Browse
Submit Data
Databases
API
Help

Dataset Information

28 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Perisaccadic Receptive Field Expansion in the Lateral Intraparietal Area.

ABSTRACT: Humans and monkeys have access to an accurate representation of visual space despite a constantly moving eye. One mechanism by which the brain accomplishes this is by remapping visual receptive fields around the time of a saccade. In this process a neuron can be excited by a probe stimulus in the current receptive field, and also simultaneously by a probe stimulus in the location that will be brought into the neuron's receptive field by the saccade (the future receptive field), even before saccade begins. Here we show that perisaccadic neuronal excitability is not limited to the current and future receptive fields but encompasses the entire region of visual space across which the current receptive field will be swept by the saccade. A computational model shows that this receptive field expansion is consistent with the propagation of a wave of activity across the cerebral cortex as saccade planning and remapping proceed.

SUBMITTER: Wang X

PROVIDER: S-EPMC7035788 | biostudies-literature | 2016 Apr

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Perisaccadic Receptive Field Expansion in the Lateral Intraparietal Area.

Wang Xiaolan X Fung C C Alan CC Guan Shaobo S Wu Si S Goldberg Michael E ME Zhang Mingsha M

Neuron 20160331 2

Humans and monkeys have access to an accurate representation of visual space despite a constantly moving eye. One mechanism by which the brain accomplishes this is by remapping visual receptive fields around the time of a saccade. In this process a neuron can be excited by a probe stimulus in the current receptive field, and also simultaneously by a probe stimulus in the location that will be brought into the neuron's receptive field by the saccade (the future receptive field), even before sacca ...[more]

PMID: 27041502

Similar Datasets

Perisaccadic and Attentional Remapping of Receptive Fields in Lateral Intraparietal Area and Frontal Eye Fields.

Project description:The nature and function of perisaccadic receptive-field (RF) remapping have been controversial. We used a delayed saccade task to reduce previous confounds and examined the remapping time course in areas LIP and FEF. In the delay period, the RF shift direction turned from the initial fixation to the saccade target. In the perisaccadic period, RFs first shifted toward the target (convergent remapping) but around the time of saccade onset/offset, the shifts became predominantly toward the post-saccadic RF locations (forward remapping). Thus, unlike forward remapping that depends on the corollary discharge (CD) of the saccade command, convergent remapping appeared to follow attention from the initial fixation to the target. We modelled the data with attention-modulated and CD-gated connections, and showed that both sets of connections emerged automatically in neural networks trained to update stimulus retinal locations across saccades. Our work thus unifies previous findings into a mechanism for transsaccadic visual stability.

| S-EPMC10542176 | biostudies-literature

Surround suppression sharpens the priority map in the lateral intraparietal area.

Project description:In the visual world, stimuli compete with each other for allocation of the brain's limited processing resources. Computational models routinely invoke wide-ranging mutually suppressive interactions in spatial priority maps to implement active competition for attentional and saccadic allocation, but such suppressive interactions have not been physiologically described, and their existence is controversial. Much evidence implicates the lateral intraparietal area as a candidate priority map in the macaque (Macaca mulatta). Here, we demonstrate that the responses of neurons in the lateral intraparietal area (LIP) to a task-irrelevant distractor are strongly suppressed when the monkey plans saccades to locations outside their receptive fields. Suppression can be evoked both by flashed visual stimuli and by a memorized saccade plan. The suppressive surrounds of LIP neurons are spatially tuned and wide ranging. Increasing the monkey's motivation enhances target-distractor discriminability by enhancing both distractor suppression and the saccade goal representation; these changes are accompanied by correlated improvements in behavioral performance.

| S-EPMC2967305 | biostudies-literature

Separating value from choice: delay discounting activity in the lateral intraparietal area.

