Covert Visual Spatial Orienting and Saccades: Overlapping Neural Systems

@article{Nobre2000CovertVS,
  title={Covert Visual Spatial Orienting and Saccades: Overlapping Neural Systems},
  author={A.C. Nobre and Darren R. Gitelman and E. C. Dias and M.-Marsel Mesulam},
  journal={NeuroImage},
  year={2000},
  volume={11},
  pages={210-216}
}
We used functional magnetic resonance imaging (fMRI) to investigate the functional anatomical relationship between covert orienting of visual spatial attention and execution of saccadic eye movements. Brain areas engaged by shifting spatial attention covertly and by moving the eyes repetitively toward visual targets were compared and contrasted directly within the same subjects. The two tasks activated highly overlapping neural systems and showed that common parietal and frontal regions are… 

Figures and Tables from this paper

Visuomotor Origins of Covert Spatial Attention

The brain network underlying serial visual search: comparing overt and covert spatial orienting, for activations and for effective connectivity.

It is concluded that dynamics within the dorsal fronto-parietal attentional system flexibly reorganize to integrate task demands and oculomotor requirements.

Supramodal Effects of Covert Spatial Orienting Triggered by Visual or Tactile Events

Results identify a supramodal network for spatial attention and reveal differential activity for inferior circuits involving the temporo-parietal junction and inferior frontal cortex (specific to invalid trials) versus more superior intraparietal-frontal circuits (common to valid and invalid trials).

Functional asymmetries revealed in visually guided saccades: an FMRI study.

The results demonstrate that, although bilateral by nature, the brain network involved in the execution of VGSs, irrespective of their direction, presented specific right and left asymmetries that were not related to anatomical differences in sulci positions.

Functional Organization of Human Intraparietal and Frontal Cortex for Attending, Looking, and Pointing

Surface-based registration of macaque cortical areas onto the map of fMRI responses suggests a relatively good spatial correspondence between human and macaque parietal areas, and large interspecies differences were noted in the topography of frontal areas.

Separable neuronal contributions to covertly attended locations and movement goals in macaque frontal cortex

The existence of neurons that indicate where the monkey was attending but not its movement goal suggests that endogenous attention is under flexible control and can be dissociated from motor intention.

Different cortical activations during visuospatial attention and the intention to perform a saccade

Functional magnetic resonance imaging is used to elaborate a differentiation between visuospatial attention and the intention for a horizontal saccade in cortical areas of visuomotor related areas, showing a subtle cortical separation for visual related attention and saccades related intention.

Saccades are phase-locked to alpha oscillations in the occipital and medial temporal lobe during successful memory encoding

Using intracranial and magnetoencephalography recordings, it is shown that saccades are locked to the phase of visual alpha oscillations and that this coordination is related to successful mnemonic encoding of visual scenes.

Overlapping neural circuits for visual attention and eye movements in the human cerebellum

...

References

SHOWING 1-10 OF 25 REFERENCES

Frontoparietal cortical networks for directing attention and the eye to visual locations: identical, independent, or overlapping neural systems?

  • M. Corbetta
  • Psychology, Biology
    Proceedings of the National Academy of Sciences of the United States of America
  • 1998
Functional anatomical and single-unit recording studies indicate that a set of neural signals in parietal and frontal cortex mediates the covert allocation of attention to visual locations, as

Functional localization of the system for visuospatial attention using positron emission tomography.

The two attention tasks evoked largely overlapping patterns of neural activation, supporting the existence of a general neural system for visuospatial attention with regional functional specialization.

A large-scale distributed network for covert spatial attention: further anatomical delineation based on stringent behavioural and cognitive controls.

Although the task required attention to be equally shifted to the left and to the right, eight of 10 subjects showed a greater area of activation in the right parietal cortex, consistent with the specialization of the right hemisphere for spatial attention.

Activation of human prefrontal cortex during spatial and nonspatial working memory tasks measured by functional MRI.

The present results support the prominent role of the PFC and, specifically, the MFG in working memory, and indicate that the mnemonic content of the task affects the relative weighting of hemispheric activation.

The Large-Scale Neural Network for Spatial Attention Displays Multifunctional Overlap But Differential Asymmetry

Both exogenous (based on spatial priming) and endogenous ( based on expectancy cueing) shifts of attention are subserved by a common network of cortical and subcortical regions, however, the differences between the two tasks, especially in the degree of rightward asymmetry, suggests that the pattern of activation within this network may show variations that reflect the specific attributes of the attentional task.

Dissociation of mnemonic and perceptual processes during spatial and nonspatial working memory using fMRI

The results support a prominent role of the prefrontal and parietal cortices in working memory, and indicate that spatial and object working memory tasks recruit differential hemispheric networks.

A PET study of visuospatial attention

PET findings indicate that parietal and frontal regions control different aspects of spatial selection, and the functional asymmetry in superior parietal cortex may be relevant for the pathophysiology of unilateral neglect.

Visual, presaccadic, and cognitive activation of single neurons in monkey lateral intraparietal area.

The results from several tasks indicate that LIP neurons are activated in a variety of circumstances and are not involved exclusively in sensory processing or motor planning, and the modulation of sensory responses by attention and anticipation suggests that cognitive factors play a major role in parietal function.