neurons and neural networks in the primary visual cortex (V1), and simulates the procedure of information processing in V1, which consists of visual perception, visual attention and representation of human action. In our model, a family of the three-dimensional spatial-temporal correlative Gabor filters is used to model the dynamic properties of the classical receptive field of V1 simple cell tuned to different speeds and orientations in time for detection of spatiotemporal information from video sequences. Based on the inhibitory effect of stimuli outside the classical receptive field caused by lateral connections of spiking neuron networks in V1, we propose surround suppressive operator to further process spatiotemporal information. Visual attention model based on perceptual grouping is integrated into our model to filter and group different regions. Moreover, in order to represent the human action, we consider the characteristic of the neural code: mean motion map based on analysis of spike trains generated by spiking neurons. The experimental evaluation on some publicly available action datasets and comparison with the state-of-the-art approaches demonstrate the superior performance of the proposed model.

| S-EPMC4489578 | biostudies-literature

Dissociated ?-band modulations in the dorsal and ventral visual pathways in visuospatial attention and perception.

Project description:Modulations of occipito-parietal ?-band (8-14 Hz) power that are opposite in direction (?-enhancement vs. ?-suppression) and origin of generation (ipsilateral vs. contralateral to the locus of attention) are a robust correlate of anticipatory visuospatial attention. Yet, the neural generators of these ?-band modulations, their interdependence across homotopic areas, and their respective contribution to subsequent perception remain unclear. To shed light on these questions, we employed magnetoencephalography, while human volunteers performed a spatially cued detection task. Replicating previous findings, we found ?-power enhancement ipsilateral to the attended hemifield and contralateral ?-suppression over occipito-parietal sensors. Source localization (beamforming) analysis showed that ?-enhancement and suppression were generated in 2 distinct brain regions, located in the dorsal and ventral visual streams, respectively. Moreover, ?-enhancement and suppression showed different dynamics and contribution to perception. In contrast to the initial and transient dorsal ?-enhancement, ?-suppression in ventro-lateral occipital cortex was sustained and influenced subsequent target detection. This anticipatory biasing of ventro-lateral extrastriate ?-activity probably reflects increased receptivity in the brain region specialized in processing upcoming target features. Our results add to current models on the role of ?-oscillations in attention orienting by showing that ?-enhancement and suppression can be dissociated in time, space, and perceptual relevance.

| S-EPMC3888375 | biostudies-literature

Neuronal Representation of Ultraviolet Visual Stimuli in Mouse Primary Visual Cortex.

Project description:The mouse has become an important model for understanding the neural basis of visual perception. Although it has long been known that mouse lens transmits ultraviolet (UV) light and mouse opsins have absorption in the UV band, little is known about how UV visual information is processed in the mouse brain. Using a custom UV stimulation system and in vivo calcium imaging, we characterized the feature selectivity of layer 2/3 neurons in mouse primary visual cortex (V1). In adult mice, a comparable percentage of the neuronal population responds to UV and visible stimuli, with similar pattern selectivity and receptive field properties. In young mice, the orientation selectivity for UV stimuli increased steadily during development, but not direction selectivity. Our results suggest that, by expanding the spectral window through which the mouse can acquire visual information, UV sensitivity provides an important component for mouse vision.

| S-EPMC4518215 | biostudies-literature

Early involvement of prefrontal cortex in visual bottom-up attention.

Project description:Visual attention is guided to stimuli either on the basis of their intrinsic saliency against their background (bottom-up factors) or through willful search of known targets (top-down factors). Posterior parietal cortex (PPC) is thought to be important for the guidance of visual bottom-up attention, whereas dorsolateral prefrontal cortex is thought to represent top-down factors. Contrary to this established view, we found that, when monkeys were tested in a task requiring detection of a salient stimulus defined purely by bottom-up factors and whose identity was unknown before the presentation of a visual display, prefrontal neurons represented the salient stimulus no later than those in the PPC. This was true even though visual response latency was shorter in parietal than in prefrontal cortex. These results suggest an early involvement of the prefrontal cortex in the bottom-up guidance of visual attention.

| S-EPMC3411913 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

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