Project description:The mathematical formulations used to study the neurophysiological signals governing choice behavior fall under one of two major theoretical frameworks: "choice probability" or "subjective value." These two formulations represent behavioral quantities closely tied to the decision process, but it is unknown whether one of these variables, or both, dominates the neural mechanisms that mediate choice. Value and choice probability are difficult to distinguish in practice, because higher-valued options are chosen more frequently in free-choice tasks. This distinction is particularly relevant for sensorimotor areas such as parietal cortex, where both value information and motor signals related to choice have been observed. We recorded the activity of neurons in the lateral intraparietal area while monkeys performed an intertemporal choice task for rewards differing in delay to reinforcement. Here we show that the activity of parietal neurons is precisely correlated with the individual-specific discounted value of delayed rewards, with peak subjective value modulation occurring early in task trials. In contrast, late in the decision process these same neurons transition to encode the selected action. When directly compared, the strong delay-related modulation early during decision making is driven by subjective value rather than the monkey's probability of choice. These findings show that in addition to information about gains, parietal cortex also incorporates information about delay into a precise physiological correlate of economic value functions, independent of the probability of choice.

| S-EPMC2898568 | biostudies-literature

Neuronal correlates of the set-size effect in monkey lateral intraparietal area.

Project description:It has long been known that the brain is limited in the amount of sensory information that it can process at any given time. A well-known form of capacity limitation in vision is the set-size effect, whereby the time needed to find a target increases in the presence of distractors. The set-size effect implies that inputs from multiple objects interfere with each other, but the loci and mechanisms of this interference are unknown. Here we show that the set-size effect has a neural correlate in competitive visuo-visual interactions in the lateral intraparietal area, an area related to spatial attention and eye movements. Monkeys performed a covert visual search task in which they discriminated the orientation of a visual target surrounded by distractors. Neurons encoded target location, but responses associated with both target and distractors declined as a function of distractor number (set size). Firing rates associated with the target in the receptive field correlated with reaction time both within and across set sizes. The findings suggest that competitive visuo-visual interactions in areas related to spatial attention contribute to capacity limitations in visual searches.

| S-EPMC2443194 | biostudies-literature

Neural activity in the middle temporal area and lateral intraparietal area during endogenously cued shifts of attention.

Project description:We measured the behavioral time course of endogenously cued attentional shifts while recording from neurons in the middle temporal area (MT) and lateral intraparietal area (LIP) of two macaque monkeys. The monkeys were required to detect a subtle speed change of one of two continuously moving stimuli. The likely location of the speed change was cued throughout each trial but could switch at an unpredictable time. Attention was evident as an improvement in detection ability and reaction time at the cued location, and the focus of attention shifted over a 400 ms period in response to a switch of the cued stimulus. Attention modulated the ongoing neural response in both MT and LIP, and the sign of this modulation also rapidly shifted after a cue switch. Our data provide a framework for understanding the link between the neural and behavioral effects of attention. The responses of single neurons to the test stimulus in MT and LIP were correlated with stimulus detection and reaction time and, at the population level, a spike-rate threshold model was able to account for the effect of attention on detection rate and reaction time. In this view, the time course of the attentional shift can be understood as an interaction between the emerging attentional modulation and the neural response to the test stimulus in LIP. We also present evidence that the threshold model is not wholly explained by sensory (feedforward) information but may also be influenced by cognitive (feedback) processes at the time of stimulus detection.

| S-EPMC2913246 | biostudies-literature

Dissociating activity in the lateral intraparietal area from value using a visual foraging task.

Project description:We make decisions about where to look approximately three times per second in normal viewing. It has been suggested that eye movements may be guided by activity in the lateral intraparietal area (LIP), which is thought to represent the relative value of objects in space. However, it is not clear how values for saccade goal selection are prioritized while free-viewing in a cluttered visual environment. To address this question, we compared the neural responses of LIP neurons in two subjects with their saccadic behavior and three estimates of stimulus value. These measures were extracted from the subjects' performance in a visual foraging task, in which we parametrically controlled the number of objects on the screen. We found that the firing rates of LIP neurons did not correlate well with the animals' behavior or any of our estimated measures of value. However, if the LIP activity was further normalized, it became highly correlated with the animals' decisions. These data suggest that LIP activity does not represent value in complex environments, but that the value can easily be extracted with one further step of processing. We propose that activity in LIP represents attentional priority and that the downstream normalization of this activity is an essential process in guiding action.

| S-EPMC3382481 | biostudies-literature

Collinear facilitation is independent of receptive-field expansion at low contrast.

Project description:Modulation of single-cell responses by compound stimuli (target plus flankers) extending outside the cell's receptive field (RF) may represent an early neural mechanism for encoding objects in visual space, enhancing their perceptual saliency. The spatial extent of contextual modulation is wide. The size of the RF is known to be dynamically variable. It has been suggested that RF expansion when target contrast decreases is the real cause of effects attributed to modulation by flankers. This is not the case. We directly compared, in the same cells, the extent of RF size changes when stimulus contrast decreased with that revealed by systematically changing the target-and-collinear-flankers separation. We found that RF expansion at low contrast was not universal, and that the spatial extent of RF expansion, when it existed, was smaller than that of collinear flanker modulation. We conclude that the two processes in striate cortex work independently from each other.

| S-EPMC3252032 | biostudies-literature

Attention reshapes center-surround receptive field structure in macaque cortical area MT.

Project description:Directing spatial attention to a location inside the classical receptive field (cRF) of a neuron in macaque medial temporal area (MT) shifts the center of the cRF toward the attended location. Here we investigate the influence of spatial attention on the profile of the inhibitory surround present in many MT neurons. Two monkeys attended to the fixation point or to 1 of 2 random dot patterns (RDPs) placed inside or next to the cRF, whereas a third RDP (the probe) was briefly presented in quick succession across the cRF and surround. The probe presentation responses were used to compute a map of the excitatory receptive field and its inhibitory surround. Attention systematically reshapes the receptive field profile, independently shifting both center and surround toward the attended location. Furthermore, cRF size is changed as a function of relative distance to the attentional focus: attention inside the cRF shrinks it, whereas directing attention next to the cRF expands it. In addition, we find systematic changes in surround inhibition and cRF amplitude. This nonmultiplicative push-pull modulation of the receptive field's center-surround structure optimizes processing at and near the attentional focus to strengthen the representation of the attended stimulus while reducing influences from distractors.

| S-EPMC2742598 | biostudies-literature

Temporal sequence of attentional modulation in the lateral intraparietal area and middle temporal area during rapid covert shifts of attention.

Project description:In the visual system, spatial attention enhances sensory responses to stimuli at attended locations relative to unattended locations. Which brain structures direct the locus of attention, and how is attentional modulation delivered to structures in the visual system? We trained monkeys on an attention-switch task designed to precisely measure the onset of attentional modulation during rapid shifts of spatial attention. Here we show that attentional modulation appears substantially earlier in the lateral intraparietal area (LIP) than in an anatomically connected lower visual area, the middle temporal area. This temporal sequence of attentional latencies demonstrates that endogenous changes of state can occur in higher visual areas before lower visual areas and satisfies a critical prediction of the hypothesis that LIP is a source of top-down attentional signals to early visual cortex.

| S-EPMC2854171 | biostudies-literature

Receptive field focus of visual area V4 neurons determines responses to illusory surfaces.

Project description:Illusory figures demonstrate the visual system's ability to infer surfaces under conditions of fragmented sensory input. To investigate the role of midlevel visual area V4 in visual surface completion, we used multielectrode arrays to measure spiking responses to two types of visual stimuli: Kanizsa patterns that induce the perception of an illusory surface and physically similar control stimuli that do not. Neurons in V4 exhibited stronger and sometimes rhythmic spiking responses for the illusion-promoting configurations compared with controls. Moreover, this elevated response depended on the precise alignment of the neuron's peak visual field sensitivity (receptive field focus) with the illusory surface itself. Neurons whose receptive field focus was over adjacent inducing elements, less than 1.5° away, did not show response enhancement to the illusion. Neither receptive field sizes nor fixational eye movements could account for this effect, which was present in both single-unit signals and multiunit activity. These results suggest that the active perceptual completion of surfaces and shapes, which is a fundamental problem in natural visual experience, draws upon the selective enhancement of activity within a distinct subpopulation of neurons in cortical area V4.

| S-EPMC3801031 | 